Programming Manual

mc-16 / mc-20 HoTT.1.en

mc-16 mc-20
2 Table of contents

Function fields in the display ......................... 32

Position indicator........................................... 32

Entry lockout.................................................. 32

Warning notices............................................. 33

HIDDEN MODE............................................. 34

Language selection

VOICE................................................. 34

Change of display language................ 35

Firmware update via SD card................... 35

STICK CALIBRATION .............................. 36

Bluetooth initialisation .............................. 37

Telemetry data display................................... 38

Commissioning the transmitter................................ 46

Downloading a firmware packet ......................... 48

Transmitter firmware updates ............................. 50

Restoring the transmitter software ..................... 52

Receiver initialization............................................... 54

Receiver power supply ....................................... 56

Receiver system power supply........................... 57

Receiver firmware updates................................. 58

Backing up receiver settings............................... 62

Installation notices................................................... 64

Definitions of terms.................................................. 66

Physical control, switch and control switch assignments....................................................................... 68

Digital trim ............................................................... 70

Winged models........................................................ 72

Receiver layout................................................... 73

Servos in wrong direction ................................... 73

Helicopter models.................................................... 74

Receiver layout................................................... 75

Program descriptions

mc

16 20*

Loading a new memory location.............................. 76

»Model select«....................................   79

»Copy / Erase«....................................   80

»Suppress codes«..............................   84

General notices

Table of contents ....................................................... 2

Environmental protection notices .............................. 3

Safety notices ............................................................ 4

Safety notices and handling regulations for 

Lithium-Ion (LiIo) and Lithium-Polymer (LiPo) 

batteries..................................................................... 8

Foreword.................................................................. 10

Remote control set description................................ 11

Technical data.......................................................... 15

General operating notices

Transmitter.......................................................... 16

Transmitter power supply............................... 16

Charging the transmitter battery.................... 16

Charging with automatic chargers................. 16

Recommended chargers (accessory) ........... 16

Removing the transmitter’s battery................ 17

Inserting the transmitter’s battery.................. 17

Battery operation timer ................................. 17

General charging notices .............................. 17

Opening the transmitter housing ................... 18

Lithium battery CR 2032 ............................... 18

Stick conversions........................................... 19

Stick length adjustment ................................. 20

Transmitter neckstrap support bars ............... 20

Transmitter description

Front side....................................................... 21

Face-side connectors

Charger socket......................................... 22

DSC jack .................................................. 22

Data jack .................................................. 23

Headset connector................................... 23

Card slot................................................... 24

Mini-USB connector ................................. 25

Bottom side transmitter interior ..................... 26

Display and keypad ....................................... 28

Operating the “data terminal“ ........................ 29

Shortcuts ....................................................... 30

Concealed menu columns............................. 31

Table of contents

»Suppress models«............................   85

»Base setup model«  

Winged model .................................................... 86

“Binding” transmitter and receiver ................. 87

Range test..................................................... 91

Helicopter model ................................................ 94

“Binding” transmitter and receiver ................. 95

Range test..................................................... 99

»Model type«.......................................   104

»Helicopter type«................................   108

»Servo adjustment« ...........................   112

»Stick mode«  

Winged model .................................................. 114

Helicopter model .............................................. 116

»Control adjust«  

Winged model .................................................. 118

Helicopter model .............................................. 122

Throttle limit function ................................... 127

Basic idle setting ......................................... 127

Throttle limit in combination with “AR” in the 

»Stick mode« menu ................................... 129

»Dual Rate / Expo«  

Winged model .................................................. 130

Helicopter model .............................................. 134

»Channel 1 curve«  

Winged model .................................................. 138

Helicopter model .............................................. 141

»Switch display«.................................   144

»Control switches«.............................   145

»logical switches« ..............................   148

How is a flight phase programmed? ...................... 150

»Phase settings«  

Winged model .................................................. 152

Helicopter model .............................................. 156

»Phase assignment«..........................   158

»Phase trim« (Winged model).............   160

»Non-delayed channels«....................   161

»Timers (general)«..............................   162

»Flight phase timers«.........................   166

What is a mixer?.................................................... 169
Table of contents 3

»Wing mixers« ....................................   170

Model type: “1AIL”............................................. 173

Model type: “1AIL 1FL”..................................... 174

Model type: “2AIL”............................................. 175

Model type: “2/4AIL 1/2/4FL”............................ 177

(Max. 2 ailerons and 2 flaps with the 

standard 8-channel mc-16 transmitter)

»Helicopter mixer« .............................   188

Fine-tuning the throttle and collective 

pitch curve........................................................ 198

Autorotation setting........................................... 202

General notes on freely programmable mixers...... 204

»Free mixers« .....................................   205

Linear mixers.................................................... 208

Curve mixers .................................................... 210

Examples.......................................................... 213

»Mix active / phase«...........................   215

»Mix-only channel« ............................   216

»Dual mixer« .......................................   218

»Swashplate mixer« ...........................   220

»Fail safe« ...........................................   220

»Teacher/Pupil«  

Connecting with a trainer lead.......................... 222

Connection schematic ...................................... 225

Wireless HoTT system ..................................... 226

»Tx. output swap« ..............................   230

»Profi trim«  

Winged model .................................................. 232

Helicopter model .............................................. 234

»Trim memory«  

Winged model .................................................. 236

Helicopter model .............................................. 238

»Telemetry«.........................................   240

Important notices:............................................. 240

SETTINGS & DATAVIEW.................................. 241

Satellite mode.............................................. 250

Sensor(s)..................................................... 251

SENSOR SELECT ........................................... 252

RF STATUS VIEW ............................................ 253

VOICE TRIGGER ............................................. 254

Environmental protection notices

The symbol on this product, its operating instructions 

or packaging gives notice that this product may not 

be discarded as common household waste at the end 

of its service life. It must be turned over to a recycling 

collection point for electric and electronic apparatus. 

The materials can be recycled according to their 

markings. You make an important contribution to 

protection of the environment by utilizing facilities for 

reuse, material recycling or other means of exploiting 

obsolete equipment.

Batteries must be removed from the 

unit and disposed of separately at an 

appropriate collection point.

Please inquire with local authorities 

about the responsible waste collection 

locations.

This manual serves only as a source of information 

and can be changed without prior notification. Graupner accepts no responsibility or liability for errors or 

inaccuracies which may be contained in 

the information section of this manual.

»Channel Sequence« .........................   256

»Multichannel«....................................   258

»Ring limiter«......................................   262

»MP3 player«.......................................   266

»Basic settings, transmitter«.............   268

»Servo display« ..................................   274

»Servo test« ........................................   275

»Code lock« ........................................   276

»Info Display« .....................................   278

*  Standard option

 Option can be unlocked at extra cost

Programming examples

Introduction............................................................ 280

Winged model

First steps......................................................... 282

Incorporating an electric drive .......................... 288

C1 joystick switchover between:

Electric motor and butterfly .................... 291

Electric motor and airbrake .................... 293

Timer confirmation with control or switch ......... 294

Parallel operating servos .................................. 296

Using flight phases

Example 1 ................................................... 298

Example 2 ................................................... 302

Control of temporal processes ......................... 308

Delta and flying wing ........................................ 310

F3A model ........................................................ 314

Helicopter models.................................................. 318

Appendix

FCC Information .................................................... 329

Declaration of Conformity ...................................... 330

Warranty Certificate............................................... 331
4 Safety notices

In order to enjoy your modeling hobby for a long time, 

please read these instructions thoroughly and give 

particular attention to the safety notices. You should 

also register right away at https://www.graupner.de/

en/service/product_registration.aspx since this is 

the only way for you to automatically receive current 

information about your product via email.

If you are a beginner with remote controlled model 

aircraft, ships or cars, you should really ask an experienced model pilot for assistance.

If this remote control system changes ownership, 

these instructions should surely be included with 

remote control system.

Intended usage

This remote control system may only be used for the 

purpose intended by the manufacturer, i.e. for the operation of unmanned remote controlled models. Any 

other usage is not permissible.

Safety notices

SAFETY IS NO ACCIDENT

and

REMOTE CONTROLLED MODELS ARE NOT TOYS

... because even small models can cause substantial 

property damage and/or personal injuries if they are 

not handled properly - even if caused by third parties.

Technical defects of an electrical or mechanical nature can lead to unexpected startup of a motor and/or 

parts being hurled through the air to pose a danger of 

injury to you and to others.

Short circuit conditions are to be avoided absolutely! 

A short circuit condition may not only destroy parts 

of the remote control system but, depending on the 

circumstances and the battery energy involved, may 

also pose acute danger of incineration or even explosion.

All motor-driven parts, such as aircraft or ship propellers, helicopter rotors, open gearboxes etc. represent 

a constant danger. Contact with these parts must be 

avoided. A rapidly turning aircraft propeller can, for 

example, sever a finger. Also pay attention that other 

objects do not come into contact with driven parts.

When a drive battery is connected or a motor is 

running: never get into the danger zone of driving 

mechanisms.

Be sure to pay attention that motors do not start up 

unintentionally while performing programming operations. Disconnect the fuel supply or battery terminals 

to motors before programming.

Protect all units from dust, dirt, moisture and other 

foreign parts. Never expose these units to vibrations 

or excessive hot or cold temperatures. Remote control operation may only be performed under “normal” 

outdoor temperatures, i.e. within a range of -10°C to 

+55°C.

Avoid mechanical jarring and pressure stresses. Always check units for damage to housings and cables. 

Do not use units which have been damaged or become wet, even after they are dry again. 

Only those components and accessories which we 

recommend may be used. Always use original Graupner plug and jack connectors which are made for one 

another out of the same materials. 

When routing cables, pay attention that they are not 

stressed, unduly kinked or broken. The sharp edges 

of adjacent parts also represent a hazard for insulated conductors.

Be sure that all plug and jack connections are firmly 

seated. Do not pull on the cable to disconnect a 

plugged connector.

No modifications whatsoever may be made to units. 

Modifications will void the operating permit and all 

insurance protection. If necessary, send the device 

concerned to your local Graupner Service Centre; 

see page 331.

Installing the receiver

The receiver is to be installed with a cushion of foam 

rubber to afford protection against jarring; in aircraft 

models behind a strong rib, for a car or ship model 

the location must be protected against dust and 

spray water. However, do not enclose your receiver 

completely, otherwise it may overheat in use.

The receiver may not be mounted in direct contact 

with the hull or chassis as this would allow motor 

vibrations and/or roadway jarring to be transferred 

directly to the receiver. When a receiver system is 

installed in a model with a combustion motor, all 

receiver parts should always be protected against the 

intrusion of exhaust gases and oil residue. Above all, 

this applies to the model’s ON/OFF switch, which is 

typically built into the model’s outer surface.

Position the receiver such that connecting cables to 

the servos and the power supply are routed with a bit 

of slack and that the receiver’s antennas are at least 

5cm away from any large metal parts or wiring except 

for other receiver wires/cables. In addition to steel, 

this also includes carbon fiber parts, servos, electric 

motors, fuel pumps and all sorts of cables, etc. 

Optimally the receiver should be placed at a readily 

accessible location that is well away from all other 

equipment. Under no circumstances may a servo 

cable be wrapped around the antenna or routed close 

to it.

Make sure that cables near the antenna cannot move 

about during flight.

Routing the receiver’s antennas

The receiver and its antennas must be positioned 

as far away as possible from drives of any kind. If 

the model’s hull is made of carbon fiber material, the 

ends of the antennas must extend outside of the hull.

If your model features a carbon fibre fuselage, the 

aerial tips must always extend outside the fuselage 

for a length of at least 35mm. If this is not possiSafety notices

Be sure to pay attention!
Safety notices 5

group. Pilots standing off to themselves not only endanger their own models but those of others as well. 

However, when 2 or more pilots using 2.4GHz remote 

control systems are closer than 5m to one another 

this can lead to return channel overdrive which, in 

turn, will trigger a range warning much too early. 

Increase your distance between one another until the 

range warning ceases.

Pre-start checks

Before switching the receiver on, be sure the throttle 

control is at its Stop/Idle position.

Always switch the transmitter on first 

and then the receiver.

Always switch the receiver off first 

and then the transmitter.

If this sequence is not maintained, such that the 

receiver is still switched on when the corresponding 

transmitter is switched to “OFF”, then the receiver 

may respond to other transmitters or general radio 

frequency noise. This can cause the model to execute 

uncontrolled operations that may cause personal 

injuries and/or property damage.

In particular, for models equipped with a mechanical 

gyro:

before switching off the receiver, disconnect the 

model’s power supply to prevent the motor from revving up unintentionally. 

The residual spin of a gyro often produces so 

much voltage that the receiver may falsely interpret a throttle signal! This will then cause the 

motor to start up unexpectedly.

Range test

Perform checks for proper operation and range before 

every session. Secure the model adequately in place 

and ensure that no one is in front of the model.

Perform a complete functional test on the ground and 

execute a complete simulated flight to exclude the 

possibility of system faults or problems with the model’s programming. When doing this, be sure to follow 

the notices provided on pages 91 and 99.

Never operate the transmitter in Model mode, i.e. 

for flying or driving, without an antenna. Be sure the 

antenna is firmly seated in its socket. 

Operating a winged aircraft, helicopter, ship or car

Never fly over spectators or other pilots. Never endanger humans or animals. Never fly in the vicinity of 

high-voltage wires. Do not operate the model in the 

vicinity of sluice locks or where real boats or ships are 

operating. Do not operate a model on public streets or 

highways, paths or plazas, etc.

Never switch the transmitter off whilst operating 

a model! If this should happen accidentally, keep 

your nerve and wait until the transmitter screen 

is entirely blank, i.e. until the transmitter has 

shut down completely; this takes at least three 

seconds. Do not switch your transmitter on again 

until this has occurred. If you neglect this, there is 

a risk that the transmitter will “hang” immediately 

after being switched on, and you will lose control 

of the model. In this case your only recourse is to 

switch the transmitter off again, allow it to shut 

down completely, and then switch on once more 

after the correct interval.

Aero-towing

When operating a powered tug, ensure that the 

receiving systems in the two models are always at 

least 50cm apart. We recommend the use of satellite 

receivers in such situations. If you neglect this, there 

is a chance of interference from the downlink channel.

Monitoring transmitter and receiver batteries

You must stop running the model to recharge the 

transmitter’s battery no later than when low transmitter battery voltage triggers the “Batt must be recharged!!” display and acoustic signal.

ble, it is essential to substitute longer aerials for the 

standard ones (approx. 145mm long) fitted to HoTT 

receiver(s).

The orientation of the aerial(s) is not critical, but it is 

advantageous to install one receiver aerial in a vertical–upright–position in the model. If your receiver 

is a Diversity type–two aerials–the active tip of the 

second aerial should be positioned at 90° to the tip of 

the first aerial, and ideally the distance between the 

two tips should be greater than 125mm.

Servo installation

Always mount servos with the provided rubber vibration-damper parts. Only in this manner can these 

parts be protected against excessively hard vibrations.

Installing control rods

Control rods must be installed such that they operate 

freely and smoothly. It is particularly important that 

all rudder levers are able to move to their full limits, 

i.e. not otherwise mechanically blocked.

In order to be able to stop a running motor at any 

time, control rods must be adjusted such that the 

carburetor tap is completely closed when the joystick 

and trim lever are brought into their end idle position.

Pay attention that no metal parts, e.g. as a result of 

rudder actuation, vibration, rotating parts, etc., rub 

against one another. Metal-to-metal contact causes 

electrical “noise” which can interfere with the correct 

operation of the receiver.

Transmitter antenna orientation

Transmission field strength is minimal in an imaginary 

line extending straight out from the end of the transmitter’s antenna. This means that “pointing” the transmitter’s antenna directly toward the model will not 

produce good reception but rather degrade reception.

When multiple remote controls are operating simultaneously, pilots should position themselves in a loose 
6 Safety notices

Check the charge in batteries routinely, particularly 

the receiver’s battery. Do not wait until the movements 

of controlled mechanisms are noticeably slower. 

Replace expended batteries before they cause problems.

The battery manufacturer’s charging instructions are 

always to be followed, this includes mandatory adherence to the length of charging time. Never leave 

batteries being charged unattended.

Never attempt to charge primary batteries (non-rechargeable batteries) because they can explode.

All secondary batteries (rechargeable batteries) must 

be charged before every session. To avoid short 

circuit conditions, first connect the charger cable’s 

banana plugs, polarity correct, into the charger and 

thereafter connect the charger cable’s plugs to the 

transmitter and receiver batteries. 

Disconnect all power sources from the model when it 

is not to be used for an extended period of time. 

Never attempt to use defective batteries, damaged 

batteries or mixed-type battery combinations as a single group. Do not use mixed combinations of old and 

new batteries or batteries of different manufacture.

Capacity and operating time

The rule: “capacity is reduced with every successive 

recharging”, applies to all batteries. Internal resistance increases at low temperatures to further reduce 

capacity. As a consequence, the battery’s ability to 

provide current and hold its voltage is reduced.

Frequent charging or the use of battery maintenance 

programs can also result in gradual loss of battery 

capacity. Therefore the capacity of batteries should 

be checked at regular intervals, not in excess of every 

six months, and replaced if performance is found to 

be significantly deficient.

Purchase only genuine Graupner batteries!

Interference suppression for electric motors

All conventional electric motors produce sparks between their collector and brushes. Depending on the 

type of motor involved, this may cause more or less 

interference with the functionality of the remote control system.

The electric motors of a properly built system should 

therefore have interference suppression features. For 

electric drive models it is particularly important that 

every one of its motors is provided with proper interference suppression. Interference filters extensively 

suppress such disturbances and should always be 

included. 

Follow the respective recommendations included in 

the motor’s operating and installation notices.

For further details about interference filters, refer to 

the Graupner RC main catalog or in Internet at 

www.graupner.de.

Servo interference filters for extension cables 

Order no. 1040

The servo interference filter is necessary when an 

extended-length servo cable is used. This filter is attached directly to the receiver output. In critical cases 

a second filter can be attached to the servo. 

Using electronic speed controllers

Choosing the right electronic controller is largely a 

matter of matching controller performance to the motor to be controlled.

In order to prevent an overload or damage to the 

speed controller, its current rating should be at least 

half of the maximum locked-rotor current draw of the 

motor to which it is connected.

Particular attention is appropriate for so-called “tuning 

motors”. Because of their low-turns coils these motors 

can draw a multiple of their rated current in a lockedrotor condition and this can lead to the destruction of 

the speed controller.

Electric ignition systems

Combustion motor ignition systems also produce 

interference that can negatively influence remote 

control functionality.

Always supply power to an electric ignition system 

from a separate, dedicated battery.

Use only interference-suppressed spark plugs, spark 

caps and shielded ignition leads.

Mount the receiver sufficiently far away from ignition 

system components.

Static charges

A remote control system will be destroyed by the 

magnetic shock waves produced by a lightning 

strike–even if the storm is miles away. Therefore ...

... stop flying right away if a storm is approaching. Static charging via the antenna also represents a lethal hazard.

Attention

• In order to fulfill FCC HF emission requirements 

for mobile transmitters, a distance of at least 20cm 

must be maintained between this system’s antenna and other persons when this system is operating. Operation of this system at a lesser distance 

is therefore not recommended. 

• To avoid disturbance caused by the electrical 

characteristics and emissions of other transmitters, keep at least a 20cm distance from other 

transmitters.

• Operation of the remote control system requires a 

correct program setting for the given country in the 

transmitter unit. This is necessary for compliance 

with diverse regulations like FCC, ETSI, CE etc. 

Follow the respective instructions provided for this 

with the transmitter and receiver.

• Prior to every flight, perform a complete functional 

test, range test and execute a complete simulated 

flight in order to exclude the possibility of system 

faults or problems with the model’s programming.

• Never program the transmitter or receiver while 

Safety notices
Safety notices

7

the model is being operated. 

Care and maintenance

Never clean the housing, antenna, etc. with cleaning 

agents, gasoline, water or similar means. Use only a 

dry, soft cloth.

Components and accessories

As manufacturer of this equipment Graupner GmbH & 

Co. KG recommends only components and accessories which have been tested and approved by 

Graupner for their suitability, functionality and safety. 

If this recommendation is followed, Graupner accepts 

responsibility for the product. 

Graupner cannot accept any responsibility for 

the parts or accessories of other manufacturers which have not been approved and Graupner

cannot evaluate every individual product made by 

other companies to assess if they are safe to use.

Liability exclusion / damage compensation

This manual serves only as a source of information 

and can be changed without prior notification. Graupner accepts no responsibility or liability for errors or 

inaccuracies which may be contained in this manual.

Graupner cannot monitor compliance with the assembly instructions, the operating instructions or the 

conditions and methods under which remote control 

components are installed, operated, utilized or maintained. Therefore Graupner accepts no form of liability 

for loss, damage or costs consequential to incorrect 

usage or operation or which can be attributed to 

same.

Unless otherwise prescribed by law, the obligation of 

Graupner to provide damage compensation, regardless of legal grounds, is limited to the invoice value of 

the quantity of Graupner goods contributing directly 

to the damage-inducing event. This does not apply if 

Graupner is found to be subject to unlimited liability 

pursuant to binding legal stipulations with respect to 

intent or gross negligence. 

Furthermore we will only consider claims if a log file 

is present; see page 24 under “Data recording”. 

For the same reason the transmitter must always be 

updated to the latest software status.

It is essential that you register at https://www.graupner.de/en/service/product_registration.aspx to ensure 

that you are constantly informed of important software updates. This is the only means by which we 

can automatically keep you aware of new updates by 

e-mail.
8 Safety notices

Safety notices and handling regulations for Lithium-Ion

(LiIo) and Lithium-Polymer (LiPo) batteries 

As applicable for all highly technical products, observance of the following safety notices and handling instructions is essential for a long service life, fault-free 

operation, and harmless utilization of lithium/polymer 

batteries. 

These instructions are to be safeguarded. If the unit is 

transferred to another user, these instructions should 

certainly be passed along to the new user.

General notices

LiIo-/LiPo batteries require particularly attentive handling. This applies to charging, discharging as well 

as for storage and other handling. Adherence to the 

following special specifications is necessary:

• Incorrect handling can lead to explosions, fire, 

smoke and poisoning hazards. Furthermore, 

disregard for instructions and warnings can lead to 

performance losses and other defects.

• The battery’s capacity is reduced by every charge/

discharge cycle. Storing the battery at temperatures which are too high or too low can also lead 

to a gradual reduction in capacity. In model operation, battery capacity drops to about 50 ... 80% 

of new battery capacity after about 50 charge/discharge cycles–even though all charge/discharge 

rules are followed. This is due in part to the high 

discharge currents and inductive currents caused 

by motors.

• Battery packs may only be connected in series or 

parallel in exceptional cases as cell capacities and 

charged state can differ too greatly. This is why the 

battery packs we deliver are selected. 

Special notices for charging LiIo-/LiPo batteries 

from Graupner

• Since Graupner GmbH & Co. KG cannot supervise the correct charging and discharging of cells, 

the entire guarantee is void in cases of improper 

charging or discharging. 

• Never leave batteries being charged unattended.

• Only approved chargers with appropriate charging 

cables may be used for charging LiIo-/LiPo batteries. Any manipulation to the charger or charger 

cables can lead to severe damage. 

• The maximum charging capacity must be limited 

to 1.05 times the battery’s capacity.

Example: 700mAh battery = 735 mAh max. charging capacity

• Use only the outlet-charger included with the set 

or a specially designed charger/discharger from 

Graupner to charge and discharge LiIo-/LiPo batteries, refer to page 17 or www.graupner.de.

• Ensure the settings for the number of cells or for 

final charging voltage and final discharge voltage are correct. Be sure to observe the operating 

instructions for your charger/discharger.

Other handling notices

• The battery to be charged must be placed on a 

non-combustible, heat resistant, non-conducting 

surface during the charging process. Combustible 

or readily ignited objects are to be kept away from 

the charging configuration. Batteries may only be 

charged under supervision. 

• LiIo-/LiPo batteries connected in series within a 

pack may only be charged as a group if the voltage of individual cells do not differ by more than 

0.05V. The LiIo battery included with the set is 

equipped with a special safety circuit such that 

“compensation” for voltage differences between 

individual cells, by way of an otherwise typical 

balancer plug connection, is not necessary.

• Under these conditions Graupner LiIo-/LiPo batteries can be charged with a maximum of 2C (the 

value 1C corresponds to the cell capacity) charging current. At a voltage of maximum 4.2V per cell 

and above, charging must continue a constant 

voltage of 4.2V per cell until charging current 

drops below 0.1 ... 0.2A.

• Charging voltage over 4.20V per cell must be 

avoided absolutely as the cell would otherwise be 

permanently damage and could cause a fire. In order to prevent the over-charging of individual cells 

in a pack, a cut-off voltage between 4.1 ... 4.15V 

per cell should be set to increase service life.

• Never attempt to charge battery cells with the 

wrong polarity. Abnormal chemical reactions take 

place when batteries are charged with reversed 

polarity and the battery will be useless. This can 

cause breaks, smoke and flames.

• The permissible temperature range for charging 

and storing LiIo-/LiPo batteries is 0 ... +50°C.

Storage 

LiIo-/LiPo cells should have a 10 ... 20% charge 

capacity when stored. If cell voltage drops below 3V, 

then LiIo-/LiPo cells must absolutely be recharged to 

a capacity of 10 ... 20% of full capacity. Otherwise, 

further deep-discharging of the battery will make it 

useless during storage in a discharged state.

Special notices for discharging LiIo-/LiPo batteries from Graupner

• A continuous current rate of about 1C does not 

represent a major problem for Graupner LiIo-/LiPo 

batteries. For larger currents, please follow the 

catalog specifications. In any case, observe the 

maximum current rating for the connector system, 

see maximum discharge current on the battery.

• Discharging below 2.5V per cell damages cells 

permanently and is therefore to be avoided absolutely. 

Short circuit conditions are to be avoided absolutely. Permanent short circuits lead to destruction of the battery, high temperatures and perhaps 

even self-ignition may follow.

• During discharge, battery temperature must not 

rise, in any case, to over +70°C. Otherwise, better 

cooling or a lower rate of discharge must be in-
Safety notices 9

troduced. The temperature can easily be checked 

with the infrared thermometer, order no. 1963. The 

battery must never be discharged via the transmitter’s charging socket. This socket is not suitable for 

this purpose.

Other handling notices

• Never short-circuit the battery. A short-circuit allows very high current to flow and this heats up 

the cells. This will lead to loss of electrolyte, the 

production of gases and perhaps even explosions. 

In the vicinity of, or while handling, Graupner LiIo-/

LiPo batteries, avoid electrically conducting surfaces because of the danger of creating a shortcircuit condition.

• Handling connectors

These connectors are not as robust as for other 

batteries. This applies particularly to the plus pole 

connector. The connections can easily be broken 

off. Due to thermal transfer, the connector tabs 

may not be soldered directly. 

• Cell connection

Direct soldering on battery cells is not permitted. 

The heat of direct soldering can damage battery 

components, such as separator or isolator.

Battery connections should only be made by industrial spot welding. A professional repair made 

by the manufacturer or distributor is necessary to 

replace missing or torn-off cables. 

• Replacing individual battery cells

The replacement of battery cells may only be 

made by the manufacturer or distributor and never 

by the user himself.

• Damaged cell usage

Damaged cells may never be used or returned to 

service.

Characteristics of damaged cells include: damaged housing packing, deformed battery cells, 

electrolyte or leaking electrolyte. In these cases, 

further use of the battery is not permissible.

Damaged or useless cells are hazardous waste 

items and must be appropriately disposed.

General warning notices

• Batteries must never be put in fire or burned. 

• Battery cells must not be submerged in liquids, 

such as water, seawater or beverages. Any contact 

with liquids, of whatever nature, is to be avoided.

• Individual battery cells and batteries are not toys 

and must therefore not get into the hands of children. Batteries/cells must be kept out of the reach 

of children.

• Batteries must not get into the vicinity of babies or 

small children. If a battery is swallowed, immediately go to a doctor or emergency medical facility.

• Batteries must not be put in a microwave oven or 

put under pressure. Smoke, fire and more can be 

the consequences.

• Never dismantle a LiIo-/LiPo battery. Dismantling 

a battery can cause internal short-circuits. Gas, 

fire, explosions and other problems can result.

• The electrolyte and electrolytic vapors in LiIo-/LiPo 

batteries are harmful. Absolutely avoid all direct 

contact with electrolytes. If electrolytes come into 

contact with skin, eyes or other body parts, immediately wash out or rinse out with generous 

amounts of fresh water then be sure to consult 

a doctor.

• Batteries built into equipment must always be 

removed from that equipment when it is not currently in use. Always switch off equipment after it is 

used to prevent deep discharging. Always charge 

batteries before it is too late. Store batteries on a 

non-combustible, heat resistant, non-conducting 

surface! Deep-discharged LiIo-/LiPo batteries are 

defective and may no longer be used!

Notice for remote control set mc-16 HoTT and 

mc-20 HoTT

Order no. 33016 / 33020

These radio control sets are fitted as standard with a 

LiIo transmitter battery with integral protective circuit 

(changes reserved). Once the factory preset voltage 

limit of 3.60V has been reached, a warning will appear in the display. 

Disposal of used batteries

Some countries have laws requiring that all used 

batteries be turned over to an authorized collection 

center.

Disposing of batteries along with common household 

garbage is forbidden. Old batteries can be turned into 

communal collection centers for disposal at no charge 

or they can be returned to one of our dealerships or 

anywhere else where batteries of that given type are 

sold. Used batteries we have delivered can also be 

sent back to us, at your cost, through the mail. Use 

the return address below:

Graupner GmbH & Co. KG

Service: Used batteries

Henriettenstr. 94-96

D-73230 Kirchheim unter Teck

This represents an essential contribution to environmental protection.

Caution:

Damaged batteries require among other things, 

special packaging, because they are very toxic!
10 Foreword

mc-16 and mc-20

The Newest Generation of Remote Control Technology

The technical advances across the entire spectrum of 

model building is an ever-present challenge to design 

engineers. This is why the introduction of new transmission technology in the 2.4GHz band represents a 

new milestone.

The HoTT-System (Hopping Telemetry Transmission) 

developed by Graupner is a synthesis of know-how, 

engineering and testing done around the world by 

professional pilots.

Established Graupner HoTT techniques theoretically 

permit over 200 models to be operated at the same 

time. However, because of the interspersed radiofrequency utilization permitted by certification for the 

2.4GHz ISM band, this number is significantly lower 

in practical application. Nevertheless, in general 

more models can be operated simultaneously in the 

2.4GHz band than would be the case in conventional 

35 or 40 MHz frequency bands. The real limiting factor is–as often before–is still likely to be the size of 

available operating space (i.e. airspace for aircraft). 

Alone the fact that it is no longer necessary to coordinate transmitting frequencies with other pilots in the 

vicinity (which is sometimes quite difficult in broken 

landscapes, such as on hillside slopes) represents an 

enormous boost for remote control operating security.

Bidirectional communication between transmitter 

and receiver, by way of a return channel built into 

the receiver, permits convenient access to data and 

programming in the HoTT receiver. For example, this 

makes it possible to swap receiver outputs or to divide 

up control functions among multiple servos (channel 

mapping). Servo travel and servo rotation directions 

in the receiver can also be matched to one another 

with these facilities. Telemetry data, like VARIO and 

GPS data, can be called up from optionally available 

modules.

The mc-16 HoTT and mc-20 HoTT radio control 

sets are based on the Graupner/JR mc-24 computer 

radio control system, which was introduced back in 

1997. The new equipment has been specially developed for the advanced RC pilot. The transmitters of 

this series offer an unprecedented level of security 

and reliability combined with outstanding operating 

convenience and ease of use.

Both these HoTT systems can easily be used to operate all current model types, whether your preference 

is for fixed-wing model aircraft or helicopters, model 

cars or boats.

For example, every mc-16 HoTT and mc-20

HoTT transmitter is fully equipped in terms of software and hardware to allow the use of the renowned 

NAUTIC modules. A further innovation is the “channel 

sequencer”–available as standard only on the mc20 HoTT–which provides a means of automating 

servo sequences involving up to three servos.

However, it is fixed-wing model aircraft and helicopters in particular which call for complex mixed functions involving the control surfaces or swashplate 

control system. In this respect the latest computer 

technology makes it extremely simple to program the 

system to cope with a vast range of model requirements: simply select the appropriate model type in 

the program of your HoTT transmitter, and the software automatically sets up all the relevant mixing 

and coupling functions. Separate modules for implementing complex coupling functions are no longer 

required, and complicated mechanical mixers in the 

model are completely superfluous.

Additional flight-phase-specific settings can be stored 

in every model memory location. For example, such 

settings can be made for various parameters that can 

be called up to implement particular flight maneuvers 

at the “press of a button”. Additional model memories can be stored on the SD card, which is included 

standard with the set. Even telemetry data can be 

recorded for subsequent evaluation on a PC. 

Since the mc-20 HoTT is equipped with two displays, the lower display has been optimized for comprehensible, simple operation of the software. The 

graphic representation of mixer functions is particularly helpful. The upper display allows telemetry data 

to be called up from the receiver.

Functionally-related options are clearly arranged by 

content in a simple organization. The clear, comprehensible program structure permits a beginner to 

quickly become familiar with the various functions and 

able to use all options pertinent to his level of expertise with remote control models.

This handbook describes every menu in detail. There 

are tips, many notices and programming examples to 

supplement the descriptions and also explanations for 

model specific technical terms, like transmitter control, dual rate, butterfly, and so on.

Please observe the safety notices and technical 

notices. Read through the instructions attentively. 

Before usage, test all functions by simply attaching 

servos to the receiver included in the set. While doing 

this, observe respective notes on page 77. This will 

help you learn the essential operating techniques and 

functions of your HoTT transmitter.

Always handle your remote controlled model with a 

sense of responsibility so that you do not endanger 

yourself or others.

The Graupner team wishes you much pleasure and 

success with your HoTT transmitter system, the newest generation of remote control systems. 

Kirchheim-Teck, November 2012
Remote control set description 11

mc-16 and mc-20 series computer systems

two remote control sets with 2,4-GHz-Graupner|SJ-HoTT technology 

(Hopping Telemetry Transmission)

Technology that enthralls.

The superior functional security of Graupner/SJ

HoTT technology accomplished with bidirectional 

communications between transmitter and receiver with integrated telemetry, freely programmable 

voice output via headset connector, and ultra-fast 

response times.

Simplified programming using capacitive touchbuttons on the mc-20 HoTT and four-way pushbuttons on the mc-16 HoTT. 

High-contrast eight-line graphic screen provides 

a clear display of all set-up parameters. Switchable blue backlighting. The mc-20 HoTT features 

an independent second screen for displaying telemetry data. Storage of telemetry data on a micro 

SD memory card.

USB connection to read and write the model’s 

memories as well as for making firmware updates.

• Integrated Graupner|SJ HoTT 2.4 GHz transmission system

• The high-speed primary processor is used for data 

transfer, ensuring ultra-fast response times.

• Maximum interference immunity made possible by 

optimized frequency hopping through as many as 

75 channels and wider channel spread

• Intelligent data transfer with correction function

• Over 200 systems can be used simultaneously

• The HoTT technique of bidirectional communication between sender and receiver, as well as the 

fastest possible transmission rate (10ms) assures 

extremely short reaction times.

• Modulation can be switched by software: when 

necessary, you can switch from “HoTT” to “EXT.” or 

“SP.” by pressing a button.

• Case incorporates integral patch aerial

• Transmitter features integral slot for SD and SDHC 

memory cards, formatted to FAT or FAT32, for 

saving log files, model programming data and supplementary functions such as transmitter firmware 

updates.

• Transmitter features alternative method of battery 

charging via the USB socket.

• 6 different languages (Dutch, English, French, 

German, Italian and Spanish) available per software update. For the availability of a given language, refer to the download area.

• Simplified arrangement of operating elements, 

such as joysticks, external switches, proportional 

controls and trim levers as control functions

• CONVENIENCE MODE SELECTOR to simplify 

changeovers between operating modes 1 ... 4 

(e.g. throttle left/throttle right)

• Extremely wide receiver operating voltage range 

of 3.6V to 8.4V (functional to 2.5V)

• Fail-safe, free channel assignment (channel mapping), mixer functions and all servo settings are 

The illustration shows the contents of the mc-20 HoTT transmitter set.
12 Remote control set description

simple to program

• Swashplate limiting: This function limits the 

swashplate’s tilt angle to prevent the potential for 

mechanical collision in helicopter 3D operation at 

full-limit roll and pitch-axis

• Multi-channel function for operating Graupner 

product line NAUTIC modules

• Digital trimming, effective per specific flight-phase

• C1 changeover, brake/elec. motor: This changeover can be implemented very easily via enhanced 

flight phase programming. The pilot determines 

the joystick positions (forward/rear) at which the 

motor is to switched off or the airbrakes are to be 

retracted.

• Twelf freely programmable mixers for fixed-wing 

or helicopter models, each with freely selectable 

input and output functions; four curve mixers with 

innovative 6-point curve technology for easy to 

set and adjust curve values at up to eight points 

for throttle, pitch, tail or other nonlinear characteristics. The arithmetic unit in the CPU employs an 

ingenious method of calculating polynomial approximations for truly-rounded, ideal MPC (multipoint curve) mixer curves.

• Curve mixer points can be offset in both axes using the four-way buttons.

• Up to seven flight-phase programs can be individually adapted for each model and given a name. 

The switchover time is programmable separately.

• SUPER SERVO menu with a perfect overview of 

all servo setting data and simple parameter correction at four “levels”: direction of rotation, midpoint setting, separate servo travel on both sides 

and separate travel limiting on both sides for 8 

(mc-16 HoTT) respectively 12 servos (mc-20

HoTT) with a total of 48 respectively 72 setting 

options.

• SUPER-DUAL-RATE, EXPO and EXPO/DUALRATE menu with 36 potential setting variants 

for three servo functions and up to seven flight 

phases

• Servo display hot-key: from virtually any menu, 

pressing the  and  buttons of the left-hand 

four-way button takes you directly to the servo 

display

• Highly practical multi-function menus for fixed-wing 

model aircraft and helicopters. Entering the number of aileron and flap servos, or collective pitch 

servos, automatically sets up all the relevant mixer 

functions in the appropriate multi-function menu.

• Helicopter swashplate mixer for 1, 2, 3, or 4 point 

steering.

• Future-proof design: updatable, high-speed 32-

bit operating system with modern flash memory, 

simple update capability via the USB port and the 

micro-SD card.

• Transmitters feature sockets for PC USB interface, 

earphone, SMART-BOX, DSC system as standard; 

they are prepared for Trainer mode operations

• ESC button switches the screen from the Main 

menu to the »Telemetry« menu and back.

• Comprehensive telemetry displays, programming 

and analysis functions directly on the transmitter 

screen

• Wired and wireless Trainer systems with total 

transfer; all settings are entered at the Teacher 

transmitter.

mc-16 HoTT

• 20 model memories with storage of all model-specific programming and set-up parameters

• Eight control functions as standard, can be expanded to twelve at extra cost

• MULTI-DATA GRAPHIC LCD monitor with blue 

backlighting for greatly improved legibility in difficult lighting conditions.

• Function encoder with two four-way push-buttons 

mc-16 and mc-20 series computer systems

two remote control sets with 2,4-GHz-Graupner|SJ-HoTT technology 

(Hopping Telemetry Transmission)

for simplified programming and accurate settings

• Key-Lock function guards against accidental operation

• Transmitter features two 3-position switches (SW 

5/6 + SW 11/12), two side-mounted proportional 

controls (Lv1 + 2) and two proportional sliders 

(Sl1 + 2) as standard; controls can be assigned to 

any function

• Certain menu points can be unlocked as an extracost option; see Contents on pages 2 and 3 and 

the start of the relevant menu points

*  Standard option

 Option can be unlocked at extra cost

mc-20 HoTT

• 24 model memories with storage of all model-specific programming and set-up parameters

• Maximum twelve control functions

• Two MULTI-DATA GRAPHIC LCD monitors with 

blue backlighting for improved legibility in difficult 

lighting conditions

• A function encoder with two touch-sensitive, fourway keys („CAP Touch“) permit simplified programming and precise settings

• Twelve toggle switches (three 3-position switches 

(SW 2/3, 5/6 + 11/12), five 2-position switches 

(SW 4, 7, 9, 13 + 15), two centre-biased 2-position switches (SW 8 + 14), two 2-position locking 

switches (SW 1 + 10), two momentary switches 

on the rear of the transmitter (SW 16 + 17 / 18 + 

19), two INC/DEC buttons (CTL 5 + 6), two sidemounted proportional controls (Lv1 + 2) and two 

proportional sliders (Sl1 + 2) installed as standard; 

controls can be assigned to any function

• Key-Lock function guards against accidental operation

• Voice and, as applicable also MP3 file, output over 

headset output or loudspeaker
Remote control set description 13

• Ring-limiter: functions similar to swashplate limitation but is used for control of up to three VoithSchneider drives in ship models.

• Channel sequencer for automating servo motion 

sequences of up to three servos, e.g. to automate 

the lowering of landing gear or to extend/retract 

drives in self-launching gliders.

Model programs

• Model type icon: graphic model type indicator 

(fixed-wing / helicopter)

• Transmitter operating hours timer

• Flight phase switch assignments: six switches, two 

with a priority function. Every switch combination 

can be named freely. This makes the number of 

flight phases independent of the number of flight 

phase switches.

• Tail type normal, V-tail, Delta/flying-wing and 2 HR 

Sv 3+8 (which immediately makes two coupled 

elevator servos available without using free mixers 

or dual mixers)

• Flap count 4 AIL/4 FL: Full support of eight wing 

servos, even without use of free mixers (standard 

feature only on the twelve-channel mc-20 HoTT 

transmitter; can be unlocked at extra cost on the 

mc-16 HoTT)

• Expanded transmitter control menu: single-sided 

centre offset facility. With the exception of the 

trims, all transmitter control elements can be assigned as transmitter controls. Option of assigning 

two switches to each input to act as a genuine 

three-stage function.

• Wing mixers: New concept for the multi-flap menu 

to simplify settings of one to eight wing servos on 

a flight-phase specific basis in a comprehensible 

manner without requiring the use of free mixers

• »Logical switches«: this function permits two 

switches to be coupled as »and« or »or« logic 

functions. The result can be employed as a virtual 

switch. Typical application: The activation of certain 

functions should only be possible in conjunction 

with other functions, e.g. wheel brake can only be 

activated when the landing gear is down. A number of functions which are normally independent 

of one another, are to be put in their base settings 

by way of an »Emergency switch«. This program 

automation can be activated by multiple switches 

that also select the appropriate program. (Standard only on the mc-20 HoTT, optional on the 

mc-16 HoTT.)

• Flight phase switching cutoff delay: the delay time 

can be switched off for individual channels on a 

flight-phase basis (e.g. for motor off in electric 

models or to activate/deactivate helicopter head 

lock). (Standard only on the mc-20 HoTT, optional on the mc-16 HoTT.)

• Expanded servo centre adjustment range: now 

+/-125%

• Number of flight phases: fixed-wing: 7, helicopter: 

6 + AR

• Phase trim available on all axes of fixed-wing models

• Servo assignments can be swapped at the receiver output

• Additional functions planned; implementation via 

software update.

General HoTT features

• Simple, extremely fast binding for each model

• Ultra-fast re-binding even at maximum range

• Any number of receivers can be bound to provide 

additional channels (max. 32 channels)

• Range: test and warning function

• Low-voltage warning

• GR-16 and GR-24 receivers used in SAME mode 

can simultaneously address a maximum of four 

servos as a block, with a frame rate of 10ms (digital servos only!)

• Thanks to cycle time reduced down to as little 

as 10ms, extremely short response times are 

achieved.

• Real-time telemetry analysis on the transmitter 

screen. As an option, telemetry data can also be 

displayed on the SMART-BOX. 

• Selectable cycle time: 10ms or 20ms/30ms, depending on receiver and operating mode

• Channel mapping in the receiver allows free distribution of control functions.

The travel distance and rotation direction settings 

integrated into the receiver make it possible, for 

example, to match up mapped servos with one another.

• The programmable fail-safe functions »Hold«, 

»Off« and »Move to preset positions« that are built 

into the receiver for every individual servo channel 

can be set separately.
14 Remote control set description

Other accessories in Internet at www.graupner.de. 

Contact or visit your local dealer. He will be glad to 

provide advice.

mc-16 and mc-20 series computer systems

two remote control sets with 2,4-GHz-Graupner|SJ-HoTT technology 

(Hopping Telemetry Transmission)

The Order No. 33016 set includes

• Microcomputer transmitter mc-16 HoTT 

with built-in LiIo transmitter battery 

1s4p/4000mAh/3.7V and two 3-position switches, 

two proportional sliders on the centre console 

and two side-mounted proportional rotary controls 

(change reserved)

• plug-in charger (4.2V, 500mA)

• Short and long stick-tops 

(Order No. 33000.2 and 33000.3)

• bidirectional receiver Graupner|SJ GR-16 HoTT 

(order no. 33508) for connection of up to 8 servos

• USB adapter/interface (order no. 7186.6) including 

suitable USB cable for connection to a PC and an 

adapter cable for receiver updates

• Micro-SD card (4 GB) with an adapter for a card 

reader

The Order No. 33020 set includes

• Microcomputer transmitter mc-20

HoTT with built-in LiIo transmitter battery 

1s6p/6000mAh/3.7V and twelve toggle switches 

(three 3-position switches, five 2-position switches, 

two centre-biased 2-position switches and two 

2-position locking switches), two momentary 

switches on the back of the transmitter, two INC/

DEC buttons (CTL 5 + 6) plus two side-mounted 

proportional rotary controls and two proportional 

sliders (specification reserved)

• plug-in charger (4.2 V, 500 mA)

• Short and long stick-tops 

(Order No. 33000.2 and 33000.3)

• bidirectional receiver Graupner|SJ GR-24 HoTT 

(order no. 33512) for connection of up to 12 servos

• USB adapter/interface (order no. 7186.6) including 

suitable USB cable for connection to a PC and an 

adapter cable for receiver updates

• Micro-SD card (4 GB) with an adapter for a card 

reader

• Metal hanger for transmitter straps

• Transmitter strap

• Hand rests

• Aluminum transmitter case

Accessories

Order No. Description

71.26 Transmitter straps, Graupner|SJ HoTT

72.40 Transmitter straps, deluxe

Teacher/pupil cable for the transmitters 

mc-16 HoTT and mc-20 HoTT, see 

page 225

Replacement parts

Order No. Description

3080 Aluminum transmitter case, HoTT, 

400 x 300 x 150mm 

33000.1 Transmitter battery, flat LiIo, single cell sixpack/6000mAh 3.7V TX

33002.1 Micro-SD card, 4GB for HoTT transmitter 

33012.2 Transmitter metal hanger for mc-16 and 

mc-20 HoTT

33012.3 Hand rests for the transmitters mc-16

and mc-20 HoTT (2 piece) 
Remote control set description 15

mc-16 HoTT and mc-20 HoTT transmitter

Frequency band 2.4 ... 2.4835GHz

Modulation FHSS

Region EURO or FRANCE, 

see page 272

Control functions mc-16 HoTT:

8 functions, 4 of these can be 

trimmed, can be expanded to 

12 functions at extra cost

mc-20 HoTT:

12 functions, 4 of these can 

be trimmed

Temperature range -10 ... +55°C

Antenna Integral patch aerial inside 

case

Operating voltage 3.2 ... 4.8V

Current draw about 400mA

Range up to about 4 000m

Dimensions about 235 x 228 x 66mm

(without hand rests)

Weight about 1200g with transmitter 

battery, without accessorys

GR-16 HoTT receiver 

order no. 33508

Operating voltage 3.6 ... 8.4V*

Current draw about 70mA

Frequency band 2.4 ... 2.4835GHz

Modulation FHSS

Antenna 2 diversity antennas, about 

145mm long, about 115mm 

of this length encapsulated 

and about 30mm active

Plug-in servos 8

Sensor sockets 1

Temperature range -10 ... +55°C

Dimensions about 46 x 21 x 14mm

Weight about 12g

GR-24 HoTT receiver 

order no. 33512

Operating voltage 3.6 ... 8.4V*

Current draw about 70mA

Frequency band 2.4 ... 2.4835GHz

Modulation FHSS

Antenna 2 diversity antennas, about 

145mm long, about 115mm 

of this length encapsulated 

and about 30mm active

Plug-in servos 12

Sensor sockets 1

Temperature range -10 ... +55°C

Dimensions about 46 x 31 x 14mm

Weight about 16g

Technical data

* The specification for permissible operating voltage range applies 

only to the receiver. Please note in this context that receiver input 

voltage is applied without regulation to connected servos but 

the voltage range for most connectible servos (speed controls, 

gyros, etc.) is only 4.8 to 6V
16 General operating notices

General operating notices

mc-16 HoTT and mc-20 HoTT transmitters

Transmitter power supply

mc-16 HoTT and mc-20 HoTT transmitters are 

fitted as standard with rechargeable Lithium-Ion batteries differing in capacity. (Change reserved.)

However, the standard built-in battery is not 

charged upon delivery of the transmitter. 

When the transmitter is used, its battery voltage 

should be monitored by way of the indicators provided 

in the LCD display. If battery voltage drops below 

the adjustable voltage setting (set via item “Batterie 

warning” in the “Basic Settings” menu, page 272,), 

default value 3,60V, an audible warning signal will 

sound and the message window shown below will appear in the screen

#01

0:22h

Stp

 

0 00

0

0V

3.5V

x

T

Batt. must

 be re-

 charged!!

No later than now, operation must be terminated so 

the battery can be charged again.

Notice:

Be sure that the correct battery type is set in the 

“Basic Settings” menu, page 272! “Lith” must be 

set as standard.

The transmitter’s rechargeable LiIo battery can be 

charged by way of the charger socket located behind 

a cover on the left, front side of the transmitter–as 

viewed from the front–with the included plug-in 

charger (order no. 32032.4), see page 22.

Charging the transmitter battery using the plugtype charger

With the plug-type charger 

(4.2V / 500mA) included 

in the set the charge time 

for the transmitter battery is up to about fifteen 

hours, depending on 

the pack’s initial state of 

charge.

Never use any other type or make of plug-type charger, nor a charger designed for other types of battery. 

There is a risk of excessive output voltage and incorrect connector polarity (see below), either of which 

can result in very serious damage. We recommend 

that you label the standard charger to avoid confusion. Please read the Safety Notes on pages 8 ... 

9.

The transmitter must be switched “OFF” during the 

entire charging procedure. Never switch on the transmitter when it is connected to the charger. Even a 

brief interruption to charging can cause charging 

voltage to rise to a level that will immediately damage 

the transmitter with over-voltage. Also for this reason, 

be sure all connectors are always plugged in securely 

and have good contact.

Charging the transmitter battery via the USB 

socket

The transmitter is supplied fitted with a genuine 

Graupner/SJ transmitter battery with integral protective circuit, Order No. 33000.1, which can also 

be charged via the USB port of the mc-16 HoTT 

and mc-20 HoTT transmitter at the usual current 

available at USB ports; see “mini-USB socket” on 

page 25.

C A U T I O N: charging a battery without integral 

protective circuit via the USB socket incurs a serious 

risk of fire! 

Charging with automatic chargers

To achieve quicker recharging of the single cell LiIo 

battery, Graupner automatic chargers can also be 

used. The table below shows a selection of these 

chargers.

Recommended chargers (accessory)

Order

No. Designation

Input voltage 220

V

Input voltage 12 

V

suitable for 

battery types NiCd NiMH LiPo/LiIo lead battery

integr. balancer

6411 Ultramat 8 x x x x x

6463 Ultramat 12 plus x x x x x x

6464 Ultramat 14 plus x x x x x x x

6466 Ultra Trio plus 14 x x x x x x x

6468 Ultramat 16S x x x x x x x

6469 Ultra Trio Plus 16 x x x x x x

6470 Ultramat 18 x x x x x x x

6475 Ultra Duo Plus 45 x x x x x x x

6478 Ultra Duo Plus 60 x x x x x x x

6480 Ultra Duo Plus 80 x x x x x x x

Charger cable, order no. 3022 is additionally needed for the transmitter and charger cable, order no. 3021 is additionally needed for 

the receiver.

Other charger units and details about the listed chargers can be 

found in the Graupner RC main catalog or in Internet at 

www.graupner.de.

The charger socket is equipped standard with a diode 

to protect against reversed polarity. Original Graupner

automatic chargers also detect battery voltage polarity. 

Observe the configuration notices for the charger 

used.
General operating notices 17

First connect the charger cable’s banana plugs 

to the charger and only then connect the cable’s 

other end into the charging jack on the transmitter. Never allow the bare ends of the banana plugs 

to come into contact with one another when the 

other end of the cable is plugged into the transmitter. 

Charging current may not exceed 1.5 A as otherwise the diode, and perhaps other components, 

could be damaged. If necessary, limit the current 

at the charger.

mc-charging jack polarity

The charger cables on the market from other manufacturers often have different polarities. Therefore use 

only an original Graupner charger cable, order no. 

3022.

Removing the transmitter’s battery

To remove the transmitter battery locate the cover of 

the battery compartment in the back of the transmitter 

and slide it off in the direction of the arrow:

Battery connector

Lift one side of the battery and withdraw it from the 

hook-and-loop tape without using force. Then disconnect the transmitter battery’s connector by carefully 

pulling on the supply line cable.

(The photo shows the battery of the mc-20 HoTT 

transmitter.)

Inserting the transmitter’s battery

The battery connector is protected against a reverse 

polarity connection by two slanted edges, see illustration. When correctly plugged in, the 

unconnected pin of the connector 

is at the bottom, as shown in the 

illustration. The plus pole (red lead) 

is in the middle and the minus pole 

(brown or black lead) is toward the 

antenna side.

Never try to force the connector onto its circuit-board 

socket.

Place the battery into its compartment and close the 

transmitter’s cover.

Battery operation timer at the bottom left of the 

screen

This timer shows the transmitter’s cumulative operating time since the transmitter’s battery was last 

charged. 

This timer is automatically reset to “0:00” when the 

transmitter is switched on and its battery voltage is 

significantly higher than when the transmitter was last 

used, e.g. because the battery was charged.

#01

0:00h

Stp

Flt

 

0:00

0:00

0.0V

4.1V

Mx

HoTT

Transmitter 

connector polarity

General charging notices

• The charging instructions for the charger as well 

as for the battery from its manufacturer to be 

observed.

• Pay attention to the maximum permissible charging current specified by the battery’s manufacturer. 

In order to prevent damage to the transmitter, 

charging current should never exceed 1A. If necessary, limit the current at the charger.

• If the transmitter battery is nevertheless to be 

charged at a current rate in excess of 1A, then it is 

imperative that this is done outside the transmitter. 

Otherwise there is a risk of damage to the transmitter’s board due to overloading its printed circuit 

paths and/or overheating of the battery.

• If an automatic charger is to be used for charging, perform several test charging procedures to 

ensure the flawless functionality of its automatic 

shut-off. This applies particularly if you want to 

charge the standard installed Lithium battery with 

an automatic charger unit. You may need to alter 

the charger’s cut-off behaviour if the charger you 

are using offers this option.

• Do not execute a battery discharge or battery 

maintenance program through the charger jack. 

The charger jack is not suitable for this purpose.

• Always connect the charger cable to the charger 

first and then to the receiver or transmitter battery. 

This avoids the possibility of shorting the bare 

banana plug ends together.

• If the battery heats up significantly, check the battery’s condition, replace the battery or reduce the 

charging current.

• Never leave a charging battery unattended.

• Follow the safety notices and handling instructions provided on page 8.
18 General operating notices

Opening the transmitter housing

Carefully read the notices below before opening the 

transmitter housing. It may be better if unexperienced 

users ask a Graupner Service location to take care of 

the procedures described below.

The transmitter should only be opened in the following situations:

• to convert a neutralized joystick to a non-neutralized joystick or a non-neutralized joystick to a 

neutralized joystick.

• to adjust joystick return tension.

Switch off the transmitter before opening its cover.

Open the battery compartment as described on 

the previous double-page. If the handrests are fitted, undo the three lower retaining screws of the six 

screws in each handrest.

Now undo the five recessed screws in the back of 

the transmitter and the battery well using a PH1-size 

cross-point screwdriver; see illustration: 

Note that the screw-holes are inclined slightly to the 

rear, so the cross-point screwdriver should be applied 

at the corresponding angle. 

Hold the two housing sections together by hand then 

turn the transmitter upright over a suitable surface so 

these 5 screws can fall out without getting lost. Now 

lift up on the backplate carefully and place it to one 

side.

Important notices:

• Ensure that the shorter screw–in the battery 

well–does not fall inside the transmitter.

• Make no modifications of any kind to the circuitry as this will void the guarantee as well as 

the unit‘s official permit.

This applies in particular to the switches installed on both sides of the front screen. If you 

wish to change the arrangement, contact your 

nearest Graupner Service Centre.

• Be sure not to touch the circuit boards with 

any metallic objects. Do not touch contacts 

with your fingers.

• Never switch the transmitter on when its housing is open.

When you close the transmitter again, be sure 

that ...

• ... no cables are caught between housing edges 

when the backplate is put into position.

• ... both housing parts are properly seated with 

one another before screwing them together. Never 

force the housing sections together.

• Turn the screws down into the existing housing 

threads without stripping them out.

• ... fit the shorter of the five screws in the battery 

compartment again.

• ... reconnect the battery.

• ... re-install the handrests if you wish.

Lithium battery CR 2032

When you remove the transmitter back panel, you will 

see the holder for a CR 2032 battery on the circuit 

board below the aerial base, slightly left of centre:

Lithium battery

This battery maintains the date and time settings 

during a transmitter power supply outage, for example 

when the transmitter’s main battery is being replaced.
General operating notices 19

Joystick restoring force

The joystick’s restoring force can also be adjusted to 

the pilot’s preference. The adjustment is located next 

to the return springs, see markings in the figure below.

Spring force for the given direction of motion can be 

adjusted by turning the respective screw with a Phillips screwdriver.

• clockwise = stronger return,

• counter-clockwise = weaker return.

vertical

horizontal

Note:

The aggregate for the right joystick is a mirror image 

of the left joystick so corresponding screws for the 

right joystick are located to the right of the middle.

Stick conversions

Neutralization

Both the left and the right joystick can be configured 

for neutralized or non-neutralized operation. Open the 

transmitter.

To change the joystick’s factory setting, locate the 

screw shown in the figure below enclosed in a white 

circle. 

Note:

The aggregate for the right joystick is a mirror image 

of the left joystick so the corresponding screw for the 

right joystick is on the right side just below the middle.

Now turn this screw down until the respective joystick 

is free to move from limit to limit–or turn the screw 

out until the joystick again completely self-restoring.

Brake spring and ratchet

The outboard screw of the two marked in the next 

figure adjusts the braking force and the inboard screw 

adjusts the strength of the ratchet for the respective 

joystick:

Note:

The aggregate for the right joystick is a mirror image 

of the left joystick so corresponding screws for the 

right joystick are located at the top left.
20 General operating notices

Transmitter neckstrap support bars

As standard the mc-20 HoTT transmitter set includes a strong support system for the attachment of 

a neckstrap. The mc-16 HoTT transmitter can be 

retro-fitted with the transmitter support system, Order 

No. 33012.2, at any time.

The support bars are inserted in the sockets in the 

transmitter case, and locked in place. After the transmitter has been used, they can be removed again in 

similar fashion:

first press, 

then turn

The support bars are installed as follows: push one 

of the bars into the socket in the transmitter case, 

angled towards the centre of the transmitter as shown 

above. Now ensure that the retaining pin attached to 

the bar is in line with the slot in the socket, and press 

the bar against the spring in the direction of the transmitter for a distance of about one centimetre. At the 

same time fold the bar outwards (do not use force) in 

order to lock it in place. Install the second support bar 

in the same manner.

To remove the support bars first unlock one of the 

bars by lightly pressing it inwards, and then fold it 

towards the centre of the transmitter. As soon as the 

retaining pin is free, you can withdraw the support bar 

from its guide. Repeat the procedure with the second 

support bar.

Stick length adjustment

The length of both joysticks can be continuously adjusted to adapt these transmitter controls to the pilot’s 

preference.

Hold the lower half of the knurled grip in place then 

turn the upper section to release its counter-locked 

threads: 

Now pull up or push down on the joystick’s end to the 

desired length. When the length is suitable, tighten 

the counter-locked threads of the upper and lower 

sections again.

The procedure is the same if you wish to replace the 

short stick-tops with the longer ones also supplied in 

the set.

The following straps are available as accessories:

Order no.Description

71.26 Transmitter straps, Graupner/SJ HoTT

72.40 Transmitter straps, deluxe
Transmitter description - Front side 21

Transmitter description

Front side

(The illustration shows the mc-20 HoTT transmitter.)

Integral aerial inside case

Option wells for switches and buttons:

The following are fitted as standard:

mc-16 HoTT: 2 three-position switches

mc-20 HoTT: 12 switches of various type and 2 

INC/DEC buttons

Function module

two sliders “Sl1” and “Sl2”

Digital trim

For the fine-tuning of servo positions (travel 

neutralization). Each click produces an increment of adjustment (position indicator in 

display). The trim increment can be selected 

in the »Stick settings« menu.

LC Display (more details available on page 28.)

Contrast adjustment in the »General settings« 

menu; see page 271.

Warning indicators:

• for underrun of preset battery voltage threshold

• for fault function of the teacher/pupil system

• C1 joystick too far toward full throttle when transmitter is switched on

• ...

ON/OFF switch (ON/OFF with LED display)

Hold the ON/OFF switch pressed in for about one 

second to switch the transmitter on. Hold it pressed in 

for about three seconds to switch off.

touch sensitive keys, left and right

LC Display (more details available on page 28.)

Function module

rotary control: left side “Lv1”,

 right side “Lv2”

Loud

speaker

Connector sockets

on the face side, protected by a cover, see beginning 

page 22 

mc-20

left four-way button:

+

ESC = select/confirm

ESC touched for about 1 s: Changeover between 

telemetry menu and basic display

= scroll in one of the four directions with every 

tap (, , , )

simultaneous horizontal tap ()

= changeover between basic display and servo 

display

simultaneous vertical tap of the left 

() keys + "SET" of the right fourway button = changeover to the "secret 

options", see page 34.

SET = select/confirm

= scroll or change value with every touch of one 

of the four direction 

symbols (, , , ) 

Circle with the finger around the circumference 

= scroll/change values. Alternative values selection with the left four-way button (, , , )

simultaneous tap on  

or  = CLEAR

right four-way button:

or

LED indicators

BATTERY: illuminates when voltage is sufficient

RF: illuminates during RF radiation

WARNING: blinks, for example, when "Throttle too 

high", "no pupil signal", "Transmitter 

battery voltage too low", ...

Joystick

Two joysticks for a total of four independent 

control functions. The length of the joysticks 

can be adjusted. The correlation of control 

functions 1 ... 4 can be set on a model 

type basis by way of the »Basic settings, 

model« menu, e.g. throttle left or right. The 

throttle joystick can be converted from neutralizing to non-neutralizing, see page 19.
22 Transmitter description - Face-side connections

sic display should show the character string “DSC” 

below the operating time clock. At this time, the 

display of telemetry data and symbols will be suppressed.

ELEVE

#11

0:01h

Stp

Flt

DSC 

0:00

0:00

4.1V HoTT

The transmitter’s upper display will show the message “CANNOT RECEIVE DATA” during this time.

Thus the transmitter is ready for operation. 

In contrast, the transmitter in teacher mode is to 

be switched on prior to plugging in the respective cable.

3. Connect the other end of the cable to the desired 

unit in compliance with the given operating instructions for that unit.

Important:

Pay attention that all plugs are inserted securely into their respective sockets and use 

only the prescribed 2-pole TRS connector 

plugs on the DSC-side.

4. In the line „DSC Output“ in the »Basic settings,

model«, page 92 or 100,–depending on the 

number of functions transferred–one of the following modes can be set: PPM10, PPM16, PPM18 or 

PPM24. Default setting: PPM10.

Notice about flight simulators:

Because of the myriad of flight simulators available on 

the market, it may be necessary to have the contact 

layout of the audio plug or DSC module appropriately 

modified by Graupner Service. 

DSC jack

The acronym “DSC” is a carryover which stands for 

the original “Direct Servo Control” function. However, 

in HoTT systems the “direct servo control” function is 

no longer available via a diagnose cable due to technical reasons.

Once the left-hand side flap has been moved away, 

the DSC socket is accessible:

The two-pole DSC socket fitted as standard to mc16 HoTT and mc-20 HoTT transmitters serves 

both as Trainer socket (Teacher and Pupil) and also 

as interface for flight simulators and external RF 

modules. 

To ensure a proper DSC connection, please observe:

1. Make any necessary menu changes.

Refer to the section beginning on page 222 to 

adapt the transmitter to a teacher/pupil system.

2. When operating a flight simulator or when operating the transmitter as a pupil transmitter, ALWAYS

switch OFF the transmitter as only in this position 

does the transmitter‘s RF module remain inactive 

after the DSC cable is inserted. This also reduces 

the transmitter‘s power consumption somewhat.

Only the red “Battery” LED should remain 

constantly illuminated and the transmitter’s baFace-side connections

Charger socket

(The illustration shows the mc-20 HoTT transmitter.)

The left-hand side flap provides access to the charge 

socket of the mc-16 HoTT and mc-20 HoTT 

transmitter: 

The transmitter’s rechargeable LiIo battery can be 

charged by way of the charger socket located behind 

a cover on the left, front side of the transmitter–as 

viewed from the front–with the included plug-in 

charger (order no. 32032.4).

Maximum permissible charging current with Graupner

automatic chargers: 1,5A.

Never use plug-in chargers from other manufacturers 

or chargers intended for other battery types. Charger 

output voltage which is too high or possibly even 

different plug polarity, see further below, can cause 

immense damage. 

More information about charging the transmitter’s 

battery can be found on page 16. Observe the 

safety notices beginning on page 8 when handling 

lithium batteries.
Transmitter description - Face-side connections 23

The left-hand side flap provides access to the DATA 

socket of the mc-16 HoTT and mc-20 HoTT 

transmitter:

This jack is intended for connection of the optional 

Smart-Box, order no. 33700.

Details about the Smart-Box can be found with the 

given product in the Graupner RC main catalog or in 

Internet at www.graupner.de.

However, the Data socket can also be used to connect external RF modules made by other manufacturers; see “EXT.” and “SP.” in the “Module” section of 

the “Basic model settings” menu on pages 88 and 

96.

Data jack

Once the right face-side cover has been moved away, 

the transmitter’s headset connector is accessible:

The jack is intended for connecting conventional earplugs or a headset by way of a 3.5 mm TRS plug. (not 

included in the set) An appropriate symbol will appear 

in the basic display when a headset is connected:

#01

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT

The transmitter’s acoustic signals as well as those 

signals associated with the telemetry menu are output via this connection. These announcements are 

made in German language by default. More about 

this can be found under “Voice output” in the section »SECRET MODE« beginning on page 34 and 

»Telemetry« beginning on page 240.

The volume of signals and voice output sent to the 

headset can be adjusted individually in the lines 

“Voice volume”, “Vario volume”, and “Beeps volume” 

of the »General basic settings« menu, page 268.

Headset connector
24 Transmitter description - Face-side connections

on the memory card. Within the “LogData” folder there 

will be log files, that are designated with names in the 

format 0001_year-month-day.bin, 0002_year-monthday.bin, etc., in sub-folders named “model name”. If 

a model memory is still “unnamed” the respective log 

files can be found in a sub-folder designated “NoName” when the memory card is removed from the 

transmitter and inserted into the card slot of a PC or 

laptop. There is a PC program available on the transmitter’s download web page at www.graupner.de with 

which the stored data can be evaluated on a compatible PC.

Importing voice files

As mentioned in section “Headsets”, here at the right, 

the transmitter’s acoustic signals as well as those 

signals and announcements associated with the »Telemetry« menu can be output by way of the headset 

connector. These announcements are made in German language by default. These announcements are 

summarized in a voice packet which is stored in a 

transmitter-internal memory but can be replaced by a 

voice packet of a different language at any time. More 

information about this can be found in the section 

»SECRET MODE« beginning on page 34.

Transmitter firmware updates

The transmitter firmware can be updated and–if 

necessary–replaced at this menu point, using the 

procedure described in the previous section entitled 

“Importing voice files”; the screen language can also 

be changed here. For more details of this please refer 

to the section entitled “SECRET MODE” which starts 

on page 34.

Updates and more information can be found on the 

product page for your specific HoTT transmitter; see 

the Download section at www.graupner.de.

Important notes:

• No claim can be considered unless a log file is 

present; see left under “Data recording / stor-

#01

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT

If the card has not previously been inserted, the 

transmitter first creates a number of folders on it; 

this is indicated in the transmitter’s base display by 

a card symbol which slowly fills from left to right. The 

memory card is ready for use as soon as this animation ceases.

You can remove the prepared memory card from the 

transmitter when required, and insert it in a suitable 

card reader. Connect the reader to your PC or laptop, 

and copy the files–previously downloaded from the 

Download page for your transmitter–into the appropriate folder. Now remove the memory card from your 

card reader and insert it in the transmitter once more.

Removing the memory card 

Press the SD or SDHC card a bit further into the 

card slot to release the slot’s latch then pull out the 

memory card.

Data acquisition / storage

The storage of data on the SD card is coupled to the 

flight timer. If this timer is started–when a suitable 

memory card is inserted in the card slot and a telemetry link to the receiver exists–data acquisition is 

also started. Data acquisition will stop again when the 

flight timer is stopped. The flight timer is started and 

stopped as described in the section »Timers (general)” on page 162. 

The amount of data written on the memory card is 

presented as a black bar graph ( ) which grows 

from left to right as data fills the memory card .

After a data acquisition session is finished, there will 

be an (empty) folder “Models” and a “LogData” folder 

The transmitter’s card slot for type micro-SD and 

micro-SDHC memory cards becomes accessible 

once the right face-side cover has been turned away.

Although a memory card is supplied as standard, the 

slot also accepts any standard commercial micro-SD 

memory cards of up to 2 GB capacity and microSDHC cards of up to 32 GB capacity. However, as 

a manufacturer we recommend the use of memory 

cards no larger than 4 GB as this is completely adequate for all normal situations.

The type of memory card to be used in the transmitter 

is that known in conjunction with digital cameras and 

cell phones. It is to be pushed into the slot, contacts 

up, until it latches, see photos above. Once the memory card has been inserted, the transmitter’s cover 

flap can be closed again. 

If the standard memory card is inserted–or another 

card which has already been inserted in the transmitter at least once–then the card is immediately ready 

for use when the transmitter is switched on. When the 

transmitter is switched on again after inserting such 

a card, the stylised memory card icon appears in the 

base display:

Card slot

micro SD and micro SDHC
Transmitter description - Face-side connections 25

The right-hand side flap of mc-16 HoTT and mc20 HoTT transmitters provides access to the software update socket, which is also used for altering 

the date and time via a PC using the Windows XP, 

Vista or 7 operating system; this socket is located on 

the right-hand side under the flap:

The USB cable, order no. 32032, which is included 

with the set is to be connected to this jack. The procedure for carrying out a software update via a PC is 

described on page 50.

The PC software required, as well as the suitable 

USB driver, can be found on the download page for 

the given product on the Graupner website at 

www.graupner.de.

Once the necessary driver and software is installed 

on the PC, this USB connection can be used to update the transmitter or even just to set the transmitter’s date and time. To set the transmitter’s date and 

time by way of this jack, refer to the »Info display« 

menu, beginning page 278. 

Note:

mc-16 HoTT and mc-20 HoTT transmitters can 

also be charged using this USB socket at the standard currents present at USB ports; see page 16.

Mini-USB connector

ing”.

• For the same reason the transmitter must always be updated to the latest software status.

• It is essential that you register at https://www.

graupner.de/en/service/product_registration.

aspx to ensure that you are constantly informed of important software updates. This is 

the only means by which we can automatically 

keep you aware of new updates by e-mail.

Importing/exporting model memories

Any model memory can be stored to an inserted 

memory card or from an inserted card into the transmitter. This feature is intended to support data exchange between identical transmitters or even use 

as data backup. More information about this can be 

found in the section »Copy / Erase« beginning on 

page 80. 

Notes:

• Some special symbols that can be used in model 

names are subject to specific restrictions associated with the FAT or FAT32 file system used by the 

memory cards and these special symbols will be 

replaced during the copy process with a tilde (~). 

• In principle the model memories of the mx-20 and 

mc-20 transmitters are compatible, BUT:

If you wish to carry out an “Import from SD card” in 

the other transmitter you must first copy or move 

the appropriate model memory to the appropriate 

folder on a PC. For example: from \\Models\mc-20 

to \\Models\mx-20, or vice versa.

See page 82 for more information on “Import 

from SD card”.

C A U T I O N :

After you have carried out an “Import from SD 

card” it is absolutely essential to check all the 

model functions with great care. Note also that the 

transmitter control and switch functions may need 

to be adjusted to suit the new transmitter.
26 Transmitter description - Bottom side transmitter interior

Bottom side transmitter interior

(The illustration shows the mc-20 HoTT transmitter.)

Socket for optional Bluetooth module

Order No. 33002.5

RF modul

Sockets for optional transmitter controls and 

switches

(In principle you can connect the switches in any 

order, but we strongly recommend that you maintain the same sequence as the case legends to 

avoid confusion.)

SW16/PB18 (when transmitter is closed), 

see “Physical control, switch and control 

switch assignments” on page 68

SW17/PB19 (when transmitter is closed), 

see “Physical control, switch and control 

switch assignments” on page 68

Lithium battery CR2032 (not rechargeable) 

Independent backup for the transmitter's date 

and time settings, see »Info display« menu on 

page 278.

Transmitter battery plug

For charging the battery and a list 

of suitable automatic chargers, see 

page 16

Notes:

Disconnect the transmitter battery at its connector when performing any type of work inside the 

transmitter. Never allow solder points to come 

into contact with objects as this can create short 

circuit conditions.

All jacks and plugs not described are to be left 

unconnected.
For your notes 27
28 Transmitter description - Display and keypad

Display and keypad

(The illustration shows the control pad of the mc-20 HoTT transmitter.)

Model memory location 

mc-16: 1 ... 20

mc-20: 1 ... 24

Operating mode

Flight phase timer display, if available; 

Flight phase name see “Flight phase timers”, page 166.

see menu »Phase settings«, page 152 or 156

left four-way button:

+

ESC = select/confirm

ESC touched for about 1 s: Changeover between 

telemetry menu and basic display

= scroll in one of the four directions with every 

tap (, , , )

simultaneous horizontal tap ()

= changeover between basic display and servo 

display

simultaneous vertical tap of the left 

() keys + "SET" of the right fourway button = changeover to the "secret 

options", see page 34.

SET = select/confirm

= scroll or change value with every touch of one 

of the four direction 

symbols (, , , ) 

Circle with the finger around the circumference 

= scroll/change values. Alternative values selection with the left four-way button (, , , )

simultaneous tap on  

or  = CLEAR

right four-way button:

or

Transmitter battery voltage with dynamic bar indicator. If the 

lithium battery voltage underruns the 3.60V (adjustable) 

threshold a warning message will appear and an acoustic 

warning will sound. (Switchover for NiMH batteries.)

Transmitter operating time. This will automatically be reset to zero after a 

charging process.

Display diagram for all four digital trim levers with numeric indicator and 

direction indicator

Model type indicator 

winged model, helicopter

Model name

Stopwatch in min:s

(upward/downward)

Flight timer in min:s

micro-SD card 

inserted

A selection of potential warnings and notices. More about this on 

page 33.

No

pupil

signal!

Throttle

too

high!

Batt. must

be recharged!!

Fail Safe

setup

t.b.d.

Receiver battery 

voltage RX-SPG

Signal strength

M = Model 

operation

P = Pupil

(pupil 

transmitter)
Transmitter description - Operating the “data terminal“ 29

Operating the “data terminal“

Entry keys ESC and SET

Display symbols

Displayed telemetry symbols

the active model memory has not yet been 

“bound” to a HoTT receiver. More about the 

“Binding” process can be found on page 87 

or 95.

Switched off on RF transmitter side

blinking antenna symbol: 

The last receiver bound to the active model is 

inactive or out of range

>M x no telemetry signal to receive

>M signal strength indicator of the connection to 

the model

>P signal strength indicator of the connection to 

the pupil transmitter in the display of the teacher transmitter for wireless teacher/pupil operation

Keys left of the display

• ESC key 

each brief tap on the ESC key will cause a stepwise return in function selection or even further to 

the base screen. Any changes made to settings 

remain.

Momentarily touching the ESC key for about 1s 

while in the base screen will open and close the 

»Telemetry« menu.

• Selection keys  

1. A tap on one of these keys will scroll, appropriate for the given arrow direction, through lists, 

such as through the model selection list or the 

multi-function list or within menus though the 

menu‘s lines. 

2. A brief simultaneous tap on the  keys will 

cause a switch from the transmitters base 

screen, as well as from almost any menu position, into the »Servo display« menu.

Keys to the right of the display

• SET key

1. After switching the transmitter on, a brief tap 

on the SET key will cause a jump from the displayed base screen to the Multi-function menu. 

In the same manner, a selected menu can now 

be called up with the SET key. 

2. Within menus having settings, activate / deactivate (confirm) the given setting fields with a tap 

on the SET key.

• Selection keys  

1. “Leafing through” the multi-function menu, and 

the menu lines within the set-up menus, in the 

same manner as the Select buttons of the lefthand four-way button, or–on the mc-20

transmitter–in the same manner as “circling” 

over the four Select buttons. 

2. Select or set parameters in setting fields after their activation with a tap on the SET key, 

whereby the  and  keys will have the 

same given function. In this case it is completely irrelevant which of these two keys are used.

3. A brief simultaneous tap on the  or 

keys will set a changed parameter value in the 

entry field back to its default value (CLEAR).

Notes:

• In contrast to the four-way buttons of the mc-16

HoTT transmitter, which are “pressed” in the same 

way as micro-switches, the touch-sensitive CapTouch buttons of the mc-20 HoTT respond to 

the lightest of touches.

• Touching the given four-way button does not itself 

initiate the given action but rather the end of the 

touch.

• In the event the four-way buttons do not exhibit any functionality immediately after switching the 

transmitter off and then on again right away, this 

is not a fault. Just switch the transmitter off again 

then wait for several seconds before switching it 

on again.
30 Transmitter description - Shortcuts

Shortcuts

The following key combinations can be used to directly call up certain menus and options:

• CLEAR

A brief simultaneous tap on the  or  keys 

of the right four-way button will reset a changed 

parameter value in the active entry field back to its 

default value.

• »Servo display«

A brief simultaneous tap on the  keys of the 

left four-way button will change from the transmitter’s base screen or from almost any menu position to the »Servo display« menu, see page 274.

• »Telemetry« menu

Tap the center ESC key of the left four-way button for about 1s to call up the »Telemetry« menu 

from the transmitter’s base screen or return to the 

base screen again, see text beginning on page 

228.

• Graphic display of telemetry data

Briefly touching one of the selection keys of the 

left or right four-way button will cause a jump from 

the base screen directly to the transmitter’s graphic display of telemetry data or will allow paging 

back and forth between individual graphic displays. 

A brief tap on the center ESC or SET key will 

cause a return back to the base screen.

• »SECRET MODE« 

(Language selection, Firmware update, Stick 

calibration etc.)

Touch and hold the  selection keys of the left 

four-way button then momentarily touch the SET

key of the right four-way button, see text beginning 

on page 34.

• Entry lockout

Entry lockout is activated and deactivated from the 

base screen by simultaneously touching the ESC

and SET keys for about 2s.

• Quick-Select

From the multi-function list, a jump can be made 

into a “Structure overview” by way of a brief, simultaneous tap on the  or  keys of the 

right four-way button. Menus are arranged in clear 

groups in this overview.

Memory

Servo setting

Transm. controls

Switches

Flight phases

Timers

Mixers

Special. funct.

Global functions

All menus

Now the desired group can be selected with the 

 selection keys of the left or right four-way button ... 

Servo setting

Transm. controls

Switches

Flight phases

All menus

Memory

... then finally tap the center SET key of the right 

four-way button briefly. As soon as the key is released, only the respective generic term for the 

given menu will remain listed. For example:

Copy / Erase

Suppress menus

Suppress models

Model select

Now you can select the desired menu point using the  or  buttons, and then call it up by 

pressing the SET button of the right-hand four-way 

button.
Transmitter description - Concealed menu columns 31

Concealed menu columns

Some menus have concealed columns to improve 

legibility. Menus with concealed columns can be recognized by virtue of a triangle pointing to the right in 

the bottom left corner of the screen. For example, in 

the menu »Servo settings«:

S1

S2

S3

Rev cent trv +

0%

0%

0%

100% 100%

100% 100%

100% 100%

0%

0%

100% 100%

100% 100%

S4

S5

In this menu, e.g. the column “- lim +” (servo travel 

limit) to the right of column “- travel +” is “concealed”.

To reach this column, use the pointing triangle at the 

bottom left of the screen to push the frame marker 

with the arrow key  of the left or right four-way button to just beyond the column for “- travel +”:

S1

S2

S3

Rev cent lim +

0%

0%

0%

150% 150%

150% 150%

150% 150%

0%

0%

150% 150%

150% 150%

S4

S5

To again return to the now-concealed column “- travel +” or even further to the left, push the frame marker 

with arrow key  of the left or right four-way button 

appropriately to the left:

S1

S2

S3

Rev cent trv +

0%

0%

0%

100% 100%

100% 100%

100% 100%

0%

0%

100% 100%

100% 100%

S4

S5

This procedure is analogous for the other menus.
32 Transmitter description - Function fields | Position indicator | Entry lockout

Note:

This option is only available as standard on the mc20 HoTT transmitter, but can be unlocked on the 

mc-16 HoTT transmitter at extra cost.

A lockout for the touch keys, and thus protection 

against inadvertent use of all setting options, can be 

established by touching and holding the ESC and 

SET keys simultaneously for about two seconds while 

the transmitter is in its basic display. This lockout 

condition is indicated by a key symbol, located at the 

intersection point of the trim bars, which is displayed 

in reverse video.

#01

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT

The lockout is effective immediately but controls remains operationally ready. 

This lockout can be removed by again touching and 

holding the ESC and SET keys for about two seconds. 

Entry lockout

Depending on the given menu, certain function fields 

will appear on the bottom display line:

CLR SEL STO SYM ASY

A marked function is activated with a tap on the 

SET key.

Function fields

• CLR (clear) erase

• SEL (select) selection

• SET (set) “set” or adjust a value

• STO (store) store (e.g. control position)

• SYM set values symmetrically 

• ASY set values asymmetrically 

• POS Only in »Trim memory« menu

• switch field symbol (assignment of 

all types of switches)

• within a menu, change to the second page, (menu continuation)

Function fields in the display

CLR, SEL, STO, SET, SYM, ASY, POS, , 

When you operate one of the two INC/DEC buttons 

CTL 5 + 6, which are fitted to the two switch boards of 

the mc-20 HoTT transmitter only, a small symbol 

appears on the left of the screen adjacent to the two 

vertical position indicators:

At the same time, for the duration of the control‘s operation, the position indicator for the two vertical bars 

in the middle will change from displaying current trim 

position to a display of the respective current position 

of the controls CTL 5 & 6.

Logically, the left control (CTL 6) is displayed by the 

left bar indicator and the right bar indicator displays 

the position of the right control (CTL 5). The two horizontal bars continue to show current trim positions of 

respective stick trim controls:

#01

2:22h

Stp

Flt

0:00

0:00

3.9V

M

HoTT

About 2 seconds after operating one of the controls 

has ended, the display will again revert to display of 

current trim positions of the four trim controls generated by the two sticks.

Note:

On the mc-16 HoTT transmitter these two INC/DEC 

buttons can be retro-fitted by your local Graupner 

Service Centre at extra cost.

Position indicator

INC/DEC buttons CTL 5 and 6
Transmitter description - Warning notices 33

Warning notices

Batt. must

 be re-

 charged!!

Operating voltage is 

too low

BIND. N/A

OK

„Bind not available“

A receiver has not yet 

been bound to the 

currently active model 

memory. A brief tap on 

the SET key will cause 

a direct jump to the appropriate option.

Power on warning

is active!

If no controls are operated on the transmitter, 

it switches itself off automatically after about 

three minutes.

Attention!

Switch-OFF

the Receiver first!

This warning appears 

if you try to change 

models in the »Model 

select« menu with the 

receiver of the previously active model still 

switched on.

CAN‘T

RECEIVE

DATA

O K

No bound receiver in 

range

Please select

RF on/off?

O N OFF

Only for a receiver 

that has already been 

bound:

Please select RF „on“ 

or „off“? RF

RF

must be

OFF

OK

Request to switch off 

the RF section.

Warning notices

Fail Safe

setup

t.b.d.

Failsafe has not yet 

been activated

Thr

 too

 high!

The throttle stick of a 

fixed-wing model, or 

the throttle limiter of 

a helicopter, is too far 

in the direction of fullthrottle.

N o

pupil

signal

Connection between 

teacher and pupil transmitter is interrupted

SD-CARD

INSERT

OK

No SD or SDHC memory card in the card slot 

or card is not legible

• If battery voltage is too low, a model switch is 

blocked for reasons of safety. An appropriate message will appear in the screen:

not possible now

voltage too low

• Is the “wireless teacher/pupil connection” that was 

active when the transmitter was last used to be 

continued, ACT or switched off INH?

Please select

Trainer link?

ACT INH

Please select

Trainer link?

ACT INH
34 Transmitter description - Hidden mode

The mc-16 HoTT and mc-20 HoTT transmitter’s »HIDDEN MODE« menu can be called up from 

almost any menu position by touching and holding 

the  selection keys of the left four-way button and 

the SET key of the right four-way button for at least 3 

seconds. This will produce the display shown below.

 HIDDEN MODE 

VOICE

STICK CALI.

FIRMWARE UPDATE

BLUETOOTH INIT.

VOICE

As mentioned in section “Headsets” on page 23, 

the transmitter’s acoustic signals as well as those 

signals and announcements associated with the »Telemetry« menu can be output by way of the headset 

connector. These announcements are made in German language by default. These announcements are 

summarized in a voice packet which is stored in a 

transmitter-internal memory but they can be replaced 

by a voice packet of a different language at any time.

At the time of this manual’s revision, the standard 

SD card delivered with the set includes the following 

languages: 

• Dutch

• English

• French

• German

• Italian

• Spanish

The given active language packet can be swapped 

out either with the PC program available as a download from the transmitter’s web page at www.graupner.de or with the SD card, as described below. If not 

already done, insert the SD card or SDHC card into 

the transmitter as described on page 24. Once the 

HIDDEN MODE

Language selection, Firmware update, Stick calibration etc.

memory card is inserted in the transmitter, switch the 

transmitter on with RF switched off.

Please select

RF on/off?

O N OFF

Now move to the »HIDDEN MDE« menu as described earlier in this section:

Language change

Use the selection keys of the left or right four-way button to select the line “VOICE” line:

 HIDDEN MODE 

VOICE

STICK CALI.

FIRMWARE UPDATE

BLUETOOTH INIT.

Use the center SET key of the right four-way button to 

switch to the selection page for the “VOICE” line:

FILE LIST

VOICE2_FRANCE.VDF

VOICE2_GERMAN.VDF

VOICE2_ITALIANO.VDF

VOICE2_SPAIN.VDF

VOICE2_ENGLISH.VDF

VOICE2_DUTCH.VDF

Now use the  keys of the left or right four-way button to choose the desired language, for example:

FILE LIST

VOICE2_FRANCE.VDF

VOICE2_SPAIN.VDF

VOICE2_GERMAN.VDF

VOICE2_ITALIANO.VDF

VOICE2 DUTCH.VDF

VOICE2_ENGLISH.VDF

Confirm the choice with another tap on the center 

SET key of the right four-way button. The selected 

language packet will be loaded into the transmitter’s 

memory:

22/100%

I

 HIDDEN MODE 

VOICE

STICK CALI.

FIRMWARE UPDATE

BLUETOOTH INIT.

The loading process is finished as soon as the progress bar at the lower edge of the display disappears:

 HIDDEN MODE 

VOICE

STICK CALI.

FIRMWARE UPDATE

BLUETOOTH INIT.

When this process is finished, switch off the transmitter. 

All settings stored in the transmitter remain intact 

after a change of language has been made.

Notes:

• If the warning ...

RF

must be

OFF

OK

... appears, then the transmitter’s RF radiation 

is still active. Jump to the »Base setup model« menu, select the “RF transmit” line, select its 

“OFF” option then repeat the procedure

• If the warning ...

SD-CARD

INSERT

OK

... appears then the transmitter does not detect a 

memory card in its card slot or the card found can-
Transmitter description - Hidden mode 35

not be read.

• If the selection window is empty ...

FILE LIST

... then the transmitter could not find an appropriate file on the inserted memory card. Check the 

contents of the SD card’s “VoiceFile” directory on a 

PC or laptop.

FIRMWARE UPDATE 

Change display language

Important notice:

Be sure to check the charge status of your transmitter’s battery or charge its battery as a precaution before every update. Also backup all occupied model memories so they can be restored if 

that should become necessary. 

 HIDDEN MODE 

VOICE

STICK CALI.

FIRMWARE UPDATE

BLUETOOTH INIT.

In the same manner as described above in the section “VOICE”, this menu item can be used to update 

or change the transmitter’s firmware, including its display language. At the time of this manual’s revision, 

the standard SD card delivered with the set includes 

the following languages: 

• Dutch

• English

• French

• German

• Italian

• Spanish

Additional languages will follow at a later date.

Updates and additional information for your system 

can be found on the product page for your specific 

HoTT transmitter in the Download section at www.

graupner.de.

FILE LIST

MC-20_1V234_France.b

MC-20_1V234_English.

MC-20_1V234_Dutch.bi

MC-20_1V234_Italiano

MC-20_1V234_Spain.bi

MC-20_1V234_German.b

Now use the  selection keys of the left or right 

four-way button to choose the desired firmware version, for example:

FILE LIST

MC-20_1V234_France.b

MC-20 1V234 Dutch.bi

MC-20_1V234_Italiano

MC-20_1V234_Spain.bi

MC-20_1V234_German.b

MC-20_1V234_English.

Confirm the choice with another tap on the center 

SET key of the right four-way button. The loading of 

firmware into the transmitter’s memory will be started 

and following two displays, visible only very briefly, 

which only make reference to the firmware update ...













Firmware Download

Prozess Start

Please Wait....













Boot Download

Success!!!

Please Wait....

..., the message:













Firmware

Downloading...

Progress 023/201

... will appear in the display. As soon as the counter 

to the left of the “/” character reaches the value shown 

on the right as the volume to be loaded, the message 

...









Firmware Upgrade

success!!!

... will appear. After a few seconds this message 

disappears, and the transmitter switches itself off. The 

transmitter is now ready for use.

Notes:

• If the warning ...

RF

must be

OFF

OK

..., then the RF section of the transmitter is still 

active. Switch it off in the “RF module” line of the 

»Basic settings« menu, and repeat the proce-
36 Transmitter description - Hidden mode

dure.

• If the warning ...

SD-CARD

INSERT

OK

... appears then the transmitter does not detect a 

memory card in its card slot or the card found cannot be read.

• If the selection window is empty ...

FILE LIST

... then the transmitter could not find a suitable 

firmware file on the inserted memory card. Check 

the contents of the SD card’s “Firmware” directory 

on a PC or laptop.

STICK CALIBRATION

If you feel the neutral position of your self-centering 

sticks (controls 1 ... 4) are not exactly 0% of their 

control travel, then this can be checked and, if necessary, corrected as follows:

Jump to the »Model select« menu and initialize a 

free model memory as described on page 79. 

Whether the model to be initialized is a winged aircraft or a helicopter is irrelevant. 

Wait for the notices which typically appear in the 

transmitter’s base screen following a model change 

then jump to the »Servo display« menu, for example 

by simultaneously touching the  keys of the left 

four-way button WITHOUT any interim changes to 

trim settings or other program settings. 

If all four of your transmitter’s stick functions are still 

self-neutralizing, this display should ideally look like 

the one shown below:

1

3

5

7

0%

0%

9

11

0%

0%

2

4

6

8

0%

0%

0%

10 0%

12 0%

0%

0%

0%

Note:

The screen-shot above, and the two which follow, 

show the screen of the mc-20 HoTT transmitter. 

The screen of the standard eight-channel mc-16

HoTT shows correspondingly fewer channels. 

Otherwise the graph bars show current setting percentages for joystick control functions which are not 

self-neutralizing–typically for the “C1” throttle/brake 

or throttle/pitch stick. For example, if the throttle/brake 

stick is in its “quarter-throttle” position, the display 

would appear as shown below:

1

3

5

7

0%

0%

9

11

0%

0%

2

4

6

8

0%

0%

0%

10 0%

12 0%

–50%

0%

0%

One after the other, put both sticks into each of their 

four possible limit positions without exerting force at 

the limit position. In each of these eight possible limit 

positions, the–side dependent–indication for exactly 

-100% or +100% should be displayed. For example, 

if transmitter control 2 is at its right limit and the other 

three stick functions are in their respective middle 

positions then the transmitter’s display should look 

like the one shown below:

1

3

5

7

0%

0%

9

11

0%

0%

2

4

6

8

–100%

0%

0%

10 0%

12 0%

0%

0%

0%

Regardless of the number of self-neutralizing stick 

functions available on your transmitter, if these checks 

produce four 0% results and eight 100% results then 

your transmitter’s sticks are optimally calibrated. You 

can terminate this process then, if appropriate, delete 

the model memory just created.

Otherwise jump (as described at the outset of the 

previous double page) to the “STICK CALIBRATION” 

line in the »SECRET MODE« menu then briefly touch 

the center SET key of the right four-way button.

STICK CALIBRATION

0%





The  selection keys of the right four-way button 

will now allow you to cyclically select the four calibrated stick planes, e.g. the left/right plane of the right 

stick:

STICK CALIBRATION

0%





Now position the right stick–without exerting extra 

force–to its left limit corresponding with the on-screen 

blinking arrow pointing to the left:
Transmitter description - Hidden mode 37

STICK CALIBRATION

+102%





... and briefly tap the center SET key of the right fourway button. This concludes this example calibration of 

the right stick’s left limit. The circle in the middle of the 

stylized stick plane will now blink as confirmation of 

the calibration:

STICK CALIBRATION

+100%





Now release the self-neutralizing stick so it can return 

to its center position and then tap again on the center 

SET key to calibrate the stick’s centered position. The 

right triangle marker will begin to blink:

STICK CALIBRATION

0%





Repeat the calibration process for the right limit of the 

right stick. The other stick planes are calibrated analogously.

Proceed similarly to calibrate the two sliders mounted 

in the middle console and the two proportional rotary 

controls on the sides of the transmitter. The calibration options for these proportional controls can be 

reached by repeatedly tapping on the  or  selection keys of the right four-way button until the desired 

calibration position is reached, e.g. ...

SLIDE CALIBRATION

0%

















LEVER CALIBRATION

0%

















Notes:

• Correct any bad calibrations by repeating the respective process.

• Within a given stick plane, each of the three calibration positions can be selected directly with the 

 selection keys of the left or right four-way button.

Briefly touching the center ESC key of the left fourway button will terminate the process and return to 

the sub-menu “STICK CALIBRATION”.

Bluetooth initialisation

 HIDDEN MODE 

VOICE

STICK CALI.

FIRMWARE UPDATE

BLUETOOTH INIT.

If you install a Bluetooth module, Order No. 33002.5, 

you should use this menu point to initialise it as described in the instructions supplied with the unit.
38 Transmitter description - Telemetry data display

The mc-16 HoTT transmitter features a single 

screen below the aerial socket which is used both for 

operating the transmitter and also to display telemetry 

data in graphic form. You can switch between the two 

operating modes by pressing one of the Select buttons  or  of the left-hand four-way button in 

the base display.

The mc-20 HoTT transmitter has two independent 

displays; a display for operating the transmitter and a 

display just below the antenna socket for the graphic 

display of telemetry data. This display is activated automatically as soon as the transmitter receives telemetry data from the receiver via the return channel.

#01

0:00h

Stp

Flt

 

0:00

0:00

0.0V

4.1V

Mx

HoTT

If however, at the lower edge of the base display, only 

“X”–as shown in the figure above–is displayed at two 

locations instead of “ ”, then the telemetry display 

will show the warning ...

CAN‘T

RECEIVE

DATA

O K

..., on the front screen of the mc-20 HoTT, displaced shortly afterwards by the Graupner/SJ logo 

and the transmitter name ... 

mc20

..., and this means that there is no receiver within 

range capable of exploiting the telemetry link. Switch 

on the model’s receiver system or bind a receiver to 

the active model memory as described in detail on 

page 87 or 95.

#01

0:01h

Stp

Flt

 

0:00

0:00

4.8V

4.1V

M

HoTT

If a telemetry link is present, the front screen of the 

mc-20 HoTT shows the “Receiver” display by 

default. The same occurs on the mc-16 HoTT transmitter after you select the Telemetry display mode ... 

RX–S QUA: 100%

RX–S STR: 100%

TX–dBm: –33dBm

RX–dBm: –33dBm

RX–VOLT:4.8V TMP

L–PACK: 10ms

R–LOW V:4.6V +22°C 

... which is described in more detail in a section by 

the same name on the next page.

Sensor Select

Up to four sensors can be connected, in any combination, to a telemetry-capable receiver. However, the 

data output by these sensors must be (as described 

on page 252) selected in the »SENSOR SELECT« 

sub-menu of the »Telemetry« menu ...

 SENSOR SELECT

RECEIVER

GENERAL MODULE

VARIO MODULE

ELECTRIC AIR.MOD

GPS

... in order to activate their display. This data from the 

selected sensors is then appropriately prepared for 

illustration by the graphic indicators as described below. You must also ensure that the receiver selected 

in the “Telemetry receiver” line of the »Telemetry« 

menu (Bind 1 or 2) is the one to which the sensors 

are connected; see pages 87 and 95. If you 

select the “wrong” receiver, the “Receiver” display will 

only show the data from that unit.

Furthermore, only sensors activated in the »SETTING & DATAVIEW« sub-menu of the »Telemetry« 

menu, beginning page 241, according to the instructions included with the given sensor will be responsive.

To switch between the screens for activated sensors 

in the »SENSOR SELECT« sub-menu of the »Telemetry« menu, tap briefly on one of the  selection 

keys of the left or right four-way button ...

 

 

 

 

 

 

 

GENERAL

ELECT. AIR

VARIO

GPS

RECEIVER

AIR ESC

... and, after the selected screen has been displayed, 

use one of the  two keys to select the line of the 

desired sensor. If no sensor is activated, then all display lines and sensors described in the next column, 

except for the “RECEIVER” line, are blended out of 

the display and the selection list:

 

 

 

 

 

 

 

RECEIVER

The selection can be confirmed right away by activating the center SET key of the right four-way button or 

Telemetry data display
Transmitter description - Telemetry data display 39

by simply waiting until, after a brief pause, the main 

display of the given selected sensor appears automatically. 

Notes:

• The sequence of the below described displays is 

a consequence–starting from the given main display–of taps on the  key.

• More details about the following named modules 

can be found in the appendix and in Internet at 

www.graupner.de in the web page for the given 

product.

RECEIVER

RX–S QUA: 100%

RX–S STR: 100%

TX–dBm: –33dBm

RX–dBm: –33dBm

RX–VOLT:4.8V TMP

L–PACK: 10ms

R–LOW V:4.6V +22°C 

This screen presents the »RX DATAVIEW« of the 

»Telemetry« menu’s »SETTING & DATAVIEW« 

sub-menu, see page 241, with data processed and 

displayed graphically. 

The displayed items are as follows:

Value Explanation

RX-S QUA signal quality in %

RX-S STR signal strength in %

RX-dBm Reception power in dBm

TX-dBm transmit power in dBm

L-PACK Indicates the longest time span in ms 

in which data packages are lost in the 

transmission from the transmitter to the 

receiver.

RX-VOLT current operating voltage of the 

receiver's power supply in volts

R-LOW V Lowest receiver operating voltage since 

last startup, in volts

TMP the thermometer depicts the receiver's 

current operating temperature

GENERAL MODUL

 

 

 

 

 

 

 

ELECT. AIR

VARIO

GPS

RECEIVER

AIR ESC

GENERAL

0.0V

BAT1

BAT2

0.0V T2 0°C

 T1 0°C

E FUEL F

CELL.V

1:0.00

2:0.00

3:0.00

4:0.00

5:0.00

6:0.00

0

0.0V

BAT1

BAT2

0.0V T2 0°C

 T1 0°C

E FUEL F

 ALT 

0m

 0m1

 0m3

 0.0A

POWER 

 0.0V

0

If attached to the receiver, this screen will display the 

data acquired by a General-Engine module, order 

no. 33610, or a General-Air module, order no. 33611. 

More details about these modules can be found in 

the appendix or in Internet at www.graupner.de in the 

web page for the given product.

Depending on how this module is equipped with sensors, this screen can permanently display the data 

shown in the table below.

The current voltage of up to two batteries (BAT1 and 

BAT2), the measurement results of up to two temperature sensors (T1 and T2) and a fill level gage for 

the fuel tank.

An alternating display along the screen’s right edge 

will display a list of current cell voltages for a LiPo 

battery with up to six cells or operational data (current 

altitude with respect to the starting location, ascent/

decent m/1s and m/3s, current current being drawn 

in amperes and current voltage of the battery connected to the sensor). 

The displayed items are as follows:

Value Explanation

BAT1 / 

BAT2

battery 1 or 2

FUEL fuel level / tank gage

E / F empty / full

T1 / T2 temperature of sensor 1 or 2

CELL V cell voltage of cells 1 ... max. 6

ALT current altitude

0m1 m/1s ascent/decent rate

0m3 m/3s ascent/decent rate

A current draw in amperes

V battery voltage

Battery and load indicators

0.0V

0.0A

0mAh

0ml

This display depicts current voltage, current current draw and, if attached, the expended capacity 

of “Batt 1” connected to the General-Engine module 

(order no. 33610) or General-Air (order no. 33611) 
40 Transmitter description - Telemetry data display

module as well as the fuel consumed in ml.

SENSOR 1

0.0V

0°C

SENSOR 1

If attached, this display depicts currently measured 

voltage and temperature from a temperature/voltage sensor, order no. 33612 or 33613, connected 

to “T(EMP)1” of the General-Engine module (order no. 33610) or the General-Air module (order 

no. 33611).

SENSOR 2

0.0V

0°C

SENSOR 2

If attached, this display depicts currently measured 

voltage and temperature from a temperature/voltage sensor, order no. 33612 or 33613, connected 

to “T(EMP)2” of the General-Engine module (order 

no. 33610) or the General-Air module (order no. 

33611).

Rotary speed sensor

rpm

0

0 0

If attached, this display depicts the measured rotary speed of a speed sensor (order no. 33615 or 

33616) attached to a General-Engine module (order 

no. 33610) or a General-Air module (order no. 33611).

Note:

The appropriate blade count must first be set in the 

module’s telemetry menu before the correct speed 

can be displayed.

Vario

0.0

0m

m

s

If attached, this display will depict the altitude (in m) 

relative to location, starting location as well as the 

current rate of ascent/descent (in m/s) data originating from a Vario integrated into a General-Engine 

module (order no. 33610) or General-Air module 

(order no. 33611).

Speed display

0km/h

If the corresponding sensor is available, this screen 

displays the model’s actual speed over the ground. 

Air pressure display

0.0Bar

If the corresponding sensor is available, this screen 

displays the actual air pressure.

“Weakest cell”

Cell0=0.00V

If the corresponding sensor is available, this screen 

displays the voltage of the weakest cell in a battery 

block, together with the number of that cell.

ELECTRIC AIR MODUL

 

 

 

 

 

 

 

VARIO

GPS

RECEIVER

AIR ESC

GENERAL

ELECT. AIR

0.0V 0m/3s

BAT1 0m/1s

BAT2

0.0V T2 0°C

T1 0°C

0

1L0.00

2L0.00

3L0.00

4L0.00

5L0.00

6L0.00

 ALT 0m

7L0.00

 0.0V 0A
Transmitter description - Telemetry data display 41

0.0V 0m/3s

BAT1 0m/1s

BAT2

0.0V T2 0°C

T1 0°C

0

1H0.00

2H0.00

3H0.00

4H0.00

5H0.00

6H0.00

 ALT 0m

7H0.00

 0.0V 0A

If attached to the receiver, this display will depict the 

data acquired by an Electric-Air module, order no. 

33620. More details about this module can be found 

in the appendix or in Internet at www.graupner.de in 

the web page for the given product.

Depending on how this module is equipped with sensors, this screen can permanently display the data 

shown in the adjacent table.

The current voltage of up to two batteries (BAT1 and 

BAT2), up to two temperature measurements (T1 

and T2), current altitude with respect to the starting 

location, the model’s ascent/decent rate in m/1s and 

m/3s and, in the middle of the screen, the current 

draw currently being taken from a power source.

Along the right edge of the screen is a table of alternating values for cell voltages at balancer connections (L) or voltages for up to 7 attached battery cell 

packs (H). 

The displayed items are as follows:

Value Explanation

V current voltage

A current current

BAT1 / 

BAT2

battery 1 or 2

ALT current altitude

m/1s m/1s ascent/decent rate

m/3s m/3s ascent/decent rate

T1 / T2 temperature of sensor 1 or 2

L or H cell voltage of cells 1 ... max. 14

L = balancer connection 1

H = balancer connection 2

Micro-copter display

0mAh

0:00

0.0V

0km/h

0

 I:

Dir:

Alt: 0m

0°

0A

0m

0°

This screen displays the data generated by a HoTTcompatible micro-copter. Key, reading from top left to 

bottom right:

Value Explanation

V Actual voltage

„0:00“ Period switched on

mAh Battery capacity consumed

„0“ Altitude relative to take-off point, 

according to GPS system

km/h Speed over ground, according to GPS 

system

Alt Actual altitude

Dir Direction of movement

I Actual current

m Distance from take-off point, according 

to GPS system

° Position in degrees relative to take-off 

point, according to GPS system

Any messages from the micro-copter sensor are 

displayed in the bottom line of the screen, which is 

empty in the screen-shot shown above.

ACCU

0.0V

0.0A

0mAh

This display depicts current voltage, current current draw and, if attached, the expended capacity of 

“Batt 1” connected to the Electric-Air module (order 

no. 33620).

SENSOR 1

0.0V

0°C

SENSOR 1

If attached, this display depicts currently measured 

voltage and temperature from a temperature/voltage sensor (order no. 33612 or 33613) connected 

to “T(EMP)1” of the Electric-Air module (order 

no. 33620).

SENSOR 2

0.0V

0°C

SENSOR 2

If attached, this display depicts currently measured 

voltage and temperature from a temperature/voltage sensor (order no. 33612 or 33613) connected 

to “T(EMP)2” of the Electric-Air module (order 

no. 33620).
42 Transmitter description - Telemetry data display

Vario

0.0

0m

m

s

If attached, this display will depict the altitude (in m) 

relative to location, starting location as well as the 

current rate of ascent/descent (in m/s) data originating from a Vario integrated into a Electric-Air module 

(order no. 33620).

Speed display

0km/h

If the corresponding sensor is available, this screen 

displays the model’s actual speed over the ground. 

“Weakest cell”

Cell0=0.00V

If the corresponding sensor is available, this screen 

displays the voltage of the weakest cell in a battery 

block, together with the number of that cell.

VARIO

 

 

 

 

 

 

 

GPS

RECEIVER

AIR ESC

GENERAL

ELECT. AIR

VARIO

RXSQ

 0

 MAX

 0m

 MIN

 0m

ALT

 0

H

L

m/1s

0.0

m/3s

0.0

m/10s

0.0

If attached to the receiver, this display will depict the 

data acquired by a Vario module, order no. 33601. 

The displayed items are as follows:

Value Explanation

ALT current altitude

RXSQ Signal quality of the signal received by 

the receiver in %, see page 241.

MAX the preset maximum altitude limit 

relative to starting location at which, 

when exceeded, will cause an audible 

warning to be sounded

MIN the preset minimum altitude limit 

relative to the starting location at which, 

when underrun, will cause an audible 

warning to be sounded

m/1s m/1s ascent/decent rate

m/3s m/3s ascent/decent rate

m/10s m/10s ascent/decent rate

Micro-copter display

0mAh

0:00

0.0V

0km/h

0

 I:

Dir:

Alt: 0m

0°

0A

0m

0°

This screen displays the data generated by a HoTTcompatible micro-copter. Key, reading from top left to 

bottom right:

Value Explanation

V Actual voltage

„0:00“ Period switched on

mAh Battery capacity consumed

„0“ Altitude relative to take-off point, 

according to GPS system

km/h Speed over ground, according to GPS 

system

Alt Actual altitude

Dir Direction of movement

I Actual current

m Distance from take-off point, according 

to GPS system

° Position in degrees relative to take-off 

point, according to GPS system

Any messages from the micro-copter sensor are 

displayed in the bottom line of the screen, which is 

empty in the screen-shot shown above.
Transmitter description - Telemetry data display 43

Vario

0.0

0m

m

s

If attached, this display will depict altitude relative to 

location or starting location (in m) as well as the current rate of ascent/decent (in m/s) from data acquired 

by a Vario module (order no. 33601).

Text display

If the corresponding sensors are available, text from 

them showing 2 x 10 or 3 x 7 characters can be 

superimposed in the two following displays when 

required:

GPS

 

 

 

 

 

 

 

RECEIVER

AIR ESC

GENERAL

ELECT. AIR

VARIO

GPS

N RXSQ 0 

DIS 0m

ALT 0m

0.0m/1s 

0m/3s 

N 0°00.0000

E 0°00.0000

W E

S

Kmh

0

If attached to the receiver, this display will depict the 

data from a GPS module with integrated Vario, Order 

No. 33600. 

Aside from the model’s current position and speed, 

the center section of this screen will also display 

current altitude with respect to the starting location 

as well as the model’s current ascent/decent rate in 

m/1s and m/3s, current reception quality and the 

model’s distance from its starting location.

The displayed items are as follows:

Value Explanation

W/N/E/S west / north / east / south

Kmh speed

RXSQ return channel signal quality

DIS distance

ALT current altitude with respect to starting

m/1s m/1s ascent/decent rate

m/3s m/3s ascent/decent rate

Micro-copter display

0mAh

0:00

0.0V

0km/h

0

 I:

Dir:

Alt: 0m

0°

0A

0m

0°

This screen displays the data generated by a HoTTcompatible micro-copter. Key, reading from top left to 

bottom right:

Value Explanation

V Actual voltage

„0:00“ Period switched on

mAh Battery capacity consumed

„0“ Altitude relative to take-off point, 

according to GPS system

km/h Speed over ground, according to GPS 

system

Alt Actual altitude

Dir Direction of movement

I Actual current

m Distance from take-off point, according 

to GPS system

° Position in degrees relative to take-off 

point, according to GPS system

Any messages from the micro-copter sensor are 

displayed in the bottom line of the screen, which is 

empty in the screen-shot shown above.
44 Transmitter description - Telemetry data display

GPS

N

W O

S

km/h

DIS 

m 

m/s 

ALT 

m 

0

0

0.0

0

If attached to the receiver, this display will depict the 

data from a GPS module with integrated Vario, Order 

No. 33600. 

The displayed items are as follows:

Value Explanation

W/N/E/S west / north / east / south

km/h speed 

DIS horizontal distance in m

m/s ascent/decent rate in m/s

ALT altitude relative to starting location in m

Vario

0.0

0m

m

s

If attached, this display will depict the altitude (in m) 

relative to location, starting location as well as the 

current rate of ascent/descent (in m/s) from data 

originating from the Vario integrated into the GPS-/

Vario module (order no. 33600).

Speed display

0km/h

If the corresponding sensor is available, this screen 

displays the model’s actual speed over the ground. 

AIR ESC

 

 

 

 

 

 

 

RECEIVER

GENERAL

ELECT. AIR

VARIO

GPS

AIR ESC

0 0rpm 0

0 0.0A 0.0A

0( 0)°C 0mAh

0.0V/ 0.0V

This screen displays the data generated by a brushless speed controller with internal telemetry, Order 

No. 33718 to 33770 and 33850 (correct at time these 

instructions were revised), which is connected to the 

receiver.

Key, reading from top left to bottom right:

Value Explanation

V Left-hand value: actual battery voltage

Right-hand value: actual battery voltage 

in present power-on period

°C Left-hand value: actual speed controller 

temperature

Value in brackets: maximum controller 

temperature in present power-on period

mAh Battery capacity consumed

A Centre and bar display: actual current

Right-hand value: maximum current in 

present power-on period

rpm Centre and bar display: actual rotational 

speed of the motor connected to the 

speed controller.

Right-hand value: maximum rotational 

speed in present power-on period

RPM display

rpm

0

0 0

This screen displays the current rotational speed of 

the motor connected to the brushless speed controller.
Transmitter description - Telemetry data display 45

Current / consumption display

0.0A

0 0.0A

0mAh

This screen displays the actual current consumption, 

the peak drain which has occurred in the present 

power-on period, and the capacity drawn from the 

battery connected to the brushless speed controller 

within the same period.
46 Commissioning the transmitter

Preliminary remarks

The Graupner/SJ HoTT system theoretically permits 

simultaneous operation of more than 200 models. 

However, because of the interspersed radio-frequency utilization permitted by certification for the 2.4 GHz 

ISM band, this number is significantly lower in practical application. Nevertheless, in general more models 

can be operated simultaneously in the 2.4 GHz band 

than would be the case in conventional 35 or 40 MHz 

frequency bands. The real limiting factor is–as often 

before–still likely to be the size of available operating 

space (i.e. airspace for aircraft). Alone the fact that 

it is no longer necessary to coordinate transmitting 

frequencies with other pilots in the vicinity (which is 

sometimes quite difficult in broken landscapes, such 

as on hillside slopes) represents an enormous boost 

for remote control operating security.

Battery charged?

Since the transmitter is delivered with an empty (not 

charged) battery, the battery must first be charged 

according to the charging instructions on page 16. 

Otherwise a warning tone will be sounded and an appropriate message will be blended 

into the basic display if the low 

voltage threshold set in the “Battery warning” line of the »General 

basic settings« menu, see page 

272, is underrun. 

Transmitter startup

After being switched on, the message shown below 

will appear in the transmitter’s screen for about two 

seconds. 

Please select

RF on/off?

O N OFF

Within this brief period there is an opportunity to 

switch RF transmission off by using the  or  key 

of the right four-way button to shift the position of the 

field shown in inverse video to the right so that ON

is in standard video and OFF is presented in inverse 

video:

Please select

RF on/off?

O N OFF

Now switch the RF module off by tapping on the 

center SET key of the right four-way button. 

The telemetry display just below the antenna socket 

will then briefly show the message ...

CAN‘T

RECEIVE

DATA

O K

... and in parallel to this, the transmitter’s basic display will appear similar to that shown below:

#01

0:00h

Stp

Flt

 

0:00

0:00

0.0V

4.1V

Mx

HoTT

The symbol combination means that the currently 

active model memory has already “bounded“ with a 

Graupner/SJ-HoTT receiver but there is no connection to that receiver at the moment. (In this example, 

Commissioning the transmitter

Preliminary remarks about the mc-16 HoTT and mc-20 HoTT transmitters

RF transmission has been switched off.) 

If, however, the transmitter is switched on without

switching RF transmission off, the symbolic antenna 

mast will blink. At the same time, an acoustic warning will sound until a connection is established with 

the respective receiver. As soon as the connection is 

established, the “X” at the base of the symbolic antenna will be replace with a field strength indicator, for 

example , and the visual and acoustic warnings 

will cease. 

If a telemetry connection has also been established 

for the incoming signal, that is output by the receiver 

in the model, then the right side of this same screen 

line will display a similar indication of signal strength 

for this reception of the receiver’s transmitted signal 

(>M ) as well as the current voltage of the receiver’s 

power supply. 

On the other hand, if the symbol combination 

appears in the display and the front display shows the 

message “Can’t receive data” then the currently active model memory is not “bound” to any receiver at 

the moment.

Under-voltage warning

If the transmitter’s voltage drops below a certain 

value set in the »General basic settings« menu, 

page 272, 3.60V by default, there will be visual and 

acoustic under-voltage warnings issued.

Important notices:

• The transmitter in the set is already preset, as 

delivered, with default values which are correct 

for operation in most European countries (except France). 

If the remote control system is to be operated in France then the transmitter’s “Region” 

setting MUST be changed over to “FRANCE” 

mode, see page 272. IN NO CASE may the 

Universal/EUROPE mode be used IN FRANCE.

• Up to eight servos can be operated with the 

Batt. must

 be re-

 charged!!
Commissioning the transmitter 47

GR-16 receiver supplied in the mc-16 HoTT 

set; this receiver is supplied already bound to 

the first model memory.

Up to twelve servos can be operated with the 

GR-24 receiver supplied in the mc-20 HoTT 

set; this receiver is supplied already bound to 

the first model memory.

In order to achieve the greatest possible flexibility but still preclude unnecessary inadvertent operator errors, control channels 5 ... 8 respectively 5 ... 12 have not been assigned 

to any controls. This means that servos connected by way of these channels will remain 

in their middle positions until an operator element has been assigned. Practically all mixers 

are initially inactive for this same reason. More 

about this can be found on page 118 (winged 

aircraft) or 122 (helicopter models).

• The fundamental procedure for initial programming of a new model memory location can be 

found on page 76 and the programming examples that begin on page 282. 

• When the remote control system is switched 

on, being bonded or when making settings, 

that the transmitter’s antenna is always far 

enough away from the receiver’s antennas. If 

the transmitter’s antenna is brought too close 

to the receiver’s antennas this will cause receiver over-modulation and its red LED will illuminate. At the same time the return channel 

will drop out and, as a consequence, the field 

strength indicator in the transmitter’s screen 

will be replaced by an “x” and the receiver’s 

current battery voltage display will show 0.0V. 

The remote control is then in Fail-Save mode, 

see page 208, i.e. servos will remain in their 

current positions until a new, valid signal can 

be received. In such a case, increase the distance (between the transmitter and the model 

containing the receiver) until the indicators are 

again “normal”.

• Never switch the transmitter off whilst operating a model! If this should happen accidentally, 

keep your nerve and wait until the transmitter 

screen is entirely blank, i.e. until the transmitter has shut down completely; this takes at 

least three seconds. Do not switch your transmitter on again until this has occurred. If you 

neglect this, there is a risk that the transmitter 

will “hang” immediately after being switched 

on, and you will lose control of the model. In 

this case your only recourse is to switch the 

transmitter off again, allow it to shut down 

completely, and then switch on once more after the correct interval.
48 Downloading a firmware packet

Transmitter firmware updates are carried out ...

• ... either as described under “FIRMWARE UPDATE / Change display language” in the section 

»Secret mode« on page 35 ... 

• ... or as described below with the help of a PC 

running a Windows XP, Vista or 7 operating system. 

Current software and information is available in Internet at www.graupner.de under the Download link for 

the given product.

Note:

You will automatically be notified of new updates per 

email after registering your transmitter at https://www.

graupner.de/en/service/product_registration.aspx.

The aforementioned “given product page” is most 

easily reached by entering “www.graupner.de” into 

your Internet browser’s address line then pressing the 

ENTER key on your PC or laptop keyboard.

On the so-called “homepage” for Graupner, click on 

one of the “flags” to switch the website to a language 

of your choice, e.g. the British flag for English. Afterwards locate the entry field with the title “Search”:

Place the cursor in this field with a mouse click then 

enter a search keyword, e.g. the article number printed on the type plate located on the rear side of the 

transmitter:

Another press of the ENTER key on the PC or laptop 

will open the sought page:

Downloading a firmware packet

Now use your Internet browser’s vertical scroll bar 

to move down the page a bit until the tabs “Characteristics”, “Spare parts”, “Accessories” and “Downloads” appear:

Move to the Download area by clicking on the “Download” tab. Select the file(s) you need, then doubleclick on “Download” below the selected file to initiate 

the downloading process.

When you download “HoTT-Software VX” you actually 

download the file “HoTT_Software_VX.zip”. This is 

a compressed file containing all the files required to 

update the transmitter, HoTT receiver, sensors etc.

Please note: at the time this manual was revised the 

program packet available is Version “4”: “HoTT-Software V4”.

If you have previously updated the software of certain 

components of your radio control system using the 

firmware from software packet Version “V3” or earlier, 

but since then have updated at least one of your components using firmware from software packet “V4”, 

then it is ESSENTIAL to update all the components 

of the radio control system with firmware from packet 
Downloading a firmware packet 49

Version “V4”. If you neglect this, individual components could malfunction. The same applies to future 

software packets, i.e. “V5” or higher.

In contrast, if changes are made to individual firmware files within a particular version “VX”, then it is 

sufficient to install just the later firmware version for 

the corresponding product. The easy way to check 

whether firmware updates are available is to look at 

the creation date of the download file. The version 

numbers of the associated firmware files also change.

Now save the compressed file in a folder of your 

choice, and unpack it using a suitable program.

If a transmitter update fails to work as described in 

the following section, please read the chapter entitled 

“Restoring your transmitter firmware” on page 52.

Note:

At the time these instructions were revised, a list 

of the current firmware versions can be called up 

using the following link: http://www.graupner.de/en/

supportdetail/4d589f17-24b4-4e50-97d2-13a0f39bd13d.

If the link does not work, you can obtain the same 

information step-by-step via www.graupner.de => 

Service & Support => Update and revision history for 

Graupner|SJ HoTT components.
50 Transmitter firmware updates

The USB interface cable (USB-A to mini-B-USB 

5-pole) included with the set, will be needed to update 

the transmitter’s software via the transmitter’s faceside USB interface connector. This cable’s connector 

is to be directly plugged into the 5-pole mini-USB 

connector socket on the rear side of the transmitter.

Important notes:

• Please note that the HoTT components in your 

radio control system can only communicate 

perfectly if the firmware is compatible. That is 

why all the programs and files required to update all HoTT components are grouped together in one file, the current version of which is 

entitled “HoTT_Software_V4.zip”.

• Be sure to check the charge status of your 

transmitter’s battery or charge its battery as a 

precaution before every update. Also backup 

all occupied model memories so they can be 

restored if that should become necessary.

• It is essential not to disconnect the transmitter from the PC or laptop during an update process! Please ensure that the lead between the 

transmitter and the computer is making good 

contact at both ends.

1. Installing drivers

Install the required driver software, included in the 

“USB Drivers” folder of the program packet, onto 

your PC or laptop so your computer can handle 

the transmitter’s integrated USB interface.

Start driver installation with a double-click on the 

respective file and follow the on-screen instructions. Once this software has been successfully installed, the computer must be re-started. Drivers 

only need to be installed once. 

2. Installing the software up-loader

Unpack the file “Firmware_Upgrade_grStudio_

Ver-XX.zip” in a suitable directory then execute the 

“Firmware_Upgrade_grStudio_Ver-XX.exe” proTransmitter firmware updates

gram file with a double-click on its filename. Follow 

the instructions provided by the installation wizard.

3. Establishing a transmitter-to-PC connection

With the transmitter switched off, connect the 

USB cable by way of its 5-pole mini-USB socket to 

the face-side of the transmitter.

4. Updating transmitter software

Start the “Firmware_Upgrade_grStudio_Ver-X.X” 

program from the directory where it is located.

Use the selection sequence “Menu”, “Port Setup” 

or open the “Controller Menu” and click on “Port 

select”.

Now in the “Port select” window, select the COM 

port connected to the USB interface. The correct 

port can be recognized by its designation “Silicon 

Labs CP210x USB to UART Bridge” in the “Device 

Name” column. In the above example this would 

be the “COM 3” port.

Now call up menu option “Firmware Upgrade” from 

“Menu” or open the “Controller Menu” and click on 

“Firmware Upgrade”.

Click on the button labeled “File Browse” and select the desired firmware update file with a “.bin” 

filename extension from the “Open file” window.

Firmware files are product-specifically coded, i.e. 

if you should accidentally select a file which does 

not correspond to the product (e.g. receiver update file instead of a transmitter update file), the 

“Product code error” popup window will appear 

and the block the update process from starting.

Now switch on the transmitter then start the transmitter update by clicking on the “Download Start” 

button.

After a brief period a warning will appear stating 

that the transmitter’s RF transmission will now be 

interrupted and that, because of this, any receiver 

system currently in operation should be switched 

off. 
Transmitter firmware updates 51

Switch off your receiver system if it is switched on 

then click on “Yes”.

This will start the actual update process. A progress bar will begin to operate above a sequence 

of running text lines.

The connection to the PC must not be interrupted during the update process!

Do not terminate the update process before the 

progress bar has reached its right end and the 

“Firmware Download Success” message appears.

Click on “OK”. Subsequently switch off the transmitter and disconnect the USB cable between the 

transmitter and the PC or Laptop.

If the progress bar hangs up without showing any 

further progress, close the program and repeat 

the update process. Be sure to watch for any error 

messages that may appear.
52 Restoring the transmitter software

Restoring the transmitter software

Program segment: “Restore”

If a transmitter firmware update should fail, or if the 

transmitter software “hangs”–it may then be impossible to switch the transmitter off using the “POWER” 

switch–then you can reload the earlier firmware into 

the transmitter using the “Restore” program segment.

If you find that the screen(s) are still switched on even 

though you have switched the transmitter off, then 

please disconnect the transmitter battery connector, 

wait a few seconds, and plug it in again.

1. Preparation

Connect the transmitter to the PC or laptop, and 

start the “Firmware_Upgrade_grStudio_VerX.X.exe” program as described under points 3 and 

4 on page 50. (Version 2.1, which is the current 

version at the time this manual was revised, starts 

without being previously installed.)

2. Starting the “Restore” program segment

Now move to the “Transmitter” section and select 

the “Emergency” entry under “Controller Menu”:

Note that the transmitter must be switched off! 

Connect the USB lead to the PC or laptop, then 

connect the other end to the USB socket under 

the transmitter’s right-hand front cover.

3. Restoring the transmitter software

Press the “File Browse” button, and a program 

window opens: search for the current firmware in 

this window. As mentioned earlier, you will find 

this in the “Official Version \33112_..._33032_mxxx_mc-32 \ SD card \ Firmware” folder in the unpacked file “HoTT_Software_VX”. The file matching your particular transmitter starts with the 

transmitter designation, e.g.: “mc-20_1vXXX_English.bin” or “mc-16_1vXXX_English.bin” (or “...German.bin” or ...).

Now initiate the update process by pressing the 

“Download Start” button. Wait for a moment until the status bar starts moving, and then switch 

the transmitter on. The screen may now light up 

without displaying any data, or–in the case of the 

mc-20 HoTT transmitter–the bottom screen 

may not light up at all; don’t worry–this is quite 

normal.

If the following message ...

... (“Boot signal receive failed”) appears before 

you switch the transmitter on, restart the update 

process by clicking on “Download Start”.

The transmitter must be switched on within the 

prescribed period. When you do this, it can easily take a minute for the actual update process to 

start:

The progress bar indicates that data are being 

transferred correctly, and [Process Step] is displayed as “No 4, Firmware Update”.

The update process must not be interrupted, so 

please ensure that the USB lead is making good 

contact at both ends.

The firmware transfer is concluded when the progress bar reaches the right-hand end. The message “Firmware update ended” indicates that the 

data transfer was successful:

Now turn the transmitter on again by holding the 

main switch pressed in for about one second. You 

will hear the usual power-on melody, the transmitter screen(s) come to life, and you see the Start 

display “mc-... HoTT” and the current firmware 

version.

Finally click on “OK”. Switch the transmitter off and 

disconnect the USB lead connecting the transmitter to the PC or laptop.
For your notes 53
54 Receiver initialization

Receiver initialization

Preliminary remarks

Receiver system

The mc-16 HoTT radio control set includes a GR16 bi-directional 2.4 GHz receiver, with sockets for 

a maximum of eight servos. The mc-20 HoTT set 

includes a GR-24 bi-directional 2.4 GHz receiver with 

sockets for a maximum of twelve servos.

If you switch on the GR-16 HoTT receiver supplied in 

the mc-16 HoTT set, or the GR-24 HoTT receiver 

supplied in the mc-20 HoTT set, and “its” transmitter is not in range, or is switched off, then the receiver’s red LED will illuminate continuously for about 1s 

then begin to blink slowly. This indicates the receiver 

has not (yet) established a link to a Graupner|SJ

HoTT transmitter. If a link has been established, the 

green LED will illuminate continuously and the red 

LED will extinguish.

In order to establish a link to the transmitter, the 

Graupner|SJ HoTT receiver must first be “bound” to 

“its” particular model memory in “its” Graupner|SJ

HoTT transmitter. This procedure is known as “binding”. This “binding” linkage is only necessary once 

for each receiver/model memory combination. Refer 

to pages 87 or 95. The “binding” procedure has 

been done at the factory for model memory 1 of the 

units delivered together as a set so this “binding” procedure will only be necessary to link additional receivers or if a memory location change becomes necessary (and–e.g. after a change of transmitter–can be 

repeated anytime).

On-board voltage display

The current voltage of the receiver’s power supply will 

be shown in the right side of the transmitter’s screen 

if a telemetry link exists between the receiver and 

transmitter:

#01

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT

Temperature warning

Should the receiver’s temperature sink below an 

adjustable threshold (default value -10°C) or rise 

above an adjustable threshold (default value +55°C), 

an acoustic warning will be issued by the transmitter 

in the form of a uniform beep of about 1s duration.

The aforementioned threshold limits are stored and 

adjusted in the receiver.

Servo connections and polarity

Graupner/SJ HoTT receiver servo connections are 

numbered. The connectors used are keyed against 

polarity reversal. Pay attention to the small side 

chamfers when plugging in these connectors. Never 

use force. 

The supply voltage is bussed across (i.e. common 

for) all numbered connections.

The two vertical sockets at the extreme edge of the 

GR-16 and GR-24 receivers are intended for the battery connection. On the GR-16 these two sockets are 

marked “1+B-” and “6+B-”. On the GR-24 these two 

sockets are marked “11+B-” and “12+B-”. However, 

you can also connect the corresponding servos to 

these two sockets in parallel with the power supply 

simply by using a Y-lead, Order No. 3936.11.

Do not reverse the polarity of this connection. 

Reversed polarity could destroy the receiver and 

devices attached to it.

The function of every individual channel is determined 

by the transmitter used, not by the receiver. It is not 

only the throttle servo connection which is different for 

every manufacturer and model type. For example, in 

Graupner remote control systems the throttle servo is 

on channel 1 for winged aircraft and on channel 6 for 

helicopter models. 

Follow the installation instructions on page 64 for 

the receiver, the receiver antenna and for mounting 

the servo.

Concluding notices:

• The significantly greater servo resolution characteristic of the HoTT system produces a noticeably 

firmer response behaviour in comparison to previous technology. Please take the time to familiarize 

yourself with this sensitive behaviour.

• If you have a speed controller with integrated 

BEC* arranged in parallel with the receiver battery, 

its positive pole (red cable) may to be removed 

from the 3-pole connector. Be sure to look for notices about this in the instructions for the speed 

controller used.

With a small screwdriver, 

carefully lift up the connector’s center latch (1) just a bit 

then pull out the red lead (2) 

and tape it up with insulation 

tape to prevent possible short 

circuits (3).

Reset

To execute a reset of the receiver, press and hold the 

SET button on the receiver’s top-side while switching 

the power supply on. Hold the receiver’s SET button pressed in for about three seconds until the LED, 

flashing slowly red / green, goes out for about two 

seconds.

If you have carried out the reset with the transmitter 

switched off, or with an unbound receiver, the green 

and red LEDs fitted to the GR-16 and GR-24 receivers (supplied as standard in the sets) flash four times 

for around three seconds, after which both LEDs go 

* Battery Elimination Circuit

red

1

2 3
Receiver initialization 55

out for just on three seconds, before only the red LED 

continues to flash. Release the button as soon as the 

LEDs go out.

At the transmitter and receiver it is now possible to 

carry out a Binding procedure immediately.

If the reset is done on a bound receiver and the corresponding model memory is active in the powered 

on transmitter, the LED will illuminate in green after 

2 or 3 seconds as an indication that the transmitter/

receiver system is again ready for operation. 

Please note the following: 

A receiver RESET will cause ALL receiver settings, except for binding information, to return to 

their factory settings. 

Therefore if a RESET is triggered unintentionally, 

any custom settings that had been present in the 

receiver before the reset will have to be established again by way of the »Telemetry« menu.

A deliberate RESET is recommended, especially 

if a receiver is to be “transferred” into another 

model. This is a rather simple method to eliminate 

settings which are no longer applicable.
56 Receiver power supply

Auxiliary function

Y-lead, 

Order No. 3936.11

PRX stabilised 

receiver power supply, 

Order No. 4136

For reasons of safety, do not use battery boxes or dry 

cell batteries.

The voltage of the on-board power supply will be displayed at the bottom right of the transmitter’s screen 

while the model is in operation:

#01

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT

If the voltage falls below the warning threshold–3.80V as standard–set in the “RX SERVO 

TEST” display of the “SETUP, DISPLAYS” sub-menu 

of the »Telemetry« menu, page 248, then the system generates a visual and audible low voltage warning.

Despite this feature, be sure to check the condition of the battery at regular intervals. Do not wait 

for the warning to be issued before recharging 

the battery.

Note:

An overview of available batteries, chargers and 

current source test instruments can be found in 

the Graupner RC main catalog or in Internet at 

www.graupner.de. A selection of suitable Computer 

chargers are listed in the table on page 16.

500mAh for every digital servo. 

For example, from this point of view a battery with 

1400mAh would be the absolute minimum to power 

a receiver system with a total of 4 analog servos. But 

be sure to also consider the receiver itself into the 

calculation because its bidirectional functionality will 

draw about 70mA of current too.

Connect the power supply preferably by way of the 

socket/s which are close to connectors of attached 

servos. Where only high-power servos are connected, 

it may be necessary to use all receiver battery connections. Even where only two batteries are used via 

1 PRX it is preferable to use the receiver connections 

closest to the servos which draw the most current. 

The figure below shows an example of a stabilized 

receiver power supply (PRX-5A, order no. 4136) for 

the connection of two batteries. As an alternative 

solution, a switch could be inserted with power supply cables to two receiver connectors. Such a double 

connection not only reduces the risks associated with 

a cable break but also ensures a more uniform supply 

of power to attached servos.

If a separate battery is connected to each receiver 

battery connection, be absolutely sure the batteries 

have the same voltage and power rating. Never connect different battery types or batteries charged to 

significantly different levels to the receiver. This can 

lead to effects similar to short circuit conditions. In 

such cases, insert voltage stabilizers, such as the 

PRX-5A receiver power supply, between the batteries 

and the receiver.

Auxiliary function

Y-lead, 

Order No. 3936.11

PRX stabilised 

receiver power supply, 

Order No. 4136

Among other aspects, the safe operation of a model 

depends on a reliable power supply. In the event that, 

despite smooth operating rods, fully charged battery, 

battery leads with adequate cross-section, minimum 

contact resistances at connectors, etc., the transmitter indicates repeated receiver voltage collapses or 

is receiver voltage is generally too low; please give 

attention to the following notices:

Give primary attention to fully charged batteries when 

model operation is to be started. Be sure that the 

contact surfaces of connectors and switches really 

are low resistance. If necessary, measure the voltage 

drop across installed switch cables when they are 

under load because even new heavy-duty switches 

can cause a voltage drop of up to 0.2V. This value 

can increase in contacts by factors as a consequence 

of aging and oxidation. The constant vibrations and 

jarring also takes its toll on contacts to produce a 

creeping increase of contact resistance. 

Servos present another possible problem source. 

Even rather small servos like a Graupner/JR DS-281 

can draw up to 0.75A of current when it is blocks under load. Just four of these servos in a “foam” model 

can therefore load down the on-board power supply 

by as much as 3A ...

A further factor is that 2.4 GHz receivers generally 

pass control signals to servos at a higher rate than 

with comparable receivers used in earlier frequency 

ranges. This equates to shorter “off” periods, which 

also has an effect on the power consumption of the 

receiving system. The current drain of many of today’s 

digital servos is also higher, reflected by their greatly 

improved ability to hold the prescribed position between control signals.

Therefore you should choose a power supply which 

will not break down under greater loads but rather 

always deliver sufficient voltage. To “calculate” necessary battery capacity you should always figure on 

at least 350mAh for every analog servo and at least 

Receiver power supply
Receiver power supply 57

Receiver system power supply

NiMH 4-cell battery packs

In compliance with the aforementioned conditions, 

your Graupner/SJ HoTT receiver system can be readily operated with traditional 4-cell battery packs as 

long as the packs have adequate capacity and voltage level.

NiMH 5-cell battery packs

Five-cell battery packs offer a greater voltage tolerance than do 4-cell packs. 

However, be aware that not every servo available on 

the market is able to tolerate the voltage level output 

by a 5-cell pack over the long term, this is particularly 

true when the battery pack is freshly charged. Some 

of these servos react to this with a noticeable “grinding” sound. 

Therefore pay attention to the specifications of the 

servos you use before making a choice for a 5-cell 

battery pack..

LiFe 6.6 V batteries with 2 cells

From a contemporary perspective, these new cells 

are the very best choice. 

LiFe cells are also available in hard plastic casings 

to protect them from mechanical damage. Like LiPo 

cells, LiFe cells can be quick charged in suitable 

chargers and they are comparatively robust.

This type of secondary cell battery is also rated for 

a significantly greater number of charge/discharge 

cycles than, for example, LiPo batteries The nominal 

6.6V output of a 2-cell LiFe battery pack does not 

present a problem for either Graupner/SJ HoTT receivers nor for those servos, speed controllers, gyros 

and other devices which have been specifically approved for operation in this–higher–voltage range. 

Please note however that practically all servos, 

speed controllers, gyros and other devices built 

in the past and most such devices currently still 

offered on the market have only a permissible 

voltage range of 4.8 to 6V. Use of these batteries 

in conjunction with these devices demand use of 

a stabilized voltage regulator, e.g. the PRX, Order 

No. 4136, see appendix. Otherwise there is danger 

that attached devices will incur damage within a short 

period of time.

LiPo 2-cell packs

For a given capacity, LiPo batteries are lighter than, 

for example, NiMH batteries. LiPo batteries are also 

available in hard plastic casings to protect them from 

mechanical damage.

The comparatively high nominal voltage, 7.4V, for 

a 2-cell LiPo pack does not present a problem for 

either Graupner/SJ HoTT receivers nor for those 

servos, speed controllers, gyros and other devices 

which have been specifically approved for operation 

in this–higher–voltage range. Please note however 

that practically all servos, speed controllers, gyros and other devices built in the past and most 

such devices currently still offered on the market 

have only a permissible voltage range of 4.8 to 

6V. Use of these batteries in conjunction with these 

devices demand use of a stabilized voltage regulator, 

e.g. the PRX, Order No. 4136, see appendix. Otherwise there is danger that attached devices will incur 

damage within a short period of time.

Charging the receiver battery

Charger cable, order no. 3021, can be plugged directly onto the receiver’s battery for charging. If the 

battery in the model is connected by way of an order 

no. 3046, 3934, 3934.1 or 3934.3 power supply cable, 

then charging can be accomplished via the charging 

jack or special charging connector integrated into the 

switch. The switch in the power supply cable must be 

in its “OFF” position for charging.

Receiver battery 

connection polarity
58 Receiver firmware updates

Receiver firmware updates for the GR-16 and GR-24 

receivers, which are supplied as standard in the RC 

sets, are carried out using the side-mounted Telemetry socket marked “- + T” and a PC or laptop running 

Windows XP, Vista or 7. You will also require the USB 

leads supplied in the mc-16 HoTT and mc-20

HoTT sets, together with the USB interface, Order 

No. 7168.6, and the adapter lead, Order No. 7168.6S, 

both of which are also included. The programs and 

files also needed can be found in Internet on the 

Graupner website at www.graupner.de under the 

downloads for the particular product. For more information please read the section entitled “Downloading 

a firmware packet” on page 48.

Note:

After registering your receiver at https://www.graupner.de/en/service/product_registration.aspx, you will 

automatically receive notification of future updates 

per email. 

Updating receiver firmware

Important notes:

• Please note that the HoTT components in your 

radio control system can only communicate 

perfectly if the firmware is compatible. That is 

why all the programs and files required to update all HoTT components are grouped together in one file, the current version of which is 

entitled “HoTT_Software_V4.zip”.

• Before any update procedure, be sure to check 

the charged status of the receiver’s battery. If 

necessary, charge the battery before beginning 

with an update.

• It is essential not to disconnect the receiver from the PC or laptop during an update process! Please ensure that the lead between the 

receiver and the computer is making good 

contact at both ends.

Receiver firmware updates

1. Installing drivers

The driver software for the USB interface, Order 

No. 7168.6, is identical to the driver software for 

the interface installed in the mc-16 HoTT and 

mc-20 HoTT transmitter. This means that the 

driver only needs to be installed once; the procedure is described on page 50.

2. Establishing a receiver / PC connection

Connect the USB interface cable, order no. 

7168.6, via the adapter cable, order no. 7168.6A, 

with the “- + T” connector on the receiver, see illustration. These connectors are protected against 

polarity reversal so pay attention to the small 

chamfers on the sides of connectors. Do not use 

brute force, these connectors should latch in rather easily.

Adapter lead

Order No. 7168.6S

If a central red wire is present, 

cut through t

Adapter lead

Order No. 7168.6S

If a central red wire is present, 

cut through it

Caution: 

If the–older–adapter cable still has wires for 

all three poles, cut the red insulated wire for 

the middle connector pin of the adapter cable, 

Order No. 7168.6A.

Afterward, connect the USB interface with the included USB cable (USB-A/mini-B-USB 5-pole interface connector) to the PC or laptop. A red LED 

on the interface board should illuminate even 

though the connection is made correctly.

If not already off, now switch the receiver off.

3. Firmware update

Start the “Firmware_Upgrade_grStudio_VerX.X.exe” program by double-clicking on it, exactly as described for updating the transmitter software–see page 50. (At the time of revision for 

this manual, this program’s current version is 2.1 

and it can be started without first being installed.)

Move to the “Upgrade” folder, open the “Controller 

Menu” and click on “Port Select”. (Alternatively select the “Port Select” entry under “Menu”.) 
Receiver firmware updates 59

Select the correct COM port in the “Port select” 

window, i.e. the port to which the USB interface is 

connected. This can be identified by the label “Silicon Labs CP210x USB to UART Bridge” in the 

“Device name” column. In the screen-shot shown 

above this would be the “COM 3” port.

In the “Devices” folder, call up the “HoTT receiver” 

option under “Controller Menu”. Alternatively select 

the “HoTT Receiver Upgrade” entry under “Menu”:

When you call up the program, you will see a row 

of numbers 1 ... 5 in the window’s title bar; the 

number “1” now flashes red to indicate that the 

program is currently in “[Process Step] 1”.

The meaning of the step which is currently flashing is always displayed immediately below the row 

of numbers:

For example, this screen-shot shows Step 1 in 

progress, and the meaning is: “Connect the USB 

lead to the HoTT receiver”.

Note:

You can position the mouse pointer over a number 

at any time to call up Quick Info: this gives a brief 

explanation of the individual steps:

If you have not already done so, you should now 

connect your receiver to the PC or laptop. Click on 

the button marked “File Browse”, and the “Open 

file” dialogue opens. Select the firmware update 

file matching your receiver; it will end in a “bin” suffix.

Assuming that you have already downloaded and 

unpacked the zip file “HoTT_Software_VX”, the 

file you need will usually be located in the folder 

whose name starts with the Order Number of the 

receiver you wish to update. If you are using one 

of the receivers supplied as standard in the RC 

sets, this would be the folder “33508_08CH_RX” 

(mc-16) or “33512_12CH_RX” (mc-20). The 

file appears in the associated window, and at the 

same time the “2” starts flashing red:

Note:

Firmware files are product-specifically coded, i.e. 

if a wrong file is accidentally selected which does 

not correspond to the product (e.g. a transmitter 

update file instead of a receiver update file), the 

“Product code error” popup window will appear 

and the update process will not start.

With the receiver still switched off, follow the direction of “[Process Step] 2” and press the “Start update” button in the “HoTT Receiver Upgrade” window. (The announcement moves to „[Process 

Step] 3“.) Wait for the progress bar to start. Depending on the speed of the computer being used, 

this may take several seconds.

Now switch on the receiver while holding its SET 

button down. After a few seconds the “Found target device ...” message will appear in the status 

display. Release the button again. The actual firmware update now starts automatically: “11, Start 

Firmware upgrade ...”. 

However, if the receiver is not detected, the “Target device ID not found” popup window will appear. 

If this should happen, check your update arrangement, and re-start the procedure:

The progress of the firmware update is shown by 

the Progress bar in the Status display. 

During the update process the red and green 

LEDs on the GR-16 and GR-24 receivers glow 

constantly.

The connection to the PC must not be interrupted during the update process!

The update is complete when the progress bar 

reaches the right-hand end. In the bottom line of 
60 Receiver firmware updates

the Status display you will see “12, Complete !!” 

and at the same time the [Process Steps] display 

changes to “5”.

When the update process is successfully concluded, the green LED on the receiver goes out, and 

the red LED starts flashing.

If this process terminates before reaching the 

100% mark, switch off your receiver’s power supply then try to start the update process all over 

again. Do this by performing the above steps 

again.

If you accidentally try to transfer firmware which is 

older than the version stored in the receiver–even 

though of the correct type–the program displays a 

warning:

Click on “No” if you do not want to load an older 

version of the firmware, and then load the correct 

*.bin file via the “Open file” button.

After this it is ESSENTIAL to initialise the receiver, i.e. reset it to the factory default values. 

To do this, switch the receiver off and remove the 

interface cable.

4. Receiver initialization

For safety reasons the receiver must be initialised before it is used again, and the display shown 

above makes this clear. Hold the SET button on 

the receiver pressed in while you switch the receiver on: if you are using a GR-16 or GR-24 receiver, as supplied as standard in the RC sets, 

the green and red LEDs flash four times for about 

three seconds, then both LEDs go out for three 

seconds, and finally the red LED alone continues 

to flash.

Release the button as soon as the LEDs go out.

Switch the transmitter on again, wait until an RF 

signal is transmitted, and you will see the green 

LED on the bound receiver light up continuously 

for two to three seconds. If the receiver is not yet 

bound, you can now carry out the binding process 

with a transmitter; see pages 87 and 95.

Important note:

The receiver is now reset to the factory default values–with the exception of the binding 

information–and any other settings previously 

programmed in the receiver must be re-entered 

if required.

If you wish to avoid this process by “rescuing” 

the data, use the “Receiver Setup” program 

in the “Link” segment of the program before 

carrying out the update process. This will save 

you the trouble of re-programming the receiver 

via the “Telemetry” menu.
For your notes 61
62 Backing up receiver settings

The “Receiver Setup” segment of the “Firmware_Upgrade_grStudio” program provides a means of backing up the data programmed in the receiver. The 

data are saved in a file on your computer, so that the 

same data set can be loaded back into the receiver if 

required; this avoids the need to re-program the settings using the “Telemetry” menu.

It is best to call up the “Receiver Setup” application 

from within the “Firmware_Upgrade_grStudio” program, but it is also possible to start it directly: you will 

find the “Receiver_Setup.exe” file in the “Graupner_

PC-Software” folder.

Note:

If you call up “Receiver_Setup.exe” from the Firmware_Upgrade program via the “Receiver Setup” 

menu point, you should check that the sub-program 

“Receiver_Setup.exe” is located in the same folder as 

the “Firmware_Upgrade_grStudio” program! 

For this program you need a USB lead together with 

the USB interface, Order No. 7168.6, which is supplied as standard in the radio control sets, and the 

interface lead, Order No. 7168.6S.

Backing up receiver settings

1. Establishing a connection between the receiver and the PC

With the receiver switched off, connect the USB 

interface, Order No. 7168.6 to the receiver socket marked “- + T” using the adapter lead, Order No. 

Backing up receiver settings

7168.6S.

The connectors are polarised; check that the small 

side chamfers are correctly aligned. On no account use force; the plugs should slide easily into 

the sockets.

Adapter lead

Order No. 7168.6S

If a central red wire is present, 

cut through t

Adapter lead

Order No. 7168.6S

If a central red wire is present, 

cut through it

Caution:

If you wish to use the earlier adapter lead, 

Order No. 7168.6A, and it is still fitted with a 

three-core lead, cut through the central red 

wire of the adapter lead before using it.

Connect the USB interface to the PC or laptop using the USB lead supplied (USB-A to 5-way mini-B-USB). When connected correctly, a red LED 

should light up on the interface circuit board.

The receiver must remain switched off.

2. Receiver Setup: selecting the port

Start the “Firmware_Upgrade_grStudio_VerX.X.exe” program by double-clicking on it, exactly as described for updating the transmitter software–see page 50. (Version 2.1, which is the 

current version at the time this manual was revised, starts without being previously installed.)

Open the “Controller Menu” and click on “Receiver 

Setup” in the “Upgrade / Link” folder.

Alternatively select the “Receiver Setup entry” under “Menu”:

A program window now appears: the first step is 

to set the “correct” COM port for the USB interface, Order No. 7168.6. If you are not sure of this, 

check the COM port in the “Port select” window of 

the “Controller Menu” (see earlier), and note the 

COM port number associated with the entry “Silicon Labs CP210x USB to UART Bridge”. If everything is as described earlier, this would be the 

“COM 3” port.

(If you select the wrong port, the program will inform you of your error.) 

3. Reading out receiver data

Click on the “Connect” button and wait until the 

lower Status bar starts moving:

Hold the SET button on the receiver pressed in 

while you switch it on. After about three seconds 

the current values stored in the receiver are displayed in the corresponding fields. If the progress 

bar is “faster than you are”, and reaches the end 

before you have switched the receiver on, the popup window shown subsequent will appear.
Backing up receiver settings 63

Repeat the procedure:

Important:

The active connection can be terminated using the 

“Disconnect” button, but you should only do this if 

you intend to initialise the receiver directly–as described on page 60–and do not wish to overwrite the contents with a data set you backed up 

earlier.

4. Saving receiver data

The “File Save” button stores the current servo 

configuration on the PC.

The Windows dialogue “Save as” now opens:

First select a suitable folder in which to save the 

file, and enter an unambiguous name under “File 

name”, so that you can assign the file again at a 

later stage. The program automatically appends 

the file suffix “rdf”. The data set is saved when you 

click on the “Save” button. When the process is 

complete, this message appears:

Click on “OK” to close this. 

Now you can reset the receiver to the factory default settings as previously mentioned and described on page 60. 

Copying a data set to the receiver

The backed-up data can be reloaded using the “File 

Load” function in the Receiver Setup program.

First connect the receiver as described in point 3 

“Reading out receiver data”, and click on the “Connect” button. If the receiver has previously been 

initialised, the software reads out the factory default 

settings.

Now select the appropriate “rdf” file from the appropriate folder, and click on “OK” in the “File Load” pop-up 

window. Clicking on the “Write” button transfers the 

data to the receiver connected to the PC.

As soon as the transfer is complete, the pop-up window “Receiver Data Write Success” appears:

Click on “OK” to conclude the data transfer procedure, 

then click on the “Disconnect” button to separate the 

Receiver Setup program from the receiver. 

Important notes:

• The “Receiver Setup” program includes additional functions which are still at the development stage, and must not be used at this juncture. You can check the current state of the 

software in the Download area for your particular receiver.

• A separate manual dealing with the whole 

“Firmware_Upgrade_grStudio_Ver-X.X” program packet is in preparation, and will be 

made available in the Download area when it 

is ready. The manual will then be continuously 

updated whenever new options become available.
64 Installation notices

Servo mounting lug

Retaining screw

Rubber grommet

Tubular brass spacer

4. Servo arms must be free to move throughout their 

entire range of motion. Pay attention that there are 

no objects which could hinder servo arm motion.

The sequence in which servos are connected to the 

receiver depends on the type of model. Follow the 

connection layouts provided for this on pages 73 

and 75.

Also observe the safety notices provided on pages 

4 ... 9.

In order to prevent uncontrolled movements of servos 

connected to the receiver during startup

always first switch on the transmitter 

and then the receiver

and when finished with operation 

first switch off the receiver 

and then the transmitter.

When programming the transmitter, be sure that electric motors cannot start running without control or that 

a combustion motor equipped with automatic starting 

cannot start up unintentionally. To be safe, disconnect 

the receiver’s drive battery or, in the case of a combustion motor, disconnect the fuel supply.

twelve) sockets. A Y-lead can then be used to connect 

the corresponding servo.

However, please note that the transverse sockets of 

the GR-12 should not be used for the connection of a 

receiver battery due to additional voltage losses.

The function of every individual channel is determined 

by the transmitter used, not by the receiver. However, channel assignments can be changed in the 

receiver by programming done in the »Telemetry« 

menu. However, it is advisable to carry this out at the 

transmitter using the »Tx. output swap« option; this 

is available as standard on the mc-20 HoTT transmitter, but has to be unlocked (at extra cost) on the 

mc-16 HoTT transmitter; see page 230.

Several notices and suggestions for installing 

remote control components into a model are provided below.

1. Wrap the receiver in a foam rubber pad that is at 

least 6mm thick. Attach the foam rubber to the receiver with rubber bands so it will be protected 

against vibration and/or the jars of a hard landing. 

However, do not enclose your receiver completely, 

otherwise it may overheat in use. 

2. All switches must be installed such that they are 

not affected by exhaust gases or vibration. The 

switch knob must be freely accessible over its entire range of movement.

3. Mount servos on rubber bushes/spacers with hollow brass bearings to protect them from vibration. Do not tighten the fastening screws down too 

tight as this would negate the vibration protection 

to be provided by the rubber bush/spacer. Only 

when servo fastening screws are properly tightened will this arrangement provide security and vibration protection for your servos. The figure below 

shows how a servo is mounted properly. The brass 

bearings are to be pushed into the rubber bushes/

spacers from below.

Installation notices

Receiver installation

Regardless of which Graupner receiver system you 

use, the procedure is always the same.

Please pay attention that the receiver’s antennas 

must be mounted at least 5cm away from all large 

metal parts or any wiring that is not directly routed 

out of the receiver itself. In addition to steel parts, this 

also includes carbon fiber parts, servos, fuel pumps 

and all kinds of cables etc. Optimally the receiver 

should be placed at a readily accessible location 

that is well away from all other equipment. Under no 

circumstances may servo cables be wrapped around 

the antennas or routed close to it.

Please note that cables are subject to the acceleration forces which occur during flight and these forces 

may cause such cables, to shift in position. Therefore 

be sure the cables in the vicinity of the antennas are 

not able to move. Such moving cables can cause 

reception disturbances.

Tests have shown that a single receiver aerial should 

be deployed in the vertical (upright) orientation for 

best results during long landing approaches. If your 

receiver is an aerial diversity type–two aerials–then 

the active tip of the second aerial should be positioned at 90° to the tip of the first aerial, and ideally 

the distance between the two tips should be greater 

than 125mm.

If your model features a carbon fibre fuselage, the 

aerial tips must always extend outside the fuselage 

for a length of at least 35mm. If this is not possible, 

it is essential to substitute longer aerials (300 mm, 

Order No. 33500.2, or 450 mm, Order No. 33500.3) 

for the standard ones (approx. 145 mm long) fitted to 

HoTT receiver(s).

The sockets marked “X+B-” on the HoTT GR-16 and 

GR-24 receivers supplied in the sets are intended for 

the battery connection. The power supply is passed 

through all the numbered sockets, and in principle 

the battery can be connected to any of the eight (or 
For your notes 65
66 Term definitions

Definitions of terms

Control function, control, function input, control channel, mixer, kind of switches

To make use of this manual easier, a number of the 

terms used repeatedly throughout this manual have 

been defined below.

Control function

A “control function” is to be perceived–initially independent of its signal path–as a signal intended to 

affect a given control function. For example, this could 

be for throttle, rudder or aileron in a winged aircraft or 

pitch, roll or crow for a helicopter. 

A control function signal can be applied directly over 

a single control channel or also through a mixer and 

then applied over multiple control channels. A typical 

example of multiple control channels is separately 

operated aileron servos or the use of two roll or crow 

servos in helicopters. The control function explicitly includes the influence of the control’s mechanical travel 

on the respective servo. This can not only be spread 

or compressed by software but even the travel characteristic can be modified from linear to extremely 

exponential.

Control

“Controls” include all operating elements on the transmitter, which are directly activated by the pilot, that 

impose an effect on servos, speed controllers etc. 

connected to the receiver. This includes: 

• both sticks for control functions 1 through 4, 

whereby these four functions can be freely 

swapped around for both model types (“winged 

aircraft” and “helicopters”) by way of software 

“Mode” settings, e.g. throttle left or right. The stick 

function for throttle/airbrake control at “winged 

aircraft” or throttle/pitch control at “helicopters” is 

often also referred to as the C1 control (channel 

1).

• both proportional controls located on the transmitter’s sides, which are, for example, given the 

designations Lv1 (left-side “rotary slider”) and Lv2 

(right-side “rotary slider”) in the »Control adjust« 

menu, page 118 and 122.

• the two INC/DEC buttons, which are fitted on both 

sides of the front screen on the mc-20 HoTT 

transmitter only. These are typically labelled Cn5 

and 6 in the »Control adjust« menu; see sections 

starting on page 118 and 122. 

If they are assigned as transmitter controls in the 

»Control adjust« menu, these buttons can be 

used to move a servo in 1% increments relative 

to the servo travel currently set (as selected in the 

»Servo adjustment« menu.) When you press one 

of the INC/DEC buttons, the positions are briefly 

superimposed on the base display. 

They are ideal for tasks such as setting flight 

phase specific flap positions and similar fine trimming. If a button is held pressed in, the rate of 

change automatically speeds up–indicated by a 

faster sequence of audible beeps; a different beep 

indicates the centre position. Since you can opt for 

the (trim) position of these two transmitter controls 

to be stored separately for each flight phase–provided that they have been assigned to one of the 

inputs 5 ... 12 in the “Control adjust” menu–you 

can use one and the same INC/DEC button in the 

same way for all flight phases you may have programmed. This does not apply to position-dependent proportional transmitter controls. 

• the two proportional sliders in the middle console 

designated Sl1 and 2, for example as shown in the 

»Control adjust« menu, page 118 and 122,

• the switches present, if they are assigned to a 

control channel in the »Control adjust« menu.

The proportional operating elements produce a direct 

effect on servos which is commensurate with the control’s position whereas switch modules can only effect 

a two or three increment change.

Just which of these controls and switches operate 

which of the servos 5 ... 8 respectively 5 ... 12 is 

freely programmable.

Important notice:

The transmitter is supplied with default programming in which certain inputs are “free”, i.e. not yet 

assigned to any function. These inputs are: 5 ... 7 

(mc-16) and 5 ... 11 (mc-20 only as standard) 

for model helicopters, and 5 ... 8 (mc-16) and 5 

... 12 (mc-20 only as standard) for fixed-wing 

model aircraft.

Function input

This is an imaginary point in the signal path and must 

not be considered the same as the point on the circuit 

board where the transmitter control is connected. The 

choice of “Stick mode” and settings in the »Control adjust« menu have their effect “downstream” of 

these imaginary connection points. Thus differences 

between the physical control’s number and the number of the downstream control channel can indeed 

emerge.

Control channel

From the point at which a signal contains all control 

information necessary for a particular servo–whether 

directly from the physical control or indirectly by way 

of a mixer–the term “control channel” is used. 

(For example, for a fixed-wing model aircraft set up 

as the model type “2AIL”, this means that the “Aileron” 

control function is divided into the control channels

left and right aileron. Similarly: for a helicopter set up 

as the “3Sv(2roll)” type, the “Roll” control function is 

split into the control channels left and right roll servo.)

The signal of this type of control channel can only 

be further influenced by the settings entered in the 

»Servo adjustment« menu (and in the »Tx. output 

swap« menu, which is available in the mc-20

HoTT transmitter only, but can be unlocked in the 

mc-16 HoTT transmitter); the signal then leaves the 

transmitter via the RF module.

Once it arrives at the receiver, this signal may still be 

modified by settings made in the »Telemetry« menu 
Term definitions 67

before finally being applied as a control quantity for 

the respective servo.

Mixer

The transmitter’s software contains a variety of mixer 

functions. These can be used to apply one control 

function to multiple servos or, conversely, to apply 

multiple control functions to a single servo. Please 

look over the numerous mixer functions in the text 

beginning on page 169 of this manual.

Switches

The standard toggle switches, the 3-way switches 

and both push-button switches can also be incorporated into control programming. However, these 

switches are generally intended for switching program 

options, e.g. to start and stop timers, to switch mixers 

on and off, or as a teacher/pupil switchover, etc. Each 

of these switches can be assigned any number of 

functions.

Appropriate examples are detailed in the manual.

Control switches

Since it is very practical to have some functions automatically switched on or off for a certain control’s 

position (e.g. switch on/off of a stopwatch for acquisition of model run time, automatic extension of spoilers and other possibilities), four control switches have 

been integrated into mc-16 HoTT and mc-20

HoTT software.

These software switches, designated “C1 ... C4”, are 

merely defined by virtue of their contact state along 

the physical control’s course of travel by the touch of 

a key. The switching action can be correlated to the 

physical control’s travel direction by software.

Of course control switches can also be freely combined with the aforementioned physical switches to 

solve even more complex problems.

There is a series of instructive examples which make 

this programming child’s play. Learn about this by taking advantage of the programming examples beginning on page 280.

Logical switches

This function, which is available as standard on the 

mc-20 transmitter only, allows two switches, control switches and / or logical switches, or any combination of the above, to be linked in an “AND” or “OR” 

circuit. Eight logical switches “L1 ... L8” can be programmed in total; see page 148.

Fixed switches FXI and FX

This type of switch turns a function, e.g. a timer, permanently on (closed fixed switch) or off (open fixed 

switch) or they can provide a fixed input signal for a 

control function, e.g. FXI = +100% and FX = -100%.

For example, in flight phase programming, these fixed 

switches can be used to switch a servo or speed 

controller between two settings.
68 Physical control, switch and control switch assignments

Physical control, switch and control switch assignments

Principle procedure

Maximum flexibility is offered by the mc-16 Hott and 

mc-20 HoTT system when it comes to assigning 

standard equipment operating elements to certain 

functions.

Since the assignment of controls and switches is 

done in the same way, even though different menus 

may be involved, it is appropriate at this point to 

explain the fundamental programming technique so 

that users can concentrate on the particular contents 

when reading the detailed menu descriptions.

Transmitter control assignment

It is possible to assign any direction of transmitter 

control (Ch1 ... Ch4), and also any available transmitter control, to inputs 5 ... 8 (mc-16) and 5 ... 

12 (mc-20 only as standard) at the transmitter, 

in order to operate servos. This is carried out in the 

third column of the »Control adjust« menu; see the 

sections starting on pages 118 and 122. When you 

press the central SET button of the right-hand touchkey the following window appears on the screen:

Move desired

control adj.

Now simply operate the transmitter control you wish 

to use.

Note:

The software only detects the transmitter control after 

it has moved a certain distance: move it left or right, 

or forward or back, until the assignment is displayed 

on the screen. If the travel in one direction is not sufficient, move the control in the opposite direction.

The same method is used throughout the other menus when transmitter controls have to be assigned.

Switch assignment

Wherever programming permits a switch to be assigned, a switch symbol will appear in the screen’s 

bottom display line:

Use the selection keys in the left or right four-way button to select the appropriate column.

How to assign a switch

1. Briefly touch the SET key of the right four-way button. The message shown below will appear in the 

screen.

Move desired switch

to ON position

(ext. switch: SET)

2. Now it is only necessary to put the selected switch 

into the desired “ON” position or, as described at 

the right in “Assignment of external switches”, to 

select a switch from the list of “External switches”. 

This concludes the assignment. The switch symbol to the right of the switch’s number indicates the 

current state of the particular switch.

Special features of SW 16 + 17 / SW 18 + 19

These two “push-buttons” are fitted in line with the 

side-mounted proportional sliders on the back of the 

mc-20 HoTT transmitter only, and can be assigned 

to operate in either of two ways:

• Change-over On / Off switch “SW 16” or “SW 17”, 

i.e. the switched state (“on” or “off”) changes every 

time you press the button briefly.

• Momentary switch (push-button) “SW 18” and “SW 

19”, i.e. the switch only remains ON for as long as 

the button is held pressed.

Important note:

When the transmitter is switched on, the switches 

“SW 16” and “SW 17” are always set to the “OFF” 

position by default.

Changing switch action

If the activation of a switch is to result in the opposite action, put the switch or stick in the desired OFF 

position, again activate the switch assignment and 

reassign the switch again so it will respond with the 

desired action.

Clear switch

A switch which has been assigned as described under point 1 can be cleared with a brief simultaneous 

tap on the  or  key combination in the right 

four-way button (CLEAR).

Assignment from the “external switch” list

Those menus in which the message ...

Move desired switch

to ON position

(ext. switch: SET)

... appears permit the assignment of switches belonging to the so-called “external switches”.

Do this by confirming the message text with the SET

key. A new window will appear with a list of the four 

control switches “C1 ... C4”, followed by two so-called 

“FX” fixed switches and the eight logical switches “L1 

... L8”.

Control/Logic/fix sw

C2 C3 C4 FX

FXi L1 L2 L3 L4

C1

Use the selection keys in the left or right four-way 

button to select the desired switch then assign it with 

a brief tap on the center SET key of the right four-way 

button.

Notes:

• Switching for some special functions may be better implemented from a certain freely programmable control position rather than switching them 

manually with a normal switch.
Physical control, switch and control switch assignments 69

To this end, there are a total of 4 so-called “control 

switches”, C1 ... C4, available whose switching direction can be established, even inverted, in the 

»Control switch« menu, page 145.

• Logical switches, which are available as standard 

on the mc-20 transmitter only (but can be unlocked on the mc-16 HoTT at extra cost) allow 

two switches and / or control switches to be linked 

together logically in an “AND” or “OR” circuit. See 

the “Logical switches” menu on page 148. A total 

of 8 logical switches “L1 ... L8” (as well as another 

8 inverted logical switches with inverted switching 

direction) are available.

The result of a logical switch function can also be 

used as an input for another logical switch function. Refer to the appropriate menu for more details about this.

• The two FX switches switch a function on “FXI” or 

off “FX ” permanently.

• All switches mentioned can have multiple assignments. Pay attention that you do not unintentionally assign reciprocally conflicting functions 

to a single switch. If necessary, note down the given switch functions.

Typical applications:

• Shut-off of an on-board glow plug heater upon underrun or overrun of an idle threshold point programmed for the C1 stick. In this case the glow 

plug heater switch is controlled by a transmitter 

mixer.

• Automatic switch on/off of the timer to measure 

pure “flight time” for a helicopter by way of a control switch on the throttle limiter.

• Automatic switch off of the “AI  Rud” mixer when 

brake flaps are extended, for example to adapt the 

roll of a model to the ground when making a landing on a slope without inducing a change of flight 

direction due to influence on the rudder.

• Extending landing flaps with elevator trim adjustment during a landing as soon as the throttle stick 

is moved beyond its switch point. 

• Switch on/off of the timer for measuring the operating time of electric motors.
70 Digital trim

Digital trim

Functional description and description of C1 cut-off

Digital trim with visible and audible indicators

Both sticks are equipped for digital trimming. When 

you give the trim lever a brief push (one „click“), 

the neutral position of the associated stick channel 

changes by one increment. If you hold the trim lever 

in one direction, the trim value changes continuously 

in the corresponding direction with increasing speed.

These changes can be made „audible“ by way of different frequency tones. This makes finding the midpoint during flight easy, without looking at the screen. 

When the midpoint is overrun, a brief pause will be 

inserted.

Current trim values are automatically stored when a 

model memory change is made. Furthermore, digital trim exercises flight phase specific control within 

a memory location (except for throttle/brake flaps 

trim)–the socalled „C1“ (channel 1) control function. 

These default settings can be altered to “global” in the 

»Stick mode« menu, which is available as standard 

on the mc-20 HoTT transmitter only, see pages 

114 and 116.

This C1 trim includes yet another special function for 

winged aircraft and helicopter models, it allows the 

carburetor‘s idle setting to easily be found for a combustion motor.

Since the trim functions described in these instructions are only effective in the direction „Motor off“, 

the presentation in the screen of your transmitter 

may only change with respect to individual throttle or 

Pitch-min positioning of the C1 stick in the „forward“ 

or „back“ direction, such as throttle/pitch „left stick“ or 

„right stick“.

The illustrations in these instructions are always 

based on „Throttle/Pitch right“ for both types of models and „Throttle back“ for winged aircraft and helicopters.

1. Winged models

C1 trimming has a special cut-off trim function intended especially for combustion motors. This cut-off trim 

function is configured as follows: First put the motor 

into a safe idle speed.

Now if you push C1 trim in a single motion toward its 

„Motor cut-off“ direction until it is in its furthest travel 

position then an additional end-position marker will 

remain in the display. When the motor is restarted you 

can again immediately set the last idle speed with a 

single movement in the direction of „more gas“.

stp

 flt

Current trim position

M

Trim at motor OFF position

Last idle position

Idle direction

Ch 1 trim lever

This cut-off trim will be deactivated when “None” is 

entered on the “Motor at C1” line of the »Model type« 

menu, see page 104.

Notice:

Since this trim function is only effective in the “Motor 

off” direction, the display illustrated above will change 

appropriately if the C1 stick’s control direction for 

minimum throttle is changed from “back” to “front” (on 

which the above illustration is based) in the “Motor at 

C1” line of the “Basic Settings” menu.

2. Helicopter models

In addition to the „Cut-off trim“ function described 

below in „Winged aircraft models“, C1 trimming also 

has another characteristic which is made possible 

by combining it with a so-called „Throttle limit“ function see page 127. As long as the throttle limit control–as standard the right-hand proportional rotary 

control Lv2 on the right-hand side of the transmitter–remains in the „rear“ half of its travel path, i.e. in 

the startup range, C1 trimming acts on the throttle 

servo as idle trim and the indication for idle trim is visible in the screen‘s display:

stop

 flt

M

Current trim position

Trim at motor OFF position

Last idle position

Throttle limit control

However, in contrast to winged aircraft models, the 

position indicator ( ) will be hidden and any preset 

idle position will be deleted when the throttle limit 

control is in the „front-side“ half of its travel path.

Stp

Flt

M

Throttle limit control

Notice for helicopters:

C1 trimming affects only the throttle servo, not the 

pitch servo. Notice also that the helicopter throttle 

servo must be connected to receiver output 6, see 

receiver layout on page 75!
For your notes 71
72 Winged models

Winged models

Convenient support is provided for up to four aileron 

servos and four flap servos on normal models or, for 

V-tail and flying wing/delta models, up to two aileron/

elevator servos plus four flap servos. 

The majority of motorized and glider models belong 

to the tail unit type “normal” and are equipped with 

one servo each for elevator, rudder and ailerons 

in addition to a motor throttle or electronic speed 

controller (or for brake flaps in the case of a glider 

model). Beyond this, tail unit type “2 HR Sv 3+8” permits the connection of two elevator servos to receiver 

outputs 3 and 8.

“V-tail” is to be selected from the »Model type« menu 

if the model has a V-tail instead of a “normal” tail. This 

V-tail option provides coupled control functions for 

elevator and rudder such that both tail flaps–each 

controlled by a separate servo–are able to handle 

both elevator and rudder functionality.

For delta and flying wing aircraft models, aileron and 

elevator functionality is affected by way of a common 

rudder flap on the trailing edge of each side (right and 

left) of the wing. The program contains appropriate 

mixer functions for both servos.

If ailerons, and conditionally the flaps, are each actuated with two separate servos then settings can be 

made for differentiated control of all aileron and flap 

pairs in the »Wing mixers« menu, i.e. settings for 

downward rudder throw independent of upward throw. 

And finally, the ideal method of controlling flap positions is to use one of the two INC/DEC transmitter 

controls, which are fitted as standard on the mc-20

HoTT transmitter only.

Alternatively, there is a phase-dependent trim function available for flaps, ailerons and elevators in the 

»Phase trim« menu.

Up to 7 flight phases can be programmed into each of 

the 20 respectively 24 model memory locations. 

Except for C1 trim, digital trim will be stored on a 

flight-phase basis. C1 trim permits easy location of a 

carburetor idle setting.

Two timers are always available for flight operation. 

The transmitter operating time expired since the last 

battery charge is also displayed.

All transmitter controls and switches can be assigned 

in the »Control adjust« menu to inputs 5 ... 8 respectively 5 ... 12 with almost no restrictions.

The “Dual Rate” and “Exponential” functions for ailerons, rudder and elevators are separately programmable and each are convertible between the two variations on a specific flight-phase basis.

In addition to eight freely assignable linear mixers, 

four curve mixers (»Free mixers« menu) and four 

dual mixers (»Dual mixers«–available as standard 

on the mc-20 HoTT transmitter only; can be unlocked on the mc-16 HoTT as an extra-cost option), 

flight-phase specific six-point curves are available for 

control channel 1 (throttle / brake); see »Channel 1 

curve« menu. 

Depending on the number of wing servos, fixeddefinition mix and coupling functions can be selected 

from a list in the »Wing mixers« menu.

• Multi-flap menu: control of flaps as ailerons, the influence aileron trim on flaps controlled as ailerons, 

flap differentiation, flap function throw magnitude 

for all aileron and flap pairs, ailerons controlled as 

flaps, elevator mixer  flaps

• Brake settings: butterfly, differential reduction, 

elevator curves

• aileron  rudder mixer

• flaps  elevator mixer

Elevator Flap

Flap Elevator

F l a p Aileron

A il eron Flap

Aileron Rudder

Elevator A leron

left

right Eel vator Flap

F al p Ele

A

vator ileron Rudder

Ailero n Flap

Airbrake Flap

Airbrake Elevator

Airbrake-Function 1

left

right

Rudder/Elevator

V-Tail

AI

FL

FL

AI

Brake FL, FL2

Brake Elevator

Brake AI, AI2 AI

FL

FL2

AI

FL

FL2

AI2

FL  AI

FL  AI

EL  FL

RU  AI

EL  AI

EL  FL

AI2

AI  FL

AI  FL
Winged models - Receiver layout 73

Installation notices 

Servos MUST be connected to the receiver in the 

sequence illustrated here. 

Outputs which are not used are simply left empty. 

Also be sure to follow the notices on the next 

pages.

Winged aircraft with and without motor having up 

to 4 aileron servos and up to 4 flap servos ...

... and tail plane type “normal” or “2 elevator 

servos”

Receiver power supply

Free or left aileron 2 or aux. function

Free or right aileron 2 or aux. function

Rudder

Aileron or left aileron

Elevator or 1st elevator

Free or 2nd elevator or aux. function

Receiver power supply

Airbrake or throttle servo

or speed controller (electric motor)

Right aileron or aux. function

Flap or left flap

Right flap or free or aux. function

Free or left flap 2 or aux. function

Free or right flap 2 or aux. function

... and tail plane type “V tail unit”

Receiver power supply

Free or aux. function

Free or aux. function

Aileron or left aileron

Free or aux. function

Receiver power supply

Airbrake or throttle servo

or speed controller (electric motor)

Right aileron or aux. function

Flap or left flap

Right flap or free or aux. function

Free or left flap 2 or aux. function

Free or right flap 2 or aux. function

Left rudder / elevator

Right rudder / elevator

Delta/flying wing aircraft models with and without 

motor having up to 4 aileron/elevator servos and 

up to 4 flap/elevator servos

Receiver power supply

Free or aux. function

Free or aux. function

Left elevon

Right elevon

Free or aux. function

Receiver power supply

Airbrake or throttle servo

or speed controller (electric motor)

Free or aux. function

Free or left flap / elevator

Free or right flap / elevator

Free or aux. function or left flap 2 / elevator

Free or aux. function or right flap 2 / elevator

Free or rudder

Because of orientation differences for installed servos and their rudder linkages, the actuating direction 

of some servos may be initially backward. The table 

below provides remedies.

Model 

type

Servo 

direction 

wrong

Remedy

V tail Rudder and 

elevator reversed

Reverse polarity of servos 3 & 4 in the »Servo 

adjustment« menu

Rudder correct, 

elevators reversed

Swap servos 3 & 4 on 

the receiver

Elevators correct,

rudder reversed

Reverse polarity of servos 3 & 4 in the »Servo 

adjustment« menu 

AND swap them on the 

receiver

Delta,

flying 

wing

Elevator and aileron 

reversed

Reverse the polarity 

of servos 2 & 3 in the 

»Servo adjustment« 

menu

Elevator correct, 

aileron reversed

Reverse polarity of servos 2 & 3 in the »Servo 

adjustment« menu 

AND swap them on the 

receiver

Aileron correct, 

elevators reversed

Swap servos 2 & 3 on 

the receiver

All “program descriptions” for menus relevant to a 

winged aircraft model are marked with a winged 

aircraft symbol ...

... so only these menus need to be dealt with to program a winged aircraft model.
74 Helicopter models

Helicopter models

Collective

Pitch Curve

Swashplate 

Rotation

Roll Throttle

Pitch-Axis Throttle

Channel 1 Throttle

Roll Tail Rotor

Pitch-Axis Tail Rotor

Channel 1 Tail Rotor

Channel 1 Tail Rotor

Tail Rotor Throttle

The advanced developments incorporated into the 

transmitter as well as those now in helicopter models 

and their components like gyros, speed regulators, 

rotor blades, etc. make it possible to master a helicopter even in 3D acrobatic flight. On the other hand, 

a beginner needs only a few settings to get started 

with hovered flight training then, step-by-step, take 

advantage of HoTT transmitter features with increasing expertise.

All current model helicopters with one to four collective pitch servos can be operated using the programs 

provided by the mc-16 HoTT and mc-20 HoTT. 

Six flight phases plus autorotation are available within 

a model memory, see menus »Control adjust«, 

»Phase settings« and »Phase assignment«.

As with winged aircraft, here too, in addition to the 

basic screen’s standard timers there are additional 

timers as well as a lap counter with flight-phasedependent stopwatch functionality which are available for selection (menus »Timers (general)« and 

»Fl. phase timers«).

Depending on the transmitter, it is possible to store 

the digital trims in “flight phase specific” or “global” 

form–for all flight phases; this does not apply to collective pitch / throttle trim. C1 trim permits easy location of an idle setting.

The control assignments for inputs 5 ... 8 respectively 5 ... 12 is made separately for each flight phase 

(»Control adjust« menu).

A flight phase copy function is helpful during flight trials (»Copy / Erase« menu).

“Dual Rate” and “Exponential” functions can be coupled for roll, nick and tail rotor and programmable in 

two variations in every flight phase.

There are 8 freely assignable linear mixers. There are 

also 4 curve mixers that can be programed and these 

can also be switched on or off, depending on the 

flight phase, in the »MIX active/phase« menu. Four 

dual mixers are also available (»Dual mixers« menu, 

provided as standard on the mc-20 HoTT transmitter only, but can be unlocked as an extra-cost option 

in the mc-16 HoTT transmitter). 

The »Helicopter mixer« menu provides flight-phasedependent 6-point curves for the non-linear characteristics pitch, throttle and tail rotor mixer as well as 

two independent swashplate mixers each for roll and 

nick. Independent of this, the control curve of the 

channel 1 stick can be defined with up to a total of 6 

points in every flight phase. The beginner will initially 

only adapt the hover flight point to the control middle 

for the non-linear characteristics. 

Pre-programmed mixers in the »Helicopter mixer« 

menu:

1. Pitch curve (6-point curve)

2. C1  throttle (6-point curve)

3. Channel 1  tail rotor (6-point curve)

4. Tail rotor  throttle

5. Roll  throttle

6. Roll  tail rotor

7. Pitch-axis  throttle

8. Pitch-axis  tail rotor

9. Gyro suppression

10.Swashplate rotation

11.Swashplate limiter

The “Throttle limit” function (input “Lim.” in the »Control adjust« menu) allows the motor to be started in 

any flight phase. The right-side proportional rotary 

slider is assigned to input “Lim.” by default. This “throttle limiter” establishes–depending on its given position–the maximum possible throttle servo position. 

This makes it possible for the motor to be controlled 

in the idle range, if necessary even by the proportional regulator. The throttle curves become effective only 

when the proportional regulator is pushed toward the 

full throttle direction.
Helicopters - Receiver layout 75

Notice for those transitioning from older Graupner systems:

In comparison to previous receiver layouts, servo 

connector 1 (pitch servo) and servo connector 6 

(throttle servo) have exchanged places. 

Installation notices

Servos MUST be connected to the receiver in the 

sequence illustrated here. 

Outputs which are not used are simply left empty. 

For more detailed information on each swashplate 

type please refer to the »Helicopter type« menu, 

described on page 108.

Also be sure to follow the notices on the next 

pages.

Note:

A speed control is also to be connected to receiver 

output “6” in order to take full advantage of the throttle 

limiter’s convenience and safety features. See page 

193 about this.

Receiver allocation for helicopter models with 

1 to 3 swashplate servos

Receiver power supply

Free or aux. function

Free or aux. function

Tail rotor servo (gyro system)

Roll 1 servo

Pitch-axis 1 servo

Free or speed governor or aux. function

Receiver power supply

Collective pitch or roll 2 or 

Pitch-axis 2 servo

Free or aux. function

Throttle servo or speed controller

Gyro gain

Free or aux. function

Free or aux. function

Receiver allocation for helicopter models with 

4 swashplate servos

Receiver power supply

Free or aux. function

Free or aux. function

Tail rotor servo (gyro system)

Roll 1 servo

Pitch-axis 1 servo

Free or speed governor or aux. function

Receiver power supply

Roll 2 servo

Pitch-axis 2 servo

Throttle servo or speed controller

Gyro gain

Free or aux. function

Free or aux. function

All menus relevant to helicopter models are marked 

in the „program descriptions“ section with a helicopter 

symbol ...

... so only these menus need to be dealt with to program a helicopter model.
76 Program description - Loading a new memory location

Anyone who has worked through to this part of the 

manual has certainly already tried out a bit of programming. Nevertheless a detailed description of 

every menu should not be left out. 

This section begins with the loading of a “free” memory location, a procedure which would be performed if 

a new model was being “programmed”:

#01

0:00h

Stp

Flt

0:00

0:00

0.0V

4.1V

M

HoTT

From the basic display, a jump to the “Multi-function 

list” is made with a tap on the center SET key of the 

right four-way button. (The center ESC key of the left 

four-way button will cause a jump back to the basic 

display.) By default, when the multi-function list is 

called for the first time after switching on the transmitter, the »Model select« menu option will be active 

and displayed in inverse video. Otherwise use the 

 or  selection keys of the left or right four-way 

button to select the »Model select« menu option, 

whereby the upper of the two following figures shows 

a selection list for a fixed-wing model and the lower 

shows the selection list for a helicopter model.

Copy / Erase

Suppress menus

Suppress models

Model select

Base setup model

Model type

Detail program description

Loading a new memory location

Copy / Erase

Suppress menus

Suppress models

Model select

Base setup model

Helicopter type

Tap briefly on the center SET key of the right four-way 

button to open this menu option:

03

04

05

02  free

01

06

R12

 free

 free

 free

 free

In the transmitter’s delivered state, the first model 

memory is initialized to the “fixed-wing model” type 

and the receiver in the delivery is “bound” to this 

model. This is indicated by the pictogram of a fixedwing model aircraft in the second column from left, 

and the receiver identification displayed at far right; in 

the example above this is R12. If the model memory 

is not “bound”, you will see “---” instead of the receiver 

identification.

The remaining memory locations, marked with 

“free”, are still unoccupied and therefore 

also “non-bound”. 

If you wish to program a fixed-wing model then, 

after leaving the »Model select« menu with a tap 

on the center ESC key of the left four-way button, 

programming of the model can begin right away ... or 

now use the  or  keys of the left or right four-way 

button to select one of the free memory locations ...

03

04

05

02  free 

01

06

R12

 free 

 free 

 free 

 free 

... and then tap on the center SET key of the right 

four-way button to confirm the choice.

Afterward you will be prompted to select the basic 

model type, i.e. either “winged model” or “helicopter 

model”:

Select model type

Use the  or  keys of the left or right four-way 

button to select the basic model type then tap on 

the center SET key of the right four-way button. This 

initializes the selected model memory with the selected model type and the display will return to the 

base screen. The memory location is now accordingly 

occupied. 

Changing over to another model type is still possible if 

you first erase this memory location (»Copy / Erase« 

menu, page 80).

Notes:

• If the currently active model memory is to be 

erased then immediately after the erase action 

one of the two model types, “Winged” or “Heli” 

must be defined. You cannot avoid this selection even if you switch the transmitter off. Only afterward the undesired occupation of that model 

memory erase from another memory location.

If a non-active memory location is erased, it will 
Program description - Loading a new memory location 77

helicopter, (by default this is the right-side rotary 

slider Lv2) into its idle position.

Whether or not this warning appears also depends 

on the settings selected for the “Motor on C1” and 

“Pitch min.” options in the »Model type« menu, 

see page 104, or »Helicopter type« menu, see 

page 108. For winged aircraft models, select 

“None” to deactivate this message if you have no 

motor to enter.

• If the transmitter already has occupied model memories then sub-menus of the »Copy / 

Erase« menu will display a pictograph of the selected model type at the respective memory location followed by a blank line or the model name 

which was entered in the »Basic settings, model« menu, page 86 or 94. 

• If battery voltage is too low, the model switchover 

cannot be made due to reasons of safety. An appropriate message will appear in the screen:

not possible now

voltage too low

As a basic principle, there are four different ways to 

assign the four control functions, aileron, elevator, 

rudder and throttle or brake flaps for winged models 

as well as rolling, pitching, tail rotor and throttle/pitch 

for helicopter models, to the two sticks. Just which of 

these methods is used depends on the preferences of 

the individual model pilot. This function is set for the 

currently active model memory in the “Stick mode” 

line of the »Basic settings, model« menu, page 

86 or 94:

1

BD1 BD2

Mod.name

Stick mode

module n/a

Base setup model

n/a

DSC Output PPM10

HoTT

subsequently be marked as “free” in the 

“Model select” menu.

• After the selected model memory is initialized with 

the desired model type, the display will switch to 

the base screen of the freshly occupied model 

memory. At this time the warning ...

BIND. N/A

OK

... will appear for several seconds as notification that a binding connection to a receiver is “not 

available”. A brief tap on the center SET key of the 

right four-way button will cause a direct jump to 

the appropriate option:

1

BD1 BD2

Mod.name

Stick mode

module n/a

Base setup model

n/a

DSC Output PPM10

HoTT

Further details about binding a receiver can be 

found on page 87 or 95.

• The “BIND n/a” warning closes automatically, after 

which the following warning also appears for a few 

seconds ...

Fail Safe

setup

t.b.d.

... will appear (also for just a few seconds) to indicate that no fail safe settings have yet been made. 

More about this can be found on page 220. 

• If the screen should display the warning ...

Thr

 too

 high!

... then move the throttle stick, or the limiter for a 

If this setting is desired as a default for future models, 

the setting can also be entered into the »General 

basic settings« menu, page 269:

1

PPM10

SEL

Basic settings

Own

Stick mode

DSC Output

Modulation HoTT

It should be noted here once again that, in the interest of greatest flexibility in combination with the prevention of unintentional operating errors, no controls 

are preassigned to control channels 5 ... 8 respectively 5 ... 12 by default.

This means that, in the system’s delivered state, 

only servos attached to receiver outputs 1 ... 4 

can typically be operated by the two sticks and 

that any servos attached to receiver connectors 

5 ... max. 12 will remain in their middle positions.

A newly initialized helicopter model is also able to 

more-or-less move servo 6–depending on the position of the right-side proportional rotary slider, which 

is the default throttle limiter control. With either model 

type, this situation will only change after appropriate 

assignments have been made in the »Control adjust« menu.

On the other hand, if a newly initialized model memory is to be put into operation then it MUST first be 

appropriately “connected” with one or more receivers 

before the servos attached to the receiver/s can be 

operated. More about this can be found in the section 

“Binding” on page 87 or 95. 

A fundamental description of programming steps for 

a winged aircraft model can be found in the programming examples section beginning on 280, or for 

helicopter models beginning on page 318.

The menu descriptions below are arranged in the 

sequence individual menus are listed in the multi-
78 Program description - Loading a new memory location

function list. However, since the mc-16 HoTT and 

mc-20 HoTT transmitter types covered by this 

manual differ in their software structure as well as 

their hardware features, these instructions always 

indicate the “soft” differences between the individual 

transmitter types at the start of a menu description, 

as they are in the Contents. The key is as follows: 

mc

 

16 20

Key:

16 applicable to mc-16 HoTT

20 applicable to mc-20 HoTT

 standard option

 can be unlocked as an extra-cost option
Program description - Model select 79

Model select

Call up model 1 ... 20 (mc-16) or 1 ... 24 (mc-20)

This option is available as standard on 

both transmitter types.

The basic operation of the transmitters 

keys was explained on pages 28 and 

29 and, on the previous double-page, explanations 

were provided for navigating to the multi-function list 

and about how to make allocations for a new model 

memory. At this point we now wish to begin with the 

“normal” description of individual menu items in the 

sequence they are arranged in the transmitter. Therefore we will begin with the menu ...

Model select

Copy / Erase

Suppress menus

Suppress models

Model select

Base setup model

Model type

Copy / Erase

Suppress menus

Suppress models

Model select

Base setup model

Helicopter type

As many as 20 respectively 24 complete model settings, including digital trim values for the trim buttons, 

can be stored. Trimming is stored automatically such 

that a switchover from one model to another does not 

cause a loss of current trim settings. To the right of 

the model number, each occupied model memory line 

in this display shows a pictograph of the model type 

as well as the model’s name entered for the model 

in its »Basic settings, model« menu, page 86 or 

94. The code, if present, for the receiver “bound” 

to the model memory location will appear in right the 

line.

Select the »Model select« menu with the selection 

keys of the left or right four-way button then briefly tap 

on the SET key of the right four-way button.

Attention!

Switch-OFF

the Receiver first!

If this message appears, there is a telemetry connection to an operationally ready receiver system. Switch 

that receiver system off:

01

03

04

05

02 ULTIMATE

GRAUBELE

STARLET

BELL47G

06

R12

R12

R12

–––

 free

 free

Now, with the  selection keys of the left or right 

four-way button, select the desired model memory 

from the list and activate it with a tap on the SET key. 

A tap on the ESC key will cause a return to the previous menu page without activating a model change.

Notes:

• If, after a model change, the “Throttle too high” 

warning appears, the throttle/pitch stick (C1) or the 

throttle limiter–by default, the right-side proportional rotary slider–is too far in the full throttle direction.

• If a model change causes the message ...

Thr

 too

 high!

... to appear, then the throttle / collective pitch 

stick (Ch1) or the throttle limiter–by default the 

right-hand side-mounted proportional rotary slider–is too far in the direction of full-throttle.

• If a model change causes the message ...

BIND. N/A

OK

... to appear then binding settings should be 

checked.

• If a model change causes the message ...

Fail Safe

setup

t.b.d.

... to appear then respective fail safe settings 

should be checked.

• If battery voltage is too low, the model switchover 

cannot be made due to reasons of safety. An appropriate message will appear in the screen:

not possible now

voltage too low

mc

 

16 20
80 Program description - Copy / Erase

Copy model  model

Select the “Copy model  model” sub-menu with the 

 selection keys of the left or right four-way button 

then tap the SET key:

Copy ligh phase

Erase model

C l l

=>

SWITCHING RF OFF 

OK

If the message shown above should appear, the 

transmitter’s RF module is still active.

You can interrupt the process by pressing the central 

ESC button of the left-hand four-way button.

Pressing the SET button of the right-hand four-way 

button resumes the process. However, if the receiving 

system is switched on, you should switch it off before 

doing this.

Choose the model to be copied with the  selection keys of the left or right four-way button ...

01

03

04

02 ULTIMATE

GRAUBELE

STARLET

BELL47G

Copy from model:

R12

R12

–––

R12

... then, following the change into the “Copy to model” 

window caused by another tap on the SET key of the 

right four-way button, the destination memory can be 

selected with the  selection keys of the left or right 

four-way button. Yet another tap on the SET key will 

then confirm the copy process or a tap on ESC key 

will cause the copy to be cancelled. A memory location which is already occupied can be overwritten.

01

03

04

02 ULTIMATE

GRAUBELE

STARLET

BELL47G

model to be erased :

R12

R12

R12

–––

... whereby another tap on the SET key will cause the 

confirmation request ...

Model really

GRAUBELE

to be erased?

NO YES

01

... to appear. A NO response will cause the process 

to be canceled and a return to the previous screen. 

Selecting the YES response with the  selection key 

of the left or right four-way button followed by confirmation of the selection with a brief tap on the SET

key will erase the selected model memory.

Caution:

This erase process cannot be undone. All data in 

the selected model memory will be erased completely.

Note:

If the currently active model memory is to be erased, 

a model type “Winged” or “Heli” must be defined immediately after the erase process. If, however, an inactive memory location is erased, it will subsequently 

appear in “Model select” list as “free”.

Copy / Erase

Erase model, copy model  model, copy from or to SD card, copy flight phases

This option is available as standard on 

both transmitter types.

Use the  selection keys on the left or 

right four-way button to select the »Copy / 

Erase« option in the multi-function menu:

Suppress menus

Suppress models

Model select

Base setup model

Model type

Copy / Erase

Suppress menus

Suppress models

Model select

Base setup model

Helicopter type

Copy / Erase

Open this menu option with a tap on the center SET

key of the four-way button pad:

Erase model

Copy flight phase

Erase model

Copy model–>model

=>

=>

Export to SD =>

Import from SD =>

=>

Select the “Erase model” sub-menu with the 

selection keys of the left or right four-way button then 

briefly tap on the SET key.

Choose the model to be erased with the  selection keys of the left or right four-way button ...

mc

 

16 20
Program description - Copy / Erase 81

01

03

04

02 ULTIMATE

GRAUBELE

STARLET

BELL47G

Copy to model:

05 free

R12

R12

R12

–––

After confirming the selected model memory with a 

tap on the SET key, a confirmation request will appear:

Modell really

ULTIMATE

to be copied?

NO YES

01

03 free

A NO response will cancel the process and return 

the screen to the originating screen. If the  YES

response is selected and confirmed with a tap on the 

SET key then the selected source model will be copied into the selected model memory destination. 

Note:

In addition to model data, binding data is also copied 

by this process. This means that a receiver system 

which was/is bound to the original model memory can 

also be operated by its copy in the SAME transmitter 

without establishing the bond again.

Exporting to SD card

Use the  selection keys of the left or right fourway button to select the “Export to SD” sub-menu 

then tap on the SET key.

=>

=>

=>

=>

Copy flight phase =>

Erase model

Copy model–>model

Export to SD

Import from SD

Choose the model to be exported with the  selection keys of the left or right four-way button ...

01

03

04

02 ULTIMATE

GRAUBELE

STARLET

BELL47G

export to SD-CARD:

R12

R12

R12

–––

After confirming the selected model memory with a 

tap on the SET key, a confirmation request will appear:

modell

ULTIMATE

export ?

NO YES

01

SD-CARD

A NO response will cancel the process and return 

the screen to the originating screen. If the  YES

response is selected then confirmed with a tap on the 

SET key, the selected model will be copied to the SD 

card.

Notes:

• Should the notice ...

SD-CARD

INSERT

OK

... appears instead of a screen for model selection, there is no SD card in the transmitter’s card 

slot, see page 24.

• In addition to model data, binding data is also copied by this process. This means that a receiver 

system which was/is bound to the original model 

memory can also be operated in the SAME transmitter by its copy without establishing the bond 

again.

• An exported fixed-wing model will be stored on the 

memory card in the \\Models\mc-16 respectively \\Models\mc-20 folder with a filename format of 

“aModelname.mdl” and a helicopter model with a 

filename format of “hModelname.mdl”. On the other hand, if a “nameless” model is exported, its data 

will be stored on the memory card under “aNoName.mdl” or “hNoName.mdl”, as appropriate.

• Some special characters that can be used in model names are subject to specific restrictions associated with the FAT or FAT32 file system used by 

the memory cards and these special characters 

will be replaced during the copy process with a tilde (~).

• A model file already on the memory having the 

same name as the file to be copied will be overwritten without warning.
82 Program description - Copy / Erase

key, or the process can be canceled with a tap on the 

ESC key. A memory location which is already occupied can be overwritten.

01

03

04

02 ULTIMATE

GRAUBELE

STARLET

BELL47G

import to model:

05 free

R12

R12

R12

–––

After confirming the selected model memory with a 

tap on the SET key, a confirmation request will appear:

modell

ULTIMATE

import ?

NO YES

03 free

A NO response will cancel the process and return 

the screen to the originating screen. If the  YES

response is selected and confirmed with a tap on the 

SET key then the selected source model will be imported into the selected destination model memory. 

Notes:

• If the message ...

SD-CARD

INSERT

OK

... appears instead of a screen for model selection, there is no SD card in the transmitter’s card 

slot, see page 24.

• In addition to model data, binding data is also imported by this process. This means that a receiver 

system which was/is bound to the original model 

memory can also be operated in the SAME transmitter by its copy without establishing the bond 

Importing from SD card

Use the  selection keys of the left or right fourway button to select the “Import from SD” sub-menu 

then tap on the SET key.

Copy ligh phase

Erase model

C d l d l

=>

>

 >

>

>

SWITCHING RF OFF

OK

If the message shown above should appear, the 

transmitter’s RF module is still active. 

You can interrupt the process by pressing the central 

ESC button of the left-hand four-way button.

Pressing the SET button of the right-hand four-way 

button resumes the process. However, if the receiving 

system is switched on, you should switch it off before 

doing this.

Select the model to be imported from the SD memory 

card with the  selection keys of the left or right 

four-way button:

EXTRA

ALPINA

COBRA

BELL47G

import from SD-CARD:

11/03/10

11/03/11

11/03/11

11/03/12

Note:

The export date posted at the right end of each model 

name line is represented in the format “year/month/

day”.

After another tap on the SET key of the right four-way 

button, the “import from SD-CARD” window will appear. Now the destination memory location can be 

selected with the  selection keys of the left or right 

four-way button then confirmed with a tap on the SET

again.

• In principle the model memories of the mx-20 and 

mc-20 transmitters are compatible, BUT:

If you wish to carry out an “Import from SD card” in 

the other transmitter you must first copy or move 

the model memory concerned to the appropriate 

folder on a PC. For example: from \\Models\mc-20 

to \\Models\mx-20, or vice versa.

C A U T I O N :

After you have carried out an “Import from SD 

card” it is absolutely essential to check all the 

model functions with great care. Note also that the 

transmitter control and switch functions may need 

to be adjusted to suit the new transmitter.

Copy flight phase

Select the “Copy flight phase” sub-menu with the 

selection keys of the left or right four-way button then 

tap on the SET key.

=>

=>

=>

=>

Copy flight phase =>

Erase model

Copy model–>model

Export to SD

Import from SD

In the “Copy flight phase” sub-menu ...

7

Copy from phase:

3

5

2

4

6

1

... the flight phase to be copied (1 ... 7 for fixed-wing 

models or 1 ... 6 for helicopter models) is selected 

with the selection keys of the left or right four-way 

button then confirmed with a brief tap on the SET

key of the right four-way button. In the next window to 
Program description - Copy / Erase 83

appear ... 

7

Copy to phase:

3

5

2

4

6

1

... a destination must be selected and it must be confirmed too. Another confirmation request will follow:

Phase to:

1 Normal

to be copied?

NO YES

2 Launch

A NO response will cancel the process and return 

the screen to the originating screen. If the  YES

response is selected and confirmed with a tap on the 

SET key then the selected source model will be imported into the selected destination model memory. 
84 Program description - Suppress menus

Suppress menus

Suppression of menus in the multifunction list

This option is available as standard on 

both transmitter types.

Use the  selection keys on the left or 

right four-way button to select the »Suppress codes« option in the multi-function menu:

Model select

Copy / Erase

Suppress menus

Suppress models

Base setup model

Model type

Model select

Copy / Erase

Suppress menus

Suppress models

Base setup model

Helicopter type

Open this menu option with a tap on the center SET

key of the four-way button pad.

Base setup model

Model type

Copy / Erase

Suppress models

Suppress: TOG

Model select

Base setup model

Helicopter type

Copy / Erase

Suppress models

Suppress: TOG

Model select

In the menu which then appears, menu items which 

are no longer needed or those which should not be 

changed, can be blocked from appearing in the multifunction list.

The option to be suppressed/displayed is selected 

with the selection keys of the left or right four-way button then its status is switched over with a tap on the 

center SET key of the right four-way button:

Model select

Base setup model

Model type

Copy / Erase

Suppress models

Suppress: TOG

Model select

Base setup model

Helicopter type

Copy / Erase

Suppress models

Suppress: TOG

This can reduce the multi-function list considerably, in 

some cases to only a few menus, thus substantially 

improving clarity of the multi-function list. Options are 

not deactivated by being suppressed. They will simply 

no longer appear in the list. This also blocks direct 

access to these functions.

Tip:

If you do not wish to block access to the multi-function 

list, in the interests of security we recommend that 

you use this list to suppress the »Code lock« menu 

from the multi-function list. This menu is available as 

standard on the mc-20 HoTT transmitter only, but 

can be unlocked as an extra-cost option on the mc16 HoTT transmitter. This setting also makes it a little 

more difficult for any unauthorised person to block 

access to the transmitter.

mc

 

16 20
Program description - Suppress models 85

Suppress models

Suppression of model memory locations

This option is available as standard on the 

mc-20 HoTT transmitter only.

Use the  selection keys on the left or 

right four-way button to select the »Suppress models« option in the multi-function menu:

Model select

Copy / Erase

Suppress menus

Suppress models

Base setup model

Model type

Model select

Copy / Erase

Suppress menus

Suppress models

Base setup model

Helicopter type

Open this menu option with a tap on the center SET

key of the four-way button pad.

Model memories which are rarely needed or to which 

access is to be blocked for other reasons can be hidden from the model selection list. This also clarifies 

the overview layout for model selection.

The model to be suppressed/displayed is selected 

with the selection keys of the left or right four-way button then its status is switched over with a tap on the 

center SET key of the right four-way button.

01

03

04

05

02 ULTIMATE

GRAUBELE

STARLET

BELL47G

R12

R12

R12

–––

 free

Suppress: TOG

A model memory which is “stricken through” will no 

longer appear in the »Model select« menu:

03

04

05

STARLET

BELL47G

06

R12

–––

 free 

 free 

01 GRAUBELE R12

07  free 

mc

 

16 20
86 Program description - Base setup models | Winged models

Base setup model

Model-specific base settings for winged aircraft models

This option is available as standard on 

both transmitter types.

Before programming specific parameters, 

there are some basic settings to be made 

which effect the currently active model memory.

Use the  selection keys on the left or right fourway button to select the »Base setup model« option 

in the multi-function menu:

Model type

Suppress models

Base setup model

Servo adjustment

Control adjust

Stick mode

Open this menu option with a tap on the center SET

key of the four-way button pad:

Model name

Mod.name

Stick mode

module

1

n/a

Base setup model

n/a

DSC Output PPM10

HoTT

Change to the next screen page with a brief tap on 

the SET key of the right four-way button. This will 

open a screen of characters for entry of the model’s 

name. A maximum of 9 characters can be used to 

specify a model name.

!"#$%&’()�+,–./0123

456789:;

Mod Name GRAUB

FGHIJKLMNOPQRSTUVWX

YZ[¥]^_`abcdefghijk

?@ ABCDE

Now the desired characters can be selected with the 

selection keys of the left four-way button. Move to the 

next position to select the next character with a tap on 

the center SET key of the right four-way button. 

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will place a space 

character at the current position.

Positioning to any character position within the entry 

field can be done with the  keys of the right fourway button.

A return to the previous menu screen is accomplished 

with a tap on the center ESC key of the left four-way 

button.

A model name entered in this manner will appear in 

the base screen of the »Model select« menu and in 

the sub-menus of the »Copy / Erase« menu item.

Stick mode

MODE 2 (Throttle at left stick)

elev. down

elev. up

left rudder

right rudder

full throttle

idle

left aileron

right aileron

full throttle

idle

left rudder

right rudder

elev. down

elev. up

left aileron

right aileron

elev. down

elev. up

left aileron

right aileron

full throttle

idle

left rudder

right rudder

full throttle

idle

left aileron

right aileron

elev. down

elev. up

left rudder

right rudder

MODE 1 (Throttle at rigth stick)

MODE 3 (Throttle at right stick) MODE 4 (Throttle at left stick)

There are four fundamental options for assigning the 

four control functions (aileron, elevator, rudder and 

throttle/brake flap) for a winged aircraft model to the 

two sticks. Just which of these options is chosen depends on the individual preferences of the individual 

model pilot. 

Use the  selection keys of the left or right fourway button to select the “Stick mode” line. The option 

field will be framed.

Mod.name

Stick mode

module

1

n/a

Base setup model

n/a

SEL

DSC Output PPM10

HoTT

GRAUBELE

Tap on the SET key. The currently displayed stick 

mode will be displayed in inverse video. Now use the 

selection keys of the right four-way button to select 

from among options 1 through 4.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the display to 

stick mode “1”.

Another tap on the SET key will again deactivate 

option selection so a change to another line can be 

affected.

Module

The mc-16 HoTT and mc-20 HoTT are fitted as 

standard with a HoTT RF module. However, it is also 

possible to switch to a non-Graupner|SJ external RF 

module by software, if such a module is connected 

to the transmitter. This is accomplished by using the 

Select buttons of the left or right-hand four-way button 

to move to the left, to the “Module select” value field:

1

bind n/a

BD1

GRAUBELE

BD2

Rcv Ch Map R12 n/a

HoTT

Mod.name

Stick mode

module

Base setup model

HoTT

Graupner/SJ HoTT receivers must be “instructed” to 

communicate exclusively with a certain model (memory) in a Graupner/SJ HoTT transmitter. This procedure is known as “binding” and must only be done 

once for every new receiver/model-memory-location 

mc

 

16 20
Program description - Base setup models | Winged models 87

because the transmitter only receives and evaluates 

data from the return channel of the receiver activated 

on this line. The second, and all other receivers, operate in parallel but are fully independent in slave mode.

“Binding” transmitter and receiver

Use the  selection keys of the left or right fourway button to move into the “Module” line: 

The marker frame will be positioned by default to 

the column for the next free binding channel. In the 

example shown in the figure below, the marker frame 

is positioned above the column label “BD2” because 

the binding channel in the column labeled “BD1” is 

already in use by default for the receiver which was 

delivered with the set:

1

bind n/a

BD1

GRAUBELE

BD2

Rcv Ch Map R12 n/a

HoTT

Mod.name

Stick mode

module

Base setup model

If already off, now switch the receiver on:

Receiver GR-16 and GR-24

The red LED on the receiver will blink..

Hold the SET button on the receiver pressed in for 

about three seconds while the LED flashes red; it will 

then flash red / green for a further three seconds. The 

SET button on the receiver can now be released. As 

long as this LED blinks red/green, the receiver is in 

bind mode.

Now, within this 3 second period, start the so-called 

“receiver binding” process for the receiver to the currently active model memory with a brief tap on the 

center SET key of the right four-way button. At this 

time, the screen’s display will blend in a message 

window for the duration of the “binding” process.

combination (and can be repeated anytime).

Important notices:

• During the binding procedure be sure the 

transmitter’s antenna is always far enough 

away from the receiver’s antenna. To be on the 

safe side, keep them at least one meter apart. 

Otherwise there is a risk of a faulty connection 

to the return channel and malfunctions will result.

• When binding additional receivers, note that 

any other–switched on–receivers already 

bound to the transmitter will fall into Fail safe 

mode during the transmitter-side “binding” period.

“Binding” multiple receivers per model

Multiple receivers per model can be bound if desired, 

whereby respective mc-16 HoTT and mc-20

HoTT programs offer the potential for managing up to 

two receivers directly and for dividing up the transmitter’s 8 or 12 control channels (max) in any arrangement among these receivers under menu control. 

Refer to additional details further down in this section. First bind the receivers individually as described 

below. 

When the system is actually in use, the only receiver which creates a telemetry link to the transmitter is either the last receiver to be bound, or 

the receiver which you selected in the “TEL.RCV.” 

line of the »Telemetry« menu, for example: 

TELEMETRY

SETTING & DATA VIEW

SENSOR SELECT

RF STATUS VIEW

VOICE TRIGGER

TEL.RCV. RCV CH1

Any telemetry sensors which may be built into the 

model should therefore be connected to this receiver 

1

d n/a

BD1

GRAUBELE

BD2

Rcv Ch Map R12 n/a

Mod.name

Stick mode

modu

Base setup model

Finding...

If the receiver’s LED, again blinking red, changes 

within about 10 seconds to continuous illumination 

in green, the binding process has been successfully 

completed. Your model-memory to receiver combination is now operationally ready. At this time the screen 

will now display “ bind “ (bound) instead of “n/a” (not 

attached), for example:

1

bind bind

BD1

GRAUBELE

BD2

Rcv Ch Map R12 R08

HoTT

Mod.name

Stick mode

module

Base setup model

On the other hand, should the LED on the receiver 

blink red for longer than about 10 seconds, the binding process has failed. In this case the screen will 

continue to show the status as “n/a”. If this should 

happen, try changing the position of antennas then 

repeat the entire procedure.

Binding other receivers

The binding channel you have chosen is already 

bound (as indicated by the “bind” status). This binding 

is to be replaced by another. After initiating the RF 

bind process, instead of displaying “BINDING”, the 

message shown below appears:
88 Program description - Base setup models | Winged models

1

bind

BD1

BELE

BD2

Rcv R08

Mod.

Stick 

modu

Base setup model

RF

must be

OFF

OK

Press the central SET button of the right-hand fourway button to erase the message. 

Drop down two lines in the screen and switch off the 

RF module as described on the page in section “RF 

module”. Afterward, return again to the “Module” line 

and restart the binding process as described above.

Alternatively, the transmitter can be switched off 

briefly then, after switching it back on again, respond 

to the message window that appears ...

Please select

RF on/off?

O N OFF

... with “OFF” ...

Please select

RF on/off?

O N OFF

... then confirm the selection with a brief tap on the 

center SET key of the right four-way button. From the 

base screen jump again into the “Module” line of the 

»Basic settings, model« menu and restart the binding process.

Dissolving a bond

Proceed as described above to initiate the binding 

process but WITHOUT first putting a receiver in binding readiness.

EXT. (PPM signal at DSC socket)

If your transmitter is fitted with a non-Graupner|SJ

external RF module connected to the DSC / Data 

socket, you can switch between the standard internal 

HoTT RF module and the external module when you 

switch model memories in the “Module” line by choosing either “HoTT”, “EXT.”, or “SP.”, as described in the 

following section.

You can now use the arrow button  of the right-hand 

four-way button to move to the first Value field in the 

“Module” line before pressing the central SET button 

of the right-hand four-way button:

1

bind bind

BD1

GRAUBELE

BD2

Rcv Ch Map R12 R08

Mod.name

Stick mode

module

Base setup model

HoTT

In the active Value field you should now use the Select buttons to choose “EXT.” or–if appropriate–the 

“SP.” mode (described below) instead of “HoTT”.

When you select “EXT.”, the HoTT-specific value fields 

are replaced by the modulation type already selected 

in the “DSC output” line; see page 92:

1

PPM10

GRAUBELE

EXT.PPM sig. normal

Mod.name

Stick mode

module

Base setup model

EXT.

The lines of the “Receiver output” and “Range test” 

options (described below) are also suppressed, as 

are all the HoTT-specific displays in the base display; 

“PPM” is also superimposed instead of “HoTT”:

GRAUBELE

#01

0:12h

Stp

Flt

 

0:00

0:00

4.0V PPM

Press the central SET button of the right-hand fourway button to conclude the Select process.

SP. (digital signal at Data socket)

However, if you require a special digital signal instead 

of the analogue PPM signal for the non-Graupner|SJ

external RF module, then connect this to the DATA 

socket and select “SP.” in the “Module” line:

1

BD

GRAUBELE

SP channel 6

SP. 1 BIND

Mod

Mod.name

Stick mode

module

Base setup model

Once again, press the central SET button of the righthand four-way button to conclude the Select process.

The lines of the “Receiver output” and “Range test” 

options (described below) are also suppressed, as 

are all the HoTT-specific displays in the base display; 

“SP.” is also superimposed instead of “HoTT”:

GRAUBELE

#01

0:12h

Stp

Flt

 

0:00

0:00

4.0V SP
Program description - Base setup models | Winged models 89

“Mode” column

1

BD

GRAUBELE

SP channel 6

SP. BIND

Mod

Mod.name

Stick mode

module

Base setup model

1

In this column you select the transmission mode of 

the external RF module:

• Mode “1”: 2-channel hopping

• Mode “2”: x-channel hopping

“BIND” column

1

BD

GRAUBELE

SP channel 6

SP.

Mod

Mod.name

Stick mode

module

Base setup model

1 BIND

The “BIND” column in the right-hand column can 

be used to initiate the “Bind” process of the nonGraupner|SJ system–the transmitter’s RF section 

must be switched off when the transmitter is first 

switched on.

Important notes:

• The output voltage of the DATA socket is 

around 5V, and must be reduced to the power supply voltage generally required by external digital RF modules (3 to max. 3.3V). This is 

accomplished using the circuit which is shown 

here in diagrammatic form:

GND

Vcc IN = 5 V

DATA +

DATA S 125000 baud signal

Vcc

GND

DATA -

22μF/6.3 V 22μF/6.3 V

Vcc OUT = 3 ... 3.3 V

Low Drop

Voltage

Regulator SP.-MODULE

with

digital input signal

• Servo travels must be limited to max. 128%.

SP channels

Note:

This menu line is suppressed in the “Module” line if 

you select “HoTT” or “EXT.”.

If necessary, use the Select buttons  of the left or 

right-hand four-way button to move to the “SP channels” line, then briefly press the central SET button of 

the right-hand four-way button to activate the Value 

window:

1

SEL

GRAUBELE

SP channel

SP.

Mod.name

Stick mode

module

Base setup model

1 BIND

6

You can now select “6” or “8” channels using the righthand Select buttons. The procedure is concluded by 

again pressing the central SET button of the righthand four-way button.

At the transmitter this selection only affects the number of control channels transferred to the external RF 

module via the DATA socket. If you choose “6”, then 

these are control channels 1 ... 6; if you choose “8”, 

these are channels 1 ... 8.

Simultaneously pressing the  or  buttons of 

the right-hand four-way button (CLEAR) returns the 

display to “6”.

EXT. PPM signal

Note:

This menu line is suppressed in the “Module” line if 

you select “HoTT”.

1

PPM10

GRAUBELE

EXT.PPM sig.

Mod.name

Stick mode

module

Base setup model

EXT.

normal

SEL

Some RF modules which can be connected to the 

DSC connector require an inverted input signal. Be 

sure to follow the respective module’s installation 

instructions for this.

The choice of “inverted” instead of the default preset 

“normal” allows for appropriate adaptation of the provided PPM signal.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the display to 

“normal”.

Receiver channel mapping

Note:

This menu line is suppressed in the “Module” line if 

you select “EXT.” or “SP.”.

As long as there is at least one “bound” HoTT receiver in the “Module” line, the next line down will be the 

“Rcv Ch map” line:

1

bind bind

SET

GRAUBELE

SET

Rcv Ch Map R12 R08

HoTT

Mod.name

Stick mode

module

Base setup model

As already mentioned in the introduction to the section entitled “Binding receivers”, mc-16 HoTT and 
90 Program description - Base setup models | Winged models

mc-20 HoTT transmitters feature a menu point in 

which the transmitter’s control channels can be redistributed in any way you like within one receiver, 

and also include an option to distribute the transmitter’s control channels to a maximum of two receivers

in any arrangement you desire. These are the eight 

standard / twelve optional control channels of the 

mc-16 HoTT transmitter, and the standard twelve 

control channels of the mc-20 HoTT. This redistribution is termed “mapping” or “channel mapping” 

(channel assignment) in the following section.

Select the receiver to be “mapped” with the selection 

keys of the left or right four-way button then tap briefly 

on the center SET key of the right four-way button.

Channel mapping within a receiver

This menu point provides a simple means of remapping the transmitter’s control channels in any 

way you like, in a similar manner to the channel assignment function termed “Channel mapping” in the 

»Telemetry« menu, as described on page 244. This 

means that you can re-distribute the transmitter’s 

control channels, which are present at the receiver 

inputs, to the selected receiver’s outputs / servo sockets in any way you like:

Receiver CH – BIND1

In Ch

In Ch

In Ch

In Ch

1

2

3

4

1

2

3

4

Out Ch

Out Ch

Out Ch

Out Ch

After selection of the desired output with the selection 

keys of the left or right four-way button, the appropriate value field will be framed. Briefly tap on the center 

SET key of the right four-way button. The current 

setting will be displayed in inverse video. Now use the 

selection keys of the right four-way button to select 

the desired input channel’s respective transmitter 

output, see page 230.

BUT CAUTION: If, for example, “2AIL” has been 

specified in the “Aileron/camber flaps” line of the 

»Model type« menu then the transmitter will have 

allocated control function 2 (ailerons) to control channels 2 & 5 for the left and right ailerons. The corresponding receiver inputs to be assigned in this case 

would be channels 2 & 5, refer to the example below.

Examples:

• You would like to control each aileron of a large 

model with two or more servos. 

Assign each of the appropriate outputs (servo connections) to one and the same input (control channel). In this case, depending on left or right wing, 

as the respective input to one of the two default aileron control channels (2 or 5).

• You would like to control the rudder of a large 

model with two or more servos. 

Assign each of the appropriate outputs (servo 

connections) to one and the same input (control 

channel). In this case, the default rudder channel 

(4), see figure right.

Notes:

• The maximum number of lines (outputs) available 

corresponds to the maximum number of servos 

which can be connected to the receiver in question.

• If you see the warning ...

CAN‘T

RECEIVE

DATA

O K

... then there is no bound receiver within range. If 

the case may be, switch your receiving system on.

• With the »Tx. output swap« option, which is available as standard on the mc-20 transmitter, and 

can be unlocked on the mc-16 HoTT transmitter 

at extra cost, see page 230, the transmitter’s control functions can be interchanged in any way; it is 

also possible to assign multiple outputs to one and 

the same control function. In the interests of clarity 

however we strongly advise that you use only one 

of these two options.

Channel assignment on second receiver

As already mentioned, the “Receiver channel mapping” menu point can be used to map (re-distribute) 

the transmitter’s control channels in any way amongst 

a maximum of two receivers; these are the eight 

standard / twelve optional control channels of the 

mc-16 HoTT transmitter, and the standard twelve 

channels of the mc-20 HoTT transmitter. In this 

case the numbering of the outputs (servo sockets) 

and the maximum number of lines (outputs) available 

reflects the maximum number of servos which can be 

connected to the receiver in question. 

Receiver CH – BIND2

In Ch 1

In Ch 2

In Ch 3

In Ch 4

8

8

8

8

Out Ch

Out Ch

Out Ch

Out Ch

Receiver CH – BIND2

In Ch

In Ch

In Ch

In Ch

12

12

12

12

1

2

3

4

Out Ch

Out Ch

Out Ch

Out Ch

Note:

The upper screen-shot above shows the screen of 

the standard mc-16 HoTT eight-channel transmitter; the lower one the screen of the mc-20 HoTT 

twelve-channel transmitter. 

After selection of the desired output with the selection 

keys of the left or right four-way button, the respective input field will be framed. Tap the center SET key 
Program description - Base setup models | Winged models 91

of the right four-way button. The current setting will 

be displayed in inverse video. Now select the desired 

input channel with the selection keys of the right fourway button. For example, suitable to the above rudder 

example:

Receiver CH – BIND2

In Ch

In Ch

In Ch

In Ch

4

4

4

1

2

3

4

Out Ch

Out Ch

Out Ch

4 Out Ch

Note:

The maximum number of lines (outputs) available 

reflects the maximum number of servos which can be 

connected to the receiver in question. 

RF transmit

This menu line provides an option for manually 

switching the transmitter’s RF transmission on and off 

to specific models while the transmitter is in operation. For example, to save power while a model is being programmed. If this line option was set to OFF, 

it will be canceled (i.e. set to ON) the next time 

the transmitter is switched on.

If necessary, use the  selection keys of the left or 

right four-way button to move into the “RF transmit“ 

line then activate the option with a brief tap on the 

center SET button of the right four-way button:

1

bind bind

SEL

Rcv Ch Map R12 R08

HoTT

Stick mode

module

Base setup model

RF transmit ON

The right selection keys can now be used to choose 

between OFF and ON. Another tap on the center 

SET key of the right four-way button will conclude the 

entry.

Range test

Note:

This menu line is suppressed if you select “EXT.” or 

“SP.” in the “Module” line. 

The built-in range test reduces transmission power 

to an extent that a functional test can be carried out 

even within a distance of less than 100m.

Perform a range test on the Graupner/SJ HoTT system according to the following instructions. If necessary, have someone assist you in carrying out the 

range test.

1. Preferably, the receiver already bound to the transmitter should be installed into the model in its intended position.

2. Switch remote control on and wait for the green 

LED to light up on the receiver/s. Now servo movements can be observed.

3. Place the model on a level surface (pavement, 

low-cut grass or bare ground) such that receiver antennas are at least 15cm above ground level. It may be necessary to put something under the 

model to raise it up enough for this.

4. Hold the transmitter at hip level and at some distance from one’s body.

5. If necessary, use the  selection keys of the 

left or right four-way button to reach the “RF range 

test” line in the menu then start range test mode 

with a tap on the center SET key of the right fourway button:

bind bind

SEL

Rcv Ch Map R12 R08

module HoTT

Base setup model

RF transmit ON

RF Range Test 99sec

When the range test has been initiated, the transmitter’s transmission power will be significantly reduced and the green LED just to the right of the 

main switch on the transmitter, marked RF, will 

begin to blink; this will also be accompanied by 

acoustic tones. At the same time, the timer in the 

transmitter’s display will start counting down and 

every 5 seconds a two-frequency tone will sound. 

GRAUBELE

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5.5V

3.9V

M

HoTT

TEST 76s

Five seconds prior to the end of the range test a 

three-frequency tone will sound once every second. After expiration of the range test’s 99th second the transmitter will again be switched to full 

output power and the LED just to the right of the 

main switch on the transmitter will again illuminate 

constantly.

6. Move away from the model while manipulating 

the sticks during this timespan. If you notice an interruption anytime while still within a distance of 

about 50m, try to reproduce this malfunction.

7. If there is a motor in the model, it may be necessary to switch it on to further check noise immunity.

8. Continue moving away from the model until perfect 

control is no longer possible. 

9. Wait at this distance for the remainder of the test 

period with the still-operationally-ready model 

to expire. After the range test is ended it should 

again respond correctly to all RC controls. If this is 

not 100% the case, do not use the system. Contact your area’s Graupner GmbH & Co. KG service 

partner.

10.Perform the range test before each flight and, in 
92 Program description - Base setup models | Winged models

doing so, simulate all servo movements which also 

take place during flight. The range must always be 

at 50m on the ground in order to assure safe model operation.

Caution:

Never start the range test on the transmitter during normal operation of the model.

DSC output

If necessary, use the  selection keys of the left or 

right four-way button to switch to the “DSC Output” 

line then, with a brief tap on the center SET key of the 

right four-way button, activate the value window:

SEL

Rcv Ch Map R12 R08

Base setup model

RF transmit ON

RF Range Test 99sec

DSC Output PPM10

Now you can use the right selection keys to choose 

between four types of modulation “PPM10”, “PPM16”, 

“PPM18” and “PPM24”. Touch the center SET key of 

the right four-way button again to complete the entry.

This choice primarily influences the maximum number of control channels which can be attached to the 

DSC (direct servo control) socket, and thus also available to a flight simulator or teacher/pupil system. By 

selecting “PPM10” this will be control channels 1 ... 5, 

for “PPM16” channels 1 ... 8, for “PPM18” channels 1 

... 9 and for “PPM24” channels 1 ... 12.

Cut off

Note:

This menu line is suppressed if “None” or “None/inv” 

is selected for the “Motor on C1” line.

Depending on the “idle forward or back” choice made 

in the “Motor on C1” line of the »Model type« menu, 

this motor “cut off” option can be coupled to a switch 

for throttling down a speed controller or to move a 

servo on the carburetor of a motor to the OFF position. This option can be used on the mc-16 HoTT 

and mc-20 HoTT transmitters as an emergency 

OFF function as well as an alternative “cut-off trim”, 

see “digital trims” on page 70. 

This motor OFF position (Thr. CutOff) is specified in 

the left column field over the column label SEL and its 

value is to be established through trial and error.

However, the speed controller or throttle servo only 

moves to the selected position when two conditions 

are fulfilled: a switch is operated, and a particular 

servo position or switching threshold is exceeded. 

This is done by setting the desired servo position 

(threshold value) into the middle column field, directly 

over the column label STO, then selecting the appropriate ON/OFF switch function in the right column.

• If the percentage value specified for the middle 

column is greater than the current servo position, i.e. the current servo position lies below the 

threshold, the switchover will occur as soon as the 

switch is put into its ON position.

• If the percentage value specified for the middle 

column is less than the current servo position, i.e. 

the current servo position is above the threshold, 

the speed controller will initially reduce motor 

speed or close the carburetor’s throttle servo only 

to the extent dictated by the value in the left column as soon as the servo’s position once underruns the threshold (max. +150%) after the switch 

is changed over to its ON position.

The speed controller or throttle servo will remain in 

this cut-off position only until the selected switch is 

again changed over followed by a one-time throttle 

servo or speed controller movement beyond the 

preset threshold with the throttle/brake stick control.

The factory setting for the left column is -100% for 

the throttle servo “cut-off” position and a threshold of 

+150% servo position setting in the middle column.

Base setup model

RF transmit ON

RF Range Test 99sec

DSC Output PPM10

cut off

SEL

+150% –––

STO

–100%

Programming procedure

To change the throttle servo’s preset “cut-off” position, tap on the center SET key of the right four-way 

button. The current setting will be displayed in inverse 

video. Now use the selection keys of the left or right 

four-way button to set a value at which the motor is 

reliably “off”. If a combustion motor is involved, be 

sure the throttle servo does not perform mechanical 

runout, e.g. -125%:

Base setup model

RF transmit ON

RF Range Test 99sec

DSC Output PPM10

cut off

SEL

+150% –––

STO

–125%

The–upper–preset value in the middle column 

ensures the motor can be stopped, throughout the 

maximum possible positioning range of the servo or 

speed controller, alone by the switch to be assigned 

in the right column. 

However, if you wish to set a lower threshold, by 

which an underrun will cause the throttle servo or 

speed controller with closed switch to switch into the 

cut-off position, reduce the preset servo travel from 

+150% by placing the throttle servo or speed controller into the desired position with the throttle/brake 

stick then touch the center SET key of the right fourway button.
Program description - Base setup models | Winged models 93

Base setup model

RF transmit ON

RF Range Test 99sec

DSC Output PPM10

cut off

SEL

+100% –––

STO

–125%

Finally, use the column at the right to specify a switch 

with which you can cut off the motor directly (emergency) or which will be activated by the threshold. 

Base setup model

RF transmit ON

RF Range Test 99sec

DSC Output PPM10

cut off

SEL

+100%

STO

–125% 8

Notes:

• Be sure the throttle servo does not run out mechanically when the cut-off function is activated.

• A threshold over +100% is reached by temporarily 

increasing the travel for servo 1 in the »Servo adjustment« menu to over 100% then, after storing 

the threshold, change servo travel back to the 

original value.

Auto timer reset

Base setup model

RF Range Test 99sec

DSC Output PPM10

cut off

SEL

–125% +100% 8

Auto timer reset yes

The “yes/no” setting made in this line determines 

whether or not all of the transmitter’s timers (except 

for “Model time” and “Transmitter operating time”) are 

automatically reset to their given starting values when 

the transmitter is switched on. In contrast, the “slot 

time”–see page 163–is always reset to the starting 

value when the transmitter is switched on.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the display to 

“yes”. 
94 Program description - Base setup models | Helicopter models

This option is available as standard on 

both transmitter types.

Before programming specific parameters, 

there are some basic settings to be made 

which effect the currently active model memory. 

Use the  selection keys on the left or right fourway button to select the »Base setup model« option 

in the multi-function menu:

Helicopter type

Suppress models

Base setup model

Servo adjustment

Control adjust

Stick mode

Open this menu option with a tap on the center SET

key of the four-way button pad:

Model name

Mod.name

Stick mode

module

1

n/a

Base setup model

n/a

DSC Output PPM10

HoTT

Change to the next screen page with a brief tap on 

the SET key of the right four-way button. This will 

open a screen of characters for entry of the model’s 

name. A maximum of 9 characters can be used to 

specify a model name.

!"#$%&’()�+,–./0123

456789:;

Mod Name STARL

FGHIJKL MNOPQRSTUVWX

YZ[¥]^_`abcdefghijk

?@ ABCDE

Now the desired characters can be selected with the 

selection keys of the left four-way button. Move to the 

next position to select the next character with a tap on 

the center SET key of the right four-way button. 

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will place a space 

character at the current position.

Positioning to any character position within the entry 

field can be done with the  keys of the right fourway button.

A return to the previous menu screen is accomplished 

with a tap on the center ESC key of the left four-way 

button.

A model name entered in this manner will appear in 

the base screen of the »Model select« menu and in 

the sub-menus of the »Copy / Erase« menu item.

Stick mode

MODE 2 (Throttle at left stick)

pitch axis

pitch axis

tail rotor

tail rotor

throttle/pitch

throttle/pitch

roll

roll

throttle/pitch

throttle/pitch

tail rotor

tail rotor

pitch axis

pitch axis

roll

roll

pitch axis

pitch axis

roll

roll

throttle/pitch

throttle/pitch

tail rotor

tail rotor

throttle/pitch

throttle/pitch

roll

roll

pitch axis

pitch axis

tail rotor

tail rotor

MODE 1 (Throttle at right stick)

MODE 3 (Throttle at right stick) MODE 4 (Throttle at left stick)

Basically there are four different ways to assign the 

four helicopter control functions, roll, nick, tail rotor 

and throttle/pitch to the two sticks. Just which of these 

is used depends on the preferences of the individual 

model pilot.

Use the  selection keys of the left or right fourway button to select the “Stick mode” line. The option 

field will be framed.

Mod.name

Stick mode

module

1

n/a

Base setup model

n/a

SEL

DSC Output PPM10

HoTT

STARLET

Tap on the SET key. The currently displayed stick 

mode will be displayed in inverse video. Now use the 

selection keys of the right four-way button to select 

from among options 1 through 4.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the display to 

stick mode “1”.

Another tap on the SET key will again deactivate 

option selection so a change to another line can be 

affected.

Module

The mc-16 HoTT and mc-20 HoTT are fitted as 

standard with a HoTT RF module. However, it is also 

possible to switch to a non-Graupner|SJ external RF 

module by software, if such a module is connected 

to the transmitter. This is accomplished by using the 

Select buttons of the left or right-hand four-way button 

to move to the left, to the “Module select” value field:

1

bind n/a

BD1

STARLET

BD2

Rcv Ch Map R12 n/a

HoTT

Mod.name

Stick mode

module

Base setup model

HoTT

Graupner/SJ HoTT receivers must be “instructed” to 

communicate exclusively with a certain model (memory) in a Graupner/SJ HoTT transmitter. This procedure is known as “binding” and must only be done 

once for every new receiver/model-memory-location 

Base setup model

Model-specific base settings for helicopter models

mc

 

16 20
Program description - Base setup models | Helicopter models 95

combination (and can be repeated anytime).

Important notices:

• During the binding procedure be sure the 

transmitter’s antenna is always far enough 

away from the receiver’s antenna. To be on the 

safe side, keep them at least one meter apart. 

Otherwise there is a risk of a faulty connection 

to the return channel and malfunctions will result.

• When binding additional receivers, note that 

any other–switched on–receivers already 

bound to the transmitter will fall into Fail safe 

mode during the transmitter-side “binding” period.

“Binding” multiple receivers per model

Multiple receivers per model can be bound if desired, 

whereby respective mc-16 HoTT and mc-20

HoTT programs offer the potential for managing up to 

two receivers directly and for dividing up the transmitter’s 8 or 12 control channels (max) in any arrangement among these receivers under menu control. 

Refer to additional details further down in this section. First bind the receivers individually as described 

below. 

When the system is actually in use, the only receiver which creates a telemetry link to the transmitter is either the last receiver to be bound, or 

the receiver which you selected in the “TEL.RCV.” 

line of the »Telemetry« menu, for example: 

TELEMETRY

SETTING & DATA VIEW

SENSOR SELECT

RF STATUS VIEW

VOICE TRIGGER

TEL.RCV. RCV CH1

Any telemetry sensors which may be built into the 

model should therefore be connected to this receiver 

because the transmitter only receives and evaluates 

data from the return channel of the receiver activated 

on this line. The second, and all other receivers, operate in parallel but are fully independent in slave mode.

“Binding” transmitter and receiver

Use the  selection keys of the left or right fourway button to move into the “Module” line: 

The marker frame will be positioned by default to 

the column for the next free binding channel. In the 

example shown in the figure below, the marker frame 

is positioned above the column label “BD2” because 

the binding channel in the column labeled “BD1” is 

already in use by default for the receiver which was 

delivered with the set:

1

bind n/a

BD1

STARLET

BD2

Rcv Ch Map R12 n/a

HoTT

Mod.name

Stick mode

module

Base setup model

If already off, now switch the receiver on:

Receiver GR-16 and GR-24

The red LED on the receiver will blink..

Press and hold the SET button on the receiver while 

the LED continues to blink red for about 3 seconds, 

then begins to blink red/green for about another 3 

seconds. The SET button on the receiver can now be 

released. As long as this LED blinks red/green, the 

receiver is in bind mode.

Now, within this 3 second period, start the so-called 

“receiver binding” process for the receiver to the currently active model memory with a brief tap on the 

center SET key of the right four-way button. At this 

time, the screen’s display will blend in a message 

window for the duration of the “binding” process.

1

d n/a

BD1

STARLET

BD2

Rcv Ch Map R12 n/a

Mod.name

Stick mode

modu

Base setup model

Finding...

If the receiver’s LED, again blinking red, changes 

within about 10 seconds to continuous illumination 

in green, the binding process has been successfully 

completed. Your model-memory to receiver combination is now operationally ready. At this time the screen 

will now display “ bind “ (bound) instead of “n/a” (not 

attached), for example:

1

bind bind

BD1

STARLET

BD2

Rcv Ch Map R12 R08

HoTT

Mod.name

Stick mode

module

Base setup model

On the other hand, should the LED on the receiver 

blink red for longer than about 10 seconds, the binding process has failed. In this case the screen will 

continue to show the status as “n/a”. If this should 

happen, try changing the position of antennas then 

repeat the entire procedure.

Binding other receivers

The binding channel you have chosen is already 

bound (as indicated by the “bind” status). This binding 

is to be replaced by another. After initiating the RF 

bind process, instead of displaying “BINDING”, the 

message shown below appears:
96 Program description - Base setup models | Helicopter models

1

bind

BD1

ET

BD2

Rcv R08

Mod.

Stick 

modu

Base setup model

RF

must be

OFF

OK

Press the central SET button of the right-hand fourway button to erase the message. 

Drop down two lines in the screen and switch off the 

RF module as described on the page in section “RF 

module”. Afterward, return again to the “Module” line 

and restart the binding process as described above.

Alternatively, the transmitter can be switched off 

briefly then, after switching it back on again, respond 

to the message window that appears ...

Please select

RF on/off?

O N OFF

... with “OFF” ...

Please select

RF on/off?

O N OFF

... then confirm the selection with a brief tap on the 

center SET key of the right four-way button. From the 

base screen jump again into the “Module” line of the 

»Basic settings, model« menu and restart the binding process.

Dissolving a bond

Proceed as described above to initiate the binding 

process but WITHOUT first putting a receiver in binding readiness.

EXT. (PPM signal at DSC socket)

If your transmitter is fitted with a non-Graupner|SJ

external RF module connected to the DSC / Data 

socket, you can switch between the standard internal 

HoTT RF module and the external module when you 

switch model memories in the “Module” line by choosing either “HoTT”, “EXT.”, or “SP.”, as described in the 

following section.

You can now use the arrow button  of the right-hand 

four-way button to move to the first Value field in the 

“Module” line before pressing the central SET button 

of the right-hand four-way button:

1

bind bind

BD1

STARLET

BD2

Rcv Ch Map R12 R08

Mod.name

Stick mode

module

Base setup model

HoTT

In the active Value field you should now use the Select buttons to choose “EXT.” or–if appropriate–the 

“SP.” mode (described below) instead of “HoTT”.

When you select “EXT.”, the HoTT-specific value fields 

are replaced by the modulation type already selected 

in the “DSC output” line; see page 100:

1

PPM10

STARLET

EXT.PPM sig. normal

Mod.name

Stick mode

module

Base setup model

EXT.

The lines of the “Receiver output” and “Range test” 

options (described below) are also suppressed, as 

are all the HoTT-specific displays in the base display; 

“PPM” is also superimposed instead of “HoTT”:

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4.0V PPM

Press the central SET button of the right-hand fourway button to conclude the Select process.

SP. (digital signal at Data socket)

However, if you require a special digital signal instead 

of the analogue PPM signal for the non-Graupner|SJ

external RF module, then connect this to the DATA 

socket and select “SP.” in the “Module” line:

1

BD

STARLET

SP channel 6

SP. 1 BIND

Mod

Mod.name

Stick mode

module

Base setup model

Once again, press the central SET button of the righthand four-way button to conclude the Select process.

The lines of the “Receiver output” and “Range test” 

options (described below) are also suppressed, as 

are all the HoTT-specific displays in the base display; 

“SP.” is also superimposed instead of “HoTT”:

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Program description - Base setup models | Helicopter models 97

“Mode” column

1

BD

STARLET

SP channel 6

SP. BIND

Mod

Mod.name

Stick mode

module

Base setup model

1

In this column you select the transmission mode of 

the external RF module:

• Mode “1”: 2-channel hopping

• Mode “2”: x-channel hopping

“BIND” column

1

BD

STARLET

SP channel 6

SP.

Mod

Mod.name

Stick mode

module

Base setup model

1 BIND

The “BIND” column in the right-hand column can 

be used to initiate the “Bind” process of the nonGraupner|SJ system–the transmitter’s RF section 

must be switched off when the transmitter is first 

switched on.

Important notes:

• The output voltage of the DATA socket is 

around 5V, and must be reduced to the power supply voltage generally required by external digital RF modules (3 to max. 3.3V). This is 

accomplished using the circuit which is shown 

here in diagrammatic form:

GND

Vcc IN = 5 V

DATA +

DATA S 125000 baud signal

Vcc

GND

DATA -

22μF/6.3 V 22μF/6.3 V

Vcc OUT = 3 ... 3.3 V

Low Drop

Voltage

Regulator SP.-MODULE

with

digital input signal

• Servo travels must be limited to max. 128%.

SP channels

Note:

This menu line is suppressed in the “Module” line if 

you select “HoTT” or “EXT.”.

If necessary, use the Select buttons  of the left or 

right-hand four-way button to move to the “SP channels” line, then briefly press the central SET button of 

the right-hand four-way button to activate the Value 

window:

1

SEL

STARLET

SP channel

SP.

Mod.name

Stick mode

module

Base setup model

1 BIND

6

You can now select “6” or “8” channels using the righthand Select buttons. The procedure is concluded by 

again pressing the central SET button of the righthand four-way button.

At the transmitter this selection only affects the number of control channels transferred to the external RF 

module via the DATA socket. If you choose “6”, then 

these are control channels 1 ... 6; if you choose “8”, 

these are channels 1 ... 8.

Simultaneously pressing the  or  buttons of 

the right-hand four-way button (CLEAR) returns the 

display to “6”.

EXT. PPM signal

Note:

This menu line is suppressed in the “Module” line if 

you select “HoTT”.

1

PPM10

STARLET

EXT.PPM sig.

Mod.name

Stick mode

module

Base setup model

EXT.

normal

SEL

Some RF modules which can be connected to the 

DSC connector require an inverted input signal. Be 

sure to follow the respective module’s installation 

instructions for this.

The choice of “inverted” instead of the default preset 

“normal” allows for appropriate adaptation of the provided PPM signal.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the display to 

“normal”.

Receiver channel mapping

Note:

This menu line is suppressed in the “Module” line if 

you select “EXT.” or “SP.”.

As long as there is at least one “bound” HoTT receiver in the “Module” line, the next line down will be the 

“Rcv Ch map” line:

1

bind bind

SET

STARLET

SET

Rcv Ch Map R12 R08

HoTT

Mod.name

Stick mode

module

Base setup model

As already mentioned in the introduction to the section entitled “Binding receivers”, mc-16 HoTT and 
98 Program description - Base setup models | Helicopter models

BUT CAUTION: If you wish to operate two servos 

with one control function, for example such as transmitter control function 2 (roll) which is divided up into 

control channels 1 & 2 for left and right roll servos 

for the “3Sv(2Roll)” option in the »Helicopter type« 

menu; then “map” the corresponding transmitter outputs, in this case for channels 1 & 2 (= inputs to the 

receiver) accordingly.

Notes:

• The maximum number of lines (outputs) available 

corresponds to the maximum number of servos 

which can be connected to the receiver in question.

• If you see the warning ...

CAN‘T

RECEIVE

DATA

O K

... then there is no bound receiver within range. If 

the case may be, switch your receiving system on.

• With the »Tx. output swap« option, which is available as standard on the mc-20 transmitter, and 

can be unlocked on the mc-16 HoTT transmitter 

at extra cost, see page 230, the transmitter’s control functions can be interchanged in any way; it is 

also possible to assign multiple outputs to one and 

the same control function. In the interests of clarity 

however we strongly advise that you use only one 

of these two options.

Channel assignment on second receiver

As already mentioned, the “Receiver channel mapping” menu point can be used to map (re-distribute) 

the transmitter’s control channels in any way amongst 

a maximum of two receivers; these are the eight 

standard / twelve optional control channels of the 

mc-16 HoTT transmitter, and the standard twelve 

channels of the mc-20 HoTT transmitter. In this 

case the numbering of the outputs (servo sockets) 

and the maximum number of lines (outputs) available 

reflects the maximum number of servos which can be 

connected to the receiver in question. 

Receiver CH – BIND2

In Ch 1

In Ch 2

In Ch 3

In Ch 4

8

8

8

8

Out Ch

Out Ch

Out Ch

Out Ch

Receiver CH – BIND2

In Ch

In Ch

In Ch

In Ch

12

12

12

12

1

2

3

4

Out Ch

Out Ch

Out Ch

Out Ch

Note:

The upper screen-shot above shows the screen of 

the standard mc-16 HoTT eight-channel transmitter; the lower one the screen of the mc-20 HoTT 

twelve-channel transmitter. 

After selection of the desired output with the selection 

keys of the left or right four-way button, the respective input field will be framed. Tap the center SET key 

of the right four-way button. The current setting will 

be displayed in inverse video. Now select the desired 

input channel with the selection keys of the right fourway button. For example, appropriate for the above 

example with roll servos:

1

2

3

4

Out Ch

Out Ch

Out Ch

Out Ch

Receiver CH – BIND2

In Ch

In Ch

In Ch

In Ch

1

2

12

12

mc-20 HoTT transmitters feature a menu point in 

which the transmitter’s control channels can be redistributed in any way you like within one receiver, 

and also include an option to distribute the transmitter’s control channels to a maximum of two receivers

in any arrangement you desire. These are the eight 

standard / twelve optional control channels of the 

mc-16 HoTT transmitter, and the standard twelve 

control channels of the mc-20 HoTT. This redistribution is termed “mapping” or “channel mapping” 

(channel assignment) in the following section.

Select the receiver to be “mapped” with the selection 

keys of the left or right four-way button then tap briefly 

on the center SET key of the right four-way button.

Channel mapping within a receiver

This menu point provides a simple means of remapping the transmitter’s control channels in any 

way you like, in a similar manner to the channel assignment function termed “Channel mapping” in the 

»Telemetry« menu, as described on page 244. This 

means that you can re-distribute the transmitter’s 

control channels, which are present at the receiver 

inputs, to the selected receiver’s outputs / servo sockets in any way you like:

Receiver CH – BIND1

In Ch

In Ch

In Ch

In Ch

1

2

3

4

1

2

3

4

Out Ch

Out Ch

Out Ch

Out Ch

After selection of the desired output with the selection 

keys of the left or right four-way button, the appropriate value field will be framed. Briefly tap on the center 

SET key of the right four-way button. The current 

setting will be displayed in inverse video. Now use the 

selection keys of the right four-way button to select 

the desired input channel’s respective transmitter 

output, see page 230.
Program description - Base setup models | Helicopter models 99

Note:

The maximum number of lines (outputs) available 

reflects the maximum number of servos which can be 

connected to the receiver in question. 

RF transmit

This menu line provides an option for manually 

switching the transmitter’s RF transmission on and off 

to specific models while the transmitter is in operation. For example, to save power while a model is being programmed. If this line option was set to OFF, 

it will be canceled (i.e. set to ON) the next time 

the transmitter is switched on.

If necessary, use the  selection keys of the left or 

right four-way button to move into the “RF transmit“ 

line then activate the option with a brief tap on the 

center SET button of the right four-way button:

1

bind bind

SEL

Rcv Ch Map R12 R08

HoTT

Stick mode

module

Base setup model

RF transmit ON

The right selection keys can now be used to choose 

between OFF and ON. Another tap on the center 

SET key of the right four-way button will conclude the 

entry.

Range test 

Note:

This menu line is suppressed if you select “EXT.” or 

“SP.” in the “Module” line. 

The built-in range test reduces transmission power 

to an extent that a functional test can be carried out 

even within a distance of less than 100m.

Perform a range test on the Graupner/SJ HoTT system according to the following instructions. If necessary, have someone assist you in carrying out the 

range test.

1. Preferably, the receiver already bound to the transmitter should be installed into the model in its intended position.

2. Switch remote control on and wait for the green 

LED to light up on the receiver/s. Now servo movements can be observed.

3. Place the model on a level surface (pavement, 

low-cut grass or bare ground) such that receiver antennas are at least 15cm above ground level. It may be necessary to put something under the 

model to raise it up enough for this.

4. Hold the transmitter at hip level and at some distance from one’s body.

5. If necessary, use the  selection keys of the 

left or right four-way button to reach the “RF range 

test” line in the menu then start range test mode 

with a tap on the center SET key of the right fourway button:

bind bind

SEL

Rcv Ch Map R12 R08

module HoTT

Base setup model

RF transmit ON

RF Range Test 99sec

When the range test has been initiated, the transmitter’s transmission power will be significantly reduced and the green LED just to the right of the 

main switch on the transmitter, marked RF, will 

begin to blink; this will also be accompanied by 

acoustic tones. At the same time, the timer in the 

transmitter’s display will start counting down and 

every 5 seconds a two-frequency tone will sound. 

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3.9V

M

HoTT

TEST 76s

Five seconds prior to the end of the range test a 

three-frequency tone will sound once every second. After expiration of the range test’s 99th second the transmitter will again be switched to full 

output power and the green LED just to the right of 

the main switch on the transmitter will again illuminate constantly.

6. Move away from the model while manipulating 

the sticks during this timespan. If you notice an interruption anytime while still within a distance of 

about 50m, try to reproduce this malfunction.

7. If there is a motor in the model, it may be necessary to switch it on to further check noise immunity.

8. Continue moving away from the model until perfect 

control is no longer possible. 

9. Wait at this distance for the remainder of the test 

period with the still-operationally-ready model 

to expire. After the range test is ended it should 

again respond correctly to all RC controls. If this is 

not 100% the case, do not use the system. Contact your area’s Graupner GmbH & Co. KG service 

partner.

10.Perform the range test before each flight and, in 

doing so, simulate all servo movements which also 

take place during flight. The range must always be 

at 50m on the ground in order to assure safe model operation.

Caution:

Never start the range test on the transmitter during normal operation of the model.
100 Program description - Base setup models | Helicopter models

DSC output

If necessary, use the  selection keys of the left or 

right four-way button to switch to the “DSC Output” 

line then, with a brief tap on the center SET key of the 

right four-way button, activate the value window:

SEL

Rcv Ch Map R12 R08

Base setup model

RF transmit ON

RF Range Test 99sec

DSC Output PPM10

Now you can use the right selection keys to choose 

between four types of modulation “PPM10”, “PPM16”, 

“PPM18” and “PPM24”. Touch the center SET key of 

the right four-way button again to complete the entry.

This choice primarily influences the maximum number of control channels which can be attached to the 

DSC (direct servo control) socket, and thus also available to a flight simulator or teacher/pupil system. By 

selecting “PPM10” this will be control channels 1 ... 5, 

for “PPM16” channels 1 ... 8, for “PPM18” channels 1 

... 9 and for “PPM24” channels 1 ... 12.

Autorotation

Autorotation is that state of descending flight in which 

the pitch of main rotor blades are set such that the 

rotor’s speed matches the natural forces of air flowing 

through, like a windmill. The rotational energy stored 

in the mass of the rotor by this process can then be 

converted into upthrust by adjusting blade pitch, in 

order to halt the descent and “rescue” the model. 

Autorotation is a means by which real and model 

helicopters are able to land safely in emergency situations, e.g. in the event of a motor failure. However, 

the prerequisite for this is a well-trained pilot familiar 

with the helicopter’s characteristics. Quick reaction 

and good perceptiveness are necessary because 

the rotor’s inertia can only be used once to generate 

recovery lift.

When this technique is evaluated during competitions, the motor must be switched off for autorotation. 

On the other hand, for training mode it is advantageous to keep the motor at idle for autorotation.

The Autorotation switch causes a switchover to the 

autorotation flight phase in which control of “throttle” 

and “pitch” are separate and all mixers which have 

an effect on the throttle servo are switched off. Corresponding parameter settings are made in the »Helicopter mixer« (see text beginning page 188); refer 

also to the “Principle of the Auto. C1 Pos.” topic which 

follows.

The “Autorotation” name is permanently assigned to 

this phase and it is included in the base screen and 

the screens of all flight phase dependent menus. This 

name can NOT be changed. It is only possible to assign a switch to this option at the right of this display, 

as described on page 68. If a switch is assigned, 

it will have absolute priority over all other flightphase switches:

Base setup model

RF transmit ON

RF Range Test 99sec

DSC Output PPM10

Autorotation –––

More about flight-phase programming can be found 

in the text beginning on page 188 in the»Helicopter 

mixer« section.

Autorotation C1 position

The autorotation flight-phase can alternatively be 

activated by a threshold point for the C1 throttle/pitch 

stick. To do this, use the  selection keys of the 

left or right four-way button to move into the “Autorot. 

C1-Pos.” line. 

As soon as this display line has been selected, its 

value field, located above the column label STO will 

be framed. 

Base setup model

RF Range Test 99sec

DSC Output PPM10

Autorotation –––

Auto.C1 Pos. 0% –––

STO

Move the C1 stick into the desired threshold switchover position then tap the center SET key of the right 

four-way button. The current value will be displayed, 

e.g.:

Base setup model

RF Range Test 99sec

DSC Output PPM10

Autorotation –––

Auto.C1 Pos. –66% –––

STO

After this has been done, use the selection keys to 

move into the column above the switch symbol then 

assign a switch to this field, as described in section 

“Physical control, switch and control switch assignments” on page 68:

Base setup model

RF Range Test 99sec

DSC Output PPM10

Autorotation –––

Auto.C1 Pos. –66% 9

STO

Once this activation switch is closed, the first occurrence of a threshold underrun will cause the program 

to switch over to “Autorotation” and then remain independent of C1 position in this flight phase until the 

activating switch, in this example switch 4, is again 

“OFF”.

“Autorot. C1-Pos.” has precedence over all other 
Program description - Base setup models | Helicopter models 101

flight-phase switches.

Corresponding parameter settings for ...

• pitch servos

• throttle servo

• tail rotor servo

• swashplate rotation, if available

• gyro setting

... are made in the »Helicopter mixer« menu, 

page 188.

Cut off

Within the framework of autorotation settings for the 

mc-16 HoTT and mc-20 HoTT transmitter’s helicopter program, there are parameters for an emergency “cut off” of the throttle servo or motor actuator, 

refer to the programming proposal on page 323. 

However, this option is not available if an idle position 

is specified in the “Throttle position AR” line of the 

»Helicopter mixer« menu instead of an (emergency) 

OFF position; for example, to avoid restarting the motor after every landing during autorotation practice. 

This option can be used on the mc-16 HoTT and 

mc-20 HoTT transmitters as an emergency OFF 

function as well as an alternative “cut-off trim”, see 

“digital trims” on page 70.

Depending on the “forw./rear” choice made for the 

“Pitch min” line of the »Helicopter type« menu, this 

“cut off” option can be coupled to a switch for throttling down a speed controller or a carburetor servo to 

the motor OFF (or idle) position. 

This cut-off (or idle) position is specified in the left 

column’s field, above the SEL column label, and its 

value is to be established through trial and error.

However, the speed controller or throttle servo only 

moves to the selected position when two conditions 

are fulfilled: a switch is operated, and a particular servo position or switching threshold is exceeded. This is 

done by setting the desired servo position (threshold 

value) into the middle column field, directly over the 

column label STO, then selecting the appropriate ON/

OFF switch function in the right column.

• If the percentage value specified for the middle 

column is greater than the current servo position, i.e. the current servo position lies below the 

threshold, the switchover will occur as soon as the 

switch is put into its ON position.

• If the percentage value specified for the middle 

column is less than the current servo position, i.e. 

the current servo position is above the threshold, 

the speed controller will initially reduce motor 

speed or close the carburetor’s throttle servo only 

to the extent dictated by the value in the left column as soon as the servo’s position once underruns the threshold (max. +150%) after the switch 

is changed over to its ON position.

The speed controller or throttle servo will remain in 

this cut-off position only until the selected switch is 

again changed over followed by a one-time throttle 

servo or speed controller movement beyond the 

preset threshold with the throttle/brake stick control.

The factory setting for the left column is -100% for 

the throttle servo “cut-off” position and a threshold of 

+150% servo position setting in the middle column:

Base setup model

DSC Output PPM10

Autorotation –––

Auto.C1 Pos. –66% 9

cut off

SEL

+150% –––

STO

–100%

Programming procedure

To change the throttle servo’s preset “cut-off” position, tap on the center SET key of the right four-way 

button. The current setting will be displayed in inverse 

video. Now use the selection keys of the left or right 

four-way button to set a value at which the motor is 

reliably “off”. If a combustion motor is involved, be 

sure the throttle servo does not perform mechanical 

runout, e.g. -125%:

Base setup model

DSC Output PPM10

Autorotation –––

Auto.C1 Pos. –66% 9

cut off

SEL

+150% –––

STO

–125%

The–upper–preset value in the middle column 

ensures the motor can be stopped, throughout the 

maximum possible positioning range of the servo or 

speed controller, alone by the switch to be assigned 

in the right column. 

However, if you prefer to set a lower switching threshold, i.e. the point below which the throttle servo or 

speed controller moves to the motor OFF position 

when the switch is closed, then use the throttle / collective pitch stick and–if in use–the throttle limiter 

(by default the right-hand side-mounted proportional 

rotary control) to move the throttle servo to your preferred position, and then press the central SET button 

of the right-hand four-way button:

Base setup model

DSC Output PPM10

Autorotation –––

Auto.C1 Pos. –66% 9

cut off

SEL

+100% –––

STO

–125%

Finally, use the column at the right to specify a switch 

with which you can cut off the motor directly (emergency) or which will be activated by the threshold. 
102 Program description - Base setup models | Helicopter models

Base setup model

DSC Output PPM10

Autorotation –––

Auto.C1 Pos. –66% 9

cut off

SEL

+100%

STO

–125% 18

Notes:

• Be sure the throttle servo does not run out mechanically when the cut-off function is activated.

• A threshold over +100% is reached by temporarily 

increasing the travel for servo 1 in the »Servo adjustment« menu to over 100% then, after storing 

the threshold, change servo travel back to the 

original value.

Auto timer reset

Base setup model

Autorotation –––

Auto.C1 Pos. –66% 9

cut off

SEL

–125% +100% 18

Auto timer reset yes

The “yes/no” setting made in this line determines 

whether or not all of the transmitter’s timers (except 

for “Model time” and “Transmitter operating time”) are 

automatically reset to their given starting values when 

the transmitter is switched on. In contrast, the “slot 

time”–see page 163–is always reset to the starting 

value when the transmitter is switched on.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the display to 

“yes”. 
For your notes 103
104 Program description - Model type | Winged models

This option is available as standard on 

both transmitter types.

Use the  selection keys on the left or 

right four-way button to select the »Model 

type« option in the multi-function menu:

Suppress models

Base setup model

Servo adjustment

Control adjust

Model type

Stick mode.

Open this menu option with a tap on the center SET

key of the four-way button pad.

This “Model type” menu is used to establish the type 

of model to be programmed. This also activates all 

characteristic mixers, coupling functions, etc. in preparation for subsequent programming of the specified 

model type.

Motor at C1

When you open the »Model type« menu, the input 

field of the “Motor at C1” line is generally already 

framed (selected). If this is not the case, use the 

Select buttons  of the left or right-hand four-way 

button to move to the “Motor at C1” line:

Tail type

Motor at C1

Normal

None

Aile/flaps 1AIL

Model type

Brake Off +100% In 1

SEL

Briefly tap the center SET key of the right four-way 

button: The current setting will be displayed in inverse 

video. Now use the selection keys of the right fourway button to select from among the following four 

options: 

• „none“

For operation of a model without a propulsion.

The warning “Throttle too high”, see page 33, 

is deactivated and the “Brake settings” sub-menu 

of the »Wing mixers«, beginning page 183, is 

available without any restrictions.

• “back”

The idle position for the throttle/brake flaps stick 

(C1) is to the rear, i.e. toward the pilot.

The warning “Throttle too high”, see page 33, 

as well as the “cut off” option in the »Basic settings, model« menu, see page 92, are activated and the “Brake settings” sub-menu of the 

»Wing mixers« menu, beginning page 183, will 

be available if the entry in the “Motor” column of 

the »Phase settings« menu, page 152, for the 

currently active flight phase is “none”.

• “front”

The idle position for the throttle/brake flaps control 

stick (C1) is at the front, i.e. away from the pilot.

The warning “Throttle too high”, see page 33, 

as well as the “cut off” option in the »Basic settings, model« menu, see page 92, are activated and the “Brake settings” sub-menu of the 

»Wing mixers« menu, beginning page 183, will 

be available if the entry in the “Motor” column of 

the »Phase settings« menu, page 152, for the 

currently active flight phase is “none”.

Notes:

• Be sure to pay attention during the programming procedures that motors do not start up 

unintentionally. Disconnect the fuel supply or 

battery terminals to motors before programming.

• C1 trimming will operate according to the choice 

made between “normal” or only “back” or “front”, 

that is, either over the control’s entire travel path or 

only in the respective idle direction.

Tail type

After selecting the “Tail type” line with the  selection keys of the left or right four-way button, the corresponding entry field will be framed.

+100%

SEL

Tail type

Motor at C1

Normal

None

Aile/flaps 1AIL

Model type

Brake Off In 1

Briefly tap the center SET key of the right four-way 

button: The current setting will be displayed in inverse 

video. Now select the type appropriate for the model 

with the selection keys of the right four-way button.

• „normal“

Elevators and rudder are each operated by a 

single servo.

• “V-tail”

Elevator and rudder control is affected by way of 

two separate, articulated, V-shaped rudders. The 

coupling function for rudder and elevator control 

will be automatically taken over by the program. 

The relationship of rudder-to-elevator proportion is set in the »Dual Rate / Expo« menu, page 

130, and servo travel in the »Servo adjustment« 

menu, page 112.

If you also wish to apply differential to the rudder 

travel, then an alternative method of controlling the 

V-tail should be chosen. This requires the »Dual 

mixer« menu–see page 218–which is available as standard on the mc-20 HoTT transmitter 

only, but can be unlocked on the mc-16 HoTT 

transmitter at extra cost. However, in this case it is 

essential to set the tail type to “normal”.

• “Delta/fl”

If you choose “2 AIL” in the “Aile / flaps” line–see 

below–then your model requires one servo in 

Model type

Establishing winged aircraft model type

mc

 

16 20
Program description - Model type | Winged models 105

each wing panel for aileron and elevator control.

If you choose “2/4 AIL 2/4 FL”, then aileron and 

elevator are controlled in accordance with the settings in the “Multi-flap” menu; see page 181.

• “2ELSv3+8”

This option is intended for models with two elevator servos. The servo connected to output 8 will 

operate in parallel with servo 3 to actuate elevators. Elevator trim affects both servos.

Note on “2ELSv3+8”:

One control, which assigns input 8 by way of the 

»Control adjust« menu, is then disconnected from 

servo “8” by software for reasons of safety i.e. it is 

made ineffective.

Aileron/camber flaps

After selecting the “Aileron/camber flaps” line with the 

 selection keys of the left or right four-way button, 

the corresponding entry field will be framed:

+100%

SEL

Tail type

Motor at C1

Normal

None

Aile/flaps 1AIL

Model type

Brake Off In 1

Briefly tap the center SET key of the right four-way 

button: The current setting will be displayed in inverse 

video. Now use the selection keys of the right fourway button to select the number of wing servos to be 

programmed for the model ...

... on the mc-16 transmitter with the standard eight 

channels:

No. of wing flaps Control channel used

1AIL 2

1AIL 1FL 2 | 6

2AIL 2 & 5

Brake offset

This function not only has potential for gliders and 

electric models but also for models with combustion 

motors and landing flaps.

The mixers described in the “Brake settings” line of 

the »Wing mixers« menu, page 183, can be operated by the C1 stick (“input 1”) or another transmitter 

operating element which has been assigned to input 

7 or 8 in the »Control adjust« menu in the case of 

the standard mc-16 HoTT eight-channel transmitter. 

Inputs 7, 8 or 9 are available for the same purpose on 

the mc-16 HoTT transmitter with the optional twelve 

channels, and the standard twelve-channel mc-20

HoTT transmitter. In this latter case, retain the “GL” 

default setting for the “Type” column in the »Control 

adjust« menu so the selected control can operate 

independent of flight phase.

In the majority of cases the default setting for “input 1” 

will remain as it is and the brake will be operated by 

way of the non-neutralizing C1 stick.

However, use of input 7, 8 or–if avalaible–9 makes it 

possible to operate the brake in an alternative manner, even by way of a supplementary control, if the C1 

stick is to be used for something else.

The neutral point (offset) can be set to any desired 

position. This is done by placing the control for input 

1, 7, 8 or 9 into the position at which the landing flaps 

are to be retracted, i.e. closed, then setting this “Offset” point in the column above the column label STO.

The selection of this offset point in this context determines not only the control position at which the brake 

system is to be retracted, i.e. closed, but also the 

activation direction of the C1 stick for extending the 

brake system.

• Brake offset values with a “+” prefix will cause 

flaps affected by the “Brake settings” option of the 

»Wing mixers« menu to be extended when the 

C1 stick is moved from front to rear, in the direction of the pilot.

2AIL 1FL 2 & 5 | 6

2AIL 2FL 2 & 5 | 6 & 7

... on the mc-20 transmitter with twelve channels, 

and the mc-16 transmitter with the optional twelve 

channels:

No. of wing flaps Control channel used

1AIL 2

1AIL 1FL 2 | 6

2AIL 2 & 5

2AIL 1FL 2 & 5 | 6

2AIL 2FL 2 & 5 | 6 & 7

2AIL 4FL 2 & 5 | 6 & 7 / 9 & 10

4AIL 2FL 2 & 5 / 11 & 12 | 6 & 7

4AIL 4FL 2 & 5 / 11 & 12 | 6 & 7 / 9 & 10

Depending on the option selected here, the given 

mixers needed and their settings will be activated in 

the »Wing mixers« menu, beginning page 183.

Tips:

• Settings for all wing flap pairs (AlL and Al2, FL 

and FL2) can be trimmed on a flight-phase basis 

in both the »Phase trim« menu as well as in the 

Wing mixers« menu, page 183.

• The functionality of all wing flap pairs (AlL and Al2, 

FL and FL2) can also be operated by way of the 

“Throttle/brake-flap stick” if this stick has not been 

assigned to other use, e.g. for certain brake settings, see »Wing mixers« menu, page 183. To 

configure this it is only necessary to assign “Control 1” to input 6 in the »Control adjust« menu, 

page 118. (If it is preferable to operate flaps with 

switches, one of the transmitter’s two or three position switches are good for this purpose.)
106 Program description - Model type | Winged models

• Brake offset values with a “-” prefix will cause 

flaps affected by the “Brake settings” option of the 

»Wing mixers« menu to be extended when the 

C1 stick is moved from rear to front, in the direction away from the pilot.

If the offset point is not set at the far end of control element travel, the remainder of travel to the end point 

will be “free travel”, i.e. this “free travel” will no longer 

influence any mixer available for “Brake settings” in 

the »Wing mixers« menu. This idle path ensures that 

all brake settings remain at “neutral”, even with minor 

deviations from the limit of the brake flap control. At 

the same time, the effective control path is automatically spread to 100%:

+90%

STO SEL

Tail type

Motor at C1

Normal

None

Aile/flaps 1AIL

Model type

Brake Off In 1

Tip:

Preferably, the servo intended for operating any airbrake flaps that may be on the model should be connected to the receiver output operated by the brake 

input channel, e.g. connect airbrake servo onto (free) 

receiver output 8 if input 8 has been chosen for the 

“brake”, etc. A second airbrake servo is most conveniently operated by way of a free mixer.
For your notes 107
108 Program description - Helicopter type

Helicopter type

Establishing helicopter model type

This option is available as standard on 

both transmitter types.

Use the  selection keys on the left or 

right four-way button to select the »Helicopter type« option in the multi-function menu:

Suppress models

Base setup model

Servo adjustment

Control adjust

Helicopter type

Stick mode

Open this menu option with a tap on the center SET

key of the four-way button pad.

This “Model type” menu is used to establish the type 

of model to be programmed. This also activates all 

characteristic mixers, coupling functions, etc. in preparation for subsequent programming of the specified 

model type.

Swashplate type

Control of the swashplate will require an appropriate 

program variant which corresponds to the number of 

servos operating pitch control.

In the meantime this selection is also influenced by 

the type of control exercised on swashplate servos. 

Since Flybar systems generally do not require transmitter-side swashplate mixers, when such a system 

is in use, “1 Servo” is generally to be selected as the 

swashplate type, regardless of the actual number of 

swashplate servos present. In this context, be sure 

the Flybar system complies with the included adjustment instructions as otherwise there is a risk 

the helicopter will not fly.

When you open the »Helicopter type« menu the 

input field of the “Swashplate type” line is generally 

already framed (selected). If not, use the Select buttons  of the left or right-hand four-way button to 

move to the “Swashplate type” line:

Linear. swashpl.

Swashplate

no

1 Servo

Rotor direct right

Heli type

Pitch min. back

SEL

Briefly tap the center SET key of the right four-way 

button. The current setting for number of pitch servos 

will be displayed in inverse video. Now choose the 

variant needed with the selection keys of the right 

four-way button. 

• „1 Servo“

A Flybar system is in use or the swashplate is 

tipped with one servo each for roll and pitch-axis. 

Pitch control will be affected by one separate servo.

(Since helicopter models, which are operated with 

only 1 pitch servo, neither need any of the three 

swashplate servos for pitch, pitch-axis and roll, like 

Flybar systems, NOR the transmitter’s mixer functions for pitch, pitch-axis and roll, the »Swashplate mixer« menu option will be suppressed in 

the Multi-function menu.)

• “2 Servo”

Two roll servos will displace the swashplate axially to affect pitch control; nick control will be decoupled by a mechanical compensation rocker.

• “3Sv(2Roll)”

Symmetric three-point control of the swashplate 

with three, radially offset articulation points, each 

offset by 120°, connected to one pitch-axis servo 

(front or rear) and two roll servos (left and right). 

All three servos push the swashplate axially to affect pitch control.

• “3Sv (140°)”

Asymmetrical three-point control of the swashplate 

is affected at three articulation points connected to 

one nick servo (rear) and two roll servos (front left 

and right). All three servos push the swashplate 

axially to affect pitch control.

• “3Sv (2Nick)”

Symmetric three-point control as described above 

but radially offset by 90°, one lateral roll servo and 

two pitch-axis servos, front and rear.

• “4Sv (90°)”

Four-point swashplate control affected by two roll 

servos and two nick servos.

Simultaneous tap on the  or  keys of the right 

four-way button (CLEAR) will reset the option back to 

“1 Servo”.

Swashplate type: 1 Servo

2

Swashplate type: 2 Servos

2

1

Swashplate type: 3 Servos (2 Roll)

3

1

2

mc

 

16 20
Program description - Helicopter type 109

Swashplate type: 3 Servos (140°)

3

1

2

Swashplate type: 3 Servos (2 Nick)

3

2

1

Swashplate type: 4 Servos (90°) 2 Nick / 2 Roll

2

5

1

3

Note:

Except for the “1 Servo” choice, swashplate mixer 

proportions must also be set in the »Swashplate 

mixer« menu, page 220.

Swashplate linearization

After selecting the “Linear. swashpl.” line with the 

selection keys of the left or right four-way button, the 

entry field will be framed:

3Sv(2rol)

SEL

Linear. swashpl.

Swashplate

no

Rotor direct right

Heli type

Pitch min. back

The “yes” entry will prevent undesired side effects 

such as pitch change due to a roll function or tension 

between swashplate servo rods.

This type of tension can arise when effected servos 

strain for different displacement positions due to travel 

which deviates from one another.

Linearizing will require a bit of familiarization on the 

part of the pilot because, in order to linearize the 

entire rotation travel of the servo arm, servo travel 

is reduced in small control movements–similar to a 

pronounced exponential setting.

Rotor direction

After selecting the “Rotor direction” line with the 

selection keys of the left or right four-way button, the 

entry field will be framed:

3Sv(2rol)

SEL

Linear. swashpl.

Swashplate

no

Rotor direct right

Heli type

Pitch min. back

After a tap on the center SET key, the main rotor’s 

direction of rotation is entered in the “Rotor direction” 

line with the selection keys of the right four-way button:

• “right”

The main rotor turns clockwise when viewed from 

above.

• “left”

The main rotor turns counter-clockwise when 

viewed from above.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will set the option to 

“right”. 

right-hand

 rotation

left-hand 

rotation

This entry is necessary for the correct orientation of 

torque and power compensation mixer settings made 

in the »Helicopter mixer« menu:

Pitch,

Channel 1  Throttle,

Channel 1  Tail rot.,

Tail rotor  Throttle

Roll  Throttle

Roll  Tail rot.

Pitch  Throttle,

Pitch-axis  Throttle

Pitch-axis  Tail rotor

Pitch min

After selecting the »Pitch min.« (pitch minimum) line 

with the  selection keys of the left or right fourway button, the entry field will be framed:

3Sv(2rol)

SEL

Linear. swashpl.

Swashplate

no

Rotor direct right

Heli type

Pitch min. back
110 Program description - Helicopter type

The “Pitch min.” line is used to adapt the actuation 

direction of the throttle/pitch stick to personal control 

preferences. All other helicopter program options 

which involve throttle and pitch functions, e.g. throttle 

curve, idle trimming, tail rotor mixer, etc., are dependent on this setting. 

Tap the center SET key of the right four-way button. 

The operating direction of the throttle/pitch stick will 

be displayed in inverse video. Now choose the variant 

needed with the selection keys of the right four-way 

button.

Pitch

These mean: 

• “front”

minimum pitch setting when the pitch stick (C1) is 

“forward”, i.e. away from the pilot.

• “back”

minimum pitch setting when the pitch stick (C1) is 

“back”, i.e. toward the pilot.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will set this option to 

“back”.

Notes:

• The C1 trim only affects the throttle servo or the 

collective pitch servos, depending on the settings 

in the “Tr” column of the »Stick mode« menu, 

which is available as standard on the mc-20

HoTT transmitter only.

• The so-called “throttle limit” is set by default, see 

text beginning page 127, by way of input “Lim.” in 

the »Control adjust« menu with which the throttle 

servo can be limited, independent of the pitch servo, in the full throttle direction.

• Since a given user’s models will typically be operated with the same pitch-min direction, this specification can be conveniently preselected in the 

“transmitter-specific” »Basic settings« menu, 

page 268. This specification will then be adopted 

automatically when a new model memory is created in the »Helicopter type« menu but, if desired, 

can be adapted on a model-specific basis as described.

Expo throttle limit

After selecting the “Expo thro lim.” line with the 

selection keys of the left or right four-way button, the 

entry field will be framed:

Expo thro lim. 0%

SEL

Linear. swashpl. no

Rotor direct right

Heli type

Pitch min. back

The “Throttle limit” function described in the »Control 

adjust« menu, see page 127, can be assigned an 

exponential characteristic curve.

A pitch progression rate between -100% and +100% 

can be set with the selection keys.

For example, it is practical to have the throttle 

limit–by default, the right-side proportional rotary 

slider–also regulate the idle setting. Further details 

about the throttle limit can be found in the text for the 

»Control adjust« menu beginning page 122.

An example of two exponential 

throttle limit curve characteristics 

for 100% servo travel.

continuous line:

negative exponential values;

dashed line:

positive exponential values



 

 

 

 

  

  



       
For your notes 111
112 Program description - Servo adjustment

normal

reversed

normal

reversed

Column 3 “cent.”

The servo midpoint (center) setting is intended for 

adapting a non-standard servo (a servo whose midpoint position does not correspond to a pulse length 

of 1.5ms, i.e. 1500μs), as well as for minor adjustments, e.g. for the fine tuning of the neutral position 

of model rudders.

Independent of trim levers and any mixer settings, 

the neutral point can be shifted in a range of -125 to 

+125% within a maximum servo travel of ±150%.

Independent of all other trim and mixer settings, this 

setting is always based directly on the respective 

servo. 

Note that extreme offsets of 

the neutral point can lead 

to one-sided restrictions of 

servo travel because overall travel is limited by both 

electronic and mechanical 

aspects to a maximum of 

±150%.

A simultaneous tap on the 

 or  keys of the right 

four-way button (CLEAR) 

will reset the entry field value displayed in inverse 

video back to “0%”.

lumn then, if desired, move the respective control 

out of its midpoint to make an asymmetric setting.

3. Briefly tap the center SET key of the right fourway button. The corresponding input field is shown 

highlighted.

4. Use the selection keys of the right four-way button 

to set the desired value.

5. Briefly tap the center SET key of the right four-way 

button to complete data entry.

6. A simultaneous tap on the  or  keys of 

the right four-way button (CLEAR) will any setting 

made back to its respective default value.

Important:

Servo designation numerals are based on the respective receiver outputs to which they are connected, 

provided that no swapping of transmitter and/or 

receiver outputs has been specified. This means that 

even a change of stick mode will not effect the numbering of servos.

Column 2 “rev”

The direction in which a servo turns is adapted to the 

practical reality of the given model so that the assembly of control rods and joints do not need to accommodate a specific servo rotation direction. Rotation 

direction is symbolized by the “=>” and “<=” character 

combinations. Servo rotation direction must be specified before making settings for the options which 

follow below.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset rotation 

direction back to “=>”. 

This option is available as standard on 

both transmitter types.

Use the  selection keys on the left or 

right four-way button to select the »Servo 

adjustment« option in the multi-function menu:

Suppress models

Base setup model

Control adjust

Model type

Servo adjustment

Stick mode

Suppress models

Base setup model

Control adjust

Helicopter type

Servo adjustment

Stick mode

Open this menu option with a tap on the center SET

key of the four-way button pad:

S1

S2

S3

Rev cent trv +

0%

0%

0%

100% 100%

100% 100%

100% 100%

0%

0%

100% 100%

100% 100%

S4

S5

This menu is used to set the direction, neutralization, 

travel and limit parameters for a given selected servo 

exclusively. Begin setting servo parameters in the left 

column.

Basic procedure:

1. Select the desired servo, 1 ... 8 or 1 ... 12, with 

the  selection keys of the left or right four-way 

button. 

2. If necessary, use the  selection keys of the left 

or right four-way button to reach the desired coServo adjustment

Servo direction, midpoint, travel and limit

Servo travel

-125% Centre adjustment +125%

mc

 

16 20
Program description - Servo adjustment 113

Column 4, “– trv +”

S1

S2

S3

Rev cent trv +

0%

0%

0%

100% 100%

100% 100%

100% 100%

0%

0%

100% 100%

100% 100%

S4

S5

This column is used to set servo travel symmetrically 

or asymmetrically for each side. The setting range is 

0 ... 150% of normal servo travel. The values set are 

based on the settings that have been made for the 

“midpoint” column. 

To create a symmetric travel path, i.e. control-side 

independent travel, the respective control (stick, proportional control or switch) is to be put into a position 

which covers travel to both sides of the marked frame. 

Note:

It may be necessary to first assign a control attached 

to one of the control channels 5 ... 8 or 5 ... 12. If 

necessary, this is to be done in the »Control adjust« 

menu, see page 118 or 122.

To set asymmetric travel, the respective control (stick, 

proportional control or switch) is to be moved to the 

side on which the marked frame only includes the 

value to be changed.

The value setting is activated with a brief tap on the 

center SET key of the right four-way button. The value 

field is shown highlighted. Values can be changed 

with the selection keys of the right four-way button. 

Complete the entry with a tap on the center SET key 

of the right four-way button.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the changed 

parameter displayed in inverse video back to “100%”.

Important:

In contrast to settings made with the »Control 

adjust« menu, all settings made in this menu affect exclusively the respective servo, independent of 

how the control signal for this servo is produced, i.e. 

directly by a stick or by way of any mixer functions.

The adjacent figure shows 

and example of a sidedependent servo setting, 

-50% and +150%. Transmitter control travel Servo travel

Column 5 “– lim +”

The “– lim +” column is reached by moving the marker 

frame, with the  selection keys of the left or right 

four-ay button, to the right beyond the “– travel +” 

column:

S1

S2

S3

Rev cent lim +

0%

0%

0%

150% 150%

150% 150%

150% 150%

0%

0%

150% 150%

150% 150%

S4

S5

To create a symmetric limit, i.e. control-side independent limit, the respective control (stick, proportional control or switch) is to be put into a position 

such that the marker frame covers both sides of the 

travel setting.

To set asymmetric travel, the respective control (stick, 

proportional control or switch) is to be moved to the 

side where it is to be set such that the marker frame 

only includes the value to be changed.

Note:

You may first need to assign a transmitter control to a 

servo connected to one of the control channels 5 ... 

8 or 5 ... 12 in the »Control adjust« menu; see the 

sections starting on pages 118 and 122.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the entry 

field value displayed in inverse video back to “0%”.

Example:

A servo is controlled separately by two controls over 

a mixer and but, for model-specific reasons, must 

only be operated over a servo travel path of 100% 

because, for example, the rudder would mechanically 

collide with the elevator if moved more than 100%.

As long as only one control is used at a time, this is 

no problem. But this does become a problem when 

the signals are summed by the simultaneous use of 

both controls (e.g. aileron and rudder) to total travel 

in excess of 100%. The linkage and servos could be 

strained excessively ...

To prevent this, the travel should certainly be limited 

by way of an individual travel limit. In the case of the 

rudder used in the example, this would be a value 

slightly less than 100%–because it is assumed the 

rudder would collide at 100%.
114 Program description - Stick mode | Winged models

This option is available as standard on the 

mc-20 HoTT transmitter only.

Both sticks are equipped for digital trimming. With each brief push (one “click”) on 

a trim switch-key it will change its neutral position by 

one increment. Holding the trim switch-key longer will 

cause trimming to run in the corresponding direction 

at increasing speed.

The current position is shown on the screen and the 

adjustment is also made “audible” with acoustic tones. 

This makes finding the mid-point during flight easy, 

without looking at the screen. If the mid-point is overrun, a brief motion pause will be inserted.

Current trim values are automatically stored when a 

model memory change is made.

By default the digital trims of the mc-16 HoTT and 

mc-20 HoTT transmitters always apply to each 

flight phase separately within a particular model 

memory–with the exception of the throttle / brake 

stick trim, generally abbreviated to control function 

“C1” (channel 1).

By default this means that the base display of the 

mc-16 HoTT and mc-20 HoTT transmitters looks 

as follows (assuming “stick mode 1”):

GRAUBELE

#01

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT

If the »Stick mode« menu is unlocked, it is possible to convert the digital trims from the default “PH” 

(phase) setting to “GL” (global), although the C1 

trim is always “global”, i.e. it is independent of flight 

phases.

This settings are visualized in the base screen by a 

“shadow” on trim bars:

Stick mode

Setting stick mode 1 through 4

• shadow present = global,

• no shadow = flight phase dependent.

In the following screen-shot of the base display of a 

transmitter with »Stick mode« unlocked (as shown 

in the screen-shot on the right under the title “”Tr” 

column”), the aileron trim is shown as “flight phase 

dependent”; this is the left / right function of the righthand stick, and assumes the default “Mode 1” transmitter configuration:

GRAUBELE

#01

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT

Basic procedure:

Use the selection keys on the left or right four-way 

button to scroll to the »Stick mode« option in the 

multi-function menu:

Servo adjustment

Dual Rate / Expo

Stick mode

Channel 1 curve

Switch display

Control adjust

Open this menu option with a tap on the center SET

key of the four-way button pad:

Ch.1

Aile

Elev

Tr time +

4

4

4

0.0s

0.0s

0.0s

Rudd 4 0.0s

0.0s

0.0s

0.0s

0.0s

GL

PH

PH

PH

St

This menu, which applies to fixed-wing models, provides a means of setting the response of the four 

digital trim levers individually (within the maximum 

trim travel of ±30%), and also of “slowing” control 

functions 1 to 4, and choosing “phase” or “global” for 

the trims.

The desired line can be reached by using the selection keys of the left or right four-way button. Once 

the appropriate function field has been selected and 

then the center SET key of the right four-way button 

is touched briefly, the field will appear in inverse video 

and the desired setting can be made with the selection keys of the right four-way button.

Column “Tr”

Except for “Channel 1”, this column can be used to 

switchover trim effect from “GL(obal)” to “PH(ase)” 

and vice versa, for example:

Tr +

4

4

4

0.0s

0.0s

0.0s

4 0.0s

0.0s

0.0s

0.0s

0.0s

GL

PH

St

PH

GL

Ch.1

Aile

Elev

time

Rudd

• “Global”

The position of the respective trim function is effective “globally” for all flight-phases programmed 

for the given model, page 150.

• “Phase”

The position of the respective trim function is effective on a phase-specific basis and will be automatically stored upon change of flight phase so 

that the setting is again available following a return 

to this flight phase.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the option 

back to “Global”.

mc

 

16 20
Program description - Stick mode | Winged models 115

Column “St”

The four digital trim switch-keys shift the neutral point 

of the respective stick in the given direction by one 

adjustable increment, as set here, for each “click”. 

This is where the increment size (step) can be adjusted for a given direction, whereby maximum trim 

travel, independent of the selected number of trim 

steps, is always about ±30% of control travel.

After selecting the “St” column ((trim) steps) and the 

desired trim control with the  selection keys of the 

left or right four-way button, the corresponding entry 

field will be framed, for example:

Tr +

4

4

4

0.0s

0.0s

0.0s

4 0.0s

0.0s

0.0s

0.0s

0.0s

GL

GL

PH

PH

St

Ch.1

Aile

Elev

time

Rudd

Briefly tap the center SET key of the right four-way 

button. The current setting will be displayed in inverse 

video. Now select the desired value, between 1 and 

10, with the selection keys of the right four-way button, for example:

Tr +

4

4

0.0s

0.0s

0.0s

4 0.0s

0.0s

0.0s

0.0s

0.0s

GL

GL

PH

PH

St

8

Ch.1

Aile

Elev

time

Rudd

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset any change 

made to the active field back to “4”.

Column “- time +”

The rate of control signal change with respect to the 

speed of stick motion can be influenced by the entries 

made in the “– time +” column. Each stick movement 

direction, i.e. stick control channels 1 through 4, can 

be set individually. This means that respective servos 

will then follow rapid control position changes only 

at an accordingly delayed rate. This time delay has a 

direct effect on the control function and therefore also 

any servos controlled by this function.

The time can be programmed symmetrically for both 

sides or separate for each control direction. This 

setting has a programmable range of 0s to 9.9s. In 

the case of side-separate settings, the stick is to be 

moved to the respective side so that the inverse video 

field will switch between sides to the one for which the 

change is to be made–for example, even to ensure 

gentle rev-up of the propulsion motor despite a (too) 

fast motion of the C1 stick.

Tr +

4

4

4

0.0s

0.0s

4 0.0s

0.0s

0.0s

0.0s

0.0s

GL

GL

PH

PH

St

Ch.1 1.1s

Aile

Elev

time

Rudd

On the other hand, for reasons of safety, the motor 

cut-off should always be “immediate”.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset any change 

made to the active field back to “0.0s”.
116 Program description - Stick mode | Helicopter models

This option is available as standard on the 

mc-20 HoTT transmitter only.

Both sticks are equipped for digital trimming. With each brief push (one “click”) on 

a trim switch-key it will change its neutral position by 

one increment. Holding the trim switch-key longer will 

cause trimming to run in the corresponding direction 

at increasing speed.

The current position is shown on the screen and the 

adjustment is also made “audible” with acoustic tones. 

This makes finding the mid-point during flight easy, 

without looking at the screen. If the mid-point is overrun, a brief motion pause will be inserted.

Current trim values are automatically stored when a 

model memory change is made.

By default the digital trims of the mc-16 HoTT and 

mc-20 HoTT transmitters always apply to each 

flight phase separately within a particular model 

memory–with the exception of the throttle / collective 

pitch stick trim, generally abbreviated to control function “C1” (channel 1).

By default this means that the base display of the 

mc-16 HoTT and mc-20 HoTT transmitters looks 

as follows (assuming “stick mode 1”):

STARLET

#02

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT

If the »Stick mode« menu is unlocked, it is possible to convert the digital trims from the default “PH” 

(phase) setting to “GL” (global), although the C1 

trim is always “global”, i.e. it is independent of flight 

phases.

This settings are visualized in the base screen by a 

“shadow” on trim bars:

Stick mode

Setting stick mode 1 through 4

• shadow present = global,

• no shadow = flight phase dependent.

In the following screen-shot of the base display of a 

transmitter with »Stick mode« unlocked (as shown in 

the second screen-shot on the right under the title ”Tr” 

column”), the tail rotor trim is shown as “flight phase 

dependent”; this is the left / right function of the lefthand stick, and assumes the default “Mode 1” transmitter configuration:

STARLET

#02

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT

Basic procedure:

Use the selection keys on the left or right four-way 

button to scroll to the »Stick mode« option in the 

multi-function menu:

Servo adjustment

Dual Rate / Expo

Stick mode

Channel 1 curve

Switch display

Control adjust

Open this menu option with a tap on the center SET

key of the four-way button pad:

Thr.

Roll

Nick

Tr time +

4

4

4

0.0s

0.0s

0.0s

Tail 4 0.0s

0.0s

0.0s

0.0s

0.0s

TL

PH

PH

PH

St

This menu, which applies to model helicopters, provides a means of setting the response of the four 

digital trim levers individually (within the maximum 

trim travel of ±30%), and also of “slowing” control 

functions 1 to 4, and choosing “phase” or “global” for 

the trims.

The desired line can be reached by using the selection keys of the left or right four-way button. Once 

the appropriate function field has been selected and 

then the center SET key of the right four-way button 

is touched briefly, the field will appear in inverse video 

and the desired setting can be made with the selection keys of the right four-way button.

Column “Tr”

Except for “Channel 1”, this column can be used to 

switchover trim effect from “GL(obal)” to “PH(ase)” 

and vice versa, for example:

Roll

Nick

Tr +

4

4

4

0.0s

0.0s

0.0s

4 0.0s

0.0s

0.0s

0.0s

0.0s

GA

PH

PH

St

PH

Thr.

time

Tail

• „TL“ (Throttle Limit)

C1 trimming operates as idle trimming when the 

“throttle limit” function regulates the motor for starting, see »Control adjust« menu, page 127.

• „TA“ (Throttle Autorotation)

C1 trim operates as idle trim exclusively in the 

«Autorot» flight phase.

This makes it possible to assign a principle (fixed) 

preset AR throttle position in the »Helicopter mixer« menu, page 202, e.g. during autorotation 

practice with the trim function “varied”.

• „PT“ (Pitch)

Due to internal coupling, C1 trimming acts equally 

on all pitch servos available without influencing the 

throttle servo.

A simultaneous tap on the  or  keys of the 

mc

 

16 20
Program description - Stick mode | Helicopter models 117

right four-way button (CLEAR) will reset the option 

back to “TL”.

On the other hand, the trim effects of respective digital trim controls for the lines “Roll”, “Pitch ax” and “Tail 

rot.” can be switched over from “Gobal” to “Phase” and 

vice versa, for example:

Roll

Nick

Tr +

4

4

4

0.0s

0.0s

0.0s

4 0.0s

0.0s

0.0s

0.0s

0.0s

PH

PH

St

GA

GL

Thr.

time

Tail

• “Global”

The position of the respective trim function is effective “globally” for all flight-phases programmed 

for the given model, page 150.

• “Phase”

The position of the respective trim function is effective on a phase-specific basis and will be automatically stored upon change of flight phase so 

that the setting is again available following a return 

to this flight phase.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the option 

back to “Global”.

Column “St”

The four digital trim switch-keys shift the neutral point 

of the respective stick in the given direction by one 

adjustable increment, as set here, for each “click”. 

This is where the increment size (step) can be adjusted for a given direction, whereby maximum trim 

travel, independent of the selected number of trim 

steps, is always about ±30% of control travel.

After selecting the “St” column ((trim) steps) and the 

desired trim control with the  selection keys of the 

left or right four-way button, the corresponding entry 

field will be framed, for example:

Roll

Nick

Tr +

4

4

4

0.0s

0.0s

0.0s

4 0.0s

0.0s

0.0s

0.0s

0.0s

GA

PH

PH

GA

St

Thr.

time

Tail

Briefly tap the center SET key of the right four-way 

button. The current setting will be displayed in inverse 

video. Now select the desired value, between 1 and 

10, with the selection keys of the right four-way button, for example:

Roll

Nick

Tr +

4

4

0.0s

0.0s

0.0s

4 0.0s

0.0s

0.0s

0.0s

0.0s

GA

PH

PH

GL

St

8

Thr.

time

Tail

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset any change 

made to the active field back to “4”.

Column “- time +”

The rate of control signal change with respect to the 

speed of stick motion can be influenced by the entries 

made in the “– time +” column. Each stick movement 

direction, i.e. stick control channels 1 through 4, can 

be set individually. This means that respective servos 

will then follow rapid control position changes only 

at an accordingly delayed rate. This time delay has a 

direct effect on the control function and therefore also 

any servos controlled by this function.

The time can be programmed symmetrically for both 

sides or separate for each control direction. This setting has a programmable range of 0s to 9.9s. 

In the case of side-separate settings, the stick is to be 

moved to the respective side so that the inverse video 

field will switch between sides to the one for which 

the change is to be made.

Example:

All three servos are to be actuated for swashplate 

pitch control, e g. a “Pitch” control movement for a 

“3Sv (2Roll)” swashplate. However, travel for the middle servo is greater than that of the other two servos 

on the shorter lever.

A rash “Pitch” control movement would not operate 

the nick servo in the middle as quickly as it would the 

two roll servos on the shorter lever. This would cause 

a momentary control motion in the “nick” direction. 

However, if response time for the “pitch” control function were to be reduced by at least the positioning 

time for the servo in the middle then all three servos 

would reach their proper positions at the same time. 

The necessary delay times typically amount to only a 

few tenths of a second. For example:

Roll

Nick

Tr +

4

4

8

0.0s

4 0.0s

0.0s

0.0s

0.0s

GA

PH

PH

GL

St

0.0s

Thr. 0.2s 0.2s

time

Tail

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset any change 

made to the active field back to “0.0s”.
118 Program description - Control adjust | Winged models

Control adjust

Basic procedure for transmitter control and switch assignment

This option is available as standard on 

both transmitter types.

Use the selection keys on the left or right 

four-way button to scroll to the »Control 

adjust« option in the multi-function menu:

Servo adjustment

Dual Rate / Expo

Stick mode

Channel 1 curve

Switch display

Control adjust

Open this menu option with a tap on the center SET

key of the four-way button pad:

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8 –––

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

fr

SEL

Although the basic hardware features of the mc-16

HoTT and mc-20 HoTT transmitters are the same, 

i.e. two dual-axis sticks for control functions 1 to 4 

and the associated trim levers, the standard supplementary controls fitted to the two transmitters are 

different.

• mc-16 HoTT

• two 3-way switches (SW 5/6 & 11/12)

• two proportional sliders on the middle console, 

designated Sl 1 & 2 in the menu

• two side-mounted “rotary sliders”, designated 

Lv1 and 2 in the menu

• mc-20 HoTT

• three 3-way switches (SW 2/3, 5/6 & 11/12)

• five 2-way switches (SW 4, 7, 9, 13 & 15)

• two self-restoring 2-way switches (SW 8 & 14)

• two unlockable 2-way switches (SW 1 & 10)

• two push-buttons on the back-side of the transmitter (SW 16 & 17 bzw. 18 & 19) 

• two switch-keys (Gb5 & Gb6)

• two proportional sliders on the middle console, 

designated Sl 1 & 2 in the menu

• two side-mounted “rotary sliders”, designated 

Lv1 and 2 in the menu

In contrast to the two sticks which, when initialized for 

a new model memory as a “Winged aircraft” model 

type will already be configured to operate the servos 

connected to receiver outputs 1 ... 4, these “other” 

operating elements initially remain inactive. 

Thus, at least in the system’s delivered state–as 

already mentioned on page 77–or even after 

initialization of a new model memory with an “aircraft” 

model type and its “binding” to the receiver intended 

for installation, only those servos connected to the 

two sticks by way of receiver outputs 1 ... 4 are able 

to be operated; any servos which may be connected 

to receiver outputs 5 and upper will initially remain 

inactive in their middle positions.

While this may appear a bit awkward at first glance 

... this is the only way to ensure a completely free 

selection from among “additional” operating elements 

while, at the same time, not requiring the “deactivation” of unused operating elements. This is because 

the only way to ensure an unused operating element can have no effect on the model, even if 

operated by accident, is to make it inactive, i.e.

not assigned to any function.

All of the aforementioned operating elements can 

be freely assigned in this »Control adjust« menu to 

any function input, see page 66, just to accommodate personal requirements. Equally, this also means 

that each of these operating elements can also be 

assigned to multiple functions at the same time, as 

needed. For example: the exact same toggle switch 

assigned to an input in this menu can, at the same 

time, also have an assignment in the »Timers (general)« menu as an “On/Off” switch, etc.

Furthermore, all inputs can be selectively set to 

global or flight-phase specific operation if they have 

been defined for flight-phases in the »Phase settings« menu, page 152, and »Phase assignment« 

menu, page 158. The names assigned to given flight 

phases then appear in the second-from-the-bottom 

display line, e.g. «Normal».

Basic procedure

1. Use the  selection keys of the left or right fourway button to select the desired input, “In5 ... In8” 

or “In5 ... In12”. 

2. If necessary, use the  selection keys of the left 

or right four-way button to change to the desired 

column.

3. Briefly tap the center SET key of the right fourway button. The corresponding input field is shown 

highlighted.

4. Operate the chosen operating element or set the 

desired value with the selection keys of the right 

four-way button.

5. Briefly tap the center SET key of the right four-way 

button to complete data entry.

6. A simultaneous tap on the  or  keys of 

the right four-way button (CLEAR) will any setting 

made back to its respective default value.

Column 2, “Typ”

Similar to the previously described »Stick mode« 

menu, this column can be used to define whether 

further settings for the given input are to have a 

“GL(obal)” or a “PH(ase-specific)” effect. Do this by 

using the selection keys of the left or right four-way 

button to select the desired input 5 through 8 or 5 

through 12 in the column labeled “Typ”, for example: 

mc

 

16 20
Program description - Control adjust | Winged models 119

0%

0%

0%

–––

––– 0%

–––

–––

GL

GL

GL

GL

normal

fr

fr

fr

fr

SEL

In5

offset

In6

In7

In8

typ

• „GL“

The settings for the input in question affect all 

flight phases programmed (if any) and thus act 

“globally” on the model memory in question.

• “PH”

The settings for this input take effect per flight 

phase and must therefore be configured separately for each flight phase.

Notes:

• See page 150 for more information about flight 

phases.

• The current positions of the INC/DEC buttons CTL 

5 & 6, which are generally assigned to inputs 5 ... 

8 or 5 ... 12, are stored in accordance with your 

chosen entry in the “Type” line, i.e. the settings are 

not lost when you switch flight phases or change 

models.

The particular advantage of these two transmitter 

controls–especially if you select the “PH” setting - 

lies in the fact that you can use one and the same 

INC/DEC button as trim controls in all the programmed flight phases, but–in contrast to a position-related proportional control–the trim values 

are retained even if you switch models.

Column 3, 

“Transmitter control and switch assignment”

Select an input, 5 through 12 max., with the  selection keys of the left or right four-way button.

Transmitter control assignment

Use the selection keys to move into the column labeled SEL. After completing the activation of transmitter control assignment by tapping the center SET

key of the right four-way button, the message shown 

below will appear in the display:

0%

0%

0%

–––

0%

GL

normal

fr

SEL

In5

offset

In6

In7

In8

typ

Move desired

control adj.

Now actuate the desired transmitter control: The notice window will disappear and the designation of the 

selected transmitter control will appear in the transmitter control assignment window.

0%

0%

0%

–––

––– 0%

–––

–––

GL

GL

GL

GL

normal

fr

Lv2

fr

fr

SEL

In5

offset

In6

In7

In8

typ

Switch assignment

If the input is to be actuated like a switch module, the 

input can alternatively be assigned to a switch.

A simple switch can be used to switch back and forth 

between two limit values, for example motor On/Off.

A 3-way momentary or toggle switch achieves the 

same effect as a 2-channel switch module, for example motor Off/Half/Full. 

Use the selection keys to move into the column above 

the switch symbol label. Briefly tap the center 

SET key of the right four-way button to activate the 

option for assigning a switch:

GL ––– 0%

normal

fr

SEL

In5

typ offset

Move desired switch

to ON position

(ext. switch: SET)

Actuate the desired toggle switch from its “OFF” to its 

“ON” position or, for a 3-way switch, beginning from 

its middle position, assign a switch direction–preferably the “second” direction. This means, if a function 

is to be switched on by moving the switch forward two 

positions, i.e. away from the pilot, then begin from the 

switch’s middle position and move the switch away 

from the pilot. 

The display will then present the switch number together with a symbol indicating the given switch direction. At the same time, the column label in the footer 

line will change from SEL into another switch symbol:

0%

0%

0%

–––

––– 0%

–––

–––

GL

GL

GL

GL

normal

fr

fr

fr

3

In5

offset

In6

In7

In8

typ

Now put the 3-way switch back into its middle position. Move the marker frame as necessary to the left 

into the column labeled with the new switch symbol, 

briefly tap on the center SET key of the right four-way 

button then assign the switch’s other switch direction 

by once again starting from the middle position but 

this time move the switch in the other direction.

The display will now present the given switch number 

together with a symbol indicating the given switch 

direction, for example:
120 Program description - Control adjust | Winged models

0%

0%

0%

–––

––– 0%

–––

GL

GL

GL

GL

normal

fr

fr

fr

2 3

In5

offset

In6

In7

In8

typ

Erasing a transmitter control or switch assignment

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) while on an input line 

with an active transmitter control or switch assignment–see above figures–will reset the given input 

back to “fr” and “---”.

Tips:

• When assigning switches, pay attention to the desired switching direction and also that all unused 

inputs remain “free” or are again reset to “free”. 

This is necessary to ensure that inadvertent actuations of these unused controls cannot cause malfunctions.

• The travel setting described below allows the appropriate end state to be established for an assigned switch.

Column 4, “offset”

The control center for the given control, i.e. its zero 

point, can be changed in this column. The adjustment 

range lies between -125% and +125%.

0%

0%

0%

–––

––– 0%

–––

GL

GL

GL

GL

normal

fr

fr

fr

2 3

In5

offset

In6

In7

In8

typ

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the entry 

field value displayed in inverse video back to “0%”.

Column 5, “– travel +”

The “-Travel+” column is accessed by using the Select 

button  of the left or right-hand four-way button to 

shift the marker frame to the right, beyond the “Offset” 

column, as indicated by the right-pointing arrow at 

bottom left of the screen.

This column is used to set servo travel symmetrically 

or asymmetrically for each side. The setting range is 

±125% of normal servo travel.

Select an input, 5 through 8 or 5 through 12, with the 

 selection keys of the left or right four-way button.

To set symmetric travel, i.e. control-side independent 

travel, the respective operating element (transmitter 

control or switch) is to be put into a position in which 

the travel setting will be covered on both sides by the 

marker frame:

– travel +

+100%

+100%

+100%

+100%

+100%

+100%

+100%

+100%

normal

In5

In6

In7

In8

To set asymmetric travel, the respective operating 

element (transmitter control or switch) is to be moved 

to the side to be set such that the marker frame only 

includes the value to be changed:

+100%

+100%

+100%

+100%

+100%

+100%

+100%

+100%

normal

– travel +

In5

In6

In7

In8

The value setting is activated by briefly touching the 

center SET key of the right four-way button. The value 

field/s will be displayed in inverse video. Values can 

be changed with the selection keys of the right fourway button:

+100%

+100%

+100%

+100%

+100%

+100%

normal

+111% +111%

– travel +

In5

In6

In7

In8

+100%

+100%

+100%

+100%

+100%

+100%

+100%

normal

+88%

– travel +

In5

In6

In7

In8

Another brief tap on the center SET key of the right 

four-way button will complete the entry.

Negative and positive parameter values are possible 

in order to appropriately adapt the control’s direction 

or effect.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the changed 

parameter displayed in inverse video back to 

“+100%”.

Important:

In contrast to servo travel settings, changing the control travel setting affects all “downstream” mixer and 

coupling inputs, i.e. any and all servos actuated by 

the given transmitter control.

Column 6, “– time +”

Each of the function inputs 5 ... 8 or 5 ... 12 can be 

assigned a symmetrical or asymmetric time delay of 

between 0 and 9.9s.

Move the marker frame to the right beyond the column labeled “– travel +” with the  selection key of 

the left or right four-way button.
Program description - Control adjust | Winged models 121

To set a symmetric, i.e. control-side independent, 

time delay, the respective operating element (transmitter control or switch) is to be put into a position in 

which the time setting is covered on both sides by the 

marker frame:

0.0s

0.0s

0.0s

0.0s

0.0s

0.0s

0.0s

0.0s

normal

– time +

In5

In6

In7

In8

To set an asymmetric time delay, move the given 

transmitter control (proportional control or switch) 

as necessary to the side to be set such that only the 

value to be changed is covered:

0.0s

0.0s

0.0s

0.0s

0.0s

0.0s

0.0s

0.0s

normal

– time +

In5

In6

In7

In8

Briefly tap the center SET key of the right four-way 

button to activate value setting. The value field will 

be displayed in inverse video. Use the selection keys 

of the right four-way button to change the value in a 

range of 0.0 to 9.9s.

Another brief tap on the center SET key of the right 

four-way button will complete the entry.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the changed 

parameter displayed in inverse video back to 0.0s.
122 Program description - Control adjust | Helicopter models

Control adjust

Basic procedure for transmitter control and switch assignment

This option is available as standard on 

both transmitter types.

Use the selection keys on the left or right 

four-way button to scroll to the »Control 

adjust« option in the multi-function menu:

Servo adjustment

Dual Rate / Expo

Stick mode

Channel 1 curve

Switch display

Control adjust

Open this menu option with a tap on the center SET

key of the four-way button pad. On the standard 

eight-channel mc-16 HoTT transmitter this looks as 

follows:

In5

offset

Thro

Gyro

Lim.

–––

–––

–––

Lv2

0%

0%

0%

0%

GL

GL

GL

GL

typ

fr

fr

fr

–––

SEL

On the mc-16 HoTT transmitter with twelve channels unlocked, and on the standard twelve-channel 

mc-20 HoTT transmitter, this looks as follows:

In5

offset

0%

0%

0%

Thro

Gyro

In8 –––

–––

–––

In9

In10

In11

Lim.

–––

–––

–––

Lv2

0%

0%

0%

0%

GL ––– 0%

GL

GL

GL

GL

GL

GL

GL

typ

fr

fr

fr

fr

fr

fr

fr

–––

SEL

Note:

To save space the remaining screen-shots in this section are based on the display of the standard eightchannel mc-16 HoTT transmitter. The pictures also 

apply in similar manner to the mc-16 HoTT transmitter with twelve channels unlocked, and the standard twelve-channel mc-20 HoTT transmitter, since 

the only difference between the transmitter displays 

is the lines “In8” to “In11” located between “Gyro” and 

“Lim.”.

Although the basic hardware features of the mc-16

HoTT and mc-20 HoTT transmitters are the same, 

i.e. two dual-axis sticks for control functions 1 to 4 

and the associated trim levers, the standard supplementary controls fitted to the two transmitters are 

different.

• mc-16 HoTT

• two 3-way switches (SW 5/6 & 11/12)

• two proportional sliders on the middle console, 

designated Sl 1 & 2 in the menu

• two side-mounted “rotary sliders”, designated 

Lv1 and 2 in the menu

• mc-20 HoTT

• three 3-way switches (SW 2/3, 5/6 & 11/12)

• five 2-way switches (SW 4, 7, 9, 13 & 15)

• two self-restoring 2-way switches (SW 8 & 14)

• two unlockable 2-way switches (SW 1 & 10)

• two push-buttons on the back-side of the transmitter (SW 16 & 17 bzw. 18 & 19) 

• two switch-keys (Gb5 & Gb6)

• two proportional sliders on the middle console, 

designated Sl 1 & 2 in the menu

• two side-mounted “rotary sliders”, designated 

Lv1 and 2 in the menu

In contrast to the two sticks which, even for a newly 

initialized “Helicopter” model type will automatically 

use the servos attached to receiver outputs 1 ... 4 

and 6, the aforementioned “other” operating elements–except for the standard assignment of servo 6 

to the right-side proportional slider, designated in this 

menu as Lv2 (throttle limiter)–are initially inactive. 

One of the effects of this is that (as already mentioned on page 77) with a factory-fresh system–as 

with a newly initialized model memory for a “Helicopter” model type following its “binding” to the intended 

receiver–only those servos connected to receiver 

outputs 1 ... 4 and–depending on the position of 

the throttle limiter–servo 6 can be moved by the two 

sticks. Any servos connected to plug-in locations 5, 

7 and 8 or 5, 7 through 12, on the other hand, will 

simply remain at their center positions.

While this may appear a bit awkward at first glance 

... this is the only way to ensure a completely free 

selection from among “additional” operating elements 

while, at the same time, not requiring the “deactivation” of unused operating elements. This is because 

the only way to ensure an unused operating element can have no effect on the model, even if 

operated by accident, is to make it inactive, i.e. 

not assigned to any function.

All of the aforementioned operating elements can 

be freely assigned in this »Control adjust« menu to 

any function input, see page 66, just to accommodate personal requirements. Equally, this also means 

that each of these operating elements can also be 

assigned to multiple functions at the same time, as 

needed. For example: the exact same toggle switch 

assigned to an input in this menu can, at the same 

time, also have an assignment in the »Timers (general)« menu as an “On/Off” switch, etc.

Furthermore, all inputs can be selectively set to 

global or flight-phase specific operation if they have 

been defined for flight-phases in the »Phase settings« menu, page 156, and »Phase assignment« 

menu, page 158. The names assigned to given flight 

phases then appear in the second-from-the-bottom 

display line, e.g. «Normal».

mc

 

16 20
Program description - Control adjust | Helicopter models 123

Transmitter control assignment

Use the selection keys to move into the column labeled SEL. After completing the activation of transmitter control assignment by tapping the center SET

key of the right four-way button, the message shown 

below will appear in the display:

In5

offset

0%

0%

0%

0%

Th

Gy

Lim.

GL

GL

typ

normal

fr

L 2

SEL

Move desired

control adj.

Now actuate the desired transmitter control: The notice window will disappear and the designation of the 

selected transmitter control will appear in the transmitter control assignment window:

0%

0%

0%

–––

0%

Gyro

Lim. –––

–––

–––

GL

GL

GL

GL

normal

Lv1

fr

fr

SEL

In5

offset

Thro

typ

Lv2

Switch assignment 

If the input is to be actuated like a switch module, the 

input can alternatively be assigned to a switch.

A simple switch can be used to switch back and forth 

between two limit values, for example motor On/Off.

A 3-way momentary or toggle switch achieves the 

same effect as a 2-channel switch module, for example motor Off/Half/Full. 

Use the selection keys to move into the column above 

the switch symbol label. Briefly tap the center 

SET key of the right four-way button to activate the 

option for assigning a switch:

Note:

As a rule, input 6 must kept “free” for a helicopter 

model. On this, see “Throttle” on the next double 

page.

Basic procedure

1. Use the  selection keys of the left or right fourway button to select the desired input: In5, Thro, 

Gyro or Lim. respectively In5, Thro, Gyro, In8 ... 

11 or Lim. 

2. If necessary, use the  selection keys of the left 

or right four-way button to select the desired column.

3. Briefly tap the center SET key of the right fourway button. The corresponding input field is shown 

highlighted.

4. Operate the chosen operating element or set the 

desired value with the selection keys of the right 

four-way button.

5. Briefly tap the center SET key of the right four-way 

button to complete data entry.

6. A simultaneous tap on the  or  keys of 

the right four-way button (CLEAR) will any setting 

made back to its respective default value.

Column 2, “typ”

Similar to the previously described »Stick mode« 

menu, this column can be used to define whether 

further settings for the given input are to have a 

“GL(obal)” or a “PH(ase-specific)” effect. Do this by 

using the selection keys of the left or right four-way 

button to select the desired input In5, Thro, Gyro or 

Lim. respectively In5, Thro, Gyro, In8 through In11 or 

Lim. in the column labeled “typ”, for example:

In5

offset

0%

0%

0%

–––

0%

Thro

Gyro

Lim. –––

–––

–––

GL

GL

GL

GL

typ

normal

fr

fr

fr

Lv2

SEL

• „GL“

The settings for the input in question affect all 

flight phases programmed (if any) and thus act 

“globally” on the model memory in question.

• “PH”

The settings for this input take effect per flight 

phase and must therefore be configured separately for each flight phase.

Notes:

• See page 150 for more information about flight 

phases.

• The current positions of the INC/DEC buttons CTL 

5 & 6, which are generally assigned to inputs 5 ... 

8 or 5 ... 12, are stored in accordance with your 

chosen entry in the “Type” line, i.e. the settings are 

not lost when you switch flight phases or change 

models.

The particular advantage of these two transmitter controls–especially if you select the “PH” setting–lies in the fact that you can use one and the 

same INC/DEC button as trim controls in all the 

programmed flight phases, but–in contrast to a 

position-related proportional control–the trim values are retained even if you change models.

Column 3, 

“Transmitter control/switch assignment”

Using the  selection keys of the left or right fourway button to select an input: In5, Thro, Gyro or Lim. 

respectively In5, Thro, Gyro, In8 ... 11 or Lim.
124 Program description - Control adjust | Helicopter models

GL ––– 0%

normal

fr

SEL

In5

typ offset

Move desired switch

to ON position

(ext. switch: SET)

Actuate the desired toggle switch from its “OFF” to its 

“ON” position or, for a 3-way switch, beginning from 

its middle position, assign a switch direction–preferably the “second” direction. This means, if a function 

is to be switched on by moving the switch forward two 

positions, i.e. away from the pilot, then begin from the 

switch’s middle position and move the switch away 

from the pilot. 

The display will then present the switch number together with a symbol indicating the given switch direction. At the same time, the column label in the footer 

line will change from SEL into another switch symbol:

0%

0%

0%

–––

0%

Gyro

Lim. –––

–––

–––

GL

GL

GL

GL

normal

fr

fr

In5 3

offset

Thro

typ

Lv2

Now put the 3-way switch back into its middle position. Move the marker frame as necessary to the left 

into the column labeled with the new switch symbol, 

briefly tap on the center SET key of the right four-way 

button then assign the switch’s other switch direction 

by once again starting from the middle position but 

this time move the switch in the other direction.

The display will now present the given switch number 

together with a symbol indicating the given switch 

direction, for example:

0%

0%

0%

0%

Gyro

Lim. –––

–––

–––

GL

GL

GL

GL

normal

fr

fr

In5 2 3

offset

Thro

typ

Lv2

Erasing a transmitter control or switch assignment

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) while on an input line 

with an active transmitter control or switch assignment–see above figures–will reset the given input 

back to “fr” and “---”.

Tips:

• When assigning switches, pay attention to the desired switching direction and also that all unused 

inputs remain “free” or are again reset to “free”. 

This is necessary to ensure that inadvertent actuations of these unused controls cannot cause malfunctions.

• The travel setting described below allows the appropriate end state to be established for an assigned switch.

Column 4, “Offset”

The control center for the given control, i.e. its zero 

point, can be changed in this column. The adjustment 

range lies between -125% and +125%.

0%

0%

0%

0%

Gyro

Lim. –––

–––

–––

GL

GL

GL

GL

normal

fr

fr

In5 2 3

offset

Thro

typ

Lv2

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the entry 

field value displayed in inverse video back to “0%”.

Column 5, “– travel +”

The “- travel +” column is accessed by using the 

Select button  of the left or right-hand four-way 

button to shift the marker frame to the right, beyond 

the “Offset” column, as indicated by the right-pointing 

arrow at bottom left of the screen.

This column is used to set servo travel symmetrically 

or asymmetrically for each side. The setting range is 

±125% of normal servo travel.

Select an input, In5, Thro, Gyro or Lim. or In5, Thro, 

Gyro, In8 through 11 or Lim., with the  selection 

keys of the left or right four-way button.

To set symmetric travel, i.e. control-side independent 

travel, the respective operating element (transmitter 

control or switch) is to be put into a position in which 

the travel setting will be covered on both sides by the 

marker frame:

– travel +

+100%

+100%

+100%

+100%

Gyro

Lim.

+100%

+100%

+100%

+100%

normal

In5

Thro

To set asymmetric travel, the respective operating 

element (transmitter control or switch) is to be moved 

to the side to be set such that the marker frame only 

includes the value to be changed:

+100%

+100%

+100%

+100%

Gyro

Lim.

+100%

+100%

+100%

+100%

normal

– travel +

In5

Thro

The value setting is activated by briefly touching the 

center SET key of the right four-way button. The value 
Program description - Control adjust | Helicopter models 125

field/s will be displayed in inverse video. Values can 

be changed with the selection keys of the right fourway button:

+100%

+100%

+100%

Gyro

Lim.

+100%

+100%

+100%

normal

+111% +111%

– travel +

In5

Thro

+100%

+100%

+100%

Gyro

Lim.

+100%

+100%

+100%

+100%

normal

+88%

– travel +

In5

Thro

Another brief tap on the center SET key of the right 

four-way button will complete the entry.

Negative and positive parameter values are possible 

in order to appropriately adapt the control’s direction 

or effect.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the changed 

parameter displayed in inverse video back to 

“+100%”.

Important:

In contrast to servo travel settings, changing the control travel setting affects all “downstream” mixer and 

coupling inputs, i.e. any and all servos actuated by 

the given transmitter control.

Column 6, “– time +”

Each of the function inputs In5, Thro, Gyro or Lim. or 

In5, Thro, Gyro, In8 ... 11 or Lim. can be assigned a 

symmetrical or asymmetric time delay of between 0 

and 9.9s.

Move the marker frame to the right beyond the column labeled “– travel +” with the  selection key of 

the left or right four-way button.

To set a symmetric, i.e. control-side independent, 

time delay, the respective operating element (transmitter control or switch) is to be put into a position in 

which the time setting is covered on both sides by the 

marker frame:

0.0s

0.0s

0.0s

0.0s

Gyro

Lim.

0.0s

0.0s

0.0s

0.0s

normal

– time +

In5

Thro

To set an asymmetric time delay, move the given 

transmitter control (proportional control or switch) 

as necessary to the side to be set such that only the 

value to be changed is covered:

0.0s

0.0s

0.0s

0.0s

Gyro

Lim.

0.0s

0.0s

0.0s

0.0s

normal

– time +

In5

Thro

Briefly tap the center SET key of the right four-way 

button to activate value setting. The value field will 

be displayed in inverse video. Use the selection keys 

of the right four-way button to change the value in a 

range of 0.0 to 9.9s.

Another brief tap on the center SET key of the right 

four-way button will complete the entry.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the changed 

parameter displayed in inverse video back to 0.0s.

“Thro(ttle)”

0%

0%

0%

–––

0%

Gyro

Lim. –––

–––

–––

GL

GL

GL

GL

normal

fr

fr

fr

Lv2

SEL

In5

offset

Thro

typ

In principle, the helicopter program also permits the 

individual inputs to be assigned to any existing transmitter control (proportional controls and switches).

However, please note here that some of the inputs 

available on this menu are already assigned to 

helicopter-specific functions, and therefore cannot be 

re-assigned in this way.

Nevertheless, the receiver layout on page 75 indicates that the throttle servo or the speed controller of 

an electrically-powered helicopter must be connected 

to receiver output “6”, since control channel “6” is 

reserved for motor power regulation.

Unlike a fixed-wing model aircraft, the throttle servo 

or speed controller is not directly controlled by the 

stick or other transmitter control but rather by a complex mixer system, see »Helicopter mixer« menu 

beginning page 188. Furthermore, the “Throttle limit 

function” described on the next page also influences 

this mixer system.

Assigning a transmitter control or switch on the 

“Throttle” line, or to its supplementary control signal, 

would unnecessarily “confuse” this complex mixer 

system. For this reason the “Throttle” input MUST 

be left “free”. 
126 Program description - Control adjust | Helicopter models

“Gyro”

0%

0%

0%

–––

0%

Gyro

Lim. –––

–––

–––

GL

GL

GL

GL

normal

fr

fr

fr

SEL

Lv2

In5

offset

Thro

typ

Most of the latest gyro systems not only feature infinitely variable proportional gyro gain setting, but also 

offer a choice of two separate types of gain mode on 

the transmitter. 

If the gyro in use also has this feature then this menu 

option provides the opportunity to specify both a “normal” gyro effect as well as a “heading-lock mode” in 

the “Offset” column within a range of ±125%. Such a 

specification can include a certain effect to fly normal, 

slow flights with maximum stability or the reduction of 

the gyro effect for fast circuit flights and aerobatics.

To proceed as described above, use flight phase 

switching to enter different settings on the “Gyro” line.

Important notice:

The value of this option is identical to the offset 

value set in the “Gyro offset” option of the »Helicopter mixer« menu, page 196. For this reason, 

any changes made always affect the other menu 

directly, and vice versa.

Beginning with these preset–static–flight phasespecific settings, a transmitter control assigned to the 

“Gyro” line, for example one of the middle console 

sliders, can be used to vary the gyro effect around the 

respective “offset point”. The center point of the control corresponds to the setting specified by the offset. 

If the transmitter control is moved from this center 

point in the direction of full travel, gyro gain increases 

proportionally; it diminishes when moved in the opposite direction. This provides a fast and straightforward 

method of adjusting gyro effect even in flight–e.g. to 

suit changing weather conditions–or to test-fly optimal settings. Furthermore, the range of the gyro’s effect within transmitter control travel in both directions 

can be restricted by software. 

In this context, be sure to comply with the instructions accompanying the gyro, otherwise there is a 

risk the helicopter will be impossible to fly.

On the mc-16 HoTT transmitter the obvious choice 

as transmitter control for the gyro is one of the two 

sliders on the centre console, or alternatively to install 

one of the optional INC/DEC buttons on the mc16 HoTT transmitter, as fitted to the mc-20 HoTT 

transmitter as standard. These buttons are virtually 

ideal for this type of task, since–in contrast to a position-related proportional control–their current position 

is automatically stored, and is therefore reproducible 

at any time, even after you change models:

0%

0%

0%

–––

0%

Gyro

Lim. –––

–––

–––

GL

PH

GL

GL

normal

fr

fr

Cn6

SEL

Lv2

In5

offset

Thro

typ

Adjusting the gyro sensor

To achieve the maximum possible level of stabilization 

for the helicopter with the gyro along the vertical axis, 

observe the following:

• The controls should have as little friction and “play” 

as possible.

• There should be no “spring” in the control linkage.

• Use a strong and–in particular–a fast servo. 

When the gyro sensor detects a model rotation, 

the faster its response–a corresponding corrective 

change to tail rotor thrust–takes effect, the further 

the gyro gain adjuster can be moved without causing 

the tail of the model to start oscillating, and the better the model’s stability about its vertical axis. If the 

response is slower, there is a risk that the model’s tail 

will start to oscillate even at low gyro gain settings. 

Here, further reductions to gyro gain will need to be 

made–either by using the default value under “Gyro” 

or the associated transmitter control–to eliminate the 

oscillation.

If the model is flying forward at high speed or hovering in a powerful headwind, the net result of the 

stabilizing effect of the vertical fin combined with the 

gyro may also lead to an overreaction that once again 

manifests itself through tail oscillation. To achieve 

optimum gyro stabilization under all conditions, make 

use of the option to adapt gyro effect with one of the 

transmitter’s proportional controls. 
Program description - Control adjust | Helicopter models 127

just imagine what could happen if, while carrying the 

helicopter to the take-off site with the motor running, 

the C1 stick were to be inadvertently operated ... 

If the carburetor or speed controller is open too far 

when the transmitter is switched on, an audible warning will be sounded and the basic display will show 

the message:

Thr

 too

 high!

Tip:

Take advantage of the »Servo display« to observe 

the influence of the throttle limit control. The »Servo 

display« screen can be reached from almost any 

menu position with a simultaneous tap on the  selection keys of the left four-way button, Bear in mind 

that servo output 6 controls the throttle servo on the 

mc-16 HoTT and mc-20 HoTT transmitters!

Basic idle setting

Put the throttle limit into its “full throttle” position by 

pushing the throttle limit regulator–by default, the 

right side proportional slider Lv2–all the way to its 

forward position limit. Set the throttle/pitch stick to the 

maximum pitch position and also check the sub-menu 

“C1  Throttle” of the menu ...

»Helicopter mixer« (beginning page 188)

... to ensure that a standard throttle curve is active. If, 

for example, the standard throttle curve has already 

been changed following the initialization of a model 

memory then this must be at least temporarily reset 

to the values “Point L = -0%”, “Point 1 = +50%” and 

“Point H = +100%”:

“Lim.”

The proportional slider Lv2, mounted on the right 

side of the transmitter, is assigned by default to input 

“Lim.”:

In5

offset

Thro

Gyro

Lim.

–––

–––

–––

Lv2

0%

0%

0%

0%

GL

GL

GL

GL

typ

fr

fr

fr

–––

SEL

This pre-assignment makes it unnecessary to program the two flight phases as may be familiar from 

use of other remote control systems–one “with idleup” and one “without idle-up”–because the given options of the transmitters mc-16 HoTT and mc-20

HoTT offers a much more flexible approach to finetuning and optimizing increases to system rotational 

speed below the hover point than the so-called “idleup”. If it is nevertheless preferable for the helicopter 

to be programmed “with idle-up”, then deactivate the 

“throttle limit” function described below by setting 

input “Lim.” to “fr”.

Meaning and application of “throttle limit”

As already mentioned under “Throttle”, and in contrast to fixed-wing models, the power output of a 

helicopter’s drive system is not controlled directly with 

the C1 stick, but only indirectly via the throttle curve 

settings in the »Helicopter mixer« menu or–if the 

model features a speed controller–via that mechanism.

Note:

Of course for different flight phases, flight phase 

programming can be used to set individual throttle 

curves.

Nevertheless, both methods of output control de facto 

result in the helicopter carburetor never approaching 

anything near its idle speed under “normal” flight conThrottle limit function

ditions, and that the motor can therefore neither be 

started or stopped cleanly without some other means 

of intervention. 

The “throttle limit” feature resolves this problem elegantly by using a separate transmitter control–by 

default the Lv2 proportional slider mounted on the 

right side of the transmitter–to limit the throttle servo 

or the output level of a speed controller. In this way, 

it is possible to “throttle back” with the throttle limit 

control, even as far as the idle setting, at which point 

the trim control for the throttle/pitch stick takes over 

or directly shuts off an electric drive. Conversely, the 

throttle servo or speed controller can only open up to 

its full-throttle position if the throttle limit control has 

also released the full servo travel path.

The value set on the (right-hand) plus side of the 

“travel” column must therefore always be set high 

enough to ensure that the maximum setting of the 

throttle limit control never restricts the full-throttle 

position achievable with throttle curve settings–which 

typically means setting a value in the range +100% to 

125%. 

– travel +

+100%

+100%

Gyro +100%

Lim.

+100%

+100%

+100%

+100%

normal

+125%

In5

Thro

The value on the (left-hand) minus side of the “travel” 

column should be set so that the throttle limit control 

can safely cut off an electric drive or close a carburetor sufficiently to cut off a combustion motor in conjunction with–digital–C1 trim. Because of this, leave 

this value (initially) at +100%.

Furthermore, this variable “limitation” of throttle travel 

not only provides a convenient means to start and 

stop the motor but may also prove to be more than 

an insignificant safety improvement! For example, 
128 Program description - Control adjust | Helicopter models

Input

Output

Point ?

+50%

+50%

+50%

C1

normal

Thro

Curve off

Note:

Since throttle trim has no effect if the throttle limiter is 

open, its position here is meaningless.

Now–without starting the combustion motor–adjust 

the throttle servo, preferably mechanically and, if necessary, also by way of the servo 6 travel adjustment 

option in the »Servo adjustment« menu, so that the 

carburetor is completely open. 

Now close the throttle limiter completely by moving 

the side proportional slider all the way to its rear limit. 

Use the trim lever of the Throttle/Pitch stick to place 

the trim position marker into the motor OFF position 

or actuate the “Thr. CutOff” option, see page 101.

Note:

In contrast, when the throttle limiter is closed, the 

position of the throttle/collective pitch stick is meaningless. It can therefore remain at the maximum collective pitch position so that, when adjusting carburetor linkages, the throttle limiter alone can be used to 

switch between full throttle (throttle limiter open) and 

“Motor OFF” (throttle limiter closed).

Now, with the throttle limiter closed, adjust the carburetor linkages so that the carburetor is (just) completely closed. Take extreme care to ensure that the 

throttle servo does not become mechanically blocked 

in either of its end positions (full throttle/motor OFF).

To complete this basic configuration, the idle trim 

adjustment range must now be matched against point 

“L” on the throttle curve. Do this by setting Point “L” of 

the “C1  Throttle” mixer, in the »Helicopter mixer« 

menu, to about +15 to +18%.

L

0%

+16%

normal

+16%

Input

Output

Point

C1 Thro

Curve off

To configure a smooth transition from the idle trim 

to the throttle curve exactly, the collective pitch stick 

should be moved to and fro slightly at its minimum 

position with the throttle limiter closed and the idle 

trim fully open. The throttle servo must not move as 

well! Any further adjustments to the throttle curve 

must of course be made later in flight.

The engine or motor is always started with the throttle 

limiter completely closed; the trim lever of the throttle 

/ collective pitch stick trim only affects the idle range, 

and the motor engine is stopped using the “cut-off 

trim” function of the digital trims; see page 70.

Notes:

• Take advantage of the »Servo display« to observe the influence of the throttle limit control. The 

»Servo display« screen can be reached from almost any menu position with a simultaneous tap 

on the  selection keys of the left four-way button, Bear in mind that servo output 6 controls the 

throttle servo on the transmitters mc-16 HoTT 

and mc-20 HoTT!

• A servo connected to output 8 or 12 can be used, 

independently of this, for other purposes by means 

of mixers, provided that this servo is decoupled 

from the operating element specified by input 

function “Lim.” via the »Mix only channel« menu; 

see page 216. On the mc-16 HoTT transmitter 

this option can be unlocked at extra cost. 

• The throttle restriction set by the throttle limiter is 

shown as a horizontal bar in the throttle curve diagram on the second display page of the “C1 

Throttle” option in the »Helicopter mixer« menu 

(see page 191). The output signal for the throttle servo cannot be higher than the level set by the 

horizontal bar:

2

+50%

+50%

+50%

normal

Throttle limiter position

Input

Output

Point

C1 Thro

Curve off

The above diagram shows precisely this scenario: in the above example, the throttle limit control 

is set to about +20% and thus restricts the movement of the throttle servo to about +20% of full 

travel.

Time delay for the throttle limiter

To safely prevent the carburetor from opening too 

rapidly, assign the throttle limiter input “Lim.” to a 

time delay that takes effect only in the direction of full 

throttle. This applies especially if the throttle limiter is 

controlled by a switch rather than, as preset, with the 

right-side proportional rotary slider.

To set a delay time, push the throttle limit control to 

its forward limit or move the switch into its full-throttle 

position then use the selection keys of the left or right 

four-way button to select the “– time +” column:

In5

– time +

0.0s

0.0s

0.0s

0.0s

Thro

Gyro

Lim.

0.0s

0.0s

0.0s

0.0s

normal

After a brief tap on the center SET key of the right 

four-way button, the selection keys of the left or right 

four-way button can be used to select the desired 

time delay, e.g. 5 seconds:
Program description - Control adjust | Helicopter models 129

In5

– time +

0.0s

0.0s

0.0s

Thro

Gyro

Lim.

0.0s

0.0s

0.0s

0.0s

normal

5.0s

A brief tap on the center SET key of the right four-way 

button or the ESC key of the left four-way button will 

complete the entry.

As already described on page 116, the digital trim of 

the throttle / collective pitch stick is only active in the 

“Auto-rotation” flight phase, assuming that you have 

selected “AR” in the “Throttle” line of the following 

menu ...

»Stick mode« (page 116)

Thro

Roll

Nick

Tr time +

4

4

4

0.0s

0.0s

0.0s

Tail 4 0.0s

0.0s

0.0s

0.0s

0.0s

GL

GL

GL

St

AR

.... which is available as standard on the mc-20

HoTT transmitter only. This means that the idle of the 

motor or engine cannot be controlled in the “normal” 

flight phases using the C1 trim lever. To ensure that 

adequate adjustment is still available, we recommend 

that you use “Expo throttle limit”.

Note:

On the mc-16 HoTT transmitter the »Stick mode« 

function can be unlocked as an extra-cost option.

The exponential curve characteristic offered by the ...

»Helicopter type« (page 108)

Expo thro lim. 0%

SEL

Linear. swashpl. no

Rotor direct right

Heli type

Pitch min. back

... menu’s sub-menu can be used to alter the control 

behavior of the throttle limit control such that the latter 

provides sufficiently sensitive regulation of the idle 

setting and can also stop the motor.

In this case, with a completely closed throttle limiter–in contrast to the previously described setThrottle limit in combination with “AR” in the »Stick mode« 

menu

ting–use the »Control adjust« menu set the “-” side 

of the column labeled “- travel +” for the “Lim.” line 

such that the throttle limiter fully closes the carburetor, i.e. the motor is safely switched off at this control 

position.

Following this, move the throttle limit control to its 

center point and change the % value of the “Expo 

thro lim.” line in the »Helicopter type« menu, page 

110, until the carburetor is in a position suitable for 

starting the motor. Now start the motor, and adjust the 

value if necessary until the motor idles reliably in this 

throttle limit control position.

The value for the plus side of the “- travel +” column 

should be increased, as described before, to +125% 

so that the full-throttle position of the throttle servo is 

also reliably released from the throttle limiter.

Finally, set an asymmetrical time delay of, say 

4.0 seconds, so the motor also picks up speed gradually even if the side proportional slider is pushed 

forward too quickly. Select the time preset to correlate 

to how far the carburetor opens up at the minimum 

collective pitch position. The value set is to be optimized by testing.
130 Program description - Dual Rate / Expo | Winged models

Dual Rate / Expo

Configurable control characteristics for aileron, elevator and rudder

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Dual 

Rate / Expo« menu option in the Multi-function menu:

Servo adjustment

Stick mode.

Channel 1 curve

Switch display

Control adjust.

Dual Rate / Expo

Open this menu option with a tap on the center SET

key of the right four-way button:

100%

100%

100%

Ail

Ele

Rud

DUAL

–––

–––

–––

SEL

The Dual-Rate-/Expo function permits flight-phase 

dependent switching and control over the deflection 

and characteristics of the aileron (Ail), elevator (Ele) 

and rudder (Rud) (control functions 2 ... 4) by way of 

switches. 

It is possible to set up an individual curve for control 

function 1 (throttle / brake) using a maximum of six 

separately programmable points. This is carried out 

in the »Channel 1 curve« menu, which is available 

on the mc-16 HoTT and the mc-20 HoTT transmitter as standard; see the section starting on page 

138.

Similar to control travel settings in the »Control adjust« menu, Dual Rate operates directly on the respective control function, independent of whether it is 

an individual servo or multiple servos connected via 

complex mixer and coupling functions. 

The control travel for each switch position can be set 

to between 0 and 125% of normal full travel. 

Expo, on the other hand, enables finer-grained control of the model for values larger than 0% around the 

center position of the primary control function (aileron, elevator and rudder), without forfeiting full movement at the end-points of stick travel. For values less 

than 0%, the reverse is true: control increases around 

the neutral position and diminishes towards the endpoints. The degree of “progression” can therefore be 

set within a total range of -100% to +100%, where 

0% equates to the normal, linear control characteristics.

Rotary-output servos, now generally commonplace, 

offer another application. This is because the actual 

control surface movement is not linear: as the rotational angle of the output disc or lever increases, the 

control surface rate of travel over the control linkage 

continually decreases. This effect can be counteracted with Expo values greater than 0% such that 

rotational angle travel increases over-proportionally 

with increasing stick throw.

The Expo setting also affects the relevant control 

function directly, whether this controls a single servo 

or multiple servos–via any number of mixer and coupling functions.

For both Dual Rate and Expo functions, switch assignment can be set up in any way desired, which 

therefore permits the triggering of multiple functions 

using one and the same switch. This, in turn, offers 

the opportunity to link the triggering of Dual Rate and 

Expo functions to a single switch: this offers many 

advantages–particularly for very high-speed models.

The graphic screen displays the curve characteristics 

directly. After selecting the appropriate line, the dotted 

vertical line will follow the movement of the respective 

stick so a better evaluation of the transmitter-controltravel dependent curve value can be made.

Flight phase-dependent Dual Rate and Expo settings

If flight phases are set up in the »Phase settings«, 

page 152, and »Phase assignment« menus, page 

158, and each assigned a name, e.g. “Normal”, the 

name in question will be displayed at the bottom left 

of the display. Just actuate the respective switch to 

switch between flight phases.

Basic procedure

1. Switch to the desired flight phase then use the 

 selection keys of the left or right four-way button to select the desired line: “Aileron”, “Elevator” 

or “Rudder”.

2. Use the  selection keys of the left or right fourway button to select the right column or the as-yet 

invisible column for Expo values, see page 31.

3. Tap the center SET key of the right four-way button. The corresponding input field is shown highlighted.

4. Use the selection keys of the right four-way button 

to set the desired value.

5. Tap the center SET key of the right four-way button to complete the entry.

6. A simultaneous tap on the  or  keys of 

the right four-way button (CLEAR) will any setting 

made back to its respective default value.

Dual Rate function

If a switchover between two variants is desired, assign a switch in the column labeled with the 

switch symbol (as described in the section “Physical 

control, switch and control switch assignments” on 

page 68):

mc

 

16 20
Program description - Dual Rate / Expo | Winged models 131

ly change the dual-rate values shown in inverse video 

for each of the two switch positions:

100%

100%

DUAL

3

–––

–––

SEL

normal

Ail 111%

Ele

Rud

100%

100%

DUAL

3

–––

–––

SEL

normal

Ail 88%

Ele

Rud

At the same time, the Dual-Rate curve will be presented in the graph. 

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

entry field value displayed in inverse video back to 

“100%”.

Caution:

For safety reasons, Dual Rate value settings should 

not be less than 20%.

Some examples of Dual Rate values: Servo travel Servo travel Servo travel

Stick deflection Stick deflection Stick deflection

Dual Rate = 100% Dual Rate = 50% Dual Rate = 20%

Ail ––– 100%

SEL

normal

Move desired switch

to ON position

(ext. switch: SET)

If necessary, this may also be one of the transmitter 

control switches C1 ... C4 or C1i ... C4i or one of the 

logical switches L1 ... L8 or L1i ... L8i from the list of 

“expanded switches”.

The switch so assigned appears on the display, together with a switch icon that indicates the switch’s 

switching direction.

In the case of “C” or “L” switches, the stick or another 

transmitter control or a certain switching logic can 

itself be used as a switch. However, such a control 

switch must have been appropriately defined in the 

»Control switch« menu, see page 145, and a 

logical switch must have been appropriately defined 

in the »Logical switch« menu, see page 148–provided that this menu point is unlocked (available) on 

the transmitter concerned.

Whichever switch has been assigned ... the respective switch will appear in the display together with a 

switch symbol indicating the switch’s direction if actuated, e.g. in the «Normal» flight phase.

100%

100%

100%

Ail

Ele

Rud

DUAL

3

–––

–––

SEL

normal

Once the value field has been activated with a brief 

tap on the SET key of the right four-way button, use 

the selection keys of the left or right four-way button 

to move into the Dual-Rate value column labeled SEL 

at the bottom edge of the display in order to separateExponential function

If you wish to program the Expo function, use the 

 button of the left or right-hand four-way button to 

move to the right, beyond the Dual Rate value column, until the word “EXPO” is displayed in the centre 

of the screen instead of “DUAL”:

0%

0%

0%

EXPO

–––

–––

–––

SEL

Ail

Ele

Rud

Normal

If a switchover between two variants is desired, assign a switch in the column labeled with the 

switch symbol (as described in the section “Physical 

control, switch and control switch assignments” on 

page 68):

Ail ––– 0%

SEL

normal

Move desired switch

to ON position

(ext. switch: SET)

If necessary, this may also be one of the transmitter 

control switches C1 ... C4 or C1i ... C4i or one of the 

logical switches L1 ... L8 or L1i ... L8i from the list of 

“expanded switches”.

The switch so assigned appears on the display, together with a switch icon that indicates the switch’s 

switching direction.

In the case of “C” or “L” switches, the stick or another 

transmitter control or a certain switching logic can 

itself be used as a switch. However, such a control 

switch must have been appropriately defined in the 

»Control switch« menu, see page 145, and a 

logical switch must have been appropriately defined 

in the »Logical switch« menu, see page 148–pro-
132 Program description - Dual Rate / Expo | Winged models

vided that this menu point is unlocked (available) on 

the transmitter concerned. 

Whichever switch has been assigned ... the respective switch will appear in the display together with a 

switch symbol indicating the switch’s direction if actuated, e.g. in the «Normal» flight phase.

0%

0%

0%

Ail

Ele

Rud

EXPO

3

–––

–––

SEL

normal

Select the right-hand column at the lower edge of the 

display marked with SEL and activate the value field 

with a brief tap on the center SET key of the right 

four-way button, the selection keys on the left or right 

four-way button can now be used to alter the EXPO 

value shown in the highlighted field, separately for 

each of the two switch positions.

Now, for example, there is an opportunity to fly with 

a linear curve characteristic with the switch in one 

direction, and to preset a value other than 0% for the 

other switch direction:

33%

0%

0%

Ail

Ele

Rud

EXPO

3

–––

–––

SEL

normal

At the same time, the Expo curve will be presented in 

the graph. 

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

entry field value displayed in inverse video back to 

“0%”.

Some examples of Expo values: Servo travel Servo travel

Servo travel

Stick deflection Stick deflection Stick deflection

Expo = +100% Expo = +50% Expo = –100%

In each of these examples, the Dual Rate value 

equals 100%.

Combining Dual Rate and Expo

If values have been entered for both the Dual Rate 

and the Expo function, the effects of both functions 

will overlap, for example, as follows: Servo travel Servo travel

Servo travel

Stick deflection Stick deflection Stick deflection

Expo = +100%, DR = 125% Expo = +100%, DR = 50% Expo = –100%, DR = 50%

Asymmetric setting of Dual Rate and Expo

To make an asymmetric setting, i.e. a Dual Rate 

or Expo setting dependent on the direction of the 

respective stick, first access the »Control switch« 

menu and assign one of the C1 ... C4 control 

switches–“C3”, for example–to the desired transmitter control, e.g. control 3 for the elevator function. Do 

not change the switching point for the stick’s neutral 

position (0%). Now return to the »Dual Rate / Expo« 

menu and select the corresponding control function 

(“Elevator” in this example).

Now, with a brief tap on the center SET key of the 

right four-way button, activate the switch assignment 

and change to the expanded switches then use the 

selection keys to move on to the previously defined 

“C3” control switch:

Ail ––– 100%

SEL

normal

Control/Logic/fix sw

C2 C4 FX

FXi L1 L2 L3 L4

C1 C3

A brief tap on the center SET key of the right four-way 

button will confirm the assignment of this switch:

100%

100%

100%

Ail

Ele

Rud

DUAL

–––

C3

–––

SEL

normal

Now use one of the selection keys to move into the 

right column then move the elevator stick into its 

appropriate end-point to enter a separate Dual Rate 

value for each direction, e.g. for “Up elevator” ... 

100%

100%

Ail

Ele

Rud

DUAL

–––

C3

–––

SEL

normal

77%

... and “Down elevator”:

100%

100%

Ail

Ele

Rud

DUAL

–––

C3

–––

SEL

normal

111%

The vertical dashed line shows the current elevator 

stick position.
Program description - Dual Rate / Expo | Winged models 133

Set the Expo values as necessary in the same manner.
134 Program description - Dual Rate / Expo | Helicopter models

Dual Rate / Expo

Configurable control characteristics for roll, pitch-axis and tail rotor

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Dual 

Rate / Expo« menu option in the Multi-function menu:

Servo adjustment

Stick mode.

Channel 1 curve

Switch display

Control adjust.

Dual Rate / Expo

Open this menu option with a tap on the center SET

key of the right four-way button:

100%

100%

100%

Roll

Nick

Tail

DUAL

–––

–––

–––

SEL

The Dual Rate / Expo function permits switching or 

controlling of control travels and characteristics for the 

control functions roll, pitch-axis, tail rotor, i.e. control 

functions 2 ... 4; it is switch-driven and flight-phase 

independent. 

It is possible to set up an individual curve for control 

function 1 (throttle / collective pitch) using a maximum 

of six separately programmable points. This is carried 

out in the »Channel 1 curve« menu, which is available on the mc-16 HoTT and the mc-20 HoTT 

transmitter as standard; see the section starting on 

page 141. It can also be set up for throttle and collective pitch separately in the »Helicopter mixer” 

menu, which is available on both transmitters; see the 

sections starting on pages 188 and 322.

Similar to control travel settings in the »Control adjust« menu, Dual Rate operates directly on the respective control function, independent of whether it is 

an individual servo or multiple servos connected via 

complex mixer and coupling functions. 

The control travel for each switch position can be set 

to between 0 and 125% of normal full travel. 

Expo, on the other hand, enables finer-grained control of the model for values larger than 0% around the 

center position of the primary control function (roll, 

pitch-axis, tail rotor), without forfeiting full movement 

at the end-points of stick travel. For values less than 

0%, the reverse is true: control increases around 

the neutral position and diminishes towards the endpoints. The degree of “progression” can therefore be 

set within a total range of -100% to +100%, where 

0% equates to the normal, linear control characteristics.

Rotary-output servos, now generally commonplace, 

offer another application. This is because the actual 

control surface movement is not linear: as the rotational angle of the output disc or lever increases, the 

control surface rate of travel over the control linkage 

continually decreases–depending on the position of 

the linkage point on the output disc. This effect can be 

counteracted with Expo values greater than 0% such 

that rotational angle travel increases over-proportionally with increasing stick throw.

The Expo setting also affects the relevant control 

function directly, whether this controls a single servo 

or multiple servos–via any number of mixer and 

coupling functions.

For both Dual Rate and Expo functions, switch assignment can be set up in any way desired, which 

therefore permits the triggering of multiple functions 

using one and the same switch. This, in turn, offers 

the opportunity to link the triggering of Dual Rate and 

Expo functions to a single switch: this offers many 

advantages–particularly for very high-speed models.

The graphic screen displays the curve characteristics 

directly. Once you select a menu line, the dotted vertical line follows the movement of the respective stick, 

so you can clearly see the dependency of the curve 

value on the transmitter control.

Flight phase-dependent Dual Rate and Expo settings

If flight phases are set up in the »Phase settings«, 

page 156, and »Phase assignment« menus, page 

158, and each assigned a name,e.g. “Normal”, the 

name in question will be displayed at the bottom left 

of the display. In this scenario, you can operate the 

corresponding switch to switch between flight phases.

Basic procedure

1. Switch to the desired flight phase then use the 

 selection keys of the left or right four-way button to select the desired line: “Roll”, “Pitch ax” or 

“Tail rot”.

2. Use the  selection keys of the left or right fourway button to select the right column or the as-yet 

invisible column for Expo values, see page 31.

3. Tap the center SET key of the right four-way button. The corresponding input field is shown highlighted.

4. Use the selection keys of the right four-way button 

to set the desired value.

5. Tap the center SET key of the right four-way button to complete the entry.

6. A simultaneous tap on the  or  keys of 

the right four-way button (CLEAR) will any setting 

made back to its respective default value.

Dual Rate function

If a switchover between two variants is desired, assign a switch in the column labeled with the 

switch symbol (as described in the section “Physical 

control, switch and control switch assignments” on 

page 68):

mc

 

16 20
Program description - Dual Rate / Expo | Helicopter models 135

Exponential-Funktion

If you wish to program the Expo function, use the 

 button of the left or right-hand four-way button to 

move to the right, beyond the Dual Rate value column, until the word “EXPO” is displayed in the centre 

of the screen instead of “DUAL”:

0%

0%

0%

EXPO

–––

–––

–––

SEL

Roll

Nick

Tail

normal

If a switchover between two variants is desired, assign a switch in the column labeled with the 

switch symbol (as described in the section “Physical 

control, switch and control switch assignments” on 

page 68):

Roll ––– 0%

SEL

normal

Move desired switch

to ON position

(ext. switch: SET)

If necessary, this may also be one of the transmitter 

control switches C1 ... C4 or C1i ... C4i or one of the 

logical switches L1 ... L8 or L1i ... L8i from the list of 

“expanded switches”.

The switch so assigned appears on the display, together with a switch icon that indicates the switch’s 

switching direction.

In the case of “C” or “L” switches, the stick or another 

transmitter control or a certain switching logic can 

itself be used as a switch. However, such a control 

switch must have been appropriately defined in the 

»Control switch« menu, see page 145, and a 

logical switch must have been appropriately defined 

in the »Logical switch« menu, see page 148–proRoll ––– 100%

SEL

normal

Move desired switch

to ON position

(ext. switch: SET)

If necessary, this may also be one of the transmitter 

control switches C1 ... C4 or C1i ... C4i or one of the 

logical switches L1 ... L8 or L1i ... L8i from the list of 

“expanded switches”.

The switch so assigned appears on the display, together with a switch icon that indicates the switch’s 

switching direction.

In the case of “C” or “L” switches, the stick or another 

transmitter control or a certain switching logic can 

itself be used as a switch. However, such a control 

switch must have been appropriately defined in the 

»Control switch« menu, see page 145, and a 

logical switch must have been appropriately defined 

in the »Logical switch« menu, see page 148–provided that this menu point is unlocked (available) on 

the transmitter concerned.

Whichever switch has been assigned ... the respective switch will appear in the display together with a 

switch symbol indicating the switch’s direction if actuated, e.g. in the «Normal» flight phase.

100%

100%

100%

Roll

Nick

Tail

DUAL

3

–––

–––

SEL

normal

Once the value field has been activated with a brief 

tap on the SET key of the right four-way button, use 

the selection keys of the left or right four-way button 

to move into the Dual-Rate value column labeled SEL 

at the bottom edge of the display in order to separately change the dual-rate values shown in inverse video 

for each of the two switch positions:

100%

100%

DUAL

3

–––

–––

SEL

normal

Roll 111%

Nick

Tail

100%

100%

DUAL

3

–––

–––

SEL

normal

Roll 88%

Nick

Tail

At the same time, the Dual-Rate curve will be presented in the graph. 

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

entry field value displayed in inverse video back to 

“100%”.

Caution:

For safety reasons, Dual Rate value settings should 

not be less than 20%.

Some examples of Dual Rate values: Servo travel Servo travel Servo travel

Stick deflection Stick deflection Stick deflection

Dual Rate = 100% Dual Rate = 50% Dual Rate = 20%
136 Program description - Dual Rate / Expo | Helicopter models

vided that this menu point is unlocked (available) on 

the transmitter concerned.

Whichever switch has been assigned ... the respective switch will appear in the display together with a 

switch symbol indicating the switch’s direction if actuated, e.g. in the «Normal» flight phase.

0%

0%

0%

EXPO

3

–––

–––

SEL

normal

Roll

Nick

Tail

Select the right-hand column at the lower edge of the 

display marked with SEL and activate the value field 

with a brief tap on the center SET key of the right 

four-way button, the selection keys on the left or right 

four-way button can now be used to alter the EXPO 

value shown in the highlighted field, separately for 

each of the two switch positions.

Now, for example, there is an opportunity to fly with 

a linear curve characteristic with the switch in one 

direction, and to preset a value other than 0% for the 

other switch direction:

33%

0%

0%

EXPO

3

–––

–––

SEL

normal

Roll

Nick

Tail

At the same time, the Expo curve will be presented in 

the graph. 

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

entry field value displayed in inverse video back to 

“0%”.

Some examples of Expo values: Servo travel Servo travel

Servo travel

Stick deflection Stick deflection Stick deflection

Expo = +100% Expo = +50% Expo = –100%

In each of these examples, the Dual Rate value 

equals 100%.

Combining Dual Rate and Expo

If values have been entered for both the Dual Rate 

and the Expo function, the effects of both functions 

will overlap, for example, as follows: Servo travel Servo travel

Servo travel

Stick deflection Stick deflection Stick deflection

Expo = +100%, DR = 125% Expo = +100%, DR = 50% Expo = –100%, DR = 50%

Asymmetric setting of Dual Rate and Expo

To make an asymmetric setting, i.e. a Dual Rate 

or Expo setting dependent on the direction of the 

respective stick, first access the »Control switch« 

menu and assign one of the C1 ... C4 control 

switches–“C3”, for example–to the desired transmitter control, e.g. control 3 for the nick function. Do 

not change the switching point for the stick’s neutral 

position (0%). Now return to the »Dual Rate / Expo« 

menu and select the corresponding control function 

(“Nick” in this example).

Now, with a brief tap on the center SET key of the 

right four-way button, activate the switch assignment 

and change to the expanded switches then use the 

selection keys to move on to the previously defined 

“C3” control switch:

Roll ––– 100%

SEL

Control/Logic/fix sw

C2 C4 FX

FXi L1 L2 L3 L4

C1 C3

A brief tap on the center SET key of the right four-way 

button will confirm the assignment of this switch:

100%

100%

100%

DUAL

–––

C3

–––

SEL

normal

Roll

Nick

Tail

Now use one of the selection keys to move into the 

right column then move the nick stick into its appropriate end-point to enter a separate Dual Rate value for 

each direction, e.g. for “Nick back” ... 

100%

100%

DUAL

–––

C3

–––

SEL

normal

Roll

Nick

Tail

77%

... and „Nick forward“:

100%

100%

DUAL

–––

C3

–––

SEL

normal

Roll

Nick

Tail

111%

The vertical dashed line shows the current nick stick 

position.
Program description - Dual Rate / Expo | Helicopter models 137

Set the Expo values as necessary in the same manner.
138 Program description - Channel 1 curve | Winged models

Channel 1 curve

Control characteristics for throttle/spoiler stick

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Channel 

1 curve« menu option in the Multi-function menu:

Servo adjustment

Stick mode

Switch display

Control adjust

Dual Rate / Expo

Channel 1 curve

Open this menu option with a tap on the center SET

key of the right four-way button:

Input

Output

Point ?

0%

0%

0%

Ch1 curve

Curve off

Since the carburetor response or the effect of the airbrakes or spoilers is often non-linear, you can make 

compensatory adjustments to these in this menu. 

The menu therefore enables you to change the 

control characteristics of the throttle / airbrake stick, 

regardless of whether this control function affects the 

servo connected to control channel 1 directly or affects multiple servos via various mixers.

If flight phases have been specified in the »Phase 

settings« and »Phase assignment« menus (see 

pages 152 and 158) this option can be adapted 

on a flight-phase basis. The given flight phase name, 

e.g. «normal», will be shown at the bottom left of 

the screen.

The control curve can be defined by up to 6 points 

(termed “reference points” below) placed anywhere 

along the path of stick travel. While the on-screen 

graph considerably simplifies the process of setting 

and adjusting the reference points, we recommend 

that you set fewer reference points to begin with.

In the basic software set-up, 2 reference 

points–namely the end-points at the bottom end of 

stick travel (“L”, low = -100% travel) and the top end 

of stick travel (“H”, high = +100% travel)–define a 

linear characteristic curve.

First, switch to your chosen flight phase, if necessary.

Setting reference points

By moving the transmitter control (throttle/airbrake 

stick), you can reposition the vertical line in the graph 

between the two end-points “L” and “H”. 

The current stick position is also displayed in numerical form on the “Input” line (-100% to +100%). The 

point at which this line crosses the curve is termed 

the “Output”, and can be varied at the reference 

points within the range -125% to +125%. The control 

signal altered in this way will then affect all subsequent mixer and coupling functions. 

In the example above, the stick is at 0% of control 

travel and also generates an output signal of 0%, 

since the characteristic curve is linear.

Up to 4 additional reference points can be set between the two end-points “L” and “H”, although the 

distance between neighboring reference points must 

not be less than approx. 25%.

If necessary, use the left or right-hand arrow button 

to move the marker frame down to the “Point” line:

Input

Output

Point ?

0%

0%

0%

Ch1 curve

normal

Curve off

Move the stick. If a question mark can be seen in the 

“Point” frame, then the next reference point can be set 

with a tap on the center SET key of the right four-way 

button. Simultaneously, the “?” is replaced by a number and the value field to the right of the reference 

point number will be shown in inverse video.

1

+50%

+50%

+50%

normal

off

Input

Output

Point

Ch1 curve

Curve

The order in which you generate the (maximum) 4 

reference points between the end-points “L” and “H” is 

irrelevant, since the reference points are continuously 

renumbered automatically from left to right as they 

are entered.

Erasing reference points

To delete one of the reference points (1 to max. 4), 

use the stick to move the vertical line into the vicinity 

of the reference point in question. As soon as the 

reference point number and the associated value are 

superimposed in the “Point” line, you can activate the 

Value field by pressing the central SET button of the 

right-hand four-way button, then erase it by simultaneously pressing the  or  buttons of the righthand four-way button (CLEAR). A brief press of the 

central ESC button of the left-hand four-way button 

concludes the procedure. 

Changing reference point values

Move the stick into the range of the reference point 

that is to be changed: “L” (low), 1 ... 4 or “H” (high). 

The number and current curve value of this point are 

displayed. Press the central SET button of the righthand four-way button to activate the Value field. The 

reference point value displayed in inverse video can 

be changed in a range of -125% to +125% without 

influencing the neighboring reference points.

mc

 

16 20
Program description - Channel 1 curve | Winged models 139

Example:

2

+50%

–75%

–75%

normal

off

Input

Output

Point

Ch1 curve

Curve

In this sample screen image, reference point “2” has 

been set to -75%.

Note:

If the stick does not coincide with the exact reference 

point, please note that the percentage value on the 

“Output” line always relates to the current stick position.

Trim point function

Alternatively, jumping through active reference points, 

in ascending or descending order, can be done with 

the  selection keys of the left four-way button. 

Note that “active” reference points are those which 

have already been set. When a jump is made from 

one to another, the point value field for the jump’s 

destination reference point in the screen’s Point line 

will be displayed in inverse video and its position in 

the graph will be marked (L, 1 ... max. 4 and H) in 

inverse video and with a small triangle. The selection 

keys on the right four-way button can then be used to 

change the reference point jumped to as described 

above, entirely independently of the control position.

2

+50%

–75%

–75%

Trim point

normal

Input

Output

Point

Ch1 curve

One touch on the center ESC key of the left four-way 

button terminates this trim point function.

Trim offset function

When a value field is active, i.e. in inverse video, it is 

not only possible, as previously described, to jump 

to and change a reference point already set with the 

 selection keys of the left four-way button but also 

an existing curve can be vertically repositioned with 

the  keys of the left four-way button within a range 

of ±25%:

1

0%

+50%

+50%

Trim offset

normal

Input

Output

Point

Ch1 curve

1

0%

0%

0%

Trim offset

normal

Input

Output

Point

Ch1 curve

A tap on the center ESC key of the left four-way button will also terminate this function.

Trim x-axis function

This function is activated by tapping the left () or 

right () selection key of the right four-way button 

with an active (i.e. inverse video) value field. You can 

then use the selection keys on the right four-way button to reposition the active point horizontally or vertically as you wish:

?

0%

–33%

0%

Trim X-axis

normal

Input

Output

Point

Ch1 curve

Notes:

• If the point is repositioned horizontally further 

away from the current control position than approx. 

±25%, a “?” sign will reappear in the line Point. 

This question mark does not refer to the repositioned point, however: instead, it signifies that a 

further point can be set at the current control position.

• Please note that the percentage value on the “Output” line always relates to the current stick position 

and not to the position of the point.

Smoothing the Channel 1 curve

In the example below, sample reference points have 

been set: 

reference point 1 to 0%,

reference point 2 to +25% and

reference point 3 to -75%

as described in the last section:

1

–50%

0%

0%

normal

off

Input

Output

Point

Ch1 curve

Curve

This “jagged” curve profile can be smoothed automatically simply by pressing a button. 

Starting from the situation in the previous illustration, 

first press the SET button of the right-hand four-way 

button to conclude the procedure. Use the Select but-
140 Program description - Channel 1 curve | Winged models

ton  of the right-hand four-way button to move up to 

the Value field of the “Curve” line, then press the SET

button of the right-hand four-way button once more:

1

–50%

0%

0%

off

normal

Input

Output

Point

Ch1 curve

Curve

Now press one of the Select buttons of the right-hand 

four-way button in order to switch from “(Curve) off” to 

“(Curve) on” (or vice versa).

1

–50%

0%

0%

on

normal

Input

Output

Point

Ch1 curve

Curve

Note:

The curves shown here are for demonstration purposes only and are not at all representative of real 

throttle or airbrake curves. A specific application 

example can be found in the programming examples 

on page 285.
Program description - Channel 1 curve | Helicopter models 141

Channel 1 curve

Control characteristics for throttle/collective pitch stick

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Channel 

1 curve« menu option in the Multi-function menu:

Servo adjustment

Stick mode

Switch display

Control adjust

Dual Rate / Expo

Channel 1 curve

Open this menu option with a tap on the center SET

key of the right four-way button:

Input

Output

Point ?

0%

0%

0%

Ch1 curve

Curve off

Since the carburetor response or the effect of collective pitch is often non-linear, you can make compensatory adjustments to these in this menu. 

The menu therefore enables modification of the control characteristics of the motor/collective pitch stick, 

regardless of whether this control function affects the 

servo connected to control channel 1 directly or affects multiple servos via various mixers.

If flight phases have been specified in the »Phase 

settings« and »Phase assignment« menus (see 

pages 156 and 158) this option can be adapted 

on a flight-phase basis. The given flight phase name, 

e.g. «normal», will be shown at the bottom left of 

the screen.

The control curve can be defined by up to 6 points 

(termed “reference points” below) placed anywhere 

along the path of stick travel. While the on-screen 

graph considerably simplifies the process of setting 

and adjusting the reference points, we recommend 

that you set fewer reference points to begin with.

Please note that the curve characteristic you set 

here acts as the input signal for specific mixers in the 

»Helicopter mixer« menu, page 188.

»Helicopter mixer«

Ch1 

Ch1  Tail rotor

Ch1-

curve

Pitch

Thro

Pitch

stick

In the basic software set-up, 2 reference 

points–namely the end-points at the bottom end of 

stick travel (“L”, low = -100% travel) and the top end 

of stick travel (“H”, high = +100% travel)–define a 

linear characteristic curve.

First, switch to your chosen flight phase, if necessary.

Setting reference points

By moving the transmitter control (motor/collective 

pitch stick), you can reposition the vertical line in the 

graph between the two end-points “L” and “H”. The 

current stick position is also displayed in numerical 

form on the “Input” line (-100% to +100%). The point 

at which this line crosses the curve is termed the 

“Output”, and can be varied at the reference points 

within the range -125% to +125%. The control signal altered in this way will then affect all subsequent 

mixer and coupling functions. 

In the example above, the stick is at 0% of control 

travel and also generates an output signal of 0%, 

since the characteristic curve is linear.

Up to 4 additional reference points can be set between the two end-points “L” and “H”, although the 

distance between neighboring reference points must 

not be less than approx. 25%. 

If necessary, use the left or right-hand arrow button 

to move the marker frame down to the “Point” line:

Input

Output

Point ?

0%

0%

0%

Ch1 curve

normal

Curve off

Move the stick. If a question mark can be seen in the 

“Point” frame, then the next reference point can be set 

with a tap on the center SET key of the right four-way 

button. Simultaneously, the “?” is replaced by a number and the value field to the right of the reference 

point number will be shown in inverse video:

1

+50%

+50%

+50%

normal

off

Input

Output

Point

Ch1 curve

Curve

The order in which you generate the (maximum) 4 

reference points between the end-points “L” and “H” is 

irrelevant, since the reference points are continuously 

renumbered automatically from left to right as they 

are entered.

Erasing reference points

To delete one of the reference points (1 to max. 4), 

use the stick to move the vertical line into the vicinity 

of the reference point in question. As soon as the 

reference point number and the associated value are 

superimposed in the “Point” line, you can activate the 

Value field by pressing the central SET button of the 

right-hand four-way button, then erase it by simultaneously pressing the  or  buttons of the righthand four-way button (CLEAR). A brief press of the 

central ESC button of the left-hand four-way button 

concludes the procedure. 

mc

 

16 20
142 Program description - Channel 1 curve | Helicopter models

Changing reference point values

Move the stick into the range of the reference point 

that is to be changed: “L” (low), 1 ... 4 or “H” (high). 

The number and current curve value of this point are 

displayed. Press the central SET button of the righthand four-way button to activate the Value field. The 

reference point value displayed in inverse video can 

be changed in a range of -125% to +125% without 

influencing the neighboring reference points.

Example:

2

+50%

–75%

–75%

normal

off

Input

Output

Point

Ch1 curve

Curve

In this sample screen image, reference point “2” has 

been set to -75%.

Note:

If the stick does not coincide with the exact reference 

point, please note that the percentage value on the 

“Output” line always relates to the current stick position.

Trim point function

Alternatively, jumping through active reference points, 

in ascending or descending order, can be done with 

the  selection keys of the left four-way button. 

Note that “active” reference points are those which 

have already been set. When a jump is made from 

one to another, the point value field for the jump’s 

destination reference point in the screen’s Point line 

will be displayed in inverse video and its position in 

the graph will be marked (L, 1 ... max. 4 and H) in 

inverse video and with a small triangle. The selection 

keys on the right four-way button can then be used to 

change the reference point jumped to as described 

above, entirely independently of the control position.

2

+50%

–75%

–75%

Trim point

normal

Input

Output

Point

Ch1 curve

One touch on the center ESC key of the left four-way 

button terminates this trim point function.

Trim offset function

When a value field is active, i.e. in inverse video, it is 

not only possible, as previously described, to jump 

to and change a reference point already set with the 

 selection keys of the left four-way button but also 

an existing curve can be vertically repositioned with 

the  keys of the left four-way button within a range 

of ±25%:

1

0%

+50%

+50%

Trim offset

normal

Input

Output

Point

Ch1 curve

1

0%

0%

0%

Trim offset

normal

Input

Output

Point

Ch1 curve

A tap on the center ESC key of the left four-way button will also terminate this function.

Trim x-axis function

This function is activated by tapping the left () or 

right () selection key of the right four-way button 

with an active (i.e. inverse video) value field. You can 

then use the selection keys on the right four-way button to reposition the active point horizontally or vertically as you wish:

?

0%

–33%

0%

Trim X-axis

normal

Input

Output

Point

Ch1 curve

Notes:

• If the point is repositioned horizontally further 

away from the current control position than approx. 

±25%, a “?” sign will reappear in the line Point. 

This question mark does not refer to the repositioned point, however: instead, it signifies that a 

further point can be set at the current control position.

• Please note that the percentage value on the “Output” line always relates to the current stick position 

and not to the position of the point.

Smoothing the Channel 1 curve

In the example below, sample reference points have 

been set: 

reference point 1 to 0%,

reference point 2 to +25% and

reference point 3 to -75%

as described in the last section:

1

–50%

0%

0%

normal

off

Input

Output

Point

Ch1 curve

Curve

This “jagged” curve profile can be smoothed automatically simply by pressing a button. 
Program description - Channel 1 curve | Helicopter models 143

Starting from the situation in the previous illustration, 

first press the SET button of the right-hand four-way 

button to conclude the procedure. Use the Select button  of the right-hand four-way button to move up to 

the Value field of the “Curve” line, then press the SET

button of the right-hand four-way button once more:

1

–50%

0%

0%

off

normal

Input

Output

Point

Ch1 curve

Curve

Now press one of the Select buttons of the right-hand 

four-way button in order to switch from “(Curve) off” to 

“(Curve) on” (or vice versa).

1

–50%

0%

0%

on

normal

Input

Output

Point

Ch1 curve

Curve

Note:

The curves shown here are for demonstration purposes only and are not at all representative of real 

throttle or airbrake curves. A specific application 

example can be found in the programming examples 

on page 285 and 323. 
144 Program description - Switch display

Switch display

Displaying switch positions

This option is available as standard on the 

mc-20 HoTT transmitter only.

Use the selection keys of the left or right 

four-way button to scroll to the »Switch 

display« menu option in the Multi-function menu:

Switch display

Control switch

Channel 1 curve

Phase settings

Phase assignment

Logical switch

Open this menu option with a tap on the center SET

key of the right four-way button:

Switch

Control Switch

C1 C3 C4

1 2 3 5

6 7 8 9 10

11 12 13 14 15

4

C2

This feature is used to check the functions and give 

an overview of switches 1 ... 15 and the programmable control switches C1... C4.

If a switch is pressed, the switch number is revealed 

by one of the display items changing from an OFF to 

an ON symbol (or vice versa). To improve the legibility 

of this screen, a closed switch field is also shown in 

inverse video (i.e. on a dark background).

For control switches C1 ... C4, activation of the corresponding transmitter control–which must have 

been previously assigned on the »Control switch« 

menu–will reveal the control switch number and 

direction.

Note:

Switch numbering 1 to 15 as shown here corresponds 

to the labeling of switch plug-in locations on the transmitter’s circuit board and not necessarily to the numbering of the transmitter’s switch board. The numbering of the switches has no effect on the programming 

of the transmitter, however. 

mc

 

16 20
Program description - Control switches 145

Control switches

Programming the control switches

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Control 

switch« menu option in the Multi-function menu:

Switch display

Channel 1 curve

Phase settings

Phase assignment

Logical switch

Control switch

Open this menu option with a tap on the center SET

key of the right four-way button:

SEL

0%

0%

0%

C1

C2

C3

C4 –––

Control switch

Gb1 0%

STO

–––

–––

–––

SEL

With many functions, it makes sense not to trigger 

their actuation by using one of the normal switches, 

but to trigger them automatically by the specific, freely 

programmable position of a transmitter control or 

stick.

Typical applications:

• On/Off switching of an on-board glow plug in conjunction with the carburetor setting and/or motor 

speed. (The glow plug heater switch for this will be 

controlled by a transmitter-side mixer.)

• Switching a stopwatch on or off to measure the 

simple running time of electric motors

• Automated switch-off of a combi “aileron  rudder” mixer when extending the airbrakes, e.g. so 

as to match the bank attitude of the model to the 

ground slope when landing on a ridge, without the 

direction of flight also being affected by the rudder 

(if the mixer were active).

• Lowering landing flaps, adjusting elevator trim 

and/or executing specific Dual Rate, Exponential 

and Differential switchings when coming in to land, 

as soon as the throttle stick is moved beyond the 

switching point. If required, a control switch can be 

overridden using a separately assigned switch in 

the 5th column.

The programs of the transmitters mc-16 HoTT and 

mc-20 HoTT are equipped with a total of four socalled control switches (“C1” to “C4”).

Accordingly, anywhere where switches can be assigned you have the option not only of using the 

maximal 19 possible transmitter switches, but also of 

choosing and assigning one of the “C1” ... “C4” control switches from the list of expanded switches–as 

described in the section “Physical control, switch and 

control switch assignments” on page 68.

Furthermore, combining a control switch with an additional switch (as described later) also permits more 

complex switching permutations.

Basic procedure:

1. If no transmitter control is assigned, the corresponding input field of the column labeled SEL

(second column from the left) will be empty.

2. Use the selection keys of the left or right four-way 

button to select the line for the desired control 

switch (1 to 4).

3. Briefly tap the center SET key of the right four-way 

button .

4. Move your selected transmitter control.

The associated transmitter control number appears in the input field of the column above the left 

SEL.

5. Use the selection keys on the left or right four-way 

button to move to the right into the column labeled 

STO.

6. Move the transmitter control to the desired switching point then briefly tap on the center SET key 

of the right four-way button to save the switching 

point.

7. Complete the remaining settings such as switching direction, etc.

8. Exit from the menu with a tap on the center ESC

key of the left four-way button .

Assigning a transmitter control to a control 

switch

Using the selection keys on the left or right four-way 

button, select your chosen line (1 to 4). Following a 

final tap on the center SET key of the right four-way 

button to activate the control assignment, the message shown below will appear in the display:

SEL

0%

C1

C2

C3

C4 –––

Control switch

STO

–––

–––

–––

SEL

Move desired

control adj.

For example, the right-side proportional slider is now 

to be assigned to control switch “C1”, the default 

throttle limiter for a helicopter model memory. So just 

move this control in any direction. As soon as this is 

detected, the control name appears on the display:

SEL

0%

0%

0%

C1

C2

C3

C4 –––

Control switch

Lv2 0%

STO

–––

–––

–––

SEL

Resetting a control switch back to “free”

To reset a control switch back to “free”, make sure the 

display is as below ...

mc

 

16 20
146 Program description - Control switches

SEL

0%

C1

C2

C3

C4 –––

Control switch

STO

–––

–––

–––

SEL

Move desired

control adj.

... then, with a brief simultaneous tap on the  or 

 keys of the right four-way button (CLEAR), the 

entry for a control will be erased.

Defining the switching point

Using the  selection key of the left or right four-way 

button to move the marker frame into the column 

labeled STO (store).

Move the selected transmitter control to the position 

at which the switching point, i.e. the switch between 

OFF/ON, should trigger and briefly tap the center 

SET key of the right four-way button. The current 

position is displayed, for example “+85%”:

SEL

0%

0%

0%

C1

C2

C3

C4 –––

Control switch

Lv2 +85%

STO

–––

–––

–––

SEL

The switching point can be altered at any time with 

another tap on the center SET key of the right fourway button.

Note:

Do not, however, set a switching point at a transmitter control’s travel end-point, since this makes reliable switching impossible. If a 2-way or 3-way switch 

is used to operate a control switch, the switch point 

should be programmed in advance with one of the 

transmitter’s proportional controls.

First, assign the corresponding proportional control 

in the 2nd column and set the switching point in such 

a way that will ensure the subsequent configuration 

for the 2-way or 3-way switch will reliably exceed 

this value. If you do not, the switching function will 

be unreliable, since the control switch triggers only 

if a value unambiguously fails to meet or exceeds 

the value set! To complete the procedure, cancel the 

transmitter control assignment then assign the 2-way 

or 3-way switch.

Setting the switching direction

The switching direction of the control switch is 

changed as required in the 4th column. Use the 

selection key of the left or right four-way button to 

move the marker frame into the column labeled SEL

(select). Following a brief tap on the center SET key 

of the right four-way button, the switch direction can 

by changed back-and-forth between “normal” and 

“reversed” with the selection keys of the left or right 

four-way button:

SEL

0%

0%

0%

C1

C2

C3

C4 –––

Control switch

Lv2 +85%

STO

–––

–––

–––

SEL

SEL

0%

0%

0%

C1

C2

C3

C4 –––

Control switch

Lv2 +85%

STO

–––

–––

–––

SEL

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the switch 

direction back to “=>”.

The current switch position of the control switch is 

displayed in the leftmost column by the switch icon 

next to the number of the control switch.

Notes:

• In this example control switch ”C1” is open as long 

as transmitter control “Lever 2” (the throttle limiter for a helicopter) is less than +85% of control 

travel. It closes once the switching point is exceeded, i.e. by a value over +85% and up to the upper limit.

• In the above example with the switching direction 

reversed, control switch “C1” remains closed while 

the transmitter control is at less than +85% of full 

travel. As soon as the switching point is exceeded, 

in this example a value between +85% and the 

upper travel end-point, “C3” will open.

• If a control switch–e.g. “C1”–has multiple assignments, you should bear in mind that the switching 

direction set here applies to all C3 switches.

• The switch state can also be inverted by reversing 

the control in the »Control adjust« menu.

Combining a control switch with a switch

The control switch can be overridden by a further 

switch, so that e.g. in certain flight situations the function to be triggered can be activated independently of 

the control position and thus the position of the control switch.

Change to the value field in the 5th column, the column above the rightmost switch symbol. In the simplest case, select one of the switches mounted in the 

two switch panels, as described in the section “Physical control, switch and control switch assignments” 

on page 68. The number of this switch, e.g. “10”, 

appears on the display in the next-to-the last column 

at the right, together with a switch icon indicating the 

switch’s current state.
Program description - Control switches 147

SEL

0%

0%

0%

C1

C2

C3

C4 –––

Control switch

Lv2 +85%

STO

–––

–––

SEL

10

While this switch is open, the “C1” control switch 

is active, i.e. it triggers at the switching point; if the 

switch is closed, the control switch now remains permanently closed as well, independently of the control 

position and switching direction:

SEL

0%

0%

0%

C1

C2

C3

C4 –––

Control switch

Lv2 +85%

STO

–––

–––

SEL

10

Combining two control switches

For more complex applications, however, it can prove 

necessary to override this control switch with a second control switch.

Example:

Control switch “C1” will now be assigned to control 

function 3 (= control 3) instead of its previous assignment “Lever2”. The switching point is at its center 

point, i.e. at 0%. The switch chosen in the next-tothe-last right column is “C2” from the list of expanded 

switches. This “C2” control switch will now be allocated in its own line to the right proportional slider 

“Slide2”, whose switch-point is +50%:

SEL

0%

0%

+50%

C1

C2

C3

C4 –––

Control switch

STO

–––

–––

Cn3 C2

Sl2

0%

SEL

The switching directions indicated in the fourth column from the left will now show control switch “C2” as 

being closed as long as stick (control 3) and/or “Slide 

2” are located on the other side of their switch-points.

Application

In order to make these control switches usable, they 

can be specified in those menus which use switches 

by calling them up via the additional “expanded 

switches” selection menu:

Move desired switch

to ON position

(ext. switch: SET)

A brief tap on the center SET key of the right four-way 

button will afford access to the expanded switches:

Control/Logic/fix sw

C2 C3 C4 FX

FXi L1 L2 L3 L4

C1

Now use the selection keys to pick the desired control 

switch “C1 ... C4”, fixed switch “FX” or logical switch 

“L1 ... L8” or the respected inverted switch “C1i ... 

C4i”, “FXi” or “L1i ... L8i”, for example, “C3”:

Control/Logic/fix sw

C2 C4 FX

FXi L1 L2 L3 L4

C1 C3

A brief tap on the center SET key of the right four-way 

button will adopt the selected switch into the menu:

8

7

15

VOICE TRIGGER

REPEAT 10SEC

TRIG

TRANSMITTER

RECEIVER

VARIO

Note regarding the inverted switches:

If you select an inverted switch during the assignment 

process–e.g. “G3i” instead of “G3”–the only difference is that the switching direction is simply reversed, 

i.e. if a particular switch is intended to activate a 

function–e.g. a mixer–when turned on, then the 

same switch with the “i” suffix (= inverted) activates 

this function when it is turned off. Typical applications 

might be a need for one and the same switch to turn 

one function on, and simultaneously to turn a second 

function off, and vice versa. These facilities, especially when used in conjunction with logical switches 

(described in the following section) can be exploited 

to cope with extremely complex switching systems.
148 Program description - Logical switches

Logical switches

Programming logical switches

This option is available as standard on the 

mc-20 HoTT transmitter only.

Use the selection keys of the left or right 

four-way button to scroll to the »Logical 

switches« menu option in the Multi-function menu:

Switch display

Channel 1 curve

Phase settings

Phase assignment

Control switch

Logical switch

Open this menu option with a tap on the center SET

key of the right four-way button:

AND

AND

AND

L1

L2

L3

L4 –––

Logical switch

AND

–––

–––

–––

SEL

L1

L2

L3

––– L4

–––

–––

–––

This function, which is available as standard on the 

mc-20 HoTT and can be unlocked on the mc16 HoTT as an extra-cost option, can be used to 

link together two switches, control switches and / or 

logical switches, or any combination of the above, in 

an “AND” or “OR” arrangement. A total of eight logical switches “L1 ... L8” can be programmed in every 

model memory.

The result of such a logical switch function–shown 

in the display’s rightmost column–can be used as 

another switch function. Allocation of a switch to a 

logical function is done in the familiar manner in the 

columns labeled by the two switch symbols, as described in the section “Physical control, switch and 

control switch assignments” on page 68. That is, 

by moving the respective switch from OFF to ON or, 

after a tap on the center SET key of the right four-way 

button, by selecting one of the expanded switches 

with the selection keys:

L4 AND

Logical switch

SEL

L4

Move desired switch

to ON position

(ext. switch: SET)

Logical switch

SEL

Control/Logic/fix sw

C2 C3 C4 FX

FXi L1 L2 L3 L4

C1

Potential applications for this:

Multiple functions, which are normally independent of 

one another, are to be put into a defined state by way 

of an »Emergency switch«.

“AND” / “OR”

Once a given value field has been activated in the 

column labeled SEL, the “AND” and “OR” logic operator can be selected with the selection keys.

• “AND” function

The logical switch is only closed when both input 

switches are closed.

• “OR” function

The logical switch is closed when at least one of 

the input switches is closed.

Note:

The difference between AND and OR logic switches 

is made clear by the settings and input states of the 

display figure below.

OR

AND

AND

L1

L2

L3

L4 –––

Logical switch

AND

4

2 L1

L2

L3

––– L4

3

1

SEL

L1 L2

“L3” is only closed when both the “L1” and “L2” 

switches are closed. This means that both switches, 

1 and 2, must be closed and, at the same time, either 

3 or 4.

Anwendung

In order to make these logical switches usable, they 

can be specified in those menus which use switches 

by calling them up via the additional “expanded 

switches” selection menu:

Move desired switch

to ON position

(ext. switch: SET)

A brief tap on the center SET key of the right four-way 

button will afford access to the expanded switches:

Control/Logic/fix sw

C2 C3 C4 FX

FXi L1 L2 L3 L4

C1

Now use the selection keys to pick the desired control 

switch “C1 ... C4”, fixed switch “FX” or logical switch 

“L1 ... L8” or the respected inverted switch “C1i ... 

C4i”, “FXi” or “L1i ... L8i”, for example, “L3i”:

Control/Logic/fix sw

C2i C3i C4i L1i L2i

L3i L4i L5i L6i L7i

A brief tap on the center SET key of the right four-way 

button will adopt the selected switch into the menu:

mc

 

16 20
Program description - Logical switches 149

Model time

Batt. time

Top :

Centr:Flight

Alarm

12:34h –––

1:23h

0s

0s

Stop L3I

L3I

SEL

Remark about inverted switches:

Selection of an inverted switch for a switch assignment, e.g “L1i” instead of “L1”, simply specifies the 

opposite switch direction (state), i.e. non-inverted 

usage results in a certain switch activating a particular function when it is in its switched-on state but 

inverted usage results in a certain switch activating a 

particular function when it is in its switched-off state. 

Such applications arise when, for example, one and 

the same switch is to switch one function on but, at 

the same time, it is to switch a second function off, 

and vice versa. Logical switches permit other, quite 

complex, switching options to be created. 
150 How is a flight phase programmed?

How is a flight phase programmed?

The concept of flight phase programming

General information on flight phase programming

During a flight, you will often want to apply different 

settings–e.g. flap or trim settings for a fixed-wing 

aircraft or collective pitch and throttle servo settings 

for a helicopter–at particular times in the flight (e.g.

take-off, approach, hover, auto-rotate, etc.). With 

transmitters mc-16 HoTT and mc-20 HoTT, you 

can access such presets automatically using switches 

or control switches.

Flight phases are also of great utility during flight 

testing. You can configure various set-ups and then 

switch between them during the flight: this enables 

you to identify the most appropriate program set-up 

for your model quickly and easily.

The basic programming procedure is a threestage process

1. First, you have to set up the different flight phases, 

i.e. you assign names to phases 1 ... max. 7. Each 

name is then shown in all phase-specific menus 

and also on the basic display. To avoid abrupt transitions when switching between the various phases, you can also program a period of time during 

which a “soft” transition to the next phase takes 

place.

For fixed-wing aircraft programs, these settings are made in the »Phase settings« menu. 

The programming of helicopters begins with either the »Basic settings, model« menu, if you 

wish to set up autorotation or, otherwise, with the 

»Phase settings« menu.

2. In the second stage, you use the »Phase assignment« menu to set up the required “phase switches”.

3. Once these are set, you can then move to the 

flight phase-dependent menus (see the tables below) to start programming the settings for the individual flight phases.

List of the flight phase relevant menus which are 

available as standard () and as extra-cost options () in the fixed-wing program of the ...

... transmitter mc-16 HoTT:

 Menu Page

 »Control adjust« 118

 »Dual Rate / Expo« 130

 »Channel 1 curve« 138

 »Phase settings« 152

 »Phase assignment« 158

 »Phase trim« 160

 »Non-delayed channels« 161

 »Flight phase timers« 166

 »Wing mixers« 170

 »Mix active / phase« 215

 »Trim memory« 236

... transmitter mc-20 HoTT:

 Menu Page

 »Control adjust« 118

 »Dual Rate / Expo« 130

 »Channel 1 curve« 138

 »Phase settings« 152

 »Phase assignment« 158

 »Phase trim« 160

 »Non-delayed channels« 161

 »Flight phase timers« 166

 »Wing mixers« 170

 »Mix active / phase« 215

 »Trim memory« 236

List of the flight phase relevant menus which are 

available as standard () and as extra-cost options () in the helicopter program of the ...

... transmitter mc-16 HoTT:

 Menu Page

 »Control adjust« 122

 »Dual Rate / Expo« 134

 »Channel 1 curve« 141

 »Phase settings« 156

 »Phase assignment« 158

 »Non-delayed channels« 161

 »Flight phase timers« 166

 »Helicopter mixer« 188

 »Mix active / phase« 215

 »Trim memory« 238

... transmitter mc-20 HoTT:

 Menu Page

 »Control adjust« 122

 »Dual Rate / Expo« 134

 »Channel 1 curve« 141

 »Phase settings« 156

 »Phase assignment« 158

 »Non-delayed channels« 161

 »Flight phase timers« 166

 »Helicopter mixer« 188

 »Mix active / phase« 215

 »Trim memory« 238

 All other menus are model-specific and thus cannot 

be programmed separately for each flight phase. Accordingly, changes you make in all other menus apply 
How is a flight phase programmed? 151

uniformly to all flight phases for that specific model. 

In some cases it may be desirable to use the »Suppress codes« menu (see page 84) to remove 

non-alterable menus from the multi-function list while 

programming flight phases. Two examples of flight 

phase programming can be found in the text beginning on page 298.
152 Program description - Phase settings | Winged models

Phase settings

Setting up flight phases

Setting up flight phases

When you set up flight phases for fixed-wing aircraft 

models, you start with this menu. You assign individual phases a name and also assign a period of time for 

a (soft) transition into each phase. Note that–depending on your model and your settings–switch times 

much longer than the default 0.1s have proven useful. You can also set up several phases with names 

and transition times even if you don’t currently have 

a use for them, since the decision as to which of the 

“occupied” phases you activate is made only on the 

»Phase assignment« menu, page 158, when setting “phase switches”.

Whether or not one of the phases 1 ... 7 currently has 

an assigned switch and the state of the switch can be 

seen in the “status” column second from left:

Symbol Meaning

– No switch assigned

+ Phase can be accessed via switch

 Indicates the phase currently active

Note:

The “Copy flight phase” option on the »Copy / Erase« 

menu is a useful aid when programming the various flight phases. First, you need to determine the 

parameters for a specific flight phase; these are then 

copied to the next flight phase, where they can then 

be modified as appropriate.

“Name” column

Briefly tap on the center SET key of the right four-way 

button then assign the needed phases (phase 1 up to 

maximum of 7 phases) by picking their names from 

the selection list with the selection keys of the left or 

right four-way button. 

The order in which phases 1 to max. 7 are assigned 

is entirely irrelevant and you can leave gaps as you 

wish. Nonetheless, you should always start with 

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Phase 

settings« menu option in the Multi-function menu:

Phase settings

Phase assignment

Phase trim

Logical switch

Timers (general)

Non-delayed chan

Open this menu option with a tap on the center SET

key of the right four-way button.

Within one model memory, the transmitters mc-16

HoTT and mc-20 HoTT lets you program up to 7 

discrete groups of settings for various conditions met 

during the flight. The grouped settings are typically 

termed “flight phases” and are programmed in the 

corresponding menus.

Depending on the setting in the “Motor at Ch1” line of 

the »Model type« menu (“Throttle min. forward/back” 

or “none”), your transmitter’s screen will offer you the 

additional columns “Motor” and “Sw.time” (transition 

time) or just the column “Sw. time” (transition time) for 

your settings to the right of the “ph. Tim” (flight phase 

timers) when you call up the »Phase settings« menu 

point ...

Pha1

Pha2

Pha3

Name ph.Tim.

Pha4

Pha5

–

–

–

–



“Phase 1”, the “Normal phase”, which is always active 

if ...

• ... no phase switch is set in the »Phase assignment« menu or if

• no phase has been assigned to specific combinations of switches.

The definition of the phase name “Normal” could 

therefore be a useful one to adopt for “Phase 1”. 

The names themselves have absolutely no technical 

significance for programming; their only purpose is to 

help you to identify which phase is active at any time 

and are thus displayed in all flight phase-dependent 

menus and also on the transmitter’s basic display.

Column “ph.Tim.”

In addition to the standard timers on the basic screen 

display, other timers are also available whose settings 

are configured in the »Flight phase timers« menu, 

page 166.

Clk 1, Clk 2, Clk 3, Lap, Time1, Time2

The flight phase timers “Clk 1 ... 3” plus “Time1” and 

“Time2” run only in the flight phase to which they 

have been assigned in this menu. During other flight 

phases they are stopped (and hidden) and the assigned stop/start switch then has no effect.

The lap counter, once started, continues to run 

through changes of phase, however, although it can 

be stopped during any flight phase via the center 

ESC key of the left four-way button.

While you can obviously record lap times using “Lap” 

and a switch, the two timers “Time1” and “Time2” 

have the following meaning:

• Time1

This timer will only measure time during which the 

switch or control switch assigned in the “Lap time/

Tim tab” line of the »Flight phase timers« menu, 

page 166, is “closed”. The frequency at which the 

switch is activated is shown on the basic display. 

mc

 

16 20
Program description - Phase settings | Winged models 153

This counter field is highlighted as soon as the 

switch for the “Time1” timer is “opened”, i.e. the 

timer is stopped:

GRAUBELE

#01

2:22h

Stp

Flt

«Speed »

0:00

0:00

5.5V

3.9V 0:00.0

M

Time1 00

When necessary, the selection keys can be used 

to access and read the sequence of switching 

times.

Application:

Measurement of e.g. motor switch-on times, if the 

same switch also actuates the motor.

• Time2

This timer stores both the “off” and the “on” periods for the associated switch, i.e. every switch actuation in either direction will cause a record to be 

written for the timer, the timer will be reset then 

starts incrementing by “1” again as time passes.

Each time count can be suspended with the center ESC key of the right four-way button, without 

actuating the switch itself. Activating the switch, in 

turn, increments the counter by 1 and restarts the 

“Time2” timer.

In order to read out the time memory with the selection keys, the “Time2” timer must first be suspended by using the ESC key of the right four-way 

button.

Application:

In addition to the motor runtimes, for example, the 

unpowered glide times between these could also 

be recorded.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset suspended 

timers shown in the basic display.

Column “Motor”

Note:

This column is only available if “forward/back” is 

present in the “Motor on C1” line of the »Model type« 

menu. 

Pha1

Pha2

Pha3

Name motor

Pha4

Pha5



+

+

Normal

Launch

Dist.

–

–

yes

yes

yes

yes

yes

• “yes”

The motor connected to receiver output 1 will be 

controlled by the C1 stick (throttle/brake stick).

The brake system to be set up on the »Wing mixers« menu is deactivated:

Brake settings

normal

OFF

• “no”

The motor connected to receiver output 1 is decoupled from the C1 stick (throttle/brake stick) and 

is held in its OFF position–as specified by the setting “Throttle min. forward / back”–automatically.

The brake system to be set up in the »Wing mixers« menu is activated and is actuated by the C1 

stick:

Elevat curve

Brake settings

AILE

Crow

D.red

0%

0%

normal

Note:

The settings available depend on the number of 

control surface servos selected on the line “Ailerons/Camber-changing flaps in the »Model type« 

menu.

Column “Sw. time”

When you switch between flight phases, it is advisable to use this column to program a switch time for a 

“soft” transition INTO (!) the respective phase. Accordingly, there is also an option for specifying a different 

time for the switchover from any phase to, for example, Phase 3 than for a switchover to Phase 1.

Use the  selection key of the left or right four-way 

button to move the marker frame to the right beyond 

the column labeled “Timer” and, if applicable, also the 

column labeled “Motor”.

Pha1

Pha2

Pha3

Name Sw.time

Pha4

Pha5



+

+

Normal

Launch

Dist.

–

–

0.1s

0.1s

0.1s

0.1s

0.1s

Following a brief tap on the center SET key of the 

right four-way button, the switchover time value in the 

field displayed in inverse video can be changed within 

a range of 0 and 9.9s: 
154 Program description - Phase settings | Winged models

Example:

Pha1

Pha2

Pha3

Name

Pha4

Pha5



+

+

–

–

3.0s

2.0s

0.1s

0.1s

Sw.time

Normal

Launch

Dist.

4.0s

The switchover time from any other phase to Phase 1 

«normal» will take 4,0 s. 

The time for a switchover from, for example, Phase 1 

to Phase 3, is set to 2,0s and the time for a switchover from Phase 1 or 3 to Phase 2 “Launch” is 3,0s.

Such asymmetric transition times can be useful when, 

e.g. switching between extremely different flight phases, such as between aerobatics and normal flight.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the time in 

the currently active value field back to 0,1s.

Note:

The “switch time” set here applies uniformly to all 

settings that are specific to flight phases, and thus to 

all mixers activated in the »Wing mixers« menu, see 

page 170. Accordingly, the transition between flight 

phase-specific mixers does not occur abruptly. However, if individual servos are to be switched without 

a delay then these can be defined accordingly in the 

»Non-delayed chan« menu, see page 161.
For your notes 155
156 Program description - Phase settings | Helicopter models

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Phase 

settings« menu option in the Multi-function menu:

Phase settings

Phase assignment

Logical switch

Timers (general)

Non-delayed chan

Fl. phase timers

Open this menu option with a tap on the center SET

key of the right four-way button.

Auto

Pha1

Pha2

Name ph.Tim.

Pha3 –

–

–

–

Pha4

 Autorot

Within one model memory, the transmitters mc-16

HoTT and mc-20 HoTT lets you program up to 6 

discrete groups of settings for various conditions met 

during the flight. These are in addition to the autorotation flight phase that can be set up in the »Basic 

settings, model« menu. The grouped settings are 

typically termed “flight phases” and are programmed 

in appropriate menus.

Setting up flight phases

When you set up flight phases for helicopter models, 

you start with this menu. You assign individual phases 

a name and also assign a period of time for a (soft) 

transition into each phase. Note that–depending on 

your model and your settings–switch times much 

longer than the default 0.1s have proven useful. You 

can also set up several phases with names and transition times even if you don’t currently have a use for 

Phase settings

Setting up flight phases

them, since the decision as to which of the “occupied” 

phases you activate is made only on the »Phase assignment« menu, page 158, when setting “phase 

switches”.

The “Status” column, second from the left, shows 

which one of the phases 1 ... 6, including the autorotation phase this is 7, has already been assigned to a 

switch, plus the current status of that switch:

Symbol Meaning

– No switch assigned

+ Phase can be accessed via switch

 Indicates the phase currently active

Note:

The “Copy flight phase” option on the »Copy / Erase« 

menu is a useful aid when programming the various flight phases. First, you need to determine the 

parameters for a specific flight phase; these are then 

copied to the next flight phase, where they can then 

be modified as appropriate.

Column “Name” 

The first line, and thus the first flight phase, is reserved for autorotation flight, see »Basic settings, 

model« menu. Accordingly, the predefined name 

cannot be changed.

Use the selection keys to move to the line “Phase 1”. 

Briefly tap on the center SET key of the right four-way 

button then assign the needed phase (phase 1 up 

to maximum of 6 phases) by picking the respective 

name from the selection list with the selection keys of 

the left or right four-way button. 

The order in which phases 1 to max. 6 are assigned 

is entirely irrelevant and you can leave gaps as you 

wish. Nonetheless, you should always start with 

“Phase 1”, the “Normal phase”, which is always active 

if ...

• ... no phase switch is set in the »Phase assignment« menu or if

• no phase has been assigned to specific combinations of switches.

The definition of the phase name “Normal” could 

therefore be a useful one to adopt for “Phase 1”. 

The names themselves have absolutely no technical 

significance for programming; their only purpose is to 

help you to identify which phase is active at any time 

and are thus displayed in all flight phase-dependent 

menus and also on the transmitter’s basic display.

Column “ph. Tim.” 

In addition to the standard timers on the basic screen 

display, other timers are also available whose settings 

are configured in the »Flight phase timers« menu, 

page 166.

Clk 1, Clk 2, Clk 3, Lap, Time1, Time2

The flight phase timers “Clk 1 ... 3” plus “Time1” and 

“Time2” run only in the flight phase to which they 

have been assigned in this menu. During other flight 

phases they are stopped (and hidden) and the assigned stop/start switch then has no effect.

The lap counter, once started, continues to run 

through changes of phase, however, although it can 

be stopped during any flight phase via the center 

ESC key of the left four-way button.

While you can obviously record lap times using “Lap” 

and a switch, the two timers “Time1” and “Time2” 

have the following meaning:

• Time1

This timer will only measure time during which the 

switch or control switch assigned in the “Lap time/

Tim tab” line of the »Flight phase timers« menu, 

page 166, is “closed”. The frequency at which the 

switch is activated is shown on the basic display. 

This counter field is highlighted as soon as the 

switch for the “Time1” timer is “opened”, i.e. the 

timer is stopped:

mc

 

16 20
Program description - Phase settings | Helicopter models 157

STARLET

#02

2:22h

Stp

Flt

«Speed »

0:00

0:00

5.5V

3.9V 0:00.0

M

Time1 00

When necessary, the selection keys can be used 

to access and read the sequence of switching 

times.

Application:

Measurement of (e.g.) flight phases with increased motor speed, if the same switch is used 

to actuate flight phase switching.

• Time2

This timer stores both the “off” and the “on” periods for the associated switch, i.e. every switch actuation in either direction will cause a record to be 

written for the timer, the timer will be reset then 

starts incrementing by “1” again as time passes.

Each time count can be suspended with the center ESC key of the right four-way button, without 

actuating the switch itself. Activating the switch, in 

turn, increments the counter by 1 and restarts the 

“Time2” timer.

In order to read out the time memory with the selection keys, the “Time2” timer must first be suspended by using the ESC key of the right four-way 

button.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset suspended 

timers shown in the basic display.

Column “Sw. time” 

When you switch between flight phases, it is advisable to use this column to program a switch time for a 

“soft” transition INTO (!) the respective phase. Accordingly, there is also an option for specifying a different 

time for the switchover from any phase to, for example, Phase 3 than for a switchover to Phase 1.

However, for reasons of safety, transition into the 

autorotation flight phase should ALWAYS be set to 

switch without any time delay. The arrow “->” in the 

column labeled “Sw.time” at the end of the “Autorot” 

line indicates that a delay can be set when transitioning FROM (!) autorotation INTO (!) another phase.

Use the  selection key of the left or right four-way 

button to move the marker frame to the right beyond 

the “ph.Tim.” column:

Pha1

Pha2

Pha3

Name Sw.time

Pha4



+

+

Normal

Hover

–

–

0.1s

0.1s

0.1s

0.1s

0.1s

Speed

Auto Autorot

Following a brief tap on the center SET key of the 

right four-way button, the switchover time value in the 

field displayed in inverse video can be changed within 

a range of 0 and 9,9s.

Example:

Pha1

Pha2

Pha3

Name Sw.time

Pha4



+

+

Normal

Hover

–

–

3.0s

2.0s

5.5s

4.0s

0.1s

Speed

Auto Autorot

A delay of 5,5s applies when switching FROM autorotation into any other phase. A delay of 0,0s always 

applies when switching TO auto-rotation.

The switchover time from any other phase to Phase 1 

«normal» will take 3,0s.

When switching from e.g. Phase 1 to Phase 3, the 

switch time is set to 4,0s.

Such asymmetric transition times can be useful when, 

e.g. switching between extremely different flight phases, such as between aerobatics and normal flight.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the time in 

the currently active value field back to 0,1s.

Note:

The “switch time” set here applies uniformly to all 

settings that are specific to flight phases, and thus to 

all mixers activated in the »Helicopter mixer« menu, 

see page 188. Accordingly, the transition between 

flight phase-specific mixers does not occur abruptly. 

If you want individual servos to be switched without 

a delay, however, define these accordingly in the 

»Non-delayed channels« menu, see page 161, 

which is available as standard on the mc-20 HoTT 

transmitter only.
158 Program description - Phase assignment

Phase assignment

Setting up flight phases

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Phase 

assignment« menu option in the Multi-function menu:

Phase settings

Phase trim

Logical switch

Timers (general)

Non-delayed chan

Phase assignment

Fl. phase timers

Phase settings

Logical switch

Timers (general)

Non-delayed chan

Phase assignment

Open this menu option with a tap on the center SET

key of the right four-way button.

Phase assignment

prior.

A B C D E F 

1 

combi

Note:

A phase name appears to the right of the phase 

number at the bottom right of the display only if you 

have assigned the name beforehand on the »Phase 

settings« menu.

In the »Phase settings« menu, described above 

separately for fixed-wing and helicopter models, 

you will have set up names for your phases. On this 

menu–which is identical for both model types–you 

must now specify the switches or switch combinations that you want to use to trigger each phase. One 

exception for helicopter menu: one of the two autorotation switches must be set on the menu »Basic 

settings, model«.

Please note the following priorities:

• If no flight phase switches nor these names have 

been assigned in this menu, the model is in flight 

phase “1”. Accordingly, by the time you start programming flight phases, you should therefore have 

already given this flight phase the phase name 

“Normal”.

• Independent of the phases with allocated switch 

settings made in this menu, the autorotation phase 

(only present for the “Helicopter” model type and 

to be assigned a switch in the »Basic settings, 

model« menu) always (!) takes precedence. Accordingly, as soon as the auto-rotation switch in 

question is activated, the following warning appears:

A B E F 

1 

Phase assignment

prior. combi

Autorot

• Phase switch “A” is given priority over all subsequent switch positions, from “B” to “F”

• Phase switch “B” is given priority over all subsequent switch positions, from “C” to “F”

• 3-way switches should always be assigned from 

the middle position.

Therefore use switch “A” and/or switch “B” only if you 

wish to change from any other flight phase–apart 

from the helicopter’s autorotation phase–directly into 

the phase that is assigned to this switch.

Programming flight phase switches

Once you have configured your desired switch position, “A” to “F”, using the selection keys on the left or 

right four-way button, a switch (whether a “normal” 

switch or an expanded switch) is then assigned as 

described in the section “Physical control, switch and 

control switch assignments” on page 68.

The order in which assignment is made is irrelevant: 

you must ensure only that you assign what are, for 

you, the “correct” switches. (In the helicopter program, 

for example, you should also take care to ensure you 

do not use this menu to re-assign any auto-rotation 

switch already assigned on the »Basic settings,

model« menu.)

Example: 4 flight phases with phase priority

A B C D E F 

1 normal

2 6 5

Phase assignment

prior. combi

Assigning flight phases to switch positions

Now that names have been assigned to the flight 

phases (1 ... max. 6) in the »Phase settings« menu 

and also programmed switches in this menu, but ... 

at the bottom right of the display screen, you only see 

<1 Normal >–regardless of the positions the switches 

are in!?

Use the selection keys on the left or right four-way 

button to move the marker frame down and to the 

right and then briefly tap the center SET key of the 

right four-way button:

mc

 

16 20
Program description - Phase assignment 159

A B C D E F 

2 6 5

1 normal

Phase assignment

prior. combi

Now close one (or more, as required) of the switches 

that you have assigned, and assign one of the flight 

phase names from the list you selected beforehand 

on the »Phase settings« menu to this switch position 

or combination. 

Here, for example, we assign the “Launch” phase to 

the closed (“I”) priority switch “A” ...

A B C D E F 

2 6 5

2 Launch

Phase assignment

prior. combi

... if, for example, we wish to switch to this phase 

regardless of the “C” ... “F” switch positions, because 

the same switch activates an electric motor, etc.

Use the same approach to set the other switches or 

combinations of switches.

Theoretically–for the situation where all three are 

closed–you could use the three single switches 

shown in the example to define an additional fifth 

flight phase on the »Phase settings« menu. However, since this example assumes just four flight 

phases, you can leave the default phase name as 

«1 Normal» for this switch position.

Leave this menu in the familiar way, with a tap on the 

center ESC key of the left four-way button.

Tips:

• If you have named more phases than you currently have switches defined for then this is not really problematic. You can repeat and change your 

switch assignment as you wish at any point in 

time. And you can also name additional phases at 

any time and then assign switches to them.

• When assigning switches, check whether the 

switches are already otherwise assigned to ensure 

that you avoid duplicate assignments.

Important notice:

Before a phase switch is assigned, the model settings configured are now to be found in the flight 

phase «1 Normal», i.e. all flight phase-dependent 

menus are reset to the standard configurations 

for all other flight phases.

To avoid having to start from scratch in every 

flight phase, you can copy over these standard 

settings by using the command “Copy flight 

phase” on the “Copy / Erase” menu to replace 

them with flight data obtained from the «Normal» 

flight phase. You then need only to make further 

flight phase-specific changes to the settings.
160 Program description - Phase trim | Winged models

Phase trim

Flap settings specific to flight phases

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Phase 

trim« menu option in the Multi-function menu:

Phase settings

Phase assignment

Logical switch

Timers (general)

Non-delayed chan

Phase trim

Open this menu option with a tap on the center SET

key of the right four-way button.

 0%

ELEV

Depending on the settings made on the “Aileron/camber flaps” line of the »Model type« menu, page 104, 

and in the »Phase settings« menu, page 152, this 

menu offers at least one control function for ELEV ...

Normal 0%

normal ELEV

... on the standard eight-channel mc-16 HoTT 

transmitter up to three control functions (ELE, AIL 

and FLAP) for flight phase specific trim settings. On 

the mc-16 HoTT transmitter with optional twelve 

channels, and the standard twelve-channel mc-20

HoTT transmitter, up to five control functions (ELE, 

AIL, AIL2, FLAP and FLAP2) for flight phase specific 

trim settings. The setting of the flight phase switches, 

to be defined beforehand in the »Phase assignment« menu, determines the line that is chosen. An 

asterisk marks the flight phase currently active. At the 

same time, the name of the respective flight phase 

is also shown at the bottom left of the screen. You 

can enter settings only for the currently active flight 

phase, e.g.:

Normal



0%

Launch ELEV

0%

AI

Launch

Thermal

Dist.

0% 0%

0% 0%

0% 0%

Column “ELEV”

In the column labeled “ELEV” a phase-specific elevator trim setting can be stored.

Important notice:

• Settings made in this column have an immediate 

effect on elevator trim and, accordingly, the trim 

setting display. 

• Please note in this context that the “elevator”, “aileron” and “rudder” trims are defined by default 

as “flight phase specific” on the mc-16 HoTT 

transmitter. However, this standard setting can 

be changed to “global” using the optional »Stick 

mode« menu, page 114, which can be unlocked 

as an extra-cost option.

• Please note in this context that the “elevator”, “aileron” and “rudder” trims are defined by default 

as “flight phase specific” on the mc-20 HoTT 

transmitter. However, this standard setting can 

be changed to “global” using the »Stick mode« 

menu, page 114.

Column “AI” and “FL” ...

... on the standard eight-channel mc-16 HoTT 

transmitter.

Column “AI”, “AI2”, “FL”, “FL2” ...

... on the mc-16 HoTT transmitter with optional 

twelve channels, as well as the mc-20 HoTT transmitter, which has twelve channels as standard:

The values in these columns (max. 4) are identical to those in the “Fl.pos” (flap position) line on the 

“Multi-flap menu” within the »Wing mixers« menu, 

see page 181. For this reason, any changes made 

always affect the other menu directly–and vice versa.

After selecting the appropriate column with the selection keys of the left or right four-way button and a 

brief tap on the center SET key of the right four-way 

button, these values can be entered, independent of 

one another, with the selection keys within a range of 

±150%.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in the currently active value field back to 0%. 

mc

 

16 20
Program description - Non-delayed channel 161

Non-delayed channel

Channel-dependent delays to switching

This option is available as standard on the 

mc-20 HoTT transmitter only.

Use the selection keys of the left or right 

four-way button to scroll to the »Nondelayed channel« menu option in the Multi-function 

menu:

Phase settings

Phase trim

Logical switch

Timers (general)

Phase assignment

Non-delayed chan

Phase settings

Logical switch

Timers (general)

Fl. phase timers

Phase assignment

Non-delayed chan

Open this menu option with a tap on the center SET

key of the right four-way button.

Non-delayed channels

non-delay

normal

normal

1 2 3 4 5 6

On the »Phase settings« menu, you will have set the 

necessary switch times for flight phase transitions.

In this menu, which is available as standard on the 

mc-20 HoTT transmitter only, you can now disable 

the transition delay set previously, per flight phase 

and for individual control channels–e.g. for the motor 

channel for electric models or heading-lock systems 

for helicopter gyros, etc.

Switch over to the corresponding flight phase. This is 

shown at the bottom left of the display.

Use the selection keys of the left or right four-way button to move the “” onto the corresponding channel 

then briefly tap the center SET key of the right fourway button.

The switch icon changes from “normal” to “non-delay” 

and vice versa:

Non-delayed channels

non-delay

normal

normal

7 8 9 10 11 12

Note:

If you have an eight-channel mc-16 HoTT transmitter with the »Non-delayed channels« menu point 

unlocked, this display will only show control channels 

1 ... 8, reflecting the reduced number of channels.

mc

 

16 20
162 Program description - Timers (general) 

Timers (general)

Timers on the basic display

This option is available as standard on 

both transmitter types.

The default transmitter display shows a 

total of three timers. These are: the transmitter operating time on the left of the display, plus a 

“Top” and a “Centr” timer on the right of the display:

GRAUBELE

#01

0:00h

Stp

Flt

0:00

0:00

0.0V

4.1V

M

HoTT

Another, flight-phase specific timer can also be configured with settings in the two menus »Flight phase 

timers«, page 166, and »Phase settings«, pages 

152 and 156. This optional flight phase timer–such 

as the lap time timer–appears underneath the “Centr” 

(flight time) timer:

GRAUBELE

#01

2:22h

Stp

Flt

«Speed »

0:00

0:00

5.5V

3.9V 0:00.0

M

Time1 00

To configure the “Top” and/or “Centr” timer, use the 

selection keys on the left or right four-way button to 

access the menu option »Timers (general)« in the 

Multi-function menu:

Non-delayed chan

Timers (general)

Fl. phase timers

Wing mixers

Free mixers

MIX active/phase

Non-delayed chan

Timers (general)

Fl. phase timers

Helicopter mixer

Free mixers

MIX active/phase

Open this menu option with a tap on the center SET

key of the right four-way button:

Model time

Batt. time

Top :

Centr:

Stop

Flight

Timer

12:34h –––

1:23h

0:00

0:00

“Model time”

This timer shows the currently registered total access 

time to the currently active model memory location. If 

necessary, this automatic time acquisition can also be 

influenced by assigning an on/off switch to this “Model 

time” timer in the rightmost column labeled with 

the switch symbol. This timer can then be switched 

on and off as desired. This switch is assigned (and 

erased again as required) as described in the section 

„Physical control, switch and control switch assignments“ on page 68.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the time back 

to “0:00 h”.

“Batt. time”

This operating hours timer records the transmitter’s 

total switch-on time since the last time the battery 

was charged, thus monitoring the transmitter battery. 

A switch cannot be assigned to this function.

This timer is automatically reset to “0:00h” when the 

transmitter detects that the voltage of the battery is 

significantly higher than the last time it was switched 

on, e.g. as a result of a charge process or the installation of a replacement battery.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will also reset this time 

back to “0:00h”.

“Top” and “Centr”

These two timers are located at the top right of the 

basic display (see the screen image immediately to 

the left) and can be assigned a different name; their 

function and mode of operation varies according to 

the name you give them. Independently of the name 

each is given, the “Top” and “Centr” timer can be 

programmed to run any length of time forwards or 

backwards–see further below.

Use the selection keys of the left or right four-way 

button to select your desired timer and complete your 

selection with another tap on the center SET key of 

the right four-way button:

Timer

12:34h –––

1:23h

0:00

0:00

Stop

SEL

Model time

Batt. time

Top :

Centr:Flight

“Stop (watch)” or “Motor(runtime)”

Both of these two timer variants can be started and 

stopped using any of the available switches.

The timer defined as “Stopwatch” or “Motor runtime” 

sums the “ON” times continually, so that once your 

aircraft has landed, you can read off the sum of all 

switch “ON” times since the timer was last reset.

“Flight(time)”

This timer is especially for measuring flight time: it 

can be started with an assigned switch and stopped 

(once the switch has been re-opened) on the basic 

display with a tap on the center ESC key of the left 

mc

 

16 20
Program description - Timers (general) 163

four-way button. Once in a stopped state, it can be 

reset to its starting value with a simultaneous tap on 

the  or  keys of the right four-way button at 

the same time (CLEAR). 

If you wish to assign a control switch, you must first 

define the switch on the »Control switch« menu 

and specify the switching point along the travel of the 

transmitter control. As an example, the timer can then 

be started by “opening the throttle” or by opening the 

throttle limiter for helicopter models.

Note:

The combination of the flight time timer and stopwatch means that you can glance at the display at 

any time and see how long you have been flying 

since the timers were started, plus the total motor 

runtime within this particular period of flight time.

“Frame (time)”

The time frame timer is intended primarily for use by 

competition pilots, who are frequently given a timeframe within which they must complete certain tasks. 

The timer is started in precisely the same way as the 

flight time timer. To stop the timer, first ensure the 

timer switch is at its OFF position. Then touch and 

hold the  or  selection keys then touch the 

center ESC key.

Switch assignment

Use the  selection key of the left or right four-way 

button to move the marker frame next to the triangle 

as shown in the screen image shown below to the 

rightmost column of the relevant line:

Alarm

12:34h –––

1:23h

0s

0s

–––

–––

SEL

Model time

Batt. time

Top :

Centr:

Stop

Flight

Here, you assign a switch as described in the section 

„Physical control, switch and control switch assignments“ on page 68.

Typical application:

The “stop watch” and “flight timer” are both to be 

started simultaneously using the C1 stick as soon as 

a user-defined switching point is exceeded.

For this purpose, define a control switch, e.g. “C1”, in 

the »Control switch« menu, page 145. To complete 

the procedure, you select this from the expanded 

switches (see the section „Physical control, switch 

and control switch assignments“ on page 68) and 

assign it to both these lines:

Alarm

12:34h –––

1:23h

0s

0s

C1

SEL

C1

Model time

Batt. time

Top :

Centr:

Stop

Flight

The stopwatch will now stop when the stick is below 

the switching point and resume running above the 

switching point. The same is not true for the flight time 

timer, however, which also starts the first time the 

switching point is exceeded. It can be stopped (with a 

tap on the center ESC key of the left four-way button) only once the stopwatch is stopped; it can then 

be reset to its starting value with a simultaneous tap 

on the  or  keys of the right four-way button 

(CLEAR).

Switchover between “forward” and “backward”

Timer runs forwards (stopwatch function)

Following switch assignment, if the stopwatch shown 

on the basic display is started with the initial value of 

“0:00”, then it will run forwards for max. 180min and 

59s and then restart from 0:00.

Timer runs backwards (countdown function)

In the–left–minutes field, select a start time between 

0 and 180min ...

Timer

12:34h –––

1:23h

0:00

180:00

SEL

Model time

Batt. time

Top :

Centr:

Stop

Flight

... and in the–right–seconds field, select a start time 

between 0 and 59s (or any combination of these):

Timer

12:34h –––

1:23h

180:59

0:00

SEL

Model time

Batt. time

Top :

Centr:

Stop

Flight

Procedure

1. Select the desired input field with the  selection keys of the left or right four-way button.

2. Now tap on SET in the center of the right 

touch pad.

3. Make a time selection in the inverse video minutes 

or seconds field with the selection keys of the right 

four-way button.

4. Complete the entry with a tap on the center 

SET key.

5. A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset any setting made back to “0” or “00”.

6. Following a switch back to the basic display (by 

tapping the center ESC key of the left four-way 

button as many times as required), make sure the 

stopwatch is stopped then simultaneously tap on 

the  or  keys of the right four-way button 

(CLEAR) to switchover the stopwatch to the “tim-
164 Program description - Timers (general) 

er” function. Look at the top right in the following 

figure.

GRAUBELE

#01

0:00h

Stp

Flt

10:01

0:00

0.0V

4.1V

M

HoTT

After the assigned switch is activated, the stopwatch 

starts at the initial value set and runs backward

(“countdown clock function”). Once the timer reaches 

zero it does not stop, but continues to run to enable 

you to read off the time elapsed after it reached 0:00. 

To make this absolutely clear, the timer is shown 

highlighted.

“Alarm” timer

The “Alarm” column is accessed by moving the 

marker frame to the right with the  selection key 

of the left or right four-way button until it is over the 

column labeled “Alarm”. In the “Alarm” column a time 

between 5 and 90 seconds (in 5-second increments) 

can be defined. This is the amount of time the timer is 

to count down before issuing an acoustic signal. This 

eliminates the need to repeatedly check the display 

continually during the flight, for example:

Alarm

12:34h –––

1:23h

0s

–––

–––

SEL

30s

Model time

Batt. time

Top :

Centr:

Stop

Flight

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset any settings 

made back to “0s”.

Audible signal sequence

30s before zero: Triple beep 

Single beep every two seconds 

20s before zero: Double beep 

Single beep every two seconds 

10s before zero: Single beep 

Single beep every second

5s before zero: every second a single beep at a 

higher frequency

zero: longer beep signal and changeover of display presentation to 

inverse video

Resetting suspended timers

In the case of timers which were previously halted, 

they are reset to the programmed Start value in the 

base display by simultaneously pressing the 

or  buttons of the right-hand four-way button 

(CLEAR).

Notes:

• Timers that are running backwards are shown on 

the basic display with a flashing colon (:) between 

the minutes and the seconds fields.

• A typical application, “Timer activation via the C1 

stick”, can be found on page 294.

• An interim timer function change becomes active 

after timer/s have been suspended and subsequently reset by a simultaneous tap on the  or 

 keys of the right four-way button (CLEAR).

• Remember that the timer switches also remain active during programming. 
For your notes 165
166 Program description - Flight phase timers

Fl. phase timers

Selecting and setting

This option is available as standard on 

both transmitter types.

A description of how timers are assigned 

to a flight phase has already been provided in the text for the »Phase settings« menu, page 

152 and 156. The same section has also described 

the properties of “Time1” and “Time2”. This section 

now proceeds to describe “Timer 1, 2 and 3” and the 

“lap counter/time table” timer variants.

The additional, flight phase-specific timer selected is 

displayed on the basic display underneath the “center” timer, as shown below:

GRAUBELE

#01

2:22h

Stp

Flt

«Speed »

0:00

0:00

5.5V

3.9V HoTT

M

Clk1 0:00

Use the selection keys of the left or right four-way button to scroll to the »Fl. phase timer« menu option in 

the Multi-function menu:

Non-delayed chan

Timers (general)

Wing mixers

Free mixers

MIX active/phase

Fl. phase timers

Non-delayed chan

Timers (general)

Helicopter mixer

Free mixers

MIX active/phase

Fl. phase timers

On this menu you can now program “Clks 1 ... 3” as 

stopwatches (i.e. timers that run forward) or as countdown/alarm timers (i.e. timers that run backwards). 

You can assign any switch to these timers, and the 

same is true of the “lap counter/timetable” timer:

Timer1

Timer2

Timer3

Lap time/Tim tab

SEL

0:00 –––

0:00

0:00

Lap Display

0s

0s

0s

–––

–––

–––

–––

SEL

The flight phase timers “Timer 1 ... 3” and the 

“Time1”/”Time2” timers (described in the »Phase 

settings« section, pp. 152 and 156) run only in the 

flight phase to which they have been assigned. They 

are also shown as appropriate on the basic display. 

During other flight phases they are stopped (and hidden) and the assigned stop/start switch then has no 

effect.

The lap counter, once started, continues to run 

through changes of phase (as discussed further 

below), however, although it can be stopped during 

any flight phase via the center ESC key of the left 

four-way button.

Clks 1, 2 and 3

These timers are started and stopped via a switch or 

control switch. To do so, first use the selection keys 

to select the appropriate column via the switch icon 

at the bottom right. Then set the switch that you want 

by briefly tapping the center SET key of the right 

four-way button, as described in the section „Physical control, switch and control switch assignments“ 

on page 68. Here, too, a control switch offers you 

the option of activating the timer via one of the sticks 

or proportional controls. The switching point along 

the transmitter control travel is set on the »Control 

switch« menu, page 145.

Remember that the timer switches also remain active 

in programming mode.

Switching between “forwards” and “backwards”

Stopwatch mode (timer runs forwards) 

In this mode, the timer starts at the initial value “0:00” 

(min:sec) when you operate the assigned switch. If it 

reaches the maximum time of 180min. and 59s, it will 

re-start at “0:00”.

“Countdown” (timer runs backwards)

Following the activation of the corresponding value 

fields (by tapping the center SET key of the right fourway button), if a time in minutes (maximum 180min) 

and/or a time in seconds (maximum 59s, right field) is 

set, then the timers will run backwards from this initial 

value following the activation of the assigned switch 

(see section „Physical control, switch and control 

switch assignments“ on page 68), i.e. a “countdown” function will apply. Once the timer reaches zero 

it does not stop, however, but continues to run (highlighted) so you can read off the time elapsed after 

reaching zero.

Note:

Timers that are running backwards are shown on the 

basic display with a flashing colon (:) between the 

minutes and the seconds fields.

A simultaneous tap on the or  keys of the 

right four-way button (CLEAR) will reset entry values 

in the currently active field back to zero.

“Alarm” timer

SEL

0:00 –––

0:00

0:00

0s

0s

–––

–––

–––

–––

SEL

Timer1 0s

Timer2

Timer3

Lap time/Tim tab

Lap Display

The input field in the “Alarm” column is activated with 

a tap on the center SET key of the right four-way button. In this field, use the selection keys on the left or 

mc

 

16 20
Program description - Flight phase timers 167

right four-way button to define a time between 5 and 

90 seconds (in 5-second increments) before zero is 

reached: at this point an audible signal will be emitted, which eliminates the need for you to check the 

screen continually during the flight. 

Audible signal sequence

30s before zero: Triple beep

Single beep every two seconds 

20s before zero: Double beep

Single beep every two seconds 

10s before zero: Single beep 

Single beep every second

5s before zero: every second a single beep at a 

higher frequency

zero: longer beep signal and changeover 

of display presentation to inverse 

video

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset entry values 

entered in the currently active field to “0s”.

Note:

If timer functionality has been changed at any point, 

then the new changes to settings are made active 

only after the timer(s) have been stopped on the 

basic display then making a simultaneous tap on the

 or  keys of the right four-way button (CLEAR) 

to reset them.

Like the two standard timers positioned above it, this 

third, phase-specific timer is reset to its starting value 

with a simultaneous tap on the  or  keys of 

the right four-way button (CLEAR). It is stopped in all 

flight phases at the same time, even if it has not been 

stopped separately in the other flight phases.

Lap counter/timetable

0:00 –––

0:00

0:00

0s

0s

–––

–––

–––

–––

Timer1 0s

Timer2

Timer3

Lap time/Tim tab

Lap Display

On the “Lap time/tim tab” line, assign a switch only as 

described in the section „Physical control, switch and 

control switch assignments“ on page 68. Preferably, 

make use of a momentary switch, which are included 

as standard equipment only in the switch panels of 

the mc-20 HoTT transmitters. The lap count is incremented each time by one lap while simultaneously 

(and automatically) the lap time elapsed during this 

lap is stopped (and recorded). This momentary switch 

simultaneously starts the stopwatch for the next lap. 

As the timer is triggered, the lap or switch impulse 

counter is shown highlighted:

GRAUBELE

#01

2:22h

Stp

Flt

«Speed »

0:00

0:00

5.5V

3.9V

M

Lap

2:33.4

11

“Time1” and “Time2” operate in the same manner; for 

more details please read the section on the »Phase 

settings« menu option on page 152 or 156.

Up to 99 lap times can be recorded and accessed, 

each with a maximum duration of 99 minutes and 

59.9 seconds.

To stop the timer in question, tap the center ESC key 

of the left four-way button on the basic display after 

the flight is over. The lap or switch impulse counter is 

now shown in “normal” mode:

GRAUBELE

#01

2:24h

Stp

Flt

«Speed »

0:00

0:00

5.5V

3.9V

M

Lap

4:33.2

22

A simultaneously tap on the  or  keys of the 

right four-way button at the same time (CLEAR) will 

reset the counter to “00” and deletes the stored 

times. However, the timers must have been stopped 

before this.

Notes:

• If you have selected a normal switch to operate 

the lap counter, take care to ensure that this 

switch is set to “OFF” before touching the center 

ESC key of the left four-way button.

• If you should forget to switch off the lap counter in 

a phase which is now not currently active, simply 

touch the center ESC key of the left four-way button.

To swap between the basic display and the “Lap Display” ...

01

02

03

04

01:23.4

02:34.5

03:45.6

05

04:56.7

05:67.8

07

08

09

10

00:00.0

00:00.0

00:00.0

11

12

00:00.0

00:00.0

06 06:78.9 00:00.0

... go to the line ...
168 Program description - Flight phase timers

Lap display

0:00 –––

0:00

0:00

0s

0s

–––

–––

–––

–––

Timer1 0s

Timer2

Timer3

Lap time/Tim tab

Lap Display

... and use the switch assigned. You assign this 

switch as described in the section “Physical control, 

switch and control switch assignments” on page 68.
What is a mixer? 169

What is a mixer?

Basic functionality

With many models, a mix of the model’s functions 

is often desirable, i.e. coupling aileron to rudder or 

coupling two servos together, in cases where rudder 

control surfaces with the same functionality are to be 

controlled together using a single servo. In all cases, 

the signal flow at the “output” of the control function 

on the transmitter control-side “branches”–, this also 

means: “downstream” of transmitter control options 

such as e.g. »Dual Rate / Expo«, »Control adjust«, 

»Channel 1 curve« etc.–in order for the signal to 

have its predefined effect on the “input” of another 

control channel and thus on another receiver output.

Example: V-tail mixer

3 3

4

Servo 4 8 V C 577

Bes Nr 101

Se vo 4 8 V

C 577

Bes Nr 410

4

V-tail mixer

Control function inputs

Control channels

(receiver outputs)

Elevator stick

Rudder stick

Right rudder / elevator

Left rudder / elevator

Rudder

Elevator

Elevator

Rudder

Rudder

Elevator

The mc-16 HoTT and mc-20 HoTT transmitter 

software contains a large number of pre-programmed 

coupling functions as standard, which are designed 

to mix together two (or more) control channels. Accordingly, the mixer named in the example just above 

can be activated in the “Tail type” line of the »Model 

type« menu by selecting “V-tail”, see page 104.

In addition, for each model memory in the fixed-wing 

and helicopter programs, the software makes available a total of eight freely programmable linear mixers, four freely programmable curve mixers and four 

dual mixers; these are available as standard on the 

mc-20 HoTT only, but can also be unlocked on the 

mc-16 HoTT transmitter as an extra-cost option.

Also be sure to read the general remarks about “free 

mixers” in this manual, beginning on page 204. 
170 Program description - Wing mixers 

control function input 1 (throttle/brake stick) on the 

»Mix-only channel« menu, which is available as 

standard on the mc-20 HoTT transmitter only, 

see page 216, and use it for another purpose 

with the help of a “free mixer”, see page 205. On 

the mc-16 HoTT transmitter this option can be 

unlocked as an extra-cost option.

• If “2AIL” is set in the »Model type« menu, page 

104, then flight-phase dependent flap functionality can be achieved with appropriate offset settings for input 5 in the »Control adjust« menu, 

page 160, or alternatively can be achieved by 

setting appropriate values in the “Offset” column 

for Input 5 in the »Control adjust« menu, see 

page 118. However, in the interests of clarity you 

should always make use of only one of the two facilities.

• For almost any menu option, you have the option 

of checking your settings by switching to the servo display screen, which is accessed with a simultaneous tap on the  selection keys of the left 

four-way button. 

Caution:

With aileron actuation the bars of the »Servo display« move in the same manner and in the opposite manner with camber changing flap actuation.

• Note that if two flap servos have been selected, 

any transmitter control assigned to input 7 will be 

decoupled in the software in order to avoid errors 

in operating the flaps. The same applies to input 

10 if you select “2/4AIL 4FL” on the mc-16 HoTT 

transmitter with twelve channels unlocked, as well 

as the standard twelve-channel mc-20 HoTT 

transmitter. 

• A range of options are available for positioning 

flaps. You can ...

a) ... simply accept one position per flight phase, 

by setting only the corresponding trim values. 

b) ... vary the flaps positioned by a) with a transnames will appear along the bottom display edge, 

e.g. «Normal»:

Aile.diff.

Brake settings

0%

AI 0%

Wing mixers

EL AI 0%0%

–––

–––

RU

normal

All options can then also be programmed specific to a 

flight phase.

Comments:

• In the »Model type« menu, see page 104, the 

airbrake mixer control can be re-programmed from 

control input 1 to 7 or 8 on the standard eightchannel mc-16 HoTT transmitter, and from 

1 to 7, 8 or 9 on the mc-16 HoTT transmitter 

with twelve channels unlocked and the standard 

twelve-channel mc-20 HoTT transmitter. In all 

three variants it is also possible to define the associated Offset point.

• Braking with raised ailerons and, if present, lowered flaps (crow system) can be implemented by 

making appropriate settings on the “Crow” line of 

the “Brake settings” sub-menu.

• If you would like to alternate between the C1 stick 

controlling an electric drive system and a butterfly 

system, then you can use the options in the “Motor” column on the »Phase settings« menu–see 

page 152 or refer to the example on page 291.

• You can also use the opportunity to set switch 

times for a “soft” transition from flight phase to 

flight phase on the »Phase settings« menu, see 

page 152.

• If your model features multiple wing flaps and a 

“crow / butterfly system” (see below), but without 

additional airbrakes, then you can separate output 1 (usually freed up by the above system) from 

Wing mixers

Calibrating the wing flap system

This option is available as standard on 

both transmitter types.

Within the menu tree of the menu »Wing 

mixers« ...

Free mixers

MIX active/phase

Fl. phase timers

Wing mixers

MIX-only channel

Dual mixer

... the sub-menus and options available depend entirely on the number of aileron and flap servos set up 

on the »Model type« menu, page 104 ... 

Tail type

Motor at C1

Normal

None

Aile/flaps 2AIL

Model type

Brake Off +100% In 1

SEL

... which means that the only settings listed are the 

ones that can actually be configured. The resulting 

menu structure gains not only in clarity but also prevents potential programming errors.

For example, if “2AIL” has been preset, display of the 

»Wing mixers« menu would appear (without camber 

flaps) as shown below:

Aile.diff.

Brake settings

0%

AI 0%

Wing mixers

EL AI 0%0%

–––

–––

RU

If various flight phases are envisioned in the settings 

of the »Phase settings«, page 152, and »Phase 

assignment«, page 158, menus, and these flight 

phases have been given names, the flight phase 

mc

 

16 20
Program description - Wing mixers 171

mitter control assigned to “Input 6” in the »Control adjust« menu, page 118, and if desired 

by also selecting flight-phase dependency “PH” 

in the “Type” column. 

The selected transmitter control directly controls the two flap servos located on receiver 

outputs 6 and 7 and, as required, also the two 

FL2 servos connected to outputs 9 and 10–assuming that corresponding flaps have been 

specified on the “Aileron/camber flaps” line in 

the »Model type« menu. This transmitter control indirectly controls the flap position of the ailerons via the percentage value entered in the 

“AILE” (and “AIL2”) column on the “FLAP” line 

of the multi-flap menu.

The two INC/DEC buttons, CTL 5 or 6, are virtually ideal for this type of task, since their position is automatically stored. These buttons are 

fitted as standard on the mc-20 HoTT transmitter, but can be fitted to the mc-16 HoTT at 

extra cost.

The particular advantage of these two transmitter controls–especially if you select the 

“PH” setting–lies in the fact that you can use 

one and the same INC/DEC button as flap trim 

controls in all the programmed flight phases, 

but–in contrast to a position-related proportional control–the trim values are retained even 

if you switch models.

However, in order to improve control sensitivity for flap settings, travel should be reduced to 

about 25% in “Input 6” line of the »Control adjust« menu.

c) ... alternatively, you can also leave the default 

entry of “0%” in the “AILE” (and “AIL2”) column 

on the “FLAP” line of the multi-flap menu, and 

use the »Control adjust« menu to assign both 

input 6 and input 5 to the same transmitter control. You can then set the degree to which both 

Assigning switches

Wing mixers “AI  RU” and “FL  EL” can be made 

optionally on/off switchable by way of a switch or 

expanded switch. Accordingly, when the respective 

line is selected, the familiar switch symbol ( ) will 

appear on the lower edge of the screen.

A switch can be assigned as described in the section 

entitled “Physical control, switch and control switch 

assignments” on page 68.

Switching delays

The delay time or switch time configured on the 

»Phase settings« menu, page 152, for the respective flight phase also affects all wing mixers and thus 

avoids abrupt changes to flap configurations when 

switching between the flight phases.

Mixer neutral points (Offset)

For all mixers on the “Brake settings” sub-menu, the 

“brake offset” to be set on the »Model type« menu is 

to be configured to the transmitter control position at 

which the airbrakes are retracted.

For this reason you should define which of the inputs 

1, 7 or 8 you wish to use as the brake control, and 

enter the appropriate offset, in the “Brake offset” line 

of the »Model type« menu on the standard eightchannel mc-16 HoTT transmitter, corresponding to 

your personal preference; see page 105. The same 

procedure is used with the mc-16 HoTT transmitter with twelve channels unlocked, and the standard 

twelve-channel mc-20 HoTT transmitter, with the 

exception that Input 9 is also available as an alternative. When selecting “input 1”, please note also that 

you may need to specify your desired “Throttle min” 

position “forward/back” before establishing the offset 

point in the “Motor at C1” line.

Note:

If the offset is not set right at the end of the transmitter travel, the rest of the travel is a “dead zone”, i.e. 

flap pairs are affected, optionally making this 

flight phase-dependent by selecting “PH” in the 

“Type” column, with the respective travel adjustment.

Basic programming procedure

1. Select the desired line with the  selection keys 

of the left or right four-way button.

Depending on the line selected, the bottom line of 

the display will either show the “Next page” ( ) 

icon or a switch icon.

2. Depending on the line selected, you will either 

switch to the next page–on which you carry out 

the same procedure as below–or the desired value field is activated by tapping the center SET key 

of the right four-way button.

3. Use the selection keys to set the mixer ratio or degree of differential.

To configure symmetrical mixer values, move the 

transmitter control or stick to its center position, so 

that the marker frame surrounds both value fields. 

To configure asymmetric values, move the transmitter control/stick to the corresponding side.

Negative and positive parameter values are possible, in order to be able to adjust the respective 

function to the direction of servo rotation or flap 

orientation.

4. A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the entry 

value in the given active (inverse video) field back 

to its default value.

5. Complete the entry with a tap on the center ESC

key of the left four-way button or the center SET

key of the right four-way button.
172 Program description - Wing mixers 

generally have relatively short moment arms. For 

the former, it must normally be compensated for by 

making a simultaneous rudder deflection in the opposite direction. However, this rudder deflection also 

generates drag and therefore further degrades flight 

characteristics. 

If, on the other hand, a differential is applied to the 

aileron orientations, by giving the aileron oriented 

downwards a smaller deflection than the aileron 

oriented upwards, the (undesirable) adverse yaw can 

be reduced–and possibly entirely negated. However, 

the basic precondition for this is that each aileron 

must have its own servo present, which can therefore 

also be embedded straight into the aerofoils. In addition, the shorter linkage paths produce an additional 

benefit: reproducible aileron configurations that also 

exhibit less “play”.

0% (normal)

50% (differential)

100% (split)

Unlike mechanical solutions, which not only commonly need to be designed and built in when constructing 

the model but also produce a slightly increased “play” 

in the control system for strong differentials, the transmitter-based differential typically used today offers 

considerable benefits.

The degree of differential can be changed at any 

time, for example, and, in extreme circumstances, the 

downward deflection of an aileron, in what is termed 

a “split” position, can be suppressed entirely. This 

approach not only reduces or even suppresses “adverse yaw”, but can, in certain circumstances, even 

generate a positive yaw: in such cases, an aileron 

command will generate a yaw about the vertical axis 

in the direction of the turn. For large glider models in 

particular, this approach lets such aircraft fly “clean” 

turns using just the ailerons, which is not otherwise 

possible unaided.

The adjustment range of -100% to +100% makes it 

possible to set a differential appropriate for each side, 

regardless of the direction of rotation of the aileron 

servos. While “0%” corresponds to a normal linkage, 

i.e. no differential, “-100%” or “+100%” represents the 

“split” function. 

For aerobatic flying, low absolute values are required 

to ensure the model rotates exactly along its longitudinal axis when an aileron command is given. Values 

near to the center (-50% or +50%) are typical for 

facilitating turns in thermals. The split setting (-100%, 

+100%) is popular with slope fliers, where ailerons 

alone are often used for turning the model.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.

Note:

Negative values are not usually necessary if channels 

are assigned properly.

the transmitter control does not influence any mixers 

on the “Brake settings” sub-menu. Otherwise, the 

mixer travel is expanded back to 100% automatically.

All other mixers in the »Wing mixers« menu have 

their neutral point with the control at its center, i.e. 

they have no effect at this control position. The value 

set is mixed in at full travel.

Mixer functions

The individual options in the »Wing mixers« menu 

are discussed below, separately for single-, dual- and 

multi-flap models. Before we start, a number of remarks on the differentials for ailerons and flaps:

Aile. diff. or Diff. (Aileron-Differential)

0%

0%0%

–––

–––

normal

Aile.diff. 0%

Brake settings

AI

Wing mixers

EL AI

RU

fl.pos 0%

AILE

normal

Diff.

AiI-tr

AI +100%

+100%

0%

For aerodynamic reasons, the drag generated on 

an aileron oriented downwards is greater than that 

generated by the same aileron when it is oriented 

upwards by the same amount. One effect of this 

unequal distribution of drag produces is a yawing motion around the vertical axis and, accordingly, a “turning away” from the intended direction of flight, which 

is why this undesirable side effect is also termed 

“adverse yaw”. This effect is naturally greater on the 

comparably long aerofoils possessed by model gliders, compared to e.g. powered aircraft models, which 
Program description - Wing mixers 173

Diff. (Flap differentiation)

fl.pos 0%

FLAP

normal

Diff.

Ail-tr

AI 0%

0%

0%

0%

FLAP2

0%

0%

0%

fl.pos

normal

Diff.

Ail-tr

AI

The “AI” (topmost) line in the Multi-flap menu, 

description starting on page 181, can be used to set 

the extent to which the flaps act as ailerons and follow 

the aileron stick.; this value is entered as a percentage. The flaps differential–to be set on the line “Diff.” 

(two lines below)–works in a similar way to the aileron differential, i.e. where an aileron command acts 

on the flaps, the respective deflection downwards can 

be reduced.

The adjustment range of -100% to +100% makes it 

possible to set a differential appropriate for each side, 

regardless of the direction of rotation of the servos. A 

value of 0% is equal to normal linkage, i.e. the servo 

travel downwards is the same as the travel upwards. 

A value of -100% to +100% means that travel downwards will be reduced to zero for aileron commands 

affecting the flaps (“split” mode). 

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.

Note:

Negative values are not usually necessary if channels 

are assigned properly.

Input

Output

Point ?

–100%

0%

0%

Brake Ele

Curve off

normal

If required, i.e. if you have the feeling that you will 

need to set pitch trim compensation when the airbrakes are extended, you can program an appropriate 

automatic mixer affecting the elevator at this point.

For detailed instructions on setting a curve mixer, 

please refer to the »Channel 1 curve« menu option 

text beginning page 138.

AI  RU (Aileron  Rudder)

Brake settings

AI 0%

Wing mixers

RU –––

normal

Here, you can set the degree to which the rudder 

follows commands acting on ailerons. This is used 

in particular in connection with aileron differential to 

suppress adverse yaw and thus make it easier to fly 

“clean” curves. You can of course still issue separate 

commands to the rudder. 

The adjustment range of ±150% lets you set the 

direction of deflection as appropriate. Optionally, this 

mixer can be activated and deactivated with one of 

the switches that is not self-restoring or a control 

switch so the model can be controlled with only the 

ailerons or rudder if desired.

Typically, this mixer is set so that the rudder is deflected to the same side as the upward-oriented aileron, 

and you will find that setting a value of around 50% is 

usually highly appropriate. 

Model type: “1AIL”

If you have entered “1AIL” for the “Aileron/camber 

flaps” line on the »Model type« menu, page 104, 

then the “Wing mixers menu” on your transmitter will 

match the following screen image:

Brake settings

AI 0%

Wing mixers

RU –––

normal

From the first line on this display screen, you can 

switch to the sub-menu with a brief tap on the center 

SET key of the right four-way button ...

Brake settings

Note:

The “Brake settings” menu is switched “off” if: “Motor 

on C1 forward / back” in the »Model type« menu, 

page 104, AND the “Motor” column of the »Phase 

settings« menu, page 152, are set to “yes” for the 

currently active flight phase. Switch the flight phase if 

required:

Elevat curve

Bake settings

normal

Since you cannot set up a butterfly or aileron differential in a model with only a single aileron servo, 

this menu offers no further configuration options with 

the exception of a “pointer” to the “Elevat curve” submenu. Therefore, move ahead from here with another 

tap on the center SET key of the right four-way button:
174 Program description - Wing mixers 

Model type: “1AIL 1FL”

If you have entered “1AIL 1FL” for the “Aileron/camber 

flaps” line on the »Model type« menu, page 104, 

then the “Wing mixers menu” on your transmitter will 

match the following screen image:

Brake settings

AI 0%

Wing mixers

EL FL 0% 0%

–––

–––

RU

normal

FL EL 0% 0% –––

From the first line on this display screen, you can 

switch to the sub-menu with a brief tap on the center 

SET key of the right four-way button ...

Brake settings

Note:

The “Brake settings” menu is switched “off” if: “Motor 

on C1 forward / back” in the »Model type« menu, 

page 104, AND the “Motor” column of the »Phase 

settings« menu, page 152, are set to “yes” for the 

currently active flight phase. Switch the flight phase if 

required:

Elevat curve

Brake settings

Crow

normal

0%

FLAP

Appropriate to the model type selected, you can now 

enter a suitable value in the “Crow” line to lower the 

flap when you activate the brake control–which is 

typically the C1 stick.

To configure the setting, first position the brake 

control in the brake position at full travel (i.e. its endpoint). Then, briefly tap the center SET key of the 

right four-way button and enter a suitable value using 

the selection keys on the left or right four-way button. 

To ensure a sufficiently strong braking effect, note 

that you should try to lower the flap as low as is mechanically possible.

From the second line on this display screen, you can 

switch to the sub-menu “Elevat curve” by briefly tapping the center SET key of the right four-way button:

Input

Output

Point ?

–100%

0%

0%

Brake Ele

Curve off

normal

If required, i.e. if you have the feeling that you will 

need to set pitch trim compensation when the flaps 

and/or airbrakes are extended, you can program an 

appropriate automatic mixer affecting the elevator at 

this point.

For detailed instructions on setting a curve mixer, 

please refer to the »Channel 1 curve« menu option 

text beginning page 138.

AI  RU (Aileron  Rudder)

Brake settings

AI 0%

Wing mixers

EL FL 0% 0%

–––

–––

RU

normal

FL EL 0% 0% –––

Here, you can set the degree to which the rudder 

follows commands acting on ailerons. This is used 

in particular in connection with aileron differential to 

suppress adverse yaw and thus make it easier to fly 

“clean” curves. You can of course still issue separate 

commands to the rudder. 

The adjustment range of ±150% lets you set the 

Settings are always made symmetrically relative to 

the neutral point of the aileron stick. 

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.
Program description - Wing mixers 175

direction of deflection as appropriate. Optionally, this 

mixer can be activated and deactivated with one of 

the switches that is not self-restoring or a control 

switch so the model can be controlled with only the 

ailerons or rudder if desired.

Typically, this mixer is set so that the rudder is deflected to the same side as the upward-oriented aileron, 

and you will find that setting a value of around 50% is 

usually highly appropriate.

Settings are always made symmetrically relative to 

the neutral point of the aileron stick.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.

EL  FL (Elevator  Flap)

Brake settings

AI 0%

Wing mixers

EL FL 0% 0%

–––

–––

RU

normal

FL EL 0% 0% –––

To provide support for the elevator for tight turns 

and aerobatics, this mixer can be used to make the 

flap function follow controls sent to the elevator. The 

mixer direction chosen must ensure that the flaps are 

deflected downwards when the elevator is oriented 

upwards and vice versa for a downward-oriented 

elevator–i.e. in opposite directions. This mixer can 

be made optionally on/off switchable with one of the 

switches that is not self-restoring or a control switch.

To configure symmetrical mixer values, move the 

elevator stick to its center position, so that the marker 

frame surrounds both value fields. To configure asymmetric values, move the stick to the corresponding 

side.

Values in the range -150% to +150% are possible, so 

as to adjust the function to the direction of servo rotation or direction of flap deflection.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.

The “typical” values configured for this mixer are 

single-digit or low two-digit values.

FL  EL (Flaps  Elevator)

Brake settings

AI 0%

Wing mixers

EL FL 0% 0%

–––

–––

RU

normal

FL EL 0% 0% –––

This mixer is used to set elevator (pitch-trim) compensation when a flap command is given. This typically 

enables you to adjust the model’s airspeed automatically when flaps are lowered.

If you have used the »Control adjust«, page 118, to 

assign Input 6 to a transmitter control or switch then 

this also affects this mixer.

To configure symmetrical mixer values, move the flap 

control to its center position, so that the marker frame 

surrounds both value fields. To configure asymmetric 

values, move the stick to the corresponding side.

Values in the range -150% to +150% are possible, so 

as to adjust the function to the direction of servo rotation or direction of elevator movement.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.

If required, the mixer can be switched on or off by assigning a switch in the right column.

The values configured for this mixer are typically in 

the single-digit range.

Model type: “2AIL”

If you have entered “2AIL” for the “Aileron/camber 

flaps” line on the »Model type« menu, page 104, 

then the “Wing mixers menu” on your transmitter will 

match the following screen image:

Aile.diff.

Brake settings

0%

AI 0%

Wing mixers

EL AI 0%0%

–––

–––

RU

normal

From the first line on this display screen, you can 

switch to the sub-menu with a brief tap on the center 

SET key of the right four-way button ...

Brake settings

Note:

The “Brake settings” menu is switched “off” if: “Motor 

on C1 forward / back” in the »Model type« menu, 

page 104, AND the “Motor” column of the »Phase 

settings« menu, page 152, are set to “yes” for the 

currently active flight phase. Switch the flight phase if 

required:

Elevat curve

Brake settings

AILE

Crow

D.red

0%

0%

normal

Depending on the model type selected, setting 

options will now be available in the “Crow” and 

“D(ifferential)red(uction)” lines for the column labeled 

“AILE”. These options should be utilized by ...

• ... putting the transmitter control for “Brake” (refer to the »Model type« menu description on 

page 104)–typically the C1 stick–in its limit 
176 Program description - Wing mixers 

position in the brake direction. Switch to the “Crow” 

line, briefly tap on the center SET key of the right 

four-way button and use the selection keys on 

the left or right four-way button to set a value that 

moves the aileron upwards as far as possible to 

brake the model or, if you are using airbrakes as 

the main braking system, the aileron should be set 

to elevate only minimally to provide an extra braking effect.

Note:

To reliably prevent the servos mechanically striking their end-stops–which draws a heavy current–you can set an appropriate limit value in the 

column labeled “– limit +” in the »Servo adjustment« menu, page 112.

• ... then finally, moving to the “D.red” line, set a % 

value there which is greater than or equal to that 

value set (or to be set) in the “Aileron differential” 

line of the display screen “before” this one.

In this way, you can suppress the aileron differential when braking, thus ensuring that you can 

count on sufficient aileron response despite your 

ailerons being deflected upwards.

From the lowest line, “Elevator curve”, you can switch 

to setting the “Elevator curve” mixer by briefly tapping 

the center SET key of the right four-way button:

Input

Output

Point ?

–100%

0%

0%

Brake Ele

Curve off

normal

If required, i.e. if you have the feeling that you will 

need to set pitch trim compensation when the flaps 

and/or airbrakes are extended, you can program an 

appropriate automatic mixer affecting the elevator at 

this point.

For detailed instructions on setting a curve mixer, 

please refer to the »Channel 1 curve« menu option 

text beginning page 138.

Aile.diff. (Aileron differentiation)

Aile.diff.

Brake settings

0%

AI 0%

Wing mixers

EL AI 0%0%

–––

–––

RU

normal

The adjustment range of ±100% makes it possible to 

set the correct direction of differential, regardless of 

the direction of rotation of the aileron servos. While 

“0%” corresponds to a normal linkage, i.e. no transmitter-side differential, “-100%” or “+100%” represents the “split” function.

For aerobatic flying, low absolute values are required 

to ensure the model rotates exactly along its longitudinal axis when an aileron command is given. Values 

near to the center (-50% or +50%) are typical for 

facilitating turns in thermals. The split setting (-100%, 

+100%) is popular with slope fliers, where ailerons 

alone are often used for turning the model.

0% (normal)

50% (differential)

100% (split)

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in an active (inverse video) field back to 0%.

Note:

Negative values are not usually necessary if channels 

are assigned properly.

AI  RU (Aileron  Rudder)

Aile.diff.

Brake settings

0%

AI 0%

Wing mixers

EL AI 0%0%

–––

–––

RU

normal

Here, you can set the degree to which the rudder 

follows commands acting on ailerons. This is used 

in particular in connection with aileron differential to 

suppress adverse yaw and thus make it easier to fly 

“clean” curves. You can of course still issue separate 

commands to the rudder. 

The adjustment range of ±150% lets you set the 

direction of deflection as appropriate. Optionally, this 

mixer can be activated and deactivated with one of 

the switches that is not self-restoring or a control 

switch so the model can be controlled with only the 

ailerons or rudder if desired.

Typically, this mixer is set so that the rudder is deflected to the same side as the upward-oriented aileron, 

and you will find that setting a value of around 50% is 

usually highly appropriate.

Settings are always made symmetrically relative to 

the neutral point of the aileron stick.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.
Program description - Wing mixers 177

EL  AI (Elevator  Aileron)

Aile.diff.

Brake settings

0%

AI 0%

Wing mixers

EL AI 0%0%

–––

–––

RU

normal

To provide support for the elevator for tight turns and 

aerobatics, this mixer can be used to make the aileron function follow controls sent to the elevator. The 

mixer direction chosen must ensure that the ailerons 

are deflected downwards when the elevator is oriented upwards and vice versa for a downward-oriented 

elevator–i.e. in opposite directions. This mixer can 

be made optionally on/off switchable with one of the 

switches that is not self-restoring or a control switch.

To configure symmetrical mixer values, move the 

elevator stick to its center position, so that the marker 

frame surrounds both value fields. To configure asymmetric values, move the stick to the corresponding 

side.

Values in the range -150% to +150% are possible, so 

as to adjust the function to the direction of servo rotation or direction of aileron movement.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.

The “typical” values configured for this mixer are 

single-digit or low two-digit values.

Model type: “2/4AIL 1/2/4FL”

If you have entered “2AIL 1FL” for the “Aileron/camber 

flaps” line on the »Model type« menu, page 104, 

then the “Wing mixers menu” on your transmitter will 

match the following screen image:

Aile.diff.

Brake settings

0%

AI 0%

Wing mixers

FL EL 0%0%

–––

–––

RU

Multi-flap menu

normal

However, if you have entered “2AIL 2FL” in the “Aileron/ flap” line of the »Model type« menu, see page 

104, of the standard eight-channel mc-16 HoTT 

transmitter, or “2/4AIL 2/4FL” on the mc-16 transmitter with twelve channels unlocked, and the standard 

twelve-channel mc-20 HoTT, then your transmitter’s “Wing mixer menu” should look like this:

0%

0%0%

–––

–––

Brake settings

AI

Wing mixers

FL EL

RU

Multi-flap menu

normal

Regardless of the combination of aileron and flap servos you choose, all of the parameters available can 

be adjusted separately for each flight phase.

Note:

For almost any menu option, you have the option 

of checking your settings by switching to the servo 

display screen, which is accessed with a simultaneous tap on the  selection keys of the left four-way 

button. If you do, note however that the bars on the 

»Servo display« move in the same direction for ailerons and in the opposite direction for flaps.

Before we address the details of this menu we would 

like to provide a brief explanation of the different display modes for the multi-flap menu:

Model type: “2 AIL 1 FL”

If servos have been connected to the receiver as described on page 73 and selected accordingly in the 

»Model type« menu, page 104, then the abbreviations “AILE” and “FLAP” refer to the following flaps:

AI

left

FL FL AI

right

Since the options available on the wing mixer menu 

and its sub-menus vary according to the number 

of aileron and flap servos specified on the »Model 

type« menu, page 104, the list contains only those 

set-up options available for the given model.

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

AILE

normal

EL FL Off. 0% –––

Therefore, with a preset to “2AIL 1FL”, the options for 

setting aileron functions to flaps will be suppressed, 

and it will only be possible to shift to the right by one 

column–to the “FL” column:
178 Program description - Wing mixers 

FL +100%

fl.pos

EL FL 0% 0%

+100%

FLAP

normal

0%

EL FL Off. 0% –––

In addition, the settings for “Aile(ron) diff(erential)” 

are not found on the “multi-flap menu”, as with “2AIL 

2/4FL”, but one level higher in the “Wing mixers” 

menu, see the screenshot on start of this section.

Model type: “2AIL 2FL“

If servos have been connected to the receiver as described on page 73 and selected accordingly in the 

»Model type« menu, page 104, then the abbreviations “AILE” and “FLAP” refer to the following flaps:

AI

left

FL

left

FL

right

AI

right

Since the options available on the wing mixer menu 

and its sub-menus vary according to the number 

of aileron and flap servos specified on the »Model 

type« menu, page 104, the list contains only those 

set-up options available for the given model.

This means that if values are preset to “2AIL 2FL”, 

then all configuration options for the aileron pair ...

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

AILE

normal

Diff. 0%

Ail-tr

AI +100%

+100%

EL FL Off. 0% –––

... are shown, and–one “step” to the right–all options 

for the flap pair as well:

FL

0%

+100%

fl.pos

EL FL 0% 0%

+100%

FLAP

normal

Diff. 0%

Ail-tr

AI 0%

0%

EL FL Off. 0% –––

Moving one further column to the right, however–to 

the “FLAP2” column–is not possible.

Model type: “2AIL 4FL”

If you have connected the servos to the receiver as 

described on page 73, and selected them for the 

appropriate tasks in the »Model type« menu, see 

page 104, of the mc-16 HoTT transmitter with 

twelve channels unlocked, or the standard twelvechannel mc-20 HoTT transmitter, then the abbreviations “AIL”, “FL” and “FL2” refer to the following 

control surfaces:

AI

left

FL

left

FL2

left

FL2

right

FL

right

AI

right

Since the options available on the wing mixer menu 

and its sub-menus vary according to the number 

of aileron and flap servos specified on the »Model 

type« menu, page 104, the list contains only those 

set-up options available for the given model.

This means that if values are preset to “2AIL 4FL”, 

then all configuration options for the aileron pair ...

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

AILE

normal

Diff. 0%

Ail-tr

AI +100%

+100%

EL FL Off. 0% –––

... are shown, and–one “step” to the right–all options 

for the first flap pair ...
Program description - Wing mixers 179

FL

0%

+100%

fl.pos

EL FL 0% 0%

+100%

FLAP

normal

Diff. 0%

Ail-tr

AI 0%

0%

EL FL Off. 0% –––

... are shown, and–one further “step” to the right–all 

options for the second flap pair as well:

FL

0%

+100%

fl.pos

EL FL 0% 0%

+100%

FLAP2

normal

Diff. 0%

Ail-tr

AI 0%

0%

EL FL Off. 0% –––

Model type: “4AIL 2FL”

If you have connected the servos to the receiver as 

described on page 73, and selected them for the 

appropriate tasks in the »Model type« menu, see 

page 104, of the mc-16 HoTT transmitter with 

twelve channels unlocked, or the standard twelvechannel mc-20 HoTT transmitter, then the abbreviations “AIL”, “AIL2” and “FL2” refer to the following 

control surfaces:

AI

left

AI2

left

FL

left

FL

right

AI2

right

AI

right

Since the options available on the wing mixer menu 

and its sub-menus vary according to the number 

of aileron and flap servos specified on the »Model 

type« menu, page 104, the list contains only those 

set-up options available for the given model.

This means that if values are preset to “4AIL 2FL”, 

then all configuration options for the first aileron pair 

...

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

AILE

normal

Diff. 0%

Ail-tr

AI +100%

+100%

EL FL Off. 0% –––

... are shown, and–one “step” to the right–all options 

for the second aileron pair ...

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

AILE2

normal

Diff. 0%

Ail-tr

AI +100%

+100%

EL FL Off. 0% –––

... are shown, and–one further “step” to the right–all 

options for the flap pair as well:

FL

0%

+100%

fl.pos

EL FL 0% 0%

+100%

FLAP

normal

Diff. 0%

Ail-tr

AI 0%

0%

EL FL Off. 0% –––
180 Program description - Wing mixers 

Model type: “4AIL 4FL”

If you have connected the servos to the receiver as 

described on page 73, and selected them for the 

appropriate tasks in the »Model type« menu, see 

page 104, of the mc-16 HoTT transmitter with 

twelve channels unlocked, or the standard twelvechannel mc-20 HoTT transmitter, then the abbreviations “AIL”, “AIL2”, “FL” and “FL2” refer to the 

following control surfaces:

AI

left

AI2

left

FL

left

FL2

left

FL2

right

FL

right

AI2

right

AI

right

Since selecting “4AIL 4FL” means choosing the maximum number of control surface servos, the columns 

“AILE” ... 

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

AILE

normal

Diff. 0%

Ail-tr

AI +100%

+100%

EL FL Off. 0% –––

... and “AILE2” ...

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

AILE2

normal

Diff. 0%

Ail-tr

AI +100%

+100%

EL FL Off. 0% –––

... are supplemented by the columns “FLAP” ...

FL

0%

+100%

fl.pos

EL FL 0% 0%

+100%

FLAP

normal

Diff. 0%

Ail-tr

AI 0%

0%

EL FL Off. 0% –––

... and “FLAP2”:

FL

0%

+100%

fl.pos

EL FL 0% 0%

+100%

FLAP2

normal

Diff. 0%

Ail-tr

AI 0%

0%

EL FL Off. 0% –––

Delta/flying wing type models with more than two 

wing flaps

If you have selected the “Delta/fl“ tail type and selected the number of wing flaps in the “Aile/flaps” line 

on the »Model type« menu (following the instructions 

given in that section on page 104), then the two 

ailerons will normally not move when you move the 

elevator stick–and the same will be true for the inner 

flaps (FL) and FL2 (if present). The reason for this is 

the default mixer ratio of 0% for all wing flaps, set for 

the “EL  FL” mixer that is to be found on the multiflap menu:

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

AILE

normal

Diff. 0%

Ail-tr

AI +100%

+100%

Accordingly, you must first specify your desired elevator control on the “EL  FL” line. Take care to ensure 

that up/down activation occurs in the right sequence.

Note:

The “Brake settings” sub-menu (see page 181) is 

also suitable for setting up the butterfly (crow) function with delta and flying wing models. In fine-tuning 

the deflection of the flap pairs AIL, FL and (if present) 

AIL2 and/or FL2, however, ensure that the moments 

created by one pair of flaps compensate the moments 

created by the other pair of flaps in each case. For 

example: the “up” effect of ailerons when deflected up 

should be compensated by a “down” effect from flaps 

when they are lowered.
Program description - Wing mixers 181

Multi-flap menu

Important notice:

Depending on the flap pairs specified in the »Model 

type« menu, page 104, this menu will present the 

column “AILE2” and/or the columns “FLAP” and 

“FLAP2” in addition to the “AILE” column. Since both 

the columns “AILE” and “AILE2” and the columns 

“FLAP” and “FLAP2” are identical except for the 

label shown at the bottom right, further display of the 

columns “AILE2” and “FLAP2” is avoided below for 

reasons of saving space. 

AI (Aileron  Flaps)

Note:

Suppressed by “2AIL 1FL”.

0%

AILE

0%

+100%

+100%

fl.pos

normal

Diff.

Ail-tr

AI

0%

FLAP

0%

0%

0%

fl.pos

normal

Diff.

Ail-tr

AI

The “AI“ line can be used to make flight-phase 

dependent settings for the percentage of aileron action to result for the camber flap pair “FLAP” and, if 

present, also “FL2” when aileron control is exercised. 

(In the “AILE” and, if present, “AILE2” column it is also 

possible to adjust the deflection of the aileron pair, if 

required.) Normally, however, the flaps should follow 

the ailerons with less of a deflection, i.e. the mixer 

ratio should be smaller than 100%.

The adjustment range of -150% to +150% means 

the direction of deflection can be adjusted, depending 

on the direction of rotation of the servos, to suit the 

ailerons.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the given 

active (inverse video) field to its default value shown 

in the figure.

Ail-tr (Aileron trim)

Note:

Suppressed by “2AIL 1FL”.

0%

AILE

0%

+100%

+100%

fl.pos

normal

Diff.

Ail-tr

AI

0%

FLAP

0%

0%

0%

fl.pos

normal

Diff.

Ail-tr

AI

In this line, you specify the percentage rate with 

which aileron trim is to affect “AILE”, “FLAP” and–if 

present–“AILE2” and/or “FLAP2”.

The available range of values is -150% to +150%, 

relative to the adjustment range of the trim lever.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the given 

active (inverse video) field to its default value shown 

in the figure.

Diff. (Differential for aileron function)

Note:

With “2AIL 1FL”, at one level higher in the »Wing mixers« menu, see figure on page 177.

0%

AILE

0%

+100%

+100%

fl.pos

normal

Diff.

Ail-tr

AI

0%

FLAP

0%

0%

0%

fl.pos

normal

Diff.

Ail-tr

AI

On this line, you set the aileron differential, plus the 

differential for the FLAP and FLAP2 wing flaps–if the 

latter are being activated as ailerons.

0% (normal)

50% (differential)

100% (split)

AI FL FL2

FL2 FL AI

If you are unsure about the meaning of differential 

travel, please read the appropriate explanation at the 

start of this section on page 172.

The setting range of -100% to +100% permits correct 

differentiation direction adjustment regardless of the 
182 Program description - Wing mixers 

direction of rotation of aileron and flap servos.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the given 

active (inverse video) field to its default value shown 

in the figure.

fl.pos. (Flap position)

0%

AILE

0%

+100%

+100%

fl.pos

normal

Diff.

Ail-tr

AI

0%

FLAP

0%

0%

0%

fl.pos

normal

Diff.

Ail-tr

AI

Here, you set the flight phase-specific wing flap positions for all of the flaps present on the model in question. In this way, you can specify the flap positions 

that apply to each flight phase. 

The adjustment range of -100% to +100% makes it 

possible to set the correct direction of travel regardless of the direction of rotation of the aileron and flap 

servos.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the given 

active (inverse video) field to its default value shown 

in the figures.

FL (Effect of flap control)

This line specifies the percentage of effect produced 

on aileron and flaps by the settings (if applicable, also 

flight-phase dependent settings) made for Input 6 in 

the »Control adjust« menu, page 118.

0%

0% 0%

AILE

0%

+100%

FL

fl.pos

normal

Diff.

Ail-tr

0%

+100% +100%

FLAP

0%

0%

FL

fl.pos

normal

Diff.

Ail-tr

For each flap pair, you can define either a symmetrical or an asymmetric effect. Position the transmitter 

control accordingly–either centrally or to the relevant 

side.

If each travel adjustment is left at +100% on the 

»Control adjust« menu, page 118, then values 

between 5% and 20% should generally be sufficient 

here.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the given 

active (inverse video) field to its default value shown 

in the figures. 

Note:

• By default, NO transmitter control is assigned to 

input 6 on the »Control adjust« menu. However, you can assign a transmitter control or switch 

to this input at any time–also in a flight phase-dependent way–thus enabling different flap settings 

within a flight phase; see also example 2 on page 

302.

• As already mentioned in the remarks in the section starting on page 170, the two INC/DEC buttons (CTL 5 or 6) are virtually ideal for this purpose, as their position is automatically stored. 

They are fitted as standard to the mc-20 HoTT 

transmitter, and available as an extra-cost option 

on the mc-16 HoTT transmitter.

EL  FL (Elevator  flaps) 

To provide support for the elevator for tight turns 

and aerobatics, this mixer can be used to make the 

flap function follow controls sent to the elevator. The 

mixer direction chosen must ensure that the flaps are 

deflected downwards when the elevator is oriented 

upwards and vice versa for a downward-oriented 

elevator–i.e. in opposite directions.

For each flap pair, you can define either a symmetrical or an asymmetric effect. Position the transmitter 

control accordingly–either centrally or to the relevant 

side. Values in the range -150% to +150% are possible:

0%

0%

0% 0%

0%

AILE

0%

FL

fl.pos

EL FL

normal

Diff.

0%

+100%

0% 0%

+100%

FLAP

0%

FL

fl.pos

EL FL

normal

Diff.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the given 

active (inverse video) field to its default value shown 

in the figures. 

The “usual” values for this mixer are in the low twodigit range.

If a switch is assigned in the next line, “EL  FL”

then the effect produced on flaps can be switched on 

and off with the elevator. 
Program description - Wing mixers 183

Important general notice:

Do not let control surfaces and servos strike their 

mechanical end-stops when large deflections are 

set! This is especially relevant in relation to the 

functions “AI” and “FL”. Use the “- limit +” 

option (travel limit) available in the “Servo adjustment” menu (page 102), as required.

EL  FL Off. (symm. elevator offset) 

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

STO

normal

EL FL Off. 0% –––

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

STO

normal

EL FL Off. 0% –––

A value entered into the “EL  FL” line offers support to the elevator during tight curves and aerobatics. This “EL  FL Offset” line determines the offset 

value introductory point where this percentage of 

effect on flaps is to take place for elevator action. 

• With an offset value of 0%, flaps will be affected 

by elevator action beginning with the neutral position of the elevator stick by the percentage set in 

the “EL  FL” line.

• With an offset value other than 0%, flaps will be 

affected by movement of the elevator stick, in 

either the “up” or “down” direction, only after reaching the preset offset point.

To set this offset point, put the elevator stick at the offset point to be set (in either of the two possible directions). A brief tap on the center SET key of the right 

four-way button will store this position.

Tap on the center SET key of the right four-way button with the elevator stick in its centered position to 

set the offset value back to 0% again. If a switch is 

assigned in column “Switch”, the effect produced with 

the elevator on flaps can be switched on and off.

Brake settings

Notes:

• The “Brake settings” menu is switched “off” if: “Motor on C1 forward / back” in the »Model type« 

menu, page 104, AND the “Motor” column of the 

»Phase settings« menu, page 152, are set to 

“yes” for the currently active flight phase. Switch 

the flight phase if required:

• The “brake mixers” described below can also–and 

should also–be configured to be specific to individual flight phases.

Crow (Butterfly)

Elevat curve

Brake settings

AILE

Crow

D.red

0%

0%

0% 0%

0% 0%

FLAP FLAP2

normal

The “Crow” mixer function is actuated by control function 1, 7, 8 or 9, depending on the input assigned on 

the “Brake Offset” line in the »Model type« menu, 

see page 104.

Tail type

Motor at C1

Normal

None

Aile/flaps 2AIL2FL

Model type

Brake off +90%

STO SEL

In 1

Note:

The Offset, i.e. the activation direction, is also set 

in the »Model type« menu, page 104. This offset 

should be set to about +90% of stick travel (if the C1 

stick is used, this is generally located at the forward 

position of the stick). To extend the flaps, the stick 

must therefore be moved back towards the pilot. The 

remaining stick travel of around 10% then has no ef-
184 Program description - Wing mixers 

• “FLAP” and–if present–“FLAP2” column

As the model is braked on the landing approach, 

both pairs of flaps can be set to deflect by different 

amounts, e.g.:

AI

FL

FL2

FL2

FL

AI

AI

FL

FL2

FL2

FL

AI

• Combining AILE(2) and FLAP(2) for “Crow”

AI

FL

FL2

FL2

FL

AI

Though the airbrake mixers are set as described 

above, there is a special flap constellation, called 

“crow position” or “butterfly”, that can also be set. 

This airbrake setting causes both ailerons move 

moderately upward while the flaps move downward as far as possible. Another mixer–see below, under the section “Elevat. curve”–is then used 

to trim the elevator such that the flight speed does 

not change significantly in comparison to the normal flight position. Otherwise, there is a danger 

that the model loses too much speed and then, after the braking system is retracted (e.g. to extend 

a landing approach that was too short, for example), pancakes or even stalls.

A tip for “seeing” the effect of brakes:

Lift the flaps and look over and under the surface 

from the front. The larger the surface projected by the 

lifted flap, the greater the braking effect achieved.

Tips for activating airbrakes:

• When, in addition to aileron and camber flap servos, there is also a built-in servo for actuating wing 

airbrakes, it can be most simply connected to that 

receiver output–if free–whose input has been selected for the brake function, i.e. either on 1, 7, 8 

or–if present–9. If this is not possible then, as an 

alternative, use a free mixer to connect the selected brake control channel with the airbrake servo.

• To activate two airbrake servos, the best approach is to leave one servo on output 1 and to 

connect the second servo to a free output of your 

choice–for example, output 9. You then also assign this output to transmitter control 1 (as standard) on the »Control adjust« menu, page 118, 

see figure.

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8 –––

–––

–––

GL

GL

GL

GL

typ

normal

fr

fr

fr

SEL

Cn1

As you do, leave the settings for offset, travel, etc. 

at their default values. Also leave the default “GL” 

value in the column labeled “TYP” so that the second airbrake, like the first, operates in the same 

way across all flight phases.

fect, although it is not “lost”, since the control travel is 

automatically expanded back to 100%.

Use the select fields of the columns labeled “AILE”, 

“AILE2”, “FL” and, if present, “FL2” to specify the 

extent and the direction that corresponding flap pairs 

are to follow when the airbrake control (control function 1, 7, 8 or–if present–9) is operated. If the model 

has no airbrakes, leave the corresponding receiver 

output free or set it to “Mix-only” in the »Mix-only 

channel«, which is available as standard on the 

mc-20 HoTT transmitter only, so that you can use 

it for other purposes. On the mc-16 HoTT transmitter this option can be unlocked as an extra-cost option.

Values in the range -150% to +150% are possible.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the given 

active (inverse video) field to its default value shown 

in the figure. 

• “AILE” and–if present–“AILE2” column

When braking the model as it comes in to land, 

neither of the aileron flaps should ever be deflected more than half of the possible travel upwards, 

to ensure that enough travel is available to control 

the model along its longitudinal axis (aileron function).

AI

FL

FL2

FL2

FL

AI
Program description - Wing mixers 185

AI

FL

FL

AI

Servo 1

Servo 9

You can assure yourself that this works as stated 

by accessing the »Servo display« menu, accessible from almost any menu level with a brief simultaneous tap on the  keys on the left four-way 

button, see page 274:

1

3

5

7

0%

0%

9

11

0%

0%

2

4

6

8

0%

0%

0%

10 0%

12

0%

0%

+100%

+100%

If this relatively simply variant should prove impossible for whichever reasons, then the alternative is 

a solution with two free mixers–and potentially involving the »Mix-only channel« menu, see page 

216, which is available as standard on the mc20 HoTT transmitter only. and potentially involving 

Note:

On the mc-16 HoTT transmitter this feature can 

be unlocked as an extra-cost option. 

In either case, however, the airbrake travels must 

then be fine-tuned on the »Servo adjustment« 

menu, page 112.

D.red (Differential reduction)

Elevat curve

Brake settings

AILE

Crow

D.red

0%

0%

0% 0%

0% 0%

FLAP FLAP2

normal

Earlier, we discussed the problems with the butterfly 

(crow) configuration. Namely: that with the use of 

aileron differential, the aileron effect can be strongly 

(negatively) affected by the aileron elevation. This is 

firstly because further deflection of the one aileron 

upwards is (almost) no longer possible and secondly 

because the downward-deflected aileron–depending on the elevation and degree of differential configured–is often unable to achieve even its “normal” 

position.

To be able to restore the effect of the aileron altered 

in this way as far as possible, you should ensure that 

you make use of the automated “Differential reduction” feature. This feature continuously reduces the 

degree of aileron differential as the airbrake system 

is extended. The feature is configurable and can even 

be set to suppress differential entirely. 

A value of 0% means that the “aileron differential” set 

at the transmitter remains fully in force. An entry that 

equals the % value set for aileron differential means 

the differential is fully eliminated once the butterfly 

function is at maximum travel, i.e. with flaps fully 

extended. Setting a reduction value greater than the 

aileron differential configured will eliminate the latter 

even before the full travel of the airbrake stick.

Values can be set in the range 0 to 150%.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.

Elevat curve (Brake  elevator)

Elevat curve

Brake settings

Crow

D.red

0%

0%

0% 0%

0% 0%

normal

If the airbrake control–to be set to 1, 7, 8 or–if 

present–9 on the “Brake Offset” line of the »Model 

type« menu, page 105–is used to extend the flaps 

as described previously for the “Brake settings” menu, 

this will often have a negative effect on the aircraft 

model’s airspeed. This mixer can be used to compensate this type of effect by applying a corrective value 

to the elevator. 

A brief tap on the center SET key of the right four-way 

button will switch to the display screen shown below:

Input

Output

Point ?

–100%

0%

0%

Brake Ele

Curve off

normal

Setting notices for “Elevat curve”

The offset set in the »Model type« menu, page 105, 

affects this mixer:

The vertical line on the display that indicates the position of the airbrake control only moves from the edge 

of the graph when the configured offset is exceeded. 

In doing so, airbrake control travel is automatically 

expanded back to 100%, as described in the »Model 

type« menu.

Accordingly, the mixer’s neutral point always lies on 

the left edge, independently of the offset configured.

Now adjust the elevator curve in the direction of the 

opposite end-point in accordance with requirements. 
186 Program description - Wing mixers 

Note that this method for setting the 6-point curve 

mixer follows the same principles that are applicable 

to the curve mixers, already described on page 138 

in the context of the »Channel 1 curve« menu.

Input

Output

Point 1

–19%

–6%

–7%

Brake

normal

EL

Curve on

The selected setting should certainly be tried out in 

sufficient altitude and, if necessary, readjusted. When 

doing this, be sure to pay attention that the model 

does not slow down too much while the brake system 

is extended! Otherwise, you run the risk that, after the 

braking system is retracted, e.g. to extend a landing 

approach that was too short, for example, your model 

pancakes or even stalls.

Display “Wing mixer

Aile.diff. (Aileron differential)

Note:

Only for “2AIL 1FL”. For the “2/4AIL 2/4 FL” selection, this is included on the Multi-flap menu, see 

page 181. 

Aile.diff

Brake settings

0%

AI 0%

Wing mixers

RU –––

Multi-flap menu

normal

On this line you can set the aileron differential for the 

two aileron servos.

If you are unsure about the meaning of differential 

travel, please read the appropriate explanation at the 

start of this section on page 172.

The setting range of ±100% permits correct differentiation direction adjustment regardless of the direction 

of rotation of aileron and flap servos.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.

AI  RU (Aileron  Rudder)

Brake settings

AI 0%

Wing mixers

FL EL 0%0%

–––

–––

RU

Multi-flap menu

normal

Here, you can set the degree to which the rudder 

follows commands acting on ailerons. This is used 

in particular in connection with aileron differential to 

suppress adverse yaw and thus make it easier to fly 

“clean” curves. You can of course still issue separate 

commands to the rudder. 

The mixer direction is typically chosen to ensure that 

the rudder moves in the direction of the aileron that is 

deflected upwards.

Settings are always made symmetrically relative to 

the neutral point of the aileron stick.

The adjustment range of ±150% lets you set the 

direction of deflection as appropriate. Optionally, this 

mixer can be activated and deactivated with of the 

switches or a control switch that is not self-restoring 

so the model can be controlled with only the ailerons 

or rudder if desired. 

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in an active (inverse video) field back to 0%.

A value of around 50% is generally an excellent starting point.

FL  EL (Flaps  Elevator)

Brake settings

AI 0%

Wing mixers

FL EL 0%0%

–––

–––

RU

Multi-flap menu

normal

When setting camber-changing flaps, one side-effect 

can be to generate moments causing movement 

around the transverse axis. Equally, however, it may 

also be desirable that e.g. your aircraft model opts for 

a more pacey flight style with the flaps slightly raised. 

This mixer can be used to achieve both results.

With this mixer, the extension of the flaps–depending 

on the value configured–automatically ensures the 

elevator position follows suit. Symmetrical or asymmetrical settings relative to the neutral point of the 

flap control are possible.

If required, the mixer can be switched on or off by as-
Program description - Wing mixers 187

signing a switch in the right column.

Values can be set in the range ±150%. The “typical” 

values configured for this mixer are single-digit or low 

two-digit values.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in a given active (inverse video) field back to 

0%.
188 Program description - Helicopter mixer

Helicopter mixer

Flight phase-specific setting of collective pitch, throttle and tail rotor

This option is available as standard on 

both transmitter types.

In this menu »Helicopter mixer« all of 

the flight phase-specific helicopter mixers 

are described, with the exception of the mixers for 

auto-rotation flight (discussed from page 202 onward.) These mixers are used for the basic set-up of 

a model helicopter:

Free mixers

MIX active/phase

Fl. phase timers

Helicopter mixer

MIX-only channel

Dual mixer

For flight phase programming, see the menus:

• »Basic settings, model«, page 94

• »Phase settings«, page 156

• »Phase assignment«, page 158

When the switch for a specific flight phase is actuated, then the name of the given flight phase, e.g.

«Normal», will be displayed at the lower left edge of 

the display screen:

C1

C1

Pitch

Throttle

Tail

Tail 0%

Roll 0%

Throttle

Roll

Throttle

Tail

Nick

Nick

Throttle

Tail

Swash rotation

Swash limiter

0%

0%

0%

0°

OFF

normal

Gyro suppress 0%

Gyro gain 0%

In each of these flight phases–with the exception of 

the auto-rotation phase–the typical helicopter mixing 

and coupling functions shown in the screen-shot 

above are available for setting up the model helicopter. These functions are described in the first part of 

this comprehensive chapter.

General information on mixers, 

(see also pages 169 and 204)

An arrow “” indicates a mixer. A mixer “branches 

off” the signal flow of a control function at a particular 

point, in order to use this flow to cause a predetermined effect on a further control channel and, ultimately, the receiver output. “C1  Tail” mixer means, 

for example, that when the pitch-axis stick is actuated, the tail rotor servo must also react within the 

scope of its setting.

Basic programming procedure:

1. Select the mixer by using the selection keys of the 

left or right four-way button.

Depending on the mixer involved, the bottom display line will show either SEL or the (indicating 

a change to a second page is necessary).

2. A brief tap on the center SET key of the right fourway button will permit direct settings for linear mixer ratios. Use the selection keys to set the mixer 

ratio.

Otherwise you will need to switch to the second 

screen page where you can set up the appropriate 

curve mixer.

A simultaneous tap on the  or  keys of 

the right four-way button (CLEAR) will reset a 

changed value in a given active (inverse video) 

field back to 0%.

3. Another tap on the center SET key of the right 

four-way button will complete the entry.

4. A tap on the center ESC key of the left four-way 

button will cause a return to the previous display 

page.

Description of helicopter mixers

To set collective pitch curves as well as the two mixers, “C1  Throttle” and “C1  Tail”, there are curve 

mixers available in all flight phases. Accordingly, these 

mixers also permit the programming of non-linear 

mixing ratios along the path of stick travel, if required. 

Switch to the display screen for curve settings with a 

brief tap on the center SET key of the right four-way 

button, see description below.

The curve is set up basically in the same way as the 

Channel 1 curve for helicopters, but we will describe 

it again here in detail using pitch configuration as 

an example, to save you having to leaf through the 

manual.

In the remaining lines, first activate the value field 

and then use the selection keys of the left or right 

four-way button to set a mixer value in the value field 

(inverse video).

The settings available are rounded off with the 

“Swashplate limiter” option: This option can be set to 

restrict maximum deflection of the swashplate servo 

in the sense of a limiter. Together, these settings configure the basic set-up of the helicopter model. 

In the “Autorotation” flight phase as described on 

page 202, however, the mixers “C1  Throttle” and 

“C1  Tail” are not needed and therefore switched to 

a configurable default value.

Changed parameters can be reset to their respective 

default values at any time with a simultaneous tap 

on the  or  keys of the right four-way button 

(CLEAR).

mc

 

16 20
Program description - Helicopter mixer 189

Pitch (Pitch curve (C1  Pitch))

If necessary, use the  selection keys of the left or 

right four-way button to move to the “Pitch” line then 

tap briefly on the center SET key of the right four-way 

button:

Input

Output

Point ?

0%

0%

0%

Pitch

normal

Curve off

Unlike the »Channel 1 curve« menu, this display is 

only associated with the control curve of pitch servos, whereas the “Channel 1 curve” affects all servos 

controlled by the throttle/pitch stick.

Note that the output signal of the “Channel 1 

curve” option thus functions as an input signal 

for the collective pitch curve programmed here: 

In the graph, the vertical line is synchronized with 

the throttle/collective pitch stick and therefore follows the current Channel 1 curve characteristic.

The control curve can be defined (separately per 

flight phase) by up to 6 points, termed “reference 

points”, placed at any point along the stick travel.

Initially, however, fewer reference points are adequate 

for setting up the collective pitch curve. We recommend beginning with three reference points to start 

with. These three points, namely the two end-points 

“Pitch low (L)” (= -100% control travel) and “Pitch 

high (H)” (= +100% control travel) plus a point at the 

center of control travel still to be set, define an initially 

linear profile for the pitch curve.

Programming details

First, switch to your chosen flight phase, e.g. «Normal».

The throttle/collective pitch stick is used to move the 

vertical line in the graph between the two end-points 

“Point L” (minimum pitch at -100%) and “Point H” 

(maximum pitch at +100% control travel): at the same 

time, the current stick position is shown numerically 

on the “Input” line (-100% to +100%).

The point at which the vertical line crosses the curve 

is termed the “Output”, and can be varied at the maximum of 6 reference points within the range -125% to 

+125%. A control signal modified in this way affects 

only the collective pitch servos. 

In the example to the left, the stick is at exactly 0% of 

control travel and also generates an output signal of 

0%, since the characteristic curve is linear.

Up to six additional reference points can be set between the two end-points “L” and “H”, although the 

distance between neighboring reference points must 

not be less than approx. 25%.

Setting reference points

If necessary, use the left or right-hand arrow button 

to move the marker frame down to the “Point” line:

Input

Output

Point ?

0%

0%

0%

Pitch

normal

Curve off

Move the stick. If the display shows a framed question 

mark, then you can set the next reference point with a 

tap on the center SET key of the right four-way button. Simultaneously, the “?” is replaced by a number 

and the value field to the right of the reference point 

number is highlighted:

1

0%

0%

Pitch

normal

0%

Input

Output

Point

Curve off

The order in which up to four reference points are 

generated between the end-points “L” and “H” is irrelevant since these reference points are continuously 

renumbered automatically from left to right as they 

are entered.

Configuring reference points

To configure a point, use the stick to move the vertical 

line onto the point you wish to change. The number 

and current curve value of this point are displayed on 

the left side of the display, on the “Point” line. Briefly 

tap the center SET key of the right four-way button. 

Use the selection keys on the right four-way button 

to change the current curve value shown in the highlighted field. The possible range is -125% to +125% 

and changes do not affect neighboring reference 

points. 

+75%

1 +75%

0%

Pitch

normal

Input

Output

Point

Curve off

In this sample screen image, reference point “1” has 

been set to +75%.

If you wish, however, other points can also be set. At 

-50%, for example ...
190 Program description - Helicopter mixer

–50%

–12%

1

Pitch

normal

–12%

Input

Output

Point

Curve off

... and/or a further point at +50%:

+50%

+88%

3

Pitch

normal

+88%

Input

Output

Point

Curve off

This point can now be adjusted as previously described ... 

+50%

–50%

3 –50%

Pitch

normal

Input

Output

Point

Curve off

... or reset again with a simultaneous tap on the 

or  selection keys of the right four-way button 

(CLEAR). 

Trim point function

Alternatively, you can skip reference points L, 1 ... 

max. 4 and H in the active (i.e. highlighted) Value field 

using the Select buttons  of the left-hand four-way 

button in the ascending or descending direction. The 

selection keys on the right four-way button can then 

be used to change the reference point jumped to as 

described above, entirely independently of the control 

position, for example:

2

–50%

–25%

normal

Pitch

+50%

Trim point

Input

Output

Point

In this simple example, the pitch stick–represented 

by the vertical line–is halfway between “Pitch 

minimum” and the midpoint of control travel (input = 

-50%). However, “Point 1” will be relocated to control 

center at a point value of +50%, resulting in a momentary output value of -25%.

One touch on the center ESC key of the left four-way 

button terminates this trim point function.

Trim offset function

When a value field is active, i.e. in inverse video, it is 

not only possible, as previously described, to jump up 

or down to reference points already set with the 

selection keys of the left four-way button and to make 

a change with the selection keys of the right four-way 

button, but also an existing curve can be vertically 

repositioned within a range of ±25% through use of 

the  keys on the left four-way button. Starting with 

a point value for “Point 1” at 0%, the control curves 

in both of the following figures have been vertically 

shifted within the ±25% range by the trim offset function:

1

0%

+25%

normal

Pitch

+25%

Trim offset

Input

Output

Point

1

0%

–25%

normal

Pitch

–25%

Trim offset

Input

Output

Point

A tap on the center ESC key of the left four-way button will also terminate this function.

Trim x-axis function

This function is activated by tapping the left () or 

right () selection key of the right four-way button 

with an active (i.e. inverse video) value field. You can 

then use the selection keys on the right four-way button to reposition the active point horizontally or vertically as you wish. In the figure below, “Point 1” which 

was just shifted to +25% with the trim point function, 

will now be shifted to the left:

?

0%

+57%

normal

Pitch

+25%

Trim X-axis

Input

Output

Point

Notes:

• If the point is repositioned horizontally further 

away from the current control position than approx. 

±25%, a “?” sign will reappear in the line Point. 

This question mark does not refer to the repositioned point, however: instead, it signifies that a 

further point can be set at the current control position.

• Please note that the percentage value on the “Output” line always relates to the current stick position 

and not to the position of the point.
Program description - Helicopter mixer 191

Smoothing the collective pitch curve

In the example below, sample reference points have 

been set ...

reference point 1 to +50%,

reference point 2 to +75% and

reference point 3 to -50%

... as described in the last section:

+50%

–50%

3 –50%

Pitch

normal

Input

Output

Point

Curve off

This “jagged” curve profile can be smoothed automatically simply by pressing a button. 

Starting from the situation shown in the previous illustration, disable the Value field by pressing the central 

ESC button of the left-hand four-way button, or the 

SET button of the right-hand four-way button.

Now use the arrow buttons of the left or right-hand 

four-way button to move the marker frame up to the 

“Curve” line, and press the central SET button of the 

right-hand four-way button once more to activate the 

Value field of the “Curve” line:

+50%

–50%

3 –50%

Pitch

normal

Input

Output

Point

Curve off

Now use the arrow buttons of the right-hand four-way 

button to set the Value field from “off” to “on”, and 

then briefly press the central SET button of the righthand four-way button, or the central ESC button of the 

left-hand four-way button, to conclude the procedure:

+50%

–50%

3 –50%

Pitch

normal

Input

Output

Point

Curve on

Notes:

• If the stick does not coincide with the exact reference point, please note that the percentage value 

on the “Output” line always relates to the current 

stick position.

• The figures on these pages show control curves 

created only for the purpose of illustration. Please 

note, therefore, that the curve characteristics displayed do not in any way represent real-life collective pitch curves. A specific application example can be found in the programming examples on 

page 322.

The following three graphs show typical 3-point pitch 

curves for various flight phases, such as hovering, 

aerobatics and 3D flight.

The vertical bar depicts the current stick position. 

Please note that trim values greater than +100% and 

less than -100% cannot be presented in the display.

Sample collective pitch curves for various flight 

phases:

+100% +100% +100%

100% 100% 100% Output Output Output

1 2 3 4 5 1 2 3 4 5 1 2 3 4 5

Control travel Control travel Control travel

Hover Aerobatics 3D

Erasing reference points

To delete one of the reference points (1 to max. 4), 

use the stick to move the vertical line into the vicinity 

of the reference point in question. As soon as the 

reference point number and its associated value is 

shown on the “Point” line (see screen image above), 

following activation of the value field on the “Point” 

line now in inverse video with a simultaneous tap 

on the or  keys of the right four-way button 

(CLEAR) it can be erased. Complete the operation 

with a brief tap on the center key ESC of the left fourway button.

The “L” and “H” points, on the other hand, CANNOT 

be deleted. 

C1  Throttle (Throttle curve)

+50%

+50%

+50%

C1 Thro

normal

?

Input

Output

Point

Curve off

Unlike the »Channel 1 curve« menu, this display is 

only associated with the control curve of the throttle 

servo, whereas the the “Channel 1 curve” affects all 

servos controlled by the throttle/pitch stick.

Note that the output signal of the “Channel 1 

curve” menu thus functions as an input signal for 

the throttle curve programmed here: In the graph, 

the vertical line is synchronized with the throttle/

collective pitch stick and therefore follows the 

current Channel 1 curve characteristic.

The throttle curve can also be defined (separately 

per flight phase) by up to 6 points, termed “reference 

points”, placed at any point along the stick travel.

The reference points are defined, adjusted and 

erased in the usual way, as explained in the previous 

section on the collective pitch curve. Start by defining 
192 Program description - Helicopter mixer

the throttle curve with three points, namely the points 

“L” and “H” at the extremes, plus the Point “1” still to 

be set in the control center in order to match the motor power curve to the collective pitch curve.

Helicopter with carburetor or electric drive system with speed CONTROLLER

This setting relates only to the control curve of the 

throttle servo or the speed controller.

Setting the throttle curve to suit a helicopter equipped 

with a speed governor is discussed in the following 

section.

As with the configuration of the collective pitch curve 

(see previous page), the throttle curve can also be 

defined by up to 6 points.

• In each case, set the control curve so that when 

the throttle/collective pitch stick is in its end position, the carburetor is fully open or the controller of an electrically-powered helicopter is set to 

maximum (except for auto-rotation flight, see page 

202).

• For the hover point, which is normally at the control center, the carburetor setting or power control 

for the speed controller must be matched to the 

collective pitch curve so that the correct system 

rotational speed is obtained. 

• At the minimum position of the throttle/collective 

pitch stick, the throttle curve must first be configured so that a glow motor runs at a speed considerably higher than idle speed and the clutch is 

firmly engaged.

Starting and stopping of the motor–whether 

combustion or electric drive–always takes place 

within the given flight phase as a consequence of 

the throttle limiter and the “Cut Off trim” option of 

the digital trim (see below).

This makes it unnecessary to program the two flight 

phases that may be familiar to you from using other 

remote control systems–namely “with idle-up” and 

“without idle-up”, and with the associated “waste” of 

a flight phase for this purpose–since the program of 

the transmitters mc-16 HoTT and mc-20 HoTT 

offers a much more flexible approach to fine-tuning 

and optimizing increases to system rotational speed 

below the hover point than the “idle-up” approach 

taken by older mc remote control systems.

Ensure that the throttle limiter is closed before starting a motor with carburetor, i.e. so that the carburetor 

can be adjusted within the idle range only with trim. 

Ensure that you follow the safety instructions on page 

200 at all times. If the throttle is set too high when 

switching on the transmitter, you will receive audible 

and visible warnings!

STARLET

#02

2:22h

Stp 0:00

0:00

5.5V

3.9

«norm 

M

Throttle

too

high !

The following three graphs show (typical) 3-point 

throttle curves for various flight phases, such as hovering aerobatics and 3D flight.

Sample throttle curves for various flight phases:

+100% +100% +100%

100% 100% 100% Output Output Output

1 2 3 4 5 1 2 3 4 5 1 2 3 4 5

Control travel Control travel Control travel

Hover Aerobatics 3D

Notes on using the “throttle limit” function:

• The throttle limit function should be used in any 

case (»Control adjust« menu, page 127). At 

the rear limit of the default transmitter control, the 

right-side throttle limit proportional rotary slider, 

the throttle servo is completely decoupled from the 

throttle curve, the motor is at idle and will respond 

only to C1 trim. This option permits the motor to be 

started in any flight phase and to shut the motor 

off with the “Cut Off trim” option of the digital trim. 

See below and/or page 70.

Once the motor has started, push the throttle limiter s l o w l y in the direction of the opposite 

end-point to put actuation of the throttle servo fully under the control of the throttle/collective pitch 

stick once again. In order to prevent the throttle 

servo from being restricted by the throttle limiter in 

the full throttle direction, set control travel on the 

plus-side of the column labeled “travel” to +125% 

in the “Lim.” line of the »Control adjust« menu. 

Leave the default value of “GL” in the “Type” column alone, however, to configure this setting globally for all flight phases.

For a more finely-tuned control travel curve for the 

throttle limit control, you can also use the “Expo 

throttle limiter”, page 110. This gives you the option of defining the idle setting at the throttle limit control’s center position, as readily determined 

both visually and audibly.

Set the throttle limiter to its center position and adjust the “EXPO thro lim.” value as far as is needed 

until the motor is idling smoothly with the throttle 

limit control set at its center point. In this position, 

the motor will then start without any problems. 

To switch off, turn or push the throttle limit control–that is, without C1 cutoff trim–to its rearmost 

end-point. As you do, ensure that the affected servo cannot hit an end-stop mechanically.

The throttle restriction set by the throttle limiter is 

made visible as a horizontal bar in the diagram:
Program description - Helicopter mixer 193

2

+50%

+50%

+50%

normal

Throttle limiter position

Input

Output

Point

C1 Thro

Curve off

The output signal for the throttle servo can never 

be higher than that set by the horizontal bar. In this 

example, about a maximum of +25%.

• Since electric drive systems have no need for an 

idle setting, the basic configuration of settings for 

an electrically-powered helicopter merely involves 

making sure that the control range of the throttle limiter is both higher and lower than the adjustment range of the speed controller (usually -100% 

to +100%) by a safe margin. If necessary, therefore, adjust the “travel” setting of the throttle limiter as appropriate on the “Lim.” line of the »Control 

adjust« menu. Leave the default value of “GL” in 

the “Type” column alone, however, to configure this 

setting globally for all flight phases. 

Fine-tuning of the throttle curve itself, however, 

must take place in flight–as with a glow-powered 

helicopter.

• If you wish to record the flight time of a (glow-powered) helicopter, you can assign a control switch to 

the throttle limit slider, and then use this to switch 

a timer on and off; see page 145.

For auto-rotation flight, an automatic switch-over 

is made from this mixer to a configurable default 

value; see page 202. 

Helicopter with speed REGULATOR

Unlike speed controllers, which merely adjust output 

level in a manner similar to a carburetor, a speed 

regulator keeps speed in the system it monitors constant by regulating its output autonomously. In the 

case of combustion motor powered helicopters, the 

regulator therefore controls the throttle servo itself 

as appropriate or, for an electric helicopter, the motor’s speed controller. Therefore, speed regulators do 

not need a traditional throttle curve but rather only a 

speed setting. A deviation from the preset speed will 

therefore only take place if the level of output required 

exceeds the maximum level available.

Usually, receiver output 8 is reserved for connecting a speed regulator; refer to the receiver layout on 

page 75. However, if this connection is used there 

will be no throttle limit function because the throttle 

limit function can only be implemented via the “C1 

Thro” mixer which is on the–then unused–output 6.

To make the comfort and safety features of a throttle 

limiter available, a speed regulator should be connected to receiver output 6 (contrary to the general 

connection notices) and only requires appropriate 

adaptation to the throttle curve so it can take over the 

task of the “conventional” transmitter control. 

Since in this case the “throttle curve” only regulates 

the target speed of the motor controller and this 

target motor speed should typically remain constant 

over the entire collective pitch adjustment range, the 

“C1  Thro” mixer must be used to set a horizontal 

line–i.e. every (pitch) input value will result in the 

same (“throttle”) output value–whose “height” is defined by the target motor speed. 

First, therefore, the reference points “1” to “4”–if 

present and set–are erased. Following this, the reference points “L” (input = 0%) and “H” (input = +100%) 

are then each set to the same value, for example:

0%

+65%

+65%

C1 Thro

normal

L

Input

Output

Point

Curve off

The value to be set depends both on the speed controller used and on the target motor speed that is 

desired, and can, of course, be varied according to 

the flight phase.

For auto-rotation flight, an automatic switch-over 

is made from this mixer to a configurable default 

value; see page 202.

C1  Tail (Static torque compensation)

0%

0%

0%

C1 Tail

normal

?

Input

Output

Point

Curve off

The default approach here is to preset a torque compensation curve with a linear mixer ratio of a uniform 

0%, as is required for a gyro sensor working in “heading lock mode”–see the screen image above. 

Important notice:

In this context, ensure that you comply with the 

instructions on adjusting your gyro: if not, you 

risk making adjustments that render your helicopter impossible to fly.

If, on the other hand, you use your gyro sensor in 

the “normal” operating mode, or if it only has what is 

termed “normal mode”, then configure the mixer as 

follows:

As with the configuration of the collective pitch curve 

(see page 189), the control curve of the tail rotor 

can also be defined by up to 6 points. If required, 
194 Program description - Helicopter mixer

therefore, you can modify the mixer at any time and 

preset both symmetrical and asymmetric mixer ratios 

both above and below the hover point. Before you do, 

however, ensure you have entered the correct direction of rotation for the main rotor on the »Helicopter 

type« menu.

+100%

+30%

C1 Tail

normal

H +30%

Input

Output

Point

Curve off

Starting with values of -30% for point “L” and +30% 

for point “H”, the mixer is to be configured in such a 

way that the helicopter, even during prolonged vertically ascending or descending flights, does not deviate from the yaw axis as a result of the main rotor’s 

altered torque while hovering. For hovered flight, trim 

should only be affected by way of the (digital) tail rotor 

trim lever. 

For a reliable torque compensation setting, it is essential that the collective pitch and throttle curves 

have been set up correctly, i.e. that the rotor speed 

remains constant over the collective pitch’s full adjustment range.

This third curve mixer applies only to the control 

curve of the tail rotor servo when the throttle/collective pitch stick is moved, whereas the “Channel 1 

curve”, see page 141, acts on all servos that are 

affected by the throttle/collective pitch stick. Note that 

the output signal of the “Channel 1 curve” option also 

functions as an input signal for the tail rotor curve 

programmed here: In the graph, the vertical line is 

synchronized with the throttle/collective pitch stick 

and follows the current Channel 1 curve characteristic 

from the »Channel 1 curve« menu.

In the auto-rotation flight phase this mixer is automatically switched off.

Roll  Throttle and Nick  Throttle

0%

0%

SEL

0%

0%

normal

C1 Tail

Tail

Roll

Throttle

Roll

Throttle

Tail

Nick Throttle

Increasing collective pitch is not the only change that 

requires the throttle to follow suit: major cyclic control 

movements also require this, i.e. if the swashplate is 

tilted in any direction. The program of the transmitters 

mc-16 HoTT and mc-20 HoTT lets you adjust 

the degree of throttle follow separately for roll and 

pitch-axis controls.

This offers particular advantages in aerobatic flying, 

e.g. when flying a roll: here, with moderate collective 

pitch values and the carburetor only about half-open, 

cyclic control travels are nonetheless executed that 

require much higher performance from the motor.

The mixer value can be varied within the range 0 to 

+100%. The correct mixer direction is automatically 

taken into account.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in an active (inverse video) field back to 0%.

In the auto-rotation flight phase this mixer is automatically switched off.

Tail  Throttle

Pitch

0%

0%

normal SEL

C1

C1

Throttle

Tail

Tail

Roll

Throttle

Throttle

While the tail rotor normally compensates for the 

effect of main rotor torque on the fuselage, it is also 

used to control the helicopter around the vertical axis. 

Increasing tail rotor thrust requires a corresponding 

adjustment to motor power, however, to avoid a fall-off 

in system rotational speed.

This mixer sets the extent to which the throttle follows 

the tail rotor. The throttle will follow on one side only, 

to the side on which the tail rotor thrust is increased. 

The setting range is therefore 0 to +100%. The direction depends on the main rotor’s direction of rotation 

(left or right), and this must first be set correctly on 

the »Helicopter type« menu. For left-hand rotation 

systems, the throttle follows the tail rotor when the 

tail rotor stick is moved to the left, and vice versa for 

right-hand rotation systems.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset a changed 

value in an active (inverse video) field back to 0%.

In the auto-rotation flight phase this mixer is automatically switched off.

Set-up notes:

To set the mixer value accurately you should either 

first fly several high-speed pirouettes against the 

direction of main rotor rotation or, if a strong wind is 

blowing, hover at right angles to the wind with a sufficiently large tail rotor deflection. Set the mixer value 

so that there is no fall-off in system rotational speed.
Program description - Helicopter mixer 195

Roll  Tail and Nick  Tail

0%

0%

SEL

0%

0%

0%

normal

Roll

Roll

Throttle

Tail

Nick

Nick

Throttle

Tail

Gyro suppress

Increasing pitch is not the only change that requires a 

corresponding torque compensation via the tail rotor: 

major cyclic control movements also require this, e.g.

if the swashplate is tilted in any direction. Here, too, 

the program of the transmitters mc-16 HoTT and 

mc-20 HoTT lets you configure settings for both 

types of tilt movement (roll and pitch-axis) separately.

For advanced aerobatics in particular, which involve 

very large control deflections in the pitch-axis controls, e.g. the “Bo-turn” (vertical pull-up followed by 

tipping over around the pitch-axis) and tight loops, 

the uncompensated torque present in these flights 

causes the model to turn to a greater or lesser degree around the yaw axis. This spoils the appearance 

of the maneuver.

These two mixers permit static torque compensation 

to be activated by the swashplate tilting in any direction. The mixers work by always increasing tail rotor 

thrust, starting from the center point of the roll and 

pitch-axis sticks, i.e. they always generate a tail rotor deflection in the same direction regardless of the 

direction of the command.

The mixer value can be varied within the range 0 to 

+100%.

The mixer direction is determined automatically by 

your definition of the direction of main rotor rotation 

on the »Helicopter type« menu, page 108.

In the auto-rotation flight phase this mixer is automatically switched off.

Depending on the transmitter control’s position, the 

gyro gain at full travel on the tail rotor stick is:

“current control position 

minus 

gyro suppression value”.

Accordingly, if the transmitter control is at the neutral 

point, and gyro suppression is set to 100%, the gyro 

gain is reduced to zero as the tail rotor deflection increases. For values between 100% and the maximum 

value of 199%, the gyro can be fully suppressed–depending on the transmitter control position–well 

before full deflection of the tail rotor; see the diagram 

on the next page.

For the Graupner/JR gyro NEJ-120 BB, order no. 

3277, both the upper and the lower values are set via 

rotary controls: control 1 sets the minimum gyro gain 

at the bottom position of the slider; control 2 sets the 

maximum gain at the top end-point of the slider; the 

transition between these two values occurs roughly in 

the middle of the slider travel. 

In contrast, the PIEZO 900, PIEZO 2000 and PIEZO 3000 gyro systems feature proportional, infinitely 

variable adjustment of gyro gain; see below for typical 

diagrams.

As an example, the option to configure flight phasespecific–and static–gyro gain gives you the opportunity to exploit maximum stabilization for normal, slow 

flying, but to reduce gyro gain for fast circuits and 

aerobatics.

Samples of various gyro settings and configuration 

notes

• Linear gyro suppression: 0% to 199%.

With the tail rotor stick in the center position, 

the resulting gyro effect is set using the selected transmitter control. Using a proportional rotary 

control or slider, the effect is infinitely variable between zero (“min”) and maximum (“max”), provided transmitter control travel is not restricted. With 

Gyro suppress

0%

0%

SEL

0%

0°

normal

0%

Nick

Nick

Throttle

Tail

Swash rotation

Gyro suppress

Gyro gain

Important: in normal situations, this function 

should not be used if your model is fitted with a 

modern gyro system. In this context, ensure that 

you comply with the instructions on adjusting 

your gyro: if not, you risk making adjustments 

that render your helicopter impossible to fly. This 

menu has nonetheless been retained in order to cater 

to a full range of requirements and flying habits.

With this option, the effect of the gyro sensor (“gyro”) 

can be varied according to the tail rotor stick position; 

this assumes the use of a gyro system whose gyro 

gain can be controlled from the transmitter via an 

auxiliary channel. This channel will be channel 7 for 

Graupner remote control systems. The gyro suppression function reduces gyro gain in a linear progression as the pilot increases the tail rotor deflection. 

Without gyro suppression–i.e. when set to 0%–the 

gyro effect is constant, regardless of the stick position.

With a transmitter control assigned on the “Gyro” line 

on the »Control adjust« menu, page 126, e.g. one 

of the proportional sliders mounted in the middle console; as applicable, also made flight-phase dependent and/or with infinitely variable gyro effect between 

minimum and maximum. In this case, gyro gain is 

maximum at full deflection of the slider, and zero at 

the opposite end-point.

Of course, the software lets you limit the gyro gain 

range on both sides by altering the transmitter control travel.
196 Program description - Helicopter mixer

full tail rotor deflection, the effective gyro gain is as 

follows:

“current control position 

minus 

gyro suppression value”.

This means that at 0% gyro suppression, gyro 

gain is constant for tail rotor stick movement; at 

50% suppression, gyro gain is reduced to half 

if the assigned transmitter control is moved to 

the +50% position (as shown here); and only at 

>150% suppression is gain reduced to zero with 

the slider at this position, well before full tail rotor 

deflection.

Exemple:

+50 %

 Gyro gain 



left

Stick deflection tail rotor

centre right

Range of 

transmitter

control 7

• Linear gyro suppression with reduced control travel, e.g. -50% to +80% of full travel. 

Gyro gain is infinitely variable within these transmitter control limits. Here too, for purposes of illustration, we plot gyro gain values in relation to 

tail rotor deflection for various parameter values of 

gyro suppression.

input “7”, in connection with gyro suppression and/or 

the two settings on the Gyro NEJ-120 BB. 

Further notes on gyros with configurable multilevel 

gyro gain (e.g. NEJ-120 BB)

Since you cannot specify the gyro gain from the 

transmitter proportionally via the transmitter control, 

the gyro’s own control 1 must be used to set the 

(weaker) gyro gain (e.g. for aerobatics) and control 2 

the stronger gyro gain (e.g. for hovered flight). Even 

though a proportional control is used for control function 7, only a switch-over between these two values 

takes place and the setting is therefore not proportional. 

You should therefore advance control 2 to the point 

where the model is on the brink of oscillating when 

hovering in calm conditions, and advance control 1 to 

the point where the model does not oscillate with its 

tail even when flying at maximum speed into a strong 

headwind. Depending on the state of the weather 

and the flight program planned, you can also switch 

over the gyro gain from the transmitter–also with 

gyro suppression dependent on tail rotor deflection if 

required.

Gyro gain (Gyro Offset)

Important notice:

The value of this option is identical to the offset 

value set in the “Gyro” line of the »Control adjust« 

menu, page 126. For this reason, any changes 

made always affect the other menu directly–and 

vice versa.

Most of the latest gyro systems not only feature infinitely variable proportional gyro gain setting, but also 

offer a choice of two separate types of gain mode on 

the transmitter. 

If the gyro in use has at least one of these features 

then this alternative offset setting provides an opportunity to preset both “normal” gyro gain as well 

Exemple:

+80 %

 Gyro gain 



left

Stick deflection tail rotor

centre right

Range of

transmitter

control 7

Adjusting the gyro sensor

To achieve the maximum possible level of stabilization 

for the helicopter with the gyro along the vertical axis, 

observe the following:

• The controls should have as little friction and “play” 

as possible.

• There should be no “spring” in the control linkage.

• Use a strong and comparably fast servo. 

When the gyro sensor detects a model rotation, 

the faster its response–a corresponding corrective 

change to tail rotor thrust–takes effect, the further the 

gyro gain adjuster can be moved without causing the 

tail of the model to start oscillating, and the better the 

model’s stability about its vertical axis. If the response 

is slower, there is a risk that the model’s tail will start 

to oscillate even at low gyro gain settings. Here, further reductions to gyro gain will need to be made to 

eliminate the oscillation.

If the model is flying forward at high speed or hovering in a powerful headwind, the net result of the 

stabilizing effect of the vertical fin combined with the 

gyro may also lead to an overreaction that once again 

manifests itself through tail oscillation. To achieve 

optimum gyro stabilization under all conditions, you 

can make use of the option to adjust gyro gain from 

the transmitter using a transmitter control assigned to 
Program description - Helicopter mixer 197

as, as appropriate, to specify a “heading-lock mode” 

whereby, even within this pre-selection, gyro gain can 

be reduced by a particular gain type for normal, slow 

flight with maximum flight stabilization, fast circuit 

flights and aerobatics. 

To proceed as described above, use flight phase 

switching to enter different settings on the “Gyro 

offset” line. Values between -125% and +125% are 

possible:

0%

0%

SEL

0%

0°

normal

0%

Nick

Nick

Throttle

Tail

Swash rotation

Gyro suppress

Gyro gain

Based on these flight-phase specific (offset) settings, 

gyro gain can also be infinitely varied by a transmitter control assigned in the “Gyro” line of the »Control 

adjust« menu, page 126.

Swash rotation

0%

0%

SEL

0%

0°

normal

0%

Nick

Nick

Throttle

Tail

Swash rotation

Gyro suppress

Gyro gain

Some rotor head control systems make it necessary 

to incline the swashplate in a different direction from 

the intended inclination of the rotor plane when a 

cyclic control command is given. If your model features a four-bladed main rotor, for example, you may 

need to use this menu to set up a software-driven 45° 

rotation of the control linkage to the right, so that the 

pushrods from the swashplate to the rotor head can 

be set exactly vertical, ensuring that the blade control 

system works correctly, without unwanted differential 

The adjacent sketch illustrates the effect for a 100% 

setting. The cross-hatched area of travel is curtailed 

and appears as a “dead zone”..

If this function is used, 

“Dual Rate” should be 

set to 100% and Dual 

Rate values above 100% 

should also not be used. If 

not, and you set a swashplate limit of 100%, for 

example, then swashplate 

movement will be restricted even if roll and pitchaxis commands are given separately.

Setting range: 100 ... 149% and “off”. 

You can reset an altered value to “OFF” by simultaneously pressing the  or  buttons of the righthand four-way button (CLEAR) in the active (highlighted) field. 

effects. This eliminates the need to make mechanical changes to the control linkages. Negative angles 

equate to a virtual rotation of the rotor head to the 

left; positive angles a virtual rotation to the right.

Swash limiter

0%

0%

SEL

0%

0°

normal

Nick Tail

Swash rotation

Swash limiter OFF

Gyro suppress

Gyro gain

This function works like a circular mechanical surround acting upon the stick which controls the swashplate, restricting the normally square stick travel to 

a circular range. In fact, if the helicopter is set up in 

such a way that the deflections for roll and/or pitchaxis exploit the maximum travel mechanically possible, e.g. for 3D helicopters, then the total tilt applied 

to the swashplate if full roll and pitch-axis commands 

are applied simultaneously will be considerably 

greater (141% in numerical terms). The swashplate 

mechanism may then strike its end-stops and, in the 

worst case, the ball-links could even be disengaged.

The mc-16 HoTT and mc-20 HoTT transmitter 

contains a configurable software function for limiting 

the total swashplate travel, i.e. it restricts the tilt angle 

of the swashplate from 100% (the travel is limited 

to the value obtainable either with roll or pitch-axis 

alone) to 149% (no effective limit). In addition, the 

function can be set to “Off” and hence completely 

deactivated. The swash limiter can also be configured 

per model and per flight phase. 

This software solution is therefore much more flexible 

than a physical circular surround attached to the stick 

unit: the latter can, in any case, only be used if the roll 

and pitch-axis functions are controlled by a common 

stick unit.
198 Program description - Helicopter mixer

Fine-tuning the throttle and collective pitch curve

Practical approach

Although the throttle and collective pitch control systems are based on separate servos, they are always 

operated together by the throttle/pitch stick (except 

during autorotation flight). This coupling is performed 

by the helicopter program automatically. 

In principle, the trim lever for control function 1 only 

affects the throttle servo in the programs of the mc16 HoTT and mc-20 HoTT transmitters–with the 

exception of the choice of “PT” in the “Throttle” line of 

the »Stick mode« menu, page 116, which is available as standard on the mc-20 HoTT transmitter 

only. This »Stick mode« menu, which can be unlocked on the mc-16 HoTT transmitter as an extracost option, also enables you to define whether the 

trim lever of control function 1 is to be used as part of 

the throttle limiter function (“GA”), or for idle trimming 

during auto-rotation exercises (“AR”).

The process of fine-tuning throttle and collective 

pitch, i.e. setting the motor power curve to match the 

collective blade pitch setting, is the most important 

aspect of setting up a model helicopter. The software 

of the transmitters mc-16 HoTT and mc-20

HoTT provides for independent configuration of the 

throttle, collective pitch and torque compensation 

curves, in addition to the C1 control curve (»Channel 

1 curve« menu, page 141). 

While these curves can be modeled using up to six 

points, fewer points are generally sufficient. We recommend starting with three-point curves to begin 

with. This involves setting individual values for the 

center point and other (optional) reference points, and 

for the two end-points (“L”, “low”, and “H”, “high”) of 

the throttle/collective pitch stick: together, these define the control curves. 

Before setting the throttle and collective pitch function, the rods of all servos should be mechanically 

pre-adjusted correctly according to the set-up instructions for the given helicopter.

Note:

The hover point should normally be set to the 

center position of the throttle / collective pitch 

stick. In special cases, e.g. for “3D” flight, deviating hover points can also be programmed. 

For example, one point for normal flight attitude 

above the center and one point for inverted flight 

attitude below the center.

Idle setting and throttle curve

Note:

Since electric drive systems have no need for an 

idle setting, motor idling does not need to be calibrated. Fine-tuning of the throttle and collective pitch 

curve(s), however, must take place as for glow-powered helicopters.

The idle setting, whose detailed description begins on 

page 127, always takes place with the throttle limiter 

closed–normally with the trim lever of the C1 function 

and only in special cases is the throttle limiter itself 

also utilized (as standard, the right-sided proportional 

rotary slider (Lv2)). 

The programming of a corresponding value for the 

“L” point of the throttle curve acts to set the descent 

speed of the motor, without influencing the hover 

configuration.

Here, for example, flight phase programming can be 

used to set different throttle curves. This increased 

system rotational speed below the hover point proves 

to be useful in certain circumstances, e.g. for fast, 

steep landing approaches with greatly reduced collective pitch, and for aerobatics.

The figure depicts a curve with a 

slightly changeable throttle setting 

below the hover point at the control 

center. 

+100%

0%OUTPUT 1 2 3 4 5

Control travel

Different throttle curves are programmed to be flightphase dependent in order to achieve the given optimal adaptation to hovering flight as well as aerobatics:

• Low system rotational speed with smooth, gentle 

control response and low noise when hovering

• Higher rotor speed for aerobatics with motor 

power set close to the maximum. In this case, the 

throttle curve must also be adjusted in the hover 

range. 

Basic set-up procedure

Even though pitch and throttle curves can be set electronically over a wide range with the mc-16 HoTT 

and mc-20 HoTT transmitter, all linkage in the 

model should already be mechanically pre-adjusted 

correctly according to the instructions for the given 

helicopter. Experienced helicopter pilots will be glad 

to help with this basic set-up.

The carburetor linkage must be set so that the throttle 

is just past the fully open setting with collective pitch 

set to maximum or, for electric helicopters, with the 

speed controller set to full. When the throttle limiter is 

closed, however, it must be possible to just close off 

the carburetor using the C1 trim lever (rapid throttle 

setting of the “digital trim”, see page 58), without the 

servo mechanically striking its end-stop. For electric 

helicopters, it must be possible to cut the electric 

motor’s speed controller safely with the throttle limiter 

closed.

Take great care when configuring these settings, by 

adjusting the control linkage as required and/or alter-
Program description - Helicopter mixer 199

the collective pitch stick to its end-point. Compared to 

the hover configuration, motor speed should remain 

unchanged. 

If motor speed falls off in the climb, even with the 

drive system working at full power and therefore no 

further power increase is possible, then reduce maximum blade pitch angle at full deflection of the collective pitch stick, i.e. the value of point “H”. Conversely, 

the attack angle should be increased if motor speed 

is to increase while climbing. Therefore, on the “Pitch” 

graph page, put the vertical line on Point “H” by moving the pitch stick then change this point’s value 

appropriately with the  selection keys of the right 

four-way button. 

This diagram shows only the 

changes when setting the maximum 

collective pitch value.

+100%

100%OUTPUT 1 2 3 4 5

Control travel

Hover

point

Then bring the model back to hover, which should, in 

turn, be achieved with the C1 stick at its center point. 

If the hover flight point is now achieved only by moving the pitch stick away from its center point toward 

“higher” values then this deviation should be compensated by increasing the hover-flight pitch value–i.e.

for point “1”–a little until the model once again hovers 

with the stick at its center point. Conversely, if the 

model hovers below the mid-point, correct this by 

reducing the angle of attack appropriately.

It may also be necessary to correct the carburetor 

opening for the hover point (point “1”) with “C1 

throttle”.

ing the linkage point on the servo or carburetor lever. 

Only then should the throttle servo’s fine-tuning be 

electronically optimized.

Caution:

Inform yourself thoroughly about the dangers and 

safety precautions applicable to handling motors 

and helicopters before starting the motor for the 

first time!

With this basic set-up complete, the motor should 

be started in accordance with the motor operating 

instructions: idling can then be configured using the 

trim lever of the throttle/collective pitch stick. The 

preset idle position will be displayed on the transmitter’s basic display by a horizontal bar next to the C1 

trim lever position indicator. Refer to the description of 

digital trim on page 70 of this manual.

The model should lift off the ground with the collective pitch stick roughly at its center point and hover 

roughly at the expected rotational speed. If this is not 

the case, proceed as follows:

1. The model does not lift off until the collective 

pitch stick is above the center point:

a) Rotational speed is too low

Remedy: On the graph page 

for “C1  Throttle” increase 

the value for point “1”.

+100%

0%OUTPUT 1 2 3 4 5

Control travel

Hover

point

b) Rotational speed is too high

Remedy: Increase the 

blade angle of attack pitch 

by increasing the value of 

point “1” on the “Pitch” graph 

page.

+100%

0%OUTPUT 1 2 3 4 5

Control travel

Hover

point

2. The model lifts off before the center point is 

reached:

a) Rotational speed is too high

Remedy: Decrease the carburetor opening by reducing 

the value of point “1” on the 

graph page for “C1  Throttle”.

+100%

0%OUTPUT 1 2 3 4 5

Control travel

Hover

point

b) Rotational speed is too low

Remedy: Decrease the 

blade angle of attack pitch 

by reducing the value of 

point “1” on the graph page 

for “Pitch”.

+100%

0%OUTPUT 1 2 3 4 5

Control travel

Hover

point

Important:

These settings must be reconfigured until the model 

hovers at the correct rotational speed with the throttle/

collective pitch stick at its center point. The configuration of all other model parameters depends on these 

settings being made correctly!

Standard set-up

Standard set-up is completed on the basis of the basic set-up described above, whereby the model hovers in normal flight at the correct rotational speed with 

the throttle/collective pitch stick set to its center point: 

This means a set-up with which the model is capable 

of both hovering and flying circuits in all phases while 

maintaining a constant rotational speed.

Climb settings

The combination of throttle hover setting, collective 

pitch setting for the hover and the maximum collective 

pitch setting (point “H”) now permits, in a simple manner, a means of attaining a constant rotational speed 

from hovering right through to maximum climb.

First, perform a prolonged, vertical climb by moving 
200 Program description - Helicopter mixer

Therefore, after the motor is started, system rotational speed should be increased s l o w l y by way of the 

throttle limiter. If a switch has been assigned to the 

throttle limiter, always ensure the »Control adjust«“ 

menu, page 122, is used to program a time constant of about 5 seconds to run up system rotational 

speed (opening the throttle limiter). Do not, however, 

program a delay for closing the throttle limiter. Leave 

the default value of “GL” in the “Type” column alone, 

however, to configure this setting globally for all flight 

phases. 

a visual and an acoustic warning if the carburetor is 

open too wide when the transmitter is switched on. 

Otherwise, if the carburetor or speed controller is 

open too far when the motor starts, there is a danger 

that the motor will run up to speed immediately after 

starting, and the centrifugal clutch will engage immediately.

Accordingly,

always hold the rotor head 

firmly when starting.

Nevertheless, if the motor is accidentally started with 

the carburetor too wide open, the golden rule is this:

Don’t panic! 

Hold the rotor head securely! 

Don’t let go! 

Instead, close the throttle limiter immediately, even 

if this risks damaging the drive system (in the worst 

case scenario).

YOU must ensure 

the helicopter never moves 

in an uncontrolled manner. 

The costs of repairing a clutch, a gearbox or even 

the motor itself are negligible in comparison to the 

injuries and damage that an uncontrolled model helicopter can cause if it is allowed to thrash about with 

spinning rotor blades.

Always make sure no other person 

is present in the 

helicopter’s hazard area.

The switchover from idle to a flight setting with increased system rotational speed must not take place 

abruptly. This will cause the rotor to accelerate very 

quickly, resulting in premature wear to the clutch and 

gear train. Since the main rotor blades are generally 

mounted on a freewheeling unit, they will be unable 

to keep pace with such rapid acceleration; they will 

respond by swinging far out of their normal position 

and may even cause a boom strike.

This diagram shows only the 

change to the hover point, i.e. collective pitch minimum and maximum 

are both left at -100% 

or +100%.

+100%

100%OUTPUT 1 2 3 4 5

Control travel

Modify these settings until they really result in a 

constant rotational speed over the full control range 

between hovering and climbing flight.

Descent setting

The descent setting should now be configured by 

placing the model in a steady descent from forward 

flight at a considerable altitude by fully reducing collective pitch; adjust the collective pitch minimum value 

(point “L”) so that the model descends at an angle of 

60° ... 70°. Therefore, on the “Pitch” graph page, put 

the vertical line on Point “L” by moving the pitch stick 

then change this point’s value appropriately with the 

selection keys of the right four-way button.

This diagram shows only the 

changes when setting the minimum 

collective pitch value.

+100%

100%OUTPUT 1 2 3 4 5

Control travel

Hover

point

Once the model can fly this maneuver properly, set 

the value for “Throttle min”–the value for point “L” on 

the graph page for “C1  Throttle”–so that the rotational speed neither increases nor decreases. This 

completes the set-up procedure for throttle and collective pitch.

Some important closing remarks

Before starting the motor, ensure that the throttle 

limiter is fully closed: this ensures that the carburetor 

now responds only to the C1 trim lever. There will be 
For your notes 201
202 Program description - Helicopter mixer / Auto-rotation setting

Helicopter mixer

Auto-rotation setting

Auto-rotation permits both full-size and model helicopters to land safely in a crisis, e.g. if the motor 

should fail. Moreover, if the tail rotor should fail, cutting the motor and landing using auto-rotation is also 

the only possible way to avoid a high-speed, uncontrollable rotation around the vertical axis and a resulting catastrophic crash–which is why a switchover TO 

the auto-rotation phase takes place immediately.

When the switchover to the auto-rotation phase is 

made, the Helicopter mixer menu screen changes as 

follows:

Pitch

0%

0°

Autorot

–90%

0%

Gyro gain 0%

Thr setting AR

Tailoffset AR

Gyro suppress

Swash rotation

Swash limiter OFF

During auto-rotation flight, the main rotor is no longer 

driven by the motor but only by its own momentum 

and the airflow through the rotor plane during descent. Since the energy stored by a rotor kept spinning in this way is rapidly consumed if the helicopter 

flares, pilots must not only have experience in handling helicopter models but must also consider carefully how the relevant functions should be configured.

The advanced pilot should therefore practice autorotation landings at regular intervals. Not only to be 

able to demonstrate mastery of the maneuver at 

competitions, but also to ensure the pilot can land 

the helicopter undamaged from a great height if the 

motor should fail. For this purpose, the program provides a range of adjustment options designed to help 

the pilot fly a motorized model in its unpowered state. 

Note that the auto-rotation settings comprise a complete seventh flight phase, which provides access to 

all the flight phase-specific configuration options, and 

to trims, collective pitch curve settings, etc., in particular. The following functions have special features 

not present in the powered flight phases:

Pitch (Collective pitch curve (C1  Pitch))

In powered flight, the maximum blade pitch angle 

is limited by available motor power. In auto-rotation, 

however, it is limited only by the point at which airflow 

ceases over the main rotor blades. Greater maximum collective pitch must therefore be set to ensure 

sufficient thrust when flaring the helicopter even as 

rotational speed is falling off. To do so, briefly tap the 

center SET key of the right four-way button to switch 

to the “Pitch” graph page and then use the stick to 

move the vertical line to point “H”. Start by setting a 

value that is about 10 to 20% greater than your “normal” maximum value for collective pitch. Initially, however, do NOT set a value that is considerably greater 

than for normal flight, since, if this is done, the behavior of the collective pitch controls may then be very 

unfamiliar following the switchover. Indeed, there is a 

danger that the pilot will oversteer during the flare and 

the model will balloon: this will case the rotor speed to 

collapse at a considerable altitude and the model will 

then crash to the ground. The value can always be 

readjusted later after flying some test auto-rotations.

The minimum value for collective pitch can differ from 

that set for normal flight. This depends on the pilot’s 

usual style for normal flight. For auto-rotation, however, always set a sufficiently generous minimum 

value for collective pitch at point “L” to ensure the 

model can be brought out of forward flight at moderate speed into a descent at an angle of around 60 

... 70 degrees when collective pitch is reduced to a 

minimum. If, like most helicopter pilots, you have used 

this kind of setting for normal flight anyway, then this 

value can simply be transferred.

If, however, you normally let your model “fall” at a 

shallower angle, then you should increase the value 

at point “L”, and vice versa.

Approach angle for various wind conditions

Approach angle

in moderate 

wind

no wind

45°

60°

75°

in strong 

wind

As a rule, the collective pitch stick itself is not positioned right at the bottom of its travel for auto-rotation. 

Instead, it is typically between the hover position and 

the bottom end-point. This offers the pilot an option for further adjustment, e.g. via pitch inclination 

through pitch-axis controls.

The approach can be shortened by pulling back 

slightly on the pitch-axis stick and gently reducing 

pitch or by extending the approach by pushing forward on the pitch-axis stick and carefully increasing 

pitch.

Throttle setting AR 

Although pilots will be expected to cut the glow motor 

completely during competitions, This is rather inconvenient during training sessions because the motor 

must be restarted after every practice auto-rotation 

landing.

Therefore, for training sessions, set this line’s value 

such that a combustion motor is held at a safe idle 

without the clutch engaging during the auto-rotation 

phase; electric drive systems should be set safely to 

“Off”. 

Note:

The “Motor Stop” option in the »Base setup model« 

menu offers an alternative “Emergency STOP” function.
Program description - Helicopter mixer / Auto-rotation setting 203

Tail rotor AR

In normal flight, the tail rotor is set so that it compensates for motor torque while the model is hovering. It 

therefore generates some a certain amount of thrust 

even in its normal position. The level of thrust is then 

varied by the tail rotor control system, and also by 

the various mixers which provide all manner of torque 

compensation, while the tail rotor trim is also used to 

compensate for varying weather conditions, fluctuations in system rotational speed and other influences.

For auto-rotation, however, the main rotor is not driven by the motor, but by the “windmill” principle. Since 

this, in turn, does not generate any torque for which 

the tail rotor must compensate, all corresponding mixers are switched off automatically.

Since the absence of torque in auto-rotation also 

means the above-mentioned thrust is superfluous, 

however, a different tail rotor configuration is also 

required:

Cut the motor and place the helicopter on the ground 

in a level attitude. With the transmitter and receiving 

system switched on, select the flight phase “Autorotation” and then fold the tail rotor blades down. Now 

change the value on the “Tail rotor” line until the tail 

rotor blade angle of attack is zero degrees. Viewed 

from the tail, the tail rotor blades should be parallel to 

one another. 

Depending on the friction and running resistance 

of the gearbox, the fuselage may still yaw slightly, 

however. This relatively slight torque must then be 

corrected if necessary by adjusting the tail rotor blade 

pitch angle. This value will always be a figure between 

zero degrees and a pitch angle opposed to the pitch 

angle in normal flight.
204 General notes on freely programmable mixers

The previous pages have described a wealth of 

ready-to-use built-in coupling functions, in the context 

of the two menus »Wing mixers« and »Helicopter 

mixers«. The fundamental significance of mixers and 

the principle by which they work are described on 

page 169. The following section provides information 

about the so-called “free mixers”. 

In addition to the pre-programmed mixers mentioned 

above, the transmitters mc-16 HoTT and mc-20

HoTT also offers a number of freely programmable 

mixers in every model memory location, whose inputs, outputs and mixer ratios can be defined to meet 

one’s own requirements. These include: 

• 8 linear mixers, numbered 1 through 8

• 4 curve mixers, numbered 9 through 12

These 12 mixers are certainly adequate for most 

applications and are certainly sufficient when the 

potential of the pre-programmed coupling functions 

are utilized. The »MIX act. / phase« menu, which is 

available as standard on the mc-20 HoTT transmitter only, see page 215, also provides a means 

of activating or disabling any of these twelve mixers 

separately for each flight phase. 

For the “free mixers”, the signal present at any control 

function (1 to 8 or 1 ... 12) can be assigned as the 

input signal or, for a so-called “switch channel” (see 

further below), the signal from any switch can be utilized. The signal that is present at the control channel 

and passed to the mixer input is always influenced by 

its own transmitter control and by any control characteristic that may have been set, e.g. those specified 

by the »Dual Rate / Expo«, »Channel 1 curve« and 

»Control adjust« menus. 

The mixer output acts on a control channel (1 to–depending on transmitter and receiver type–a maximum of 12) that can also be assigned freely. Before 

this channel routes the signal to the servo, it can only 

still be influenced by the »Servo adjustment« menu, 

i.e. by the servo reverse, neutral point offset, servo 

travel and servo travel limit functions, and possibly by 

the »Tx. output swap« option, which is available as 

standard on the mc-20 HoTT transmitter only, but 

can be unlocked on the mc-16 HoTT transmitter as 

an extra-cost option.

One control function can be used for any number of 

mix inputs simultaneously: if, for example, several 

mixers are to be switched to act in parallel. 

Conversely, it is possible for any number of mixers to 

affect one and the same control channel. Particularly 

in the latter case, however, it is very important to 

ensure that the servo concerned does not strike its 

mechanical end-stops when several mixer signals accumulate excessively. For safety’s sake, it may therefore be necessary to set an appropriate travel limit in 

the »Servo adjustment« menu, page 112.

For more complex applications, mixers can be 

switched in sequence. In this case, it is not the 

(transmitter) signal at the “output” of a control function which forms the input signal of the “series-wired” 

mixer, but the (mixed) signal “further back” at the “input” of a control channel. The following description of 

the free mixers includes several examples of this type.

In the software, a “free mixer” is always initially activated. Optionally the mixer can also be assigned to 

an ON/OFF switch. Since there are so many functions to which switches can be assigned, be careful 

to avoid (undesired) multiple assignments to a single 

switch.

The two key mixer parameters are: 

• ... the mixer ratio, which defines the extent to 

which the input signal acts on the output of the 

control channel connected to the mixer output. 

The mixer ratio for linear mixers can be set as 

symmetrical or asymmetric. Curve mixers can also 

be configured with up to 6 points to suit one’s own 

application and even implement extremely non-linear curves.

• ... the neutral point of a mixer, which is also 

referred to as the “offset”. 

The offset is that specific point along the movement of a transmitter control (stick, proportional 

control or switch) at which the mixer no longer influences the control channel connected to its output. Normally, the neutral point is the center point 

of the transmitter control. However, the offset can 

also be set at any other point along the control 

travel. Since there are no restrictions on the design of the curve mixers, setting a mixer neutral 

point only makes sense for the 8 linear mixers.

Switch channel “S” as a mixer input

Occasionally, however, only a constant control signal is required at the mixer output, e.g. for a slightly 

increased “up-elevator” trim when the aero-tow release is closed–fully independently of its normal trim 

setting.

In this case a switch is assigned both to the aero-tow 

release and the mixer; it is then used not only to open 

and close the release, but also to pass the desired 

trim signal to the elevator via the mixer ratio. To identify this special arrangement, this mixer input control 

function in the program is designated “S” for “Switch 

channel”. 

In addition, if the corresponding “target channel” 

should now no longer be influenced by its “normal” 

transmitter control, separate its transmitter control 

from the function input of the associated control 

channel in the »Mix-only channel«, see page 216, 

which is available as standard on the mc-20 HoTT 

transmitter only. Here too, for clarification of this there 

is an example of the function provided in the following 

menu description. 

General notes on freely programmable mixers
Program description - Free mixers 205

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Free mixers« menu option in the Multi-function menu:

MIX active/phase

Fl. phase timers

Wing mixers

MIX-only channel

Dual mixer

Free mixers

MIX active/phase

Fl. phase timers

Helicopter mixer

MIX-only channel

Dual mixer

Free mixers

Open this menu option with a tap on the center SET

key of the right four-way button.

Regardless of the model type selected, each of the 

20 (mc-16 HoTT) or 24 (mc-20 HoTT) model 

memory locations offers eight linear mixers (M1 ... 8) 

...

fr

M1

M2

M3

?? ??

?? ??

M4

M5

?? ??

?? ??

?? ??

... and 4 curve mixers (C9 ... 12), which also offer 

non-linear control characteristics:

fr

M8

C9

C10

?? ??

?? ??

C11

C12

?? ??

?? ??

?? ??

The »MIX act. / phase« menu, see page 215, which 

is available as standard on the mc-20 HoTT transmitter only, but can be unlocked at extra cost on the 

mc-16 HoTT transmitter, also provides a means of 

activating and disabling specific mixers separately 

for each flight phase. On the “Free mixers” menu, 

the blocked mixers are then suppressed in the 

corresponding flight phase. If you are hunting for 

a mixer that is not shown, you should therefore 

switch to the appropriate flight phase!

In this first section, however, we will concentrate on 

how to program the first screen page of the “free mixers”. We will then move on to the method of programming mixer ratios, both for linear mixers and curve 

mixers, as found on the second screen page of this 

menu.

Basic programming procedure

1. Select the mixer you want by using the  selection keys on the left or right four-way button.

2. Tap the center SET key of the right four-way button. The input field on the column marked “fr” at 

the lower edge of the screen is now shown highlighted.

3. Use the selection keys on the right four-way button 

to select the “fr” mixer input.

Additional column names now appear in the bottom line of the screen. 

4. Tap the center SET key of the right four-way button; using the  selection key of the left or right 

four-way button, switch to the column marked “to” 

at the lower edge of the screen then tap the center 

SET key of the right four-way button once again. 

The input field “to” is shown highlighted.

5. Use the selection keys on the right four-way button 

to select the “to” mixer output.

6. Tap the center SET key of the right four-way button. Optionally use the selection key of the left 

or right four-way button to switch to the column 

marked “ty” at the lower edge of the screen in order to include the trim of the respective stick in the 

mixer input signal (“Tr” for trim or “P” for phase) 

and/or to add series switching (“”) for mixers ...

... and/or use the  selection key of the left or 

right four-way button to change into the column 

marked with the switch icon (“ ”) on the lower 

edge of the screen. To do this, tap the center SET

key of the right four-way button once again and assign a switch as described in the section “Physical 

control, switch and control switch assignments” on 

page 68.

7. Using the  selection key of the left or right fourway button, switch to the column (“ ”) then tap the 

center SET key of the right four-way button. 

8. Define the mixer ratios on the second screen 

page.

9. Return to the first page by using the center ESC

key of the left four-way button.

“fr(om)”

After selecting a mixer line and a subsequent tap on 

the center SET key of the right four-way button, select 

one of the control functions, 1 ... 8 respectively 1 ... 

12 or S, for the value field now in inverse video with 

the selection keys of the right touch.

For the sake of clarity, control functions 1 ... 4 are 

marked as follows when setting wing mixers:

C1 Throttle/airbrake stick

AI Aileron stick

EL Elevator stick

Free mixers

Freely-programmable linear and curve mixers

mc

 

16 20
206 Program description - Free mixers

Mixer switches

In the sample screen image shown above, switches 

“4” and “2” have been assigned to linear mixers 1 and 

4 and to mixer 2 of the control switch “C4”.

The switch symbol to the right of the switch number 

shows the current switch state.

Any mixers not assigned to a switch, as indicated 

by an empty cell for the column marked by the 

switch icon (“ ”) on the screen’s bottom line, 

are fundamentally active!

A switch must be assigned to LinearMIX 4 if you wish 

to switch between two fixed mixer values (still to be 

set) that correspond to the two end-points of a (proportional) transmitter control. Accordingly, the “switch 

channel” mixer cannot also be switched “on” or “off” 

as with the other mixers.

If you intend to assign a control switch (G1 ... G4) 

or a logical switch (L1 ... 8) as the mixer switch, 

then please remember that you also must define the 

switch as such in the »Control switches« menu, or 

in the »Logical switches« menu, which is available 

as standard on the mc-20 HoTT transmitter only, 

but can be unlocked in the mc-16 HoTT transmitter 

as an extra-cost option. If you do not, you will assign 

an undefined control or logical switch and therefore 

one that functions as a fixed switch.

“Ty(pe)”

Including the trim

For control functions 1 ... 4, you can also allow trimming of the digital trim lever for the given stick effect 

the mixer’s input. In this case, briefly tap the center 

SET key of the right four-way button then use the 

selection keys to select “Tr” in the inverse video field:

RU Rudder stick

... and, for the helicopter program:

1 Throttle/collective pitch stick

2 Roll stick

3 Pitch-axis stick

4 Tail rotor stick

Note:

If you select any of the control functions 5 ... 12 max. 

for fixed-wing models or 5, 7 ... 12 max. for helicopter 

models, do not forget to assign a transmitter control 

for each of these in the »Control adjust« menu!

“S” as switch channel

Selecting “S” (switch channel) in the “fr” column has 

the effect of passing a constant input signal to the 

mixer input, e.g. in order to add a little more “upelevator” trim when the aero-tow release is closed, as 

mentioned on the previous page.

After assigning a control function or the “S” switch 

channel in the “fr” column, the following is also displayed ...

“to”

... on the lower edge of the screen. 

Use this column’s input field to specify the destination 

of the mixer, i.e. assign mixer output, to one of the 

control channels. At the same time, additional fields 

will appear in the bottom line of the screen:

ty fr to

M1

M2

M3

6 EL

C1 EL

M4

M5

3 8

S EL

?? ??

C4

4

2

Tr

In this example, four mixers have already been defined. The second mixer is already familiar in principle 

as “Elevat curve” from the “Brake settings” sub-menu 

of the »Wing mixers« menu and the third is familiar 

from the line “Tail” (“2ELSv3+8”) of the »Model type« 

menu. As a general rule, however, you should first 

make use of the pre-programmed mixers. However, 

if you need asymmetric mixer ratios, want to program non-linear curves or need to offset the mixer 

neutral point, then you should set or leave the preprogrammed mixers at “0%” and replace these with 

free mixers.

Erasing mixers

To erase a previously-defined mixer, select the appropriate line with the  selection keys on the left or 

right four-way button, switch to the “fr” column, if necessary, with the  selection keys then briefly tap 

the center SET button on the right four-way button:

ty fr to

M1

M2

M3

6 EL

C1 EL

M4

M5

 8

S EL

?? ??

Tr

C4

4

2

3

The field in the “fr“ column for the mixer you want to 

delete will now be shown in inverse video: tap both 

 selection keys or  on the right four-way button at the same time (CLEAR):

fr

M1

M2

M3

6 EL

C1 EL

M4

M5

??

S EL

?? ??

C4

4

2

??
Program description - Free mixers 207

ty fr to

M1

M2

M3

6 7

7 8

M4

M5 ?? ??

?? ??

?? ??

Example:

Two mixers (MIX 6  7 and 7  8):

a) WITHOUT series switching:

6 6

7

Servo 4 8 V

C 577

Bes -Nr 4 01

Se vo 4 8 V

C 577

Bes Nr 410

7

8

Servo 4 8 

C 577

Bes -Nr 410

MIX 1

MIX 2

b) The same mixers WITH series switching:

6 6

7

Servo 4 8 V

C 577

Bes Nr 410

Servo 4 8 V

C 577

B s -Nr 4101

7

8

Se vo 4 8 V

C 577

Bes Nr 410

MIX 1

MIX 2

In this highly simplified example, if mixer 2 is switched 

in series, then it does not “take over” solely the transmitter signal of control function 7–as shown under 

a)–but, instead, the entire (mixed) signal present at 

the servo side of control channel 7, as shown under 

b). It then directs this in accordance with its configured mixer ratio forwards to control channel 8. In 

this case, the effect of transmitter control “6” extends 

as far as output “8”. This kind of serial linkage can be 

extended as far as you wish. For example, another 

mixer “8  12” can be used to route the control signal 

from “6” as far as output “12”, taking into consideration the associated mixer ratios. Of course, even with 

an active serial link, each separate mixer can still be 

controlled via the transmitter control assigned to the 

mixer input. Fixed-wing and helicopter mixers also 

work in the same way, when set up to switch “in sequence”.

Including phase trim

If you wish to apply the FLAP channel (“6”) or FLAP2 

channel (“9”) trim values stored in the »Phase trim« 

menu–flight phase dependent–then first tap the 

center SET key of the right four-way button and use 

its selection keys to select “P”:

ty fr to

M1

M2

M3

6 11

M4

M5 ?? ??

?? ??

?? ??

P

?? ??

Depending on the mixer value configured, a mixer 

can, as shown in the example above, route the signal 

from a flap control present (e.g.) on input 6 to control 

channel 11, while also applying the FLAP trim value 

set on the »Phase trim« menu, page 160, for the 

respective flight phase.

Other special features of free mixers

Mixer input = mixer output

If you set up a mixer whose input is the same as 

its output, e.g. “C1  C1”, you can achieve some 

very special effects in conjunction with the option of 

switching a free mixer on and off in any way you like. 

A typical application of this can be found at the end of 

this section, as Example 2 on page 213.

ty fr to

M1

M2

M3

6 EL

C1 EL

M4

M5

3 8

S EL

?? ??

C4

4

2

Tr

The effect of the C1 trim lever on mixer output will 

depend on the function assigned in the »Model type« 

menu, page 104, in the “Motor on C1” column for 

fixed-wing models ...

Trim Effect on mixer output

None linear over full trim lever travel

Forward Only effective if C1 stick is forward

Back Only effective if C1 stick is back

... or–in the case of model helicopters–in the “Thr.” 

line of the »Stick mode« menu, which is available on 

the mc-20 HoTT transmitter only:

Trim Effect on mixer output

TA

(Thr-AR)

linear over full trim lever travel to output 6 (throttle servo)

TL

(Throttle 

limit)

only effective at minimum position of 

the assigned throttle limit control (the 

right side proportional rotary control as 

standard)

PT

(Pitch)

linear over full trim lever travel to control function “Pitch”

Switching mixers in series

As already explained on page 204, you can also 

switch mixers in series: Where mixers are switched 

in “sequence”, the “input signal” of a control channel 

already on its way to the servo “branches off” and is 

directed to a further channel. In the “ty” column, select 

the right angle bracket “ ” or “Tr ”, if the trim should 

also act simultaneously on the mixer input:
208 Program description - Free mixers

Mixer Effect

N.N.*  2 servo pair 2 + 5 responds with an 

aileron function

N.N.*  5 servo pair 2 + 5 responds with a 

flap function

N.N.*  6 servo pair 6 + 7 responds with a 

flap function

N.N.*  7 servo pair 6 + 7 responds with an 

aileron function

N.N.*  9 servo pair 9 + 10 responds with a 

flap function

N.N.*  10 servo pair 9 + 10 responds with an 

aileron function

N.N.*  11 servo pair 11 + 12 responds with a 

flap function

N.N.*  12 servo pair 11 + 12 responds with 

an aileron function

• Model helicopters:

With helicopter mixers, collective pitch control may 

be provided by up to 4 servos connected to receiver outputs 1, 2, 3 and 5, depending on helicopter 

type. The software links these together to control 

collective pitch, roll and pitch-axis.

Other than within the »Helicopter mixers« menu, 

it is not advisable to mix a free mixer into these 

channels because this can lead to very complex 

interactions. One of the few exceptions is “Collective pitch trim using a separate transmitter control”–see example 3 on page 213.

Important notices:

• With serial links in particular, remember that 

the travels of the individual mixers are cumulative if multiple stick commands are made simultaneously: there is a risk that the servo(s) 

Tip:

If you separate a control function–for example ,“9”–in 

the »Mix-only channel« menu, see page 216, then 

the servo’s response is determined exclusively by the 

mixer input of a mixer programmed from “9  9”. This 

menu is available as standard on the mc-20 HoTT 

transmitter only, but can be unlocked as an extra-cost 

option on the mc-16 HoTT. Thus, with linear mixers M1 ... 8 or curve mixers C9 ... 12, 6-point control 

curves can be defined for any transmitter control in a 

manner analogous to that described in the »Channel 

1 curve« menu and these can also be used in flight 

phase switching if needed. This method of “linking” is 

not only also switchable but can even be subject to a 

delay by assigning an appropriate delay in the “– time 

+” column of the »Control adjust« menu.

Mixer output affecting default software coupling 

of aileron, camber-changing flap or collective 

pitch servos

Before we start specifying the mixer ratio, we must 

first give some thought to what happens if we permit 

a mixer to affect the default software coupling of aileron, camber-changing flap or collective pitch servos:

• Fixed-wing models:

Depending on the number of wing servos available 

on the “Aile/flaps” line of the »Model type« menu, 

control channels 2 and 5 are connected via special mixers for the “aileron” function, 6 and 7 for the 

“flap” function, outputs 9 and 10 (if present) for the 

FLAP2 servos and 11 and 12 for AILE2 servos.

If mixer outputs are programmed to affect these 

kinds of couplings, then their effect on the respective flap pair derived from the “receiving” control 

channel must be accounted for:

may strike a mechanical end-stop. If necessary, reduce “servo travel” to avoid this; alternatively, set “Travel limit” on the “Servo adjustment” menu and/or reduce mixer values.

• Take advantage of the ever-present option to 

switch over to the transmitter’s »Servo display« menu, see page 274. This menu is 

reached from almost any menu with a brief, simultaneous tap on the  keys of the left 

four-way button. This menu gives you the opportunity to check the effects of all of your settings on a single screen.

Mixer ratios and mixer neutral point

Now that we have explained the wide-ranging nature 

of the mixer functions, the following section describes 

how to program linear and non-linear mixer curves. 

For each of the 12 available mixers, the mixer curves 

are programmed on a second page of the screen 

display. Use the selection keys  on the left or right 

four-way button to select the desired mixer line. If 

necessary, use the four-way button’s selection keys 

to move to the right column (“ ”) then briefly tap the 

center SET key of the right four-way button to access 

the graph page.

M1 ... 8: Setting linear mixer values

As a practical example, we will now define a linear 

mixer curve to resolve the following problem:

For a motorized aircraft model, the two servos connected to receiver outputs 6 and 7–defined on 

the “Aile/flaps” line of the »Model type« menu as 

“... 2FL”–are to be used for actuating landing flaps. 

That is; when a transmitter control is moved, they 

must deflect downwards only. This requires a simultaneous elevator trim, however.

First allocate, for example, input 6 to the left slider 

control Sl1 located in the middle of the console by 

making settings in the »Control adjust« menu. 

A transmitter control on input 6,–as shown in the * N.N. = Nomen Nominandum (der zu nennende Name)
Program description - Free mixers 209

above table–will control the two servos connected 

to receiver outputs 6 and 7 by default as flaps. Leave 

the default value of “GL” in the “Type” column alone, 

however, to configure this setting globally for all flight 

phases–as is the case for the free mixer.

»Control adjust« menu

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8 –––

–––

–––

GL

GL

GL

GL

typ

normal

fr

Sl1

fr

fr

SEL

Note:

Note that if two flap servos have been selected, any 

transmitter control assigned to input 7 will be decoupled in the software in order to avoid errors in operating the flaps. However, in the interests of safety, you 

should make a habit of leaving all inputs not currently 

required to “free”, or of resetting these back to “free”!

Start by moving this transmitter control to its forward 

limit and adjust the landing flaps so that they are 

retracted or closed in this position. If you now move 

the dial to the rear, the flaps should move downward; 

if not the direction of servo rotation must be adapted.

We now turn our attention to the first mixer shown in 

the screen image on page 206 (“6  EL”), to which 

switch 4 was assigned:

ty fr to

M1

M2

M3

6 EL

C1 EL

M4

M5

S EL

?? ??

C4

4

2

?? ??

Briefly tap the center SET key of the right four-way 

button to open the second screen page:

OFF

L.Mix 1 6 EL

If this screen appears, the mixer has not yet been 

activated in combination with the assigned toggle 

switch–“4”, in this example. If so, operate the switch:

L.Mix 1

0% 0%

0%

Offset

SYM ASY

6 EL

Mix input

The continuous vertical line represents the current 

position of the transmitter control linked to input 6. 

(However, it is not visible in the above graphic because it is at the left edge since slider control Sl1, in 

this example assigned to input 6 (see previous page), 

is at its forward limit.) The dotted vertical line in the 

middle of the diagram indicates the position of the 

mixer neutral point–see under “Offset”, below. The 

solid horizontal line shows the mixer ratio, which currently has the value zero over the entire stick travel; 

accordingly, the elevator will not yet follow the movement of the flaps.

First, the ...

Offset (mixer neutral point)

... should be defined. This is accomplished by using 

the Select button  of the left or right-hand four-way 

button to move to the line below “Offset”:

L.Mix 1

0% 0%

0%

Offset

STO SET

6 EL

Mix input

The dotted vertical line in the middle of the diagram 

indicates the position of the mixer neutral point (“Offset”), i.e. the specific point along the control travel at 

which the mixer does NOT influence the control channel connected to its output. The default position for 

this point is at the control center.

However, since in our example the flaps should be 

closed or retracted with the slider control at its forward limit and therefore the elevator should not be 

further influenced in this position, the mixer neutral 

point must be relocated to precisely this point. To 

do so, push the slider control used (in this example, 

slider control Sl1) to its forward limit if you have not 

already done so, then briefly tap the center SET key 

of the right four-way button. The dotted vertical line 

moves across to this point, the new mixer neutral 

point, which by definition always retains the “initial” 

value of zero. 

However, to better illustrate our example, we now 

wish to set this “Offset” value to only -75%:

L.Mix 1

0% 0%

+75%

Offset

STO SET

6 EL

Mix input

Notes:

• By selecting SET with the  selection key of the 

left or right four-way button followed by a tap on 

the center SET key of the right four-way button ...
210 Program description - Free mixers

* N.N. = Nomen Nominandum (der zu nennende Name)

L.Mix 1

0% 0%

Offset

STO SET

6 EL

Mix input

+75%

... the offset value can be set manually or adjusted in 1 % increments with the selection keys on 

the left or right four-way button.

• By selecting SET ...

L.Mix 1

0% 0%

Offset

STO

6 EL

Mix input

+75%

SET

• ... set the mixer’s neutral point automatically back 

to control center with a simultaneous tap on both 

the  or  selection keys of the right four-way 

button (CLEAR).

Symmetrical mixer ratios

The next task is to define the mixer values above and 

below the mixer neutral point–starting from its current 

position. 

If necessary, use selection keys  on the left or 

right four-way button to select the SYM field in order 

to establish a mixer value which is symmetric to the 

offset point just set. Following a brief tap on the center SET key of the right four-way button, set both SYM

fields (now in inverse video) via the selection keys of 

the right four-way button to values between -150% 

and +150%. Note that the mixer value set always 

refers to the input signal of the respective transmitter 

control (control signal)! Negative mixer values reverse 

the direction of the mixer.

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) will erase the 

mixer ratio in the inverse video field.

The “optimum” value in our example will certainly 

need flight-testing.

L.Mix 1

+75%

Offset

SYM ASY

6 EL

Mix input

+20% +20%

Earlier, we set the mixer neutral point at -75% of control travel: as a result, the elevator (“EL”) will exhibit a 

(slight) down-elevator effect even at the neutral point 

of the landing flaps and this is naturally undesirable. 

Accordingly, you should reposition the mixer neutral 

point to -100% of control travel, as described earlier:

L.Mix 1

+20% +20%

+100%

Offset

STO SET

6 EL

Mix input

If the offset, now -100%, is reset to 0% of control 

travel by using selection key  on the left or right 

four-way button to select the SET field then tapping 

either the selection key combination  or  on 

the right four-way button (CLEAR), the following 

screen will appear:

L.Mix 1

+20% +20%

0%

Offset

STO

6 EL

Mix input

SET

Asymmetric mixer ratios

In many cases, however, we require different mixer 

values on each side of the mixer neutral point. 

Do this by first resetting the offset of the mixer used 

in the example, “6  EL” again to 0%, if necessary, 

refer to the figure above. Now select the ASY field 

with the selection key  on the left or right four-way 

button then tap the center SET key of the right fourway button. If slider control Sl1, assigned to input 6 

in this example, is now moved in each corresponding 

direction, the mixer ratios for each of the two control 

directions, i.e. left and right of the established offset 

point, can be adjusted with the selection keys of the 

right four-way button:

L.Mix 1

0%

Offset

SYM ASY

6 EL

Mix input

+55% +20%

Note:

If you are using a type “S  N.N.*” switch channel 

mixer you will need to actuate the assigned switch. 

The vertical line then jumps between the left and 

right side.

Setting curve mixers C9 ... 12

These four curve mixers allow the definition of extremely non-linear mixer curves by placing up to 

four freely positionable points between the two endpoints “L” (low = -100% control travel) and “H” (high = 

+100% control travel) along the control travel.

If you have already read the »Channel 1 curve« 

menu description or about programming 6-point 

curves in the »Helicopter mixers« menu, you can 

safely skip the following description.
Program description - Free mixers 211

Programming details

The control curve is defined by up to 6 points, known 

as “reference points”. In the default software configuration, 2 reference points are already defined, namely 

only the two end-points, “L” and “H”; see the next 

screen image.

The following section applies to “any” mixer to which 

we wish to assign a non-linear curve characteristic.

The examples shown in the following section are 

merely illustrative, however, and they do not represent real-life mixer curves.

Setting reference points

When you move the transmitter control assigned to 

the mixer input–here control function 8–a vertical 

line in the graph follows the movement between the 

two end-points. The current control position is also 

shown numerically on the “Input” line. The point at 

which this line intersects with the curve in question 

is named the “Output” and can be varied between 

-125% and +125% by setting reference points; see 

further below. This control signal acts on the mixer 

output.

In the above example, the transmitter control is on 

input 8 at -50% of control travel. The output signal 

continue to show 0%, however, since no value has 

yet been entered.

Up to four additional reference points can be set 

between the two end-points “L” and “H”, although the 

distance between neighboring reference points must 

not be less than approx. 25%.

Move the transmitter control of the control channel 

you have selected–in this example the left of the two 

proportional sliders fitted to the centre console (“Sl1”). 

While a question mark is displayed in the Point line, 

you can set the next reference point by pressing the 

central SET button of the right-hand four-way button:

–45%

0%

0%

Input

Output

Point ?

C.Mix 9

Curve off

8 10

When you now briefly tap the center SET key of the 

right four-way button, the “?” is replaced by a point 

number and the value field to the right is activated, 

i.e. presented in inverse video:

–45%

0%

1

8 10

0%

Input

Output

Point

C.Mix 9

Curve off

Using the selection keys on the right four-way button 

you can now change the point value within a range of 

±125%, e.g.:

–45%

+50%

1

8 10

+50%

Input

Output

Point

C.Mix 9

Curve off

Note:

If the stick does not coincide with the exact reference 

point, please note that the percentage value on the 

“Output” line always relates to the current stick position.

Continue in this way to set other reference points. 

Note that the order in which you generate the (maximum) four reference points between end-points “L” 

and “H” is irrelevant, since the reference points are 

continuously renumbered automatically from left to 

right as they are entered:

+35%

–55%

2

8 10

–55%

Input

Output

Point

C.Mix 9

Curve off

Erasing reference points

To erase one of the reference points between “L” and 

“H”, use the transmitter control in question to move 

the vertical line onto or into the vicinity of the reference point in question. The reference point number 

and associated reference point value are shown on 

the “Point” line. If necessary, activate the Value field 

by pressing the central SET button of the right-hand 

four-way button.

With the Value field now highlighted, press the two 

Select buttons  or  of the right-hand four-way 

button (CLEAR) simultaneously.

The selected reference point is erased, and the numbering of the remaining reference points is updated 

as required. Briefly tap the center ESC key of the left 

four-way button to complete the procedure.

Note that the reference points “L” and “H” cannot be 

erased.

Changing reference point values

To change reference point values, use the associated transmitter control to move the vertical line onto 

the point you wish to change: “L”, 1 ... 4 or “H”. The 

number and current curve value of this point are displayed. After activating the value field on the “Point” 

line by briefly tapping the center SET key, use the 

selection keys on the right four-way button to change 

the current curve value shown in the highlighted field. 

The possible range is -125% to +125% and changes 

do not affect neighboring reference points. Briefly 

tap the center ESC key of the left four-way button to 
212 Program description - Free mixers

complete the procedure.

Note:

If the stick does not coincide with the exact reference 

point, please note that the percentage value on the 

“Output” line always relates to the current stick position.

Trim point function

Alternatively, with the Point value field active (i.e.

highlighted) you can use the Select buttons  of 

the left-hand four-way button to skip reference points 

L, 1 ... max. 4 and H which you have already set, in 

the ascending or descending direction. The selection 

keys on the right four-way button can then be used to 

change the reference point jumped to as described 

above, entirely independently of the control position. 

+35%

–55%

2

8 10

–55%

Trim point

Input

Output

Point

C.Mix 9

In this simple example, slider control Sl1–represented by the vertical line–is halfway between the 

backward limit and the midpoint of control travel 

(input = -50%). However, “Point 2” will be relocated to 

control center at a point value of -55%, resulting in a 

momentary output value of -55%.

One touch on the center ESC key of the left four-way 

button will terminate this trim point function.

Trim offset function

When a value field is active, i.e. in inverse video, it is 

not only possible, as previously described, to jump up 

or down to reference points already set with the 

selection keys of the left four-way button and to make 

a change with the selection keys of the right four-way 

button, but also an existing curve can be vertically 

repositioned within a range of ±25% through use of 

the  keys on the left four-way button. Starting with 

a point value for “Point 1” at -55%, the control curves 

in both of the following figures have been vertically 

shifted within the ±25% range by the trim offset function:

+35%

–30%

2

8 10

–30%

Trim offset

Input

Output

Point

C.Mix 9

+35%

–80%

2

8 10

–80%

Trim offset

Input

Output

Point

C.Mix 9

You can also exit this function by tapping the center 

ESC key of the left four-way button.

Trim x-axis function

This function is activated by tapping the left () or 

right () selection key of the right four-way button 

with an active (i.e. inverse video) value field. You can 

then use the selection keys on the right four-way button to reposition the active point horizontally or vertically as you wish. In the figure below, “Point 2” which 

was just shifted to -55% with the trim point function, 

will now be shifted to the left, from input value +35% 

to 0%:

0%

–55%

?

8 10

–55%

TrimmX-axis

Input

Output

Point

C.Mix 9

Notes:

• If the point is repositioned horizontally further 

away from the current control position than approx. 

±25%, a “?” sign will reappear in the line Point. 

This question mark does not refer to the repositioned point, however: instead, it signifies that a 

further point can be set at the current control position.

• Please note that the percentage value on the “Output” line always relates to the current stick position 

and not to the position of the point.

Smoothing the curve

This “angular” curve profile created in the example 

can be smoothed automatically simply by pressing a 

button. 

Starting from the situation in the previous illustration, 

first press the SET button of the right-hand four-way 

button to conclude the procedure. Now use the Select 

button  of the right-hand four-way button to move 

up to the Value field of the “Curve” line, and press the 

SET button of the right-hand four-way button once 

more:

0%

–12%

?

8 10

0%

Input

Output

Point

C.Mix 9

Curve off

Now press one of the Select buttons of the right-hand 

four-way button in order to switch from “off” to “on”, 
Program description - Free mixers 213

then briefly press the central SET button of the righthand touch-button, or the central ESC button of the 

left-hand touch-button, to conclude the procedure:

0%

–12%

?

8 10

0%

on

Input

Output

Point

C.Mix 9

Curve

Note:

The curves shown here are for demonstration purposes only and are not at all representative of real mixer 

curves. For real-world application examples, see the 

programming examples on pages 285 and 323.

Examples

1. To open and close an aero-tow, a switch, e.g. SW 

2, has already been assigned to control channel 8 

in the »Control adjust« menu:

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

––– 2

Subsequent aero-tow flying has proven that you 

always have to fly with the up-elevator held slightly in during the tow. The solution will be to set up a 

mixer that applies slight up-elevator trim to the elevator servo connected to receiver output 3 when 

the aero-tow release is closed. The screen-shot 

will be familiar from page 206: here, the fourth 

linear mixer has been set up for this function, 

with the switch channel “S” as mixer input: Move 

the selected switch to the OFF position and then 

switch ... 

ty fr to

M1

M2

M3

6 EL

C1 EL

M4

M5

3 8

S EL

?? ??

C4

4

2

Tr

... to the mixer configuration page. 

Here select STO under “Offset” then tap the center 

SET key of the right four-way button briefly ... depending on the selected travel setting in the »Control adjust« menu and the switch setting, the offset value will jump to +X% or -X%, for example:

L.Mix 4

0% 0%

+100%

Offset

STO SET

S EL

Mix input

Now use the Select button  of the left or righthand four-way button to move to the line below 

“Mix input”. Select SYM if appropriate, then press 

the central SET button of the right-hand four-way 

button. The value fields are now highlighted. After you have moved the selected switch to the mixer ON position, use the selection keys on the right 

four-way button to set the required symmetrical 

mixer ratio, for example: 

L.Mix 1

+100%

Offset

SYM ASY

6 EL

Mix input

+10% +10%

2. If a multi- flap wing featuring a “crow or butterfly system” with (additional) airbrakes is intended, and this brake system is to be tested with 

and without airbrakes, then move to the »Mix-only channel« menu, see page 216. This menu 

is available as standard on the mc-20 HoTT 

transmitter only, but can be unlocked on the mc16 HoTT transmitter at extra cost. Simply set 

Channel 1 to “MIX-only” ...

MIX-only channel

only

normal

1 2 3 4 5 6

... and follow this by programming a free mixer 

“C1  C1” to restore control over the airbrakes via 

servo 1. If you also assign a switch to this mixer, 

then you will be able to switch this mixer on and 

off as you please.

3. The final example applies to model helicopters:

In the helicopter program, if you wish affect pitch 

trim with a proportional control, e.g. one of the 

slider controls in the middle of the console, then 

assign one of these controls to this function in the 

»Control adjust« menu; for example the “In9” input. (However, leave the default value of “GL” in the 

“Type” column as it is so this configuration, analogous to the free mixer yet to be programmed, will 

be applicable globally for all flight phases.) Finally, simply define a LinearMIX “9  1” with a symmetric mixer ratio of, for example, 25%. Due to the 

internal coupling, this transmitter control then acts 

equally on all of the model’s collective pitch servos 

without affecting the throttle servo. 
214 Program description - Free mixers

L.Mix 1

0%

Offset

SYM ASY

9 1

Mix input

+25% +25%

However, you should also de-couple the assigned 

transmitter control from control channel 9, so that 

any servo which may be connected to receiver 

output 9 can no longer be operated by this transmitter control. This is accomplished in the »Mixonly channel« menu, see page 216, which 

is available as standard on the mc-20 HoTT 

transmitter only, but can be unlocked on the mc16 HoTT transmitter at extra cost. 
Program description - Mix active / phase 215

MIX active / phase

Selecting free mixers for flight phases

This option is available as standard on the 

mc-20 HoTT transmitter only.

Use the selection keys of the left or right 

four-way button to scroll to the »MIX active / phase« menu option in the Multi-function menu:

Fl. phase timers

Wing mixers

MIX-only channel

Dual mixer

Free mixers

MIX active/phase

Helicopter mixer

Fl. phase timers

MIX-only channel

Dual mixer

Free mixers

MIX active/phase

Open this menu option with a tap on the center SET

key of the right four-way button:

LinearM1

LinearM2

LinearM3

6 EL

C1 EL

LinearM4

3 8

S EL

yes

SEL

yes

yes

yes

Mix act. in phase

The “free mixers” on the previous menu can be enabled and disabled for specific flight phases. You therefore have complete freedom in assigning specific 

mixers only to specific flight phases.

Switch to your chosen flight phase and use the selection keys to page through this menu. The mixers on 

the »Free mixers« menu are displayed in the center 

column.

Following the activation of the value field by briefly 

tapping the center SET key of the right four-way 

button, if the respective mixer is set to “no” by using 

the selection keys on the left or right four-way button, then this mixer is deactivated in the flight phase 

shown at the bottom of the display and, simultaneously, removed from the »Free mixers« menu list:

LinearM1

LinearM2

LinearM3

6

LinearM4

3 8

S

Speed SEL

no

EL

C1 EL

EL

yes

yes

yes

Mix act. in phase

If a mixer is “lost” in the »Free mixers« menu ...

ty fr to

M1

M3

6 EL

M4

M5

3 8

S EL

?? ??

4

2

M6 ?? ??

... then you should either switch through the flight 

phases until it appears again ... or, alternatively, 

switch to this menu and temporarily reactivate the 

mixer you are looking for:

ty fr to

M1

M2

M3

6 EL

C1 EL

M4

M5

3 8

S EL

?? ??

Tr C4

4

2

mc

 

16 20
216 Program description - MIX-only channel

MIX-only channel

Separating control functions from control channels for all flight phases

This option is available as standard on the 

mc-20 HoTT transmitter only.

Use the selection keys of the left or right 

four-way button to scroll to the »MIX-only 

channel« menu option in the Multi-function menu:

Fl. phase timer

Wing mixers

Dual mixer

Free mixers

MIX active/phase

MIX-only channel

Fl. phase timer

Helicopter mixer

Dual mixer

Free mixers

MIX active/phase

MIX-only channel

Open this menu option with a tap on the center SET

key of the right four-way button:

Mix-only channel

only

normal

1 2 3 4 5 6

This menu can be used to interrupt the normal signal 

flow between the input side control function and the 

output side control channel, therefore the “classic” 

control-to-servo connection is actually separated.

Use the potential offered by this flight phase independent menu, particularly to keep one of the control 

channels “free” in all flight phases from assignment to 

a transmitter control or switch for specific flight phases in the »Control adjust« menu.

Conversely of course, such a stick, transmitter control 

or switch “robbed” of its servo can still be used freely 

as a control in other way–indeed even in flight phase 

dependence–, refer to the programming examples at 

the end of this section.

A stick, transmitter control or switch robbed of its 

servo by setting the channel to “MIX only” will then 

namely affect mixer inputs only ...

... and the servo connected to a channel set to “MIX 

only” is then also only accessible from the mixers programmed to its control channel, i.e. “(with) MIX(ers) 

only”.

Accordingly, for any channel set to “MIX only”, you 

can utilize both its control function and its control 

channel entirely independently of one another for 

any special functions you need; see the examples 

at the end of this section. A further option provided 

by a channel set to “MIX-only” status is the facility to 

program timed sequences using a mixer programmed 

to the same channel, and set up using the “- Time 

+” option of the »Control adjust« menu; see pages 

118 and 122. See page 308 for a programming 

example. 

Basic programming procedure

Use the Select buttons of the left or right-hand fourway button to select the desired channel 1 to 8 () on 

the standard eight-channel mc-16 HoTT transmitter 

...

Mix-only channel

only

normal

1 2 3 4 5 6

Mix-only channel

only

normal

7 8

... or 1 to 12 () on the mc-16 HoTT transmitter 

with twelve channels unlocked, and the standard 

twelve-channel mc-20 HoTT transmitter.

Use the selection keys on the left or right four-way 

button to select the desired channel to switch at will 

between “normal” ( ) and “MIX only” ( ) modes: 

normal

7 8 9 10 11 12

Mix-only channel

only

Examples:

• For model glider aircraft without airbrakes, the butterfly function, page 183, is generally used as a 

landing aid. Just as with “normal” airbrakes, this is 

generally controlled using the C1 stick. While the 

(airbrakes) servo typically connected to channel 1 

is then generally absent as a rule, receiver output 

1 is still not “free”, since the control signal of the 

brake stick is still present at this location.

Its control signal–which in this specific case is not 

desired–can be decoupled from control channel 

“1” to thus “free up” this channel from the C1 stick 

signal by setting channel 1 to “MIX only” in the 

»MIX-only channel« menu. This makes it possible 

to use control channel “1”, together with receiver 

connection “1”, at any time for other purposes, via 

freely-programmable mixers–e.g. to connect up a 

speed controller.

mc

 

16 20
Program description - MIX-only channel 217

Mix-only channel

only

normal

1 2 3 4 5 6

• If your model has built-in airbrakes, however, and 

you would like to perhaps test the performance of 

a butterfly system with and without airbrakes, simply set channel 1 to “MIX only” and program a free 

mixer “C1  C1”, so as to restore your ability to 

control the airbrakes via servo 1. If you also assign a switch to this mixer, then you will be able to 

switch this mixer on and off as you please. 
218 Program description - Dual mixers

Dual mixers

Same-sense/opposite-sense mixing of two control channels

This option is available as standard on the 

mc-20 HoTT transmitter only.

Use the selection keys of the left or right 

four-way button to scroll to the »Dual mixers« menu option in the Multi-function menu:

Fl. phase timers

Wing mixers

Free mixers

MIX active/phase

MIX-only channel

Dual mixer

Helicopter mixer

Fl. phase timers

Free mixers

MIX active/phase

MIX-only channel

Dual mixer

Open this menu option with a tap on the center SET

key of the right four-way button:

Diff.

Dual mixer

Mixer1

Mixer2

?? ??

Mixer3

Mixer4

?? ??

?? ??

?? ??

0%

0%

0%

0%

Similarly to a V-tail mixer, the four flight phase independent dual mixers couple ...

3 3

4

Servo 4 8 V C 577

B s Nr 410

Servo 4 8 V

C 577

Bes Nr 101

4

V-tail mixer

Control function inputs

Control channels

(receiver outputs)

Elevator stick

Rudder stick

Right rudder / elevator

Left rudder / elevator

Rudder

Elevator

Elevator

Rudder

Rudder

Elevator

... a same-sense “ ” and an opposite-sense “

” control function, although they permit any channel 

to be used and offer differential travel for the opposing 

function.

Important notice:

Since the same and opposite sense influences of the 

given input on the two servos or rudder flaps–coupled to one another by the dual mixer–are determined by, among other things, their installation situation and the direction of rotation specified in the 

»Servo adjustment« menu, the symbols “ ” and 

“ ” are to be perceived more as synonyms rather 

than as consistently appropriate definitions! Accordingly, if wing flaps are deflected in the wrong direction, simply swap the two inputs or use the “servo reverse” option in the »Servo adjustment« menu; see 

page 112. 

In the software, the V-tail mixer already mentioned is 

supplemented by other “dual mixers” for realization 

of the two aileron servos on receiver outputs 2 and 

5 and for the flap pairs on outputs 6 and 7, possibly 

also 9 and 10. These are activated via the aileron 

stick and the transmitter control that has been assigned to input “6” on the »Control adjust« menu.

In the same way, the four freely-programmable dual 

mixers on this menu can be used to couple two further control functions, a feature that would otherwise 

only be possible with time-consuming programming of 

free mixers.

Here, we will use a “V-tail with rudder differential” as 

our example to explain the programming of a dual 

mixer (see also the examples on page 296):

Use the Select buttons of the left or right-hand fourway button to select the column you wish to access. 

Press the central SET button of the right-hand fourway button to activate the Value field, and then set the 

desired value using the Select buttons:

Diff.

Mixer1

Mixer2

EL

Mixer3

Mixer4

?? ??

?? ??

?? ??

0%

0%

0%

RU +25%

Dual mixer

In the dual mixer shown in our example the two servos connected to receiver outputs 3 and 4 move in 

the same or opposite direction depending on the direction of movement of the associated stick, and thus 

operate as elevators or rudders. The differentiation, 

according to dual mixer configuration, is only effective 

for rudder activation. 

In this case, both corresponding trim lever are effective. No additional free mixers are required for this 

arrangement. 

When using this mixer, however, the tail type 

MUST be entered as “normal” on the “Model type” 

menu.

Tip:

All settings can be checked directly in the »Servo 

display« menu, which can be accessed from almost 

any other menu by simultaneously tapping the 

keys on the left four-way button.

Example:

Model with two rudders, with differential travel and 

outward movement (e.g. swept-back flying wing):

mc

 

16 20
Program description - Dual mixers 219

Diff.

Mixer1

Mixer2

 8

Mixer3

Mixer4

?? ??

?? ??

?? ??

0%

0%

0%

RU +75%

Dual mixer

When a rudder command is given, the second servo 

connected to output 8 follows suit. (With this type of 

programming, differential travel can be configured 

for the rudders.) In this case, too, trim from the rudder stick affects both servos. If the rudders are also 

required to deflect outwards when the airbrakes are 

activated, then you should assign the C1 stick (transmitter control 1) to input 8 on the »Control adjust«“ 

menu. Afterwards, change to the “Offset” column then 

modify the offset value until both rudders are again in 

their neutral positions. It may be necessary to “play” a 

bit with the offset and travel adjustments. 
220 Program description - Swashplate mixer and Fail-safe

This option is available as standard on 

both transmitter types.

Note:

If “1 servo” is selected on the “Swashplate” line of the »Helicopter type«“ menu, this option is not shown on the multi-function menu.

Use the selection keys of the left or right four-way button to scroll to the »Swashplate mixer« menu option 

in the Multi-function menu:

Helicopter mixer

Free mixers

MIX active/phase

MIX-only channel

Dual mixer

Swaschplate mixer

Open this menu option with a tap on the center SET

key of the right four-way button:

Swashplate mixer

Pitch

Roll

Nick

+61%

+61%

+61%

SEL

The number of servos installed in your helicopter for 

pitch control was established in the “Swashplate” line 

of the »Helicopter type« menu, see page 108. This 

information is used to automatically couple together 

the functions for roll, pitch-axis and collective pitch, 

so that you do not need to define any other mixers 

yourself.

For helicopter models with only a single collective 

pitch servo, this »Swashplate mixer« menu option is 

of course superfluous because the software controls 

a total of three swashplate servos for pitch, nick and 

roll independently of one another, i.e. without a mixer. 

In this scenario, this menu option is therefore no 

Swashplate mixer

Collective pitch, roll, pitch-axis mixer

longer available to you from the multi-function menu. 

With all other swashplate linkages employing 2 ... 4 

pitch servos, mixer ratios and mixer directions are set 

up by default as shown above. The default is +61% in 

each case but the value can be varied from -100% to 

+100% if required by briefly tapping the center SET

key of the right four-way button and its selection keys. 

Simultaneously tapping both  or  selection 

keys on the right four-way button (CLEAR) will reset 

the mixer ration in inverse video again to the +61% 

default value. 

If the swashplate control system (collective pitch, roll 

and pitch-axis) does not respond to the sticks properly, you should alter the mixer directions (“+” or “-”) 

before trying to correct the directions of servo rotation.

Note:

Ensure that changed mixer values do not result in the 

servos mechanically striking their end-stops. 

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Fail-safe 

adjust« menu option in the Multi-function menu:

Teacher / pupil

Tx. output swap

Telemetry

Fail-safe adjust

Profi trim

Trim memory

Open this menu option with a tap on the center SET

key of the right four-way button:

Fail-safe adjust

Pos

hold

1 2 3 4 5 6

 DELAY : 0.25s STO

The higher level of operating safety exhibited by the 

HoTT system when compared to traditional PPM 

technology results from the fact that the microprocessor built into the HoTT receiver not only exclusively 

processes the signals of “its” transmitter, but can 

also clean up “dirty” control signals that it receives. 

Only when these signals become too error-prone or 

garbled due to outside interference does the processor automatically replace the disrupted signals with 

the last received correct signal, temporarily stored 

in the receiver. This feature is configured by the 

settings as described below. This feature also suppresses brief interference caused by e.g. local drops 

in field strength, which otherwise result in the familiar 

“glitches”. In this case, the red LED lights up on the 

receiver.

If you have not already programmed Fail-Safe settings in the currently active model memory, the followFail-safe

Fault condition setpoints

mc

 

16 20

mc

 

16 20
Program description - Fail-safe 221

ing message will appear in the base display for a few 

seconds when you switch the transmitter on:

Fail Safe

setup

t.b.d.

Programming procedure

The “Fail Safe” function determines the behavior of 

the receiver if communication between the transmitter 

and the receiver is disrupted. Receiver outputs 1 ... 8 

on the standard eight-channel mc-16 HoTT transmitter, or 1 ... 12 on the mc-16 HoTT transmitter 

with twelve channels (unlocked as an extra-cost option) or the standard twelve-channel mc-20 HoTT 

transmitter can optionally ...

1. preserve the current position (“hold”):

If communication is disrupted, all servos programmed to “hold” mode remain at the positions 

judged to be the last valid positions by the receiver until the receiver picks up another valid control 

signal, or

2. move to a freely selectable position (“Pos”) if interference should occur, following the expiry of the 

“time delay”. 

Use selection keys  on the left or right four-way 

button to select the desired servo connection 1 ... 8 

() or 1 ... 12 () then briefly tap the center SET key 

of the right four-way button to freely switch between 

“hold” ( ) and “Pos” mode ( ):

1 2 3 4 5 6

STO

Fail-safe adjust

Pos

hold

 DELAY : 0.25s

Following this, use the selection keys  on the left 

or right four-way button to select the “DELAY” option 

shown at the bottom of the display ...

7 8 9 10 11 12

STO

Fail-safe adjust

Pos

hold

 DELAY : 0.25s

... and then briefly tap the center SET key of the right 

four-way button. Now use the four-way button’s selection keys to make your choice from the four possible 

time delays (0.25s, 0.5s, 0.75s and 1s) offered.

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) will reset the 

inverse video field to its default value 0.25s.

Afterwards, select the STO field at the bottom right of 

the display with the  selection keys on the left or 

right four-way button. Now put the servos which have 

been switched into position mode into their desired 

positions SIMULTANEOUSLY with the respective 

operating elements.

Briefly tap the center SET key of the right four-way 

button to store these positions as the fail-safe setting 

for the receiver, so that it can revert back to them if 

interference is experienced. 

Successful storage of the positions is confirmed 

briefly on the screen:

7 8 9 10 11 12

STO

Position

stored

Fail-safe adjust

Pos

hold

 DELAY : 0.25s

Attention:

• Please note that decisive fail-safe settings are 

stored in the receiver! Therefore, following a 

change of receivers, these fail-safe settings 

should be renewed and in the previous receiver they should be erased, if necessary per Reset, see page 60.

• Ensure you make use of this safety net by at 

least programming the following for a fail-safe 

incident: for glow-powered models, set the motor throttle position to idle; for electric models, set the motor function to stop, or “Hold” 

for helicopter models. If interference should 

occur, the model is then less likely to fly off on 

its own and cause damage to property or even 

personal injury. Consider asking an experienced pilot for advice.
222 Program description - Teacher/pupil

Teacher/pupil

Connecting two transmitters for trainer mode with a trainer lead

This option is available as standard on 

both transmitter types.

The transmitters mc-16 HoTT and 

mc-20 HoTT are equipped as standard–as viewed from the front, under the left front 

flap–with a DSC socket. This is not only usable for 

connecting flight simulators–as described on page 

22–but also to integrate the transmitter into a 

cable-coupled teacher/pupil system. 

To accommodate the settings necessary for this, 

scroll with the selection keys on the left or right fourway button to the »Teacher/pupil« menu option in 

the Multifunction menu: 

Tx. output swap

Telemetry

Fail-safe adjust

Profi trim

Trim memory

Teacher / pupil

Open this menu option with a tap on the center SET

key of the right four-way button:

Teacher / Pupil

Pupil

Teacher

2 3 4 5

SW: ––– BIND:

1

n/a

6

Note:

The screen image shown above shows the menu 

in its initial state: No transmitter controls have been 

released by the pupil ( ) and no switch is assigned 

(“SW: ---” bottom left in the screen image).

When assigning control functions, the usual conventions must be observed:

Channel Function

1 Motor throttle/collective pitch

2 Aileron/roll

3 Elevator/pitch-axis

4 Rudder/tail rotor

Teacher-pupil settings

Up to eight function inputs (see “Definitions of terms” 

on page 66) of an mc-16 HoTT transmitter set 

up as Teacher transmitter can be transferred individually, or in any combination you wish, from the Teacher 

transmitter “L” to the Pupil transmitter “S”. The same 

applies with a maximum of twelve function inputs

(see “Definitions of terms” on page 66) of an mc16 HoTT transmitter with twelve channels unlocked 

and set up as Teacher transmitter, and the standard 

twelve-channel mc-20 HoTT transmitter.

The lower display line, designated with “Teacher”, 

therefore indicates the function inputs with which 

control functions 1 ... 4 (stick functions for fixed-wing 

and helicopter models) are permanently connected 

as well as inputs 5 ... max. 12, which can be freely 

assigned in the »Control adjust« menu. 

Note:

Just which controls are assigned to any inputs turned 

over to the pupil is basically of no consequence. However, their assignment in the »Control adjust« menu 

is possible only when the trainer mode connection is 

inactive.

Use the  selection keys of the left or right fourway button to select the function inputs 1 through 

max. 12 for transfer to the pupil () then briefly tap 

center SET key of the right four-way button for each 

switch to be switched between “Teacher” ( ) and 

“Pupil” ( ):

Teacher / Pupil

Pupil

Teacher

2 3 4 5

SW: ––– BIND:

1

n/a

6

To be able to carry out the transfer, you must then 

assign a trainer mode switch on the left of the display. 

Do this by placing the marker just to the right of the 

“SW” at the bottom left of the screen display by using 

the selection keys of the left or right four-way button then assign a switch as described in the section 

“Physical control, switch and control switch assignments” on page 68. 

Preferably you should utilize a momentary switch to 

allow a return of control to the teacher transmitter at 

any time:

Teacher / Teacher

Pup

Teac

8 9 10 11

SW: BIND: n/a

12

8

N o

pupil

signal

–

Since at this early stage of programming a trainer 

system it is unlikely that an operational pupil transmitter is connected to the teacher transmitter, the transmitter responds immediately to the switches closed 

during the switch assignment process with appropriate visual and audible warning notices. You should 

therefore re-open the switch you have just assigned:

Teacher / Teacher

Pupil

Teacher

8 9 10 11

SW: BIND:

7

n/a

12

8



mc

 

16 20
Program description - Teacher/pupil 223

Note:

The switch assignment just described also determines the transmitter used to issue the teacher and 

pupil functions, respectively. For this reason, a pupil 

transmitter must NEVER be assigned a switch on 

this menu. The header line therefore also switches 

from “Teacher / Pupil” to “Teacher / Teacher” once 

a switch has been assigned.

The model to be controlled by the pupil must be 

programmed completely–i.e. with all its functions 

including trims and any mixer functions–in one of the 

model memories of the mc-16 HoTT or mc-20

HoTT teacher transmitter. The HoTT receiver of the 

model in question must also be “bound” to the teacher 

transmitter, since the latter ultimately controls the 

model, even in pupil mode.

ALWAYS ENSURE YOU SWITCH ON THE teacher 

transmitter FIRST BEFORE PLUGGING THE CONNECTION CABLE INTO THIS UNIT. Otherwise the 

RF module will not be activated.

The mc-16 HoTT or mc-20 HoTT teacher transmitter can be connected to any suitable pupil transmitter, even transmitters using the “traditional” 35/40 

MHz range. This means, for example, that a mc-16

HoTT or mc-20 HoTT teacher transmitter can indeed also be connected to a mc-24 pupil transmitter. 

However, if the pupil-side connection is NOT made 

via a two-pole DSC socket but rather via a three-pole 

trainer socket (for example, out of the Graupner product line), then the basic prerequisite for a correct 

connection to a pupil transmitter–which is completely independent of the type of modulation 

used in the teacher transmitter–must ALWAYS be 

set to modulation type PPM (10, 16, 18 or 24) in 

the pupil transmitter. 

Pupil transmitter set-up

The model to be controlled by the pupil must be programmed completely, i.e. with all its functions including trims and any mixer functions, in one of the model 

memories of the teacher transmitter and, if applicable, 

the HoTT receiver of the model in question must also 

be “bound” to the teacher transmitter. In principle, 

a mc-16 HoTT or mc-20 HoTT pupil transmitter can also be connected to a teacher transmitter 

operating on the “traditional” 35/40 MHz bands. This 

is possible because the PPM signal required by the 

teacher transmitter is available in the (pupil) transmitter’s DSC socket.

Almost any transmitter with at least four control functions from previous and current Graupner series can 

be used as a pupil transmitter. More detailed information can be found in the RC main catalogue and on 

the www.graupner.de/en website.

If required, the pupil transmitter should be fitted with 

the connection module for pupil transmitters. This is to 

be connected to the transmitter board in accordance 

with the supplied installation instructions. 

Information on the pupil modules required in each 

case can be found in the Graupner RC main catalog 

and on the www.graupner.de website.

The connection to the teacher transmitter is made 

using the appropriate lead; see the following double page.

The control functions of the pupil transmitter 

MUST act directly on the control channels, i.e. the 

receiver outputs, without intermediary mixers. 

If you are using an “mc” or “mx” series transmitter, 

it is best to activate a free model memory with the 

required model type (“Fixed-wing” or “Heli”). Assign 

the model name “Pupil” and set up the stick mode 

(mode 1 ... 4) and “Throttle min. forward/back” to suit 

the pupil’s preferences. All other settings are left at 

their default values, however. If you have selected the 

“Helicopter” model type, you must also set the throttle/ collective pitch direction and idle trim on the pupil 

transmitter. All other settings, including mixer and 

coupling functions, are configured exclusively on the 

teacher transmitter, which in turn transmits them to 

the model.

If the pupil transmitter is a mx-20 HoTT, mc-16

HoTT, mc-20 HoTT or mc-32 HoTT series 

model then it may also be necessary to adapt the 

type of modulation in the “DSC output” line of the 

»Base setup model« menu in order to accommodate 

the number of control channels to be transmitted. 

For example, the signal packet for modulation type 

“PPM10” contains only control channels 1 ... 5 but 

not channel 6 and upper. However, if this channel is 

to be used by the pupil then a modulation type must 

be selected in which it is included. A further point is 

that “HoTT” must be entered in the “Module” line of 

the »Base setup model« menu if you wish to set up 

one of the transmitters in Pupil mode, but using an 

existing model memory rather than a newly initialised 

memory. If you neglect this it is possible that the PPM 

signal present at the DSC socket will be inverted.

For transmitters of–older–type “D” and “FM” it is necessary to check servo operating directions and their 

control correlations. It may be necessary to reconnect 

cables appropriately. All mixers must also be switched 

off or set to “zero”.

When assigning control functions, the usual conventions must be observed:

Channel Function

1 Motor throttle/collective pitch

2 Aileron/roll

3 Elevator/pitch-axis

4 Rudder/tail rotor

If other control functions are to be transferred to the 

pupil transmitter in addition to the functions of the two 

dual axis sticks (1 ... 4), access the »Control adjust« 

menu in the pupil transmitter and assign those inputs

which correspond to enabled function inputs 5 ... 

max. 12 as shown in the »Teacher/pupil« menu of 
224 Program description - Teacher/pupil

the teacher transmitter. Afterwards, assign the operating elements appropriately.

Important:

• If you should forget to assign a transmitter 

control on the pupil side, then the affected servo or servos will remain in the center position 

when the transfer is made to the pupil transmitter.

• The pupil transmitter must always be operated 

in PPM mode, regardless of the RF connection 

type used between the teacher transmitter and 

the model.

• If the transmitter is connected using a DSC 

socket on the pupil side, ALWAYS leave the pupil transmitter’s On/Off switch in the “OFF” position: this is the only way to guarantee that no 

RF signal is sent from the pupil transmitter’s 

transmitter module, even after the DSC lead 

has been plugged in.

Trainer mode operations

Both transmitters are connected to one another using 

a suitable lead (see summary on next page): The plug 

marked “M” (master) must be inserted into the socket 

on the teacher transmitter, and the plug marked “S” 

(student) into the pupil transmitter’s socket. (Note that 

not all leads may have such “M” and “S” labeling.) 

Important notices:

• Check that the model aircraft is operational 

and check that all functions issue the correct 

commands BEFORE setting up trainer mode.

• The ends of the trainer lead, usually marked as 

either “S” or “M”, terminate in a three-pole TRS 

jack. Do not insert these jacks into a DSC system socket, as it is not suitable for this application. The DSC socket is exclusively designed 

for cables with 2-pole TRS jacks.

Checking functionality

Activate the assigned trainer mode switch:

• The trainer mode system is working properly if 

the display now changes from “ Teacher” to “

Pupil”.

• However, if the WARNING LED at the right, 

next to the transmitter’s On/Off switch, blinks and 

an acoustic signal sounds off at the same time, 

then the connection between pupil and teacher 

transmitters is faulty. 

The basic display also displays the following warning notice ...

N o

pupil

signal

... and the left side of the screen display for the 

»Teacher/pupil« menu will change to show “-Pupil”. In this case, all control functions are retained 

by the teacher transmitter automatically, regardless of switch position: this ensures the model is 

always under control.

Possible faults:

• Pupil transmitter not ready

• Interface in pupil transmitter not correctly connected in place of the RF module

• Cables connected wrongly: see right for cable connections

• Pupil transmitter not switched over to PPM (10, 

16, 18, 24) mode

Other possible faults:

• Teacher transmitter not properly “bound” to HoTT 

receiver in training model

Trainer cables

4179.1 for trainer operation between any two 

Graupner transmitters equipped with DSC 

sockets–distinguished by a two-pole TRS 

jack at both ends.

3290.7 trainer cable for connecting a teacher transmitter with DSC socket (e.g. mx-12 ... 

mc-32 HoTT) or a transmitter retrofitted with an optional DSC module, order no. 

3290.24) to a Graupner pupil transmitter 

with an opto-electronic system pupil socket–identifiable by the mark “S” on the side 

of the three-pole TRS jack.

3290.8 trainer cable for connecting a pupil transmitter with DSC socket (e.g. mx-12 ... mc32 HoTT or a transmitter retrofitted with an 

optional DSC module, order no. 3290.24) to 

a Graupner teacher transmitter with an opto-electronic system teacher socket–identifiable by the mark “M” on the side of the 

three-pole TRS jack.

Further details about the cables and modules 

mentioned in this section for teacher and pupil 

transmitters can be found in the respective transmitter handbook, in the Graupner RC main catalogue or in Internet at www.graupner.de.
Program description - Teacher/pupil 225

Trainer mode with the transmitters mc-16 HoTT and mc-20 HoTT

Due to the continuous improvements made to the product range, please consult our website at www.graupner.de for the latest information

Teacher transmitter 

with DSC socket

Teacher transmitter with 

teacher module, order 

no. 3290.2, 3290.19, 3290.22

Teacher/pupil cable, 

order no. 3290.8

M

Pupil transmitter mc-16 HoTT and mc-20 HoTT

mx-12 HoTT, 

mx-16 HoTT, 

mx-20 HoTT 

mc-16 HoTT

mc-20 HoTT

mc-32 HoTT

mc-19 through mc-24, 

mx-22(iFS), mx-24s

Pupil transmitter 

with DSC socket

Pupil transmitter with pupil 

module, order no. 3290.3, 

3290.10, 3290.33

D 14, FM 414, FM 4014, 

FM 6014, mc-10 ... mc-24, 

mx-22(iFS), mx-24s

S

Teacher transmitter mc-16 HoTT and mc-20 HoTT

mx-12 HoTT, 

mx-16 HoTT, 

mx-20 HoTT 

mc-16 HoTT

mc-20 HoTT

mc-32 HoTT

Note:

The lists present the possible transmitters/transmitter 

combinations at the time of going in revision.

Teacher/pupil cable, 

order no. 4179.1

Teacher/pupil cable, 

order no. 3290.7

Teacher/pupil cable, 

order no. 4179.1 
226 Program description - Teacher/pupil

Wireless HoTT system

Wireless operation of the mc-16 HoTT and mc20 HoTT trainer mode system is also possible. To 

do so, the teacher transmitter must be “connected” to 

a pupil transmitter as described below. Prior to this, 

however, the training model’s receiver must be bound 

to the PUPIL transmitter. This configuration is possible between transmitters which have the “BIND:” 

option in the »Teacher/pupil« menu.

Preparing for training mode

Teacher transmitter

The training model must be programmed completely,

i.e. with all of its functions including trims and any 

mixer functions, in one model memory of the HoTT 

teacher transmitter. The model to be used for training must therefore be under the complete control 

of the teacher transmitter. The final step in preparation, however, is to bind the training model to 

the pupil transmitter. For a detailed description of 

the binding process, please consult pages 87 

and 95. 

Pupil transmitter

If you are using an “mc” or “mx” series transmitter, it 

is best to activate a free model memory with the required model type (“Fixed-wing” or “Heli”). Assign the 

model name “Pupil” and set up the stick mode (mode 

1 ... 4) and “Throttle (or collective pitch) min. forward/

back” to suit the pupil’s preferences. All other options are left at their default values. All other settings, 

including all mixer and coupling functions, are configured exclusively on the teacher transmitter, which in 

turn transmits them to the model.

When assigning control functions, the usual conventions must be observed:

Channel Function

1 Motor throttle/collective pitch

2 Aileron/roll

3 Elevator/pitch-axis

4 Rudder/tail rotor

If other control functions are to be transferred to the 

pupil transmitter in addition to the functions of the two 

dual axis sticks (1 ... 4), access the »Control adjust« 

menu in the pupil transmitter and assign those inputs

which correspond to enabled function or transmitter 

control inputs 5 ... max. 12 as shown in the »Teacher/pupil« menu of the teacher transmitter. Afterwards, 

assign the operating elements appropriately. 

Important:

If you should forget to assign a transmitter control on the pupil side, then the affected servo or 

servos will remain in the center position when the 

transfer is made to the pupil transmitter.

Preparing the teacher and pupil transmitters

Once you have bound the training model to the pupil 

transmitter, now switch on the teacher transmitter. On 

both transmitters, use the selection keys on the left or 

right four-way button, to page to the »Teacher/pupil« 

menu option on the multi-function menu:

Tx. output swap

Telemetry

Fail-safe adjust

Profi trim

Trim memory

Teacher / pupil

Briefly tap the center SET key of the right four-way 

button to open this menu option:

Teacher / Pupil

Pupil

Teacher

2 3 4 5

SW: ––– BIND:

1

n/a

6

Note:

The screen image shown above shows the menu 

in its initial state: No transmitter controls have been 

released to the pupil ( ) and no switch has been assigned (“SW: ---” bottom left in the screen image).

Pupil transmitter

Use the selection keys on the left or right four-way 

button to move the marker frame to the “BIND” input 

field. If there is a switch shown at the right of “SW:” 

then this must first be erased, see screen image:

Teacher / Pupil

Pupil

Teacher

2 3 4 5

SW: ––– BIND:

1

n/a

6

Teacher transmitter

Up to eight function inputs (see “Definitions of terms” 

on page 66) of an mc-16 HoTT transmitter set 

up as Teacher transmitter can be transferred individually, or in any combination you wish, from the Teacher 

transmitter “L” to the Pupil transmitter “S”. The same 

applies with a maximum of twelve function inputs

(see “Definitions of terms” on page 66) of an mc16 HoTT transmitter with twelve channels unlocked 

and set up as Teacher transmitter, and the standard 

twelve-channel mc-20 HoTT transmitter.

The lower display line, designated with “Teacher”, 

therefore indicates the function inputs with which 

control functions 1 ... 4 (stick functions for fixed-wing 

and helicopter models) are permanently connected 

as well as inputs 5 ... max. 12, which can be freely 

assigned in the »Control adjust« menu. 

Note:

Just which controls are assigned to any inputs turned 

over to the pupil is basically of no consequence. How-
Program description - Teacher/pupil 227

ever, their assignment in the »Control adjust« menu 

is possible only when the trainer mode connection is 

inactive.

Use the  selection keys of the left or right fourway button to select the function inputs 1 through 

max. 12 for transfer to the pupil () then briefly tap 

center SET key of the right four-way button for each 

switch to be switched between “Teacher” ( ) and 

“Pupil” ( ):

Teacher / Pupil

Pupil

Teacher

2 3 4 5

SW: ––– BIND:

1

n/a

6

To be able to carry out the transfer, you must now 

assign a trainer mode switch. Do this by placing the 

marker frame just to the right of the “SW:” at the bottom left of the screen display by using the selection 

keys of the left or right four-way button then assign a 

switch as described in the section “Physical control, 

switch and control switch assignments” on page 68.

Preferably you should utilize a momentary switch to 

allow a return of control to the teacher transmitter at 

any time:

Teacher / Teacher

Pup

Teac

8 9 10 11

SW: BIND:

7

n/a

12

8

N o

pupil

signal

–

Since at this stage of programming the wireless 

trainer system no connection yet exists to a pupil 

transmitter, the transmitter responds immediately to 

the switches closed during the switch assignment 

process with appropriate visual and audible warning 

notices. You should therefore re-open the switch you 

have just assigned:

Teacher / Teacher

Pupil

Teacher

8 9 10 11

SW: BIND:

7

n/a

12

8



Note:

The switch assignment just described also determines the transmitter used to issue the teacher and 

pupil functions, respectively. For this reason, a pupil 

transmitter must NEVER be assigned a switch on 

this menu. The header line therefore also switches 

from “Teacher / Pupil” to “Teacher / Teacher” once 

a switch has been assigned.

Using the selection keys on the left or right four-way 

button, now move the marker frame to the right, to 

“BIND: n/a”:

Teacher / Teacher

Pupil

Teacher

8 9 10 11

SW: BIND:

7

n/a

12

8



Binding the pupil transmitter to the teacher transmitter

Note:

The distance between the two transmitters should not 

be too great during the binding process. If necessary, 

change the positions of the transmitters and initiate 

the binding process again.

Initiate the “BINDING” process from the pupil transmitter by tapping the center SET key of the right fourway button ...

Teacher / Pupil

Pupil

Teacher

2 3 4 5

SW: ––– BIND:

1

Binding

6

... and repeat this immediately on the teacher transmitter:

Teacher / Teacher

Pupil

Teacher

8 9 10 11

SW: BIND:

7

Binding

12

8



As soon as this process is complete, both screens will 

show “ON” instead of the flashing “BINDING”:

Teacher / Pupil

Pupil

Teacher

2 3 4 5

SW: ––– BIND:

1

ON

6

Teacher / Teacher

Pupil

Teacher

8 9 10 11

SW: BIND:

7

ON

12

8



You can return to the basic display on both screens 

and start the training session after carefully checking 

all of the relevant functions. 

If neither transmitter or only one transmitter displays 

“ON”, this means the binding process has failed: try 

changing the positions of both transmitters and then 

repeat the entire procedure.
228 Program description - Teacher/pupil

Important notice:

Check that the model aircraft is operational and 

check that all functions issue the correct commands BEFORE setting up trainer mode.

During the ...

Training session

... the teacher and pupil can maintain a variable distance from one another. But you should stay “within 

earshot” (max. 50m) under any circumstances, 

however, no one else should be standing between 

the teacher and the pupil since these persons could 

reduce the connection range of the return channel 

used by the two transmitters. 

In this operating mode, the basic display of the teacher transmitter is as shown below ...

GRAUBELE

#01

2:22h

Stp

Flt

«normal »

0:00

0:00

5.5V

3.9V

P

HoTT

RFC –Teach

... and the pupil transmitter’s display will look something like this:

ELEVE

#01

3:33h

Stp

Flt

 

0:00

0:00

3.8V HoTT

RFC –Pupil

If, however, the connection between the teacher and 

pupil transmitters should be lost during the training 

session, then the teacher transmitter will automatically assume control of the model.

If the trainer mode switch is in the “Pupil” position 

when connectivity is lost, the Warning LED on 

the teacher transmitter will blink and audible warning 

signals will also be sounded for as long as the signal 

is lost. The basic display also displays the following 

warning notice:

N o

pupil

signal

However, if only the character string “HF –” blinks on 

the transmitter’s basic display accompanied by the 

audible warning signals, the pupil signal has been 

lost but the trainer mode switch is set to the “Teacher” 

position.

In both cases, your first step should be to reduce the 

distance between the two transmitters. If this does not 

help, then you should land immediately and establish 

the cause.

If both transmitters are operational and the receiver 

system is switched off, then the teacher transmitter’s basic display will show the icons instead of the 

“familiar” . The antenna icon will also flash and an 

audible warning signal will sound twice per second.

Resuming trainer mode

If you switch off one or both transmitters during the 

session–for whatever reason–then the basic display 

of the transmitter(s) shows the following question 

after being switched back on:

Please select

Trainer link?

ACT INH

If “INH” (set) is confirmed by tapping the center SET

key of the right four-way button or, alternatively, by 

waiting for approx. two seconds until the message 

disappears. then you will reset the transmitter in 

question back to its “normal” operating mode. You will 

then have to re-establish a connection between the 

teacher and pupil transmitters.

If, on the other hand, the selection keys on the left or 

right four-way button are used to select “ACT” ... 

Please select

Trainer link?

ACT INH

... and this selection is confirmed by tapping the 

center SET key of the right four-way button, then the 

existing teacher connection is restored. The same 

approach is used if the transmitter is configured as a 

pupil transmitter.
For your notes 229
230 Program description - Tx. output swap

This option is available as standard on the 

mc-20 HoTT transmitter only.

Use the selection keys of the left or right 

four-way button to scroll to the »Tx. output swap« menu option in the Multi-function menu:

Tx. output swap

Telemetry

Fail-safe adjust

Profi trim

Trim memory

Teacher / pupil

Open this menu option with a tap on the center SET

key of the right four-way button:

To ensure that receiver channel assignment is as flexible as possible, the software of the mc-20 HoTT 

transmitter includes the facility to swap over any of 

transmitter outputs 1 to maximum 12 as a standard 

feature. On the mc-16 HoTT transmitter this option 

can be unlocked as an extra-cost option.

Programming procedure 

This option lets you distribute the transmitter’s 8 or 

12 “control channels” to any of the transmitter outputs

1 ... 8 or 12. If you do, you must remember that the 

»Servo display« screen–accessible from almost any 

menu option by simultaneously tapping the  and 

keys on the left four-way button–refers exclusively to 

the “control channels” as preset by the receiver socket assignment: it therefore does NOT take any output 

swaps into account.

Tx Ch

Tx Ch

Tx Ch

Tx Ch

1

2

3

4

1

2

3

4

Output

Output

Output

Output

Tx. output swap

SEL

Use the  selection keys on the left or right fourTx. output swap

Swapping the outputs on the transmitter

way button to select the channel/output combination 

to be changed then briefly tap the center SET key of 

the right four-way button. You can now use the right 

selection keys to assign your selected (control) channel to the desired output, confirming this with the SET

key ... 

2

3

4

1

2

3

4

SEL

Tx Ch 6

Tx Ch

Tx Ch

Tx Ch

Output

Output

Output

Output

Tx. output swap

... or, by tapping the  or  selection keys on the 

right four-way button at the same time (CLEAR), you 

can restore the original assignment. 

Any subsequent changes, such as servo travel 

adjustments, Dual Rate / Expo, mixers etc., must 

always be performed in accordance with the original receiver socket assignment!

Example:

In the helicopter program of the mc-16 HoTT and 

mc-20 HoTT transmitters, the outputs for a collective pitch servo and the throttle servo are swapped 

around, compared to some older GRAUPNER/JR 

mc units. The throttle servo now occupies transmitter output “6” and the collective pitch servo output “1”. 

Perhaps, however, you wish to retain the previous 

configuration? In this case, you will swap over channels 1 and 6 as appropriate, so that (control) channel 

6 is located on output 1 and vice versa–as shown 

above:

Note:

“Channel Mapping” (channel assignment) is the 

receiver-side channel correlation function integrated 

into the mc-16 HoTT and mc-20 HoTT transmitter’s telemetry menu. With channel mapping, the 

transmitter’s control channels (12 maximum) can be 

freely distributed to multiple receivers or receiver outputs having the same control function, for example to 

operate two servo controls per aileron surface instead 

of just being able to control one servo, etc. To keep 

controls manageable, however, we strongly recommend using only one of the options at a time. 

mc

 

16 20
For your notes 231
232 Program description - Profi trim | Winged models

Profi trim

Flaps and aileron trimming

This option is available as standard on 

both transmitter types.

The transmitters mc-16 HoTT and 

mc-20 HoTT has an integrated software function for direct trimming of all flaps and ailerons. 

This feature, named »Profi trim« because of its 

functional similarity to the Profi-Trim module for the 

mc-24 but only available on that transmitter as a retrofit option. Select this feature from the multi-function 

menu with the selection keys of the left or right fourway button ... 

Tx. output swap

Telemetry

Fail-safe adjust

Profi trim

Trim memory

Teacher / pupil

... then open this menu option with a brief tap on the 

center SET key of the right four-way button.

Profi trim

AI AI FL FL

TR

CTL

ON/OFF

OFF OFF OFF OFF

––– ––– ––– –––

–––

SET SET SET SET

Programming procedure 

To set the desired option, move the marker frame 

onto the desired line or column with the selection 

keys of the left or right four-way button then briefly tap 

the center SET key of the right four-way button. Select 

the desired entry in the field now displayed in inverse 

video with the selection keys on the left or right fourway button or move the desired transmitter control. 

Conclude the procedure with a tap on the ESC key.

Programming is done in three steps:

First of all, in the “TR” line it will be established just 

which flap pair is to be trimmed as “AI” and/or “FL”. 

The “CTL” line specifies the control channel over 

which the given trim function is to be performed and, 

finally, a switch is defined in the “ON/OFF” line by 

which this profi-trim function can be switched on or off 

globally.

TR

Notes:

• Please note that, depending on the number of aileron and flap servos specified in the »Model 

type« menu, page 105, some settings cannot 

be used. For example, with only 1 aileron and/or 1 

flap servo there is no aileron flap activation possible, and the opposite is also true. Since this is the 

case, a number of settings in various columns remain ineffective.

• Pay attention to potential double-assignments 

when making trim control choices.

The trim functions which can be activated (ON) or 

deactivated (OFF) on the first line of this menu, either 

individually or in any combination, make pre-flight corrections to aileron and flap settings quick and easy, 

without the complexity of having to call up individual 

setting options. 

Individually, these are functions for ...

• Trim of the aileron function for aileron (“AI”)

• Trim of the flap function for aileron (“AI”)

• Trim of the aileron function for flaps (“FL”)

• Trim of the flap function for flaps (“FL”)

Tap on the  or  selection keys of the right 

four-way button at the same time (CLEAR) to reset 

the value of the field displayed in inverse video back 

to “OFF”.

Note:

Regardless of a switch’s ON/OFF setting (see further 

below), the reset of a value field in the “Trim” line has 

the effect an immediate return of the affected trim 

function to its original reference point.

mc

 

16 20
Program description - Profi trim | Winged models 233

CTL

Profi trim

AI AI FL FL

TR

CTL

ON/OFF

ON ON OFF OFF

––– ––– ––– –––

–––

SET SET SET SET

The second line of this menu is for selecting transmitter control assignments which appear advantageous 

from the many controls available on the transmitter. 

To assign a transmitter control, use the selection keys 

to navigate to the desired column then tap briefly on 

the center SET key of the right four-way button ...:

Profi trim

FL

TR

CT

ON/OFF

OFF

–––

–––

SET SET SET SET

Move desired

control adj.

... and move the desired transmitter control:

Profi trim

AI AI FL FL

TR

CTL

ON/OFF

ON ON OFF OFF

Lv1 ––– ––– –––

–––

SET SET SET SET

The mid-point position of enabled proportional controls corresponds to the programmed flap setting.

The trim range for a given transmitter control is about 

±25%. However, these “trim” controls are only effective when, as described in section “ON/OFF” further 

below, has been assigned a profi-trim switch and 

switched on.

An active transmitter control assignment can be 

erased with a simultaneous tap on the  or 

selection keys of the right four-way button (CLEAR).

Note:

Trim values retain their settings until the next closure 

of the ON/OFF switch, even then when the trim functions in the “Control” line have been temporally reset 

to “free”. 

ON/OFF

The “ON/OFF” line is used to assign a switch which 

permits the profi-trim function to be switched on/off 

globally. This assignment is done in the manner described in the section “Physical control, switch and 

control switch assignments” on page 68. Another 

option is to select an “FX” switch from the range of 

expanded switches, if you wish the “Profi-Trim” option 

to remain switched on permanently. 

In this context, pay attention to the following dependencies:

• Only when the ON/OFF switch in the “Trim” line is 

set to “ON” will the trim functions assigned to trim 

controls in the “TR” line be able to affect trim within 

a range of ±25%. 

• As soon as the ON/OFF switch is opened or 

erased, the current trim positions will be stored 

and the selected trim controls become ineffective. 

A tap, at the same time, on the  or  selection 

keys of the right four-way button (CLEAR) when a 

switch assignment is active will reset a field’s value 

back to “---”:

Profi trim

AI AI FL FL

TR

CTL

ON/OFF

ON ON OFF OFF

Lv1 Lv2 ––– –––

FXI

SET SET SET SET
234 Program description - Profi trim | Helicopter models

Profi trim

Pitch, throttle, tail-rotor, and C1 curve trimming

This option is available as standard on 

both transmitter types.

The mc-16 HoTT and mc-20 HoTT 

transmitter’s software has an integrated 

function for additional trimming of 6-point curves; in 

Heli programs »Channel 1 curve« page 141, and 

»Helicopter mixer« page 188. These are intended 

for “Pitch”, “C1  Throttle” and “C1  Tail” curves.

This feature, named »Profi trim« because of its 

functional similarity to the Profi-Trim module for the 

mc-24 but only available on that transmitter as a retrofit option. Select this feature from the multi-function 

menu with the selection keys of the left or right fourway button ... 

Tx. output swap

Telemetry

Fail-safe adjust

Profi trim

Trim memory

Teacher / pupil

... then open this menu option with a brief tap on the 

center SET key of the right four-way button.

SEL

–––

Mixer

–––

–––

–––

None

None

None

None

PH

L 1

P

L

L

L

1

1

1

1. Column “Trim control”

Note:

Pay attention to potential double-assignments when 

making trim control choices.

This menu’s first line is for assigning those transmitter 

controls (from the available on the transmitter) which 

appear most advantageous for this purpose. 

To assign a transmitter control, use the selection keys 

to navigate to the desired line then tap briefly on the 

center SET key of the right four-way button ...

SEL

–––

Mixer

––

––

––

None

PH

L 1

P

1

1

1

Move desired

control adj.

... then move the desired transmitter control:

SEL

Lv1

Mixer

–––

–––

–––

None

None

None

None

PH

L 1

P

L

L

L

1

1

1

Erase trim control

Select the transmitter control assignment in the appropriate line as already described, e.g.:

SEL

Lv1

Mixer

––

––

–––

None

PH

L 1

P

1

1

1

Move desired

control adj.

A tap, at the same time, on the  or  selection 

keys of the right four-way button (CLEAR) will now 

reset the field’s value back to “free”.

2. Column “Mixer“

This column contains a total of four Value fields, in 

which you can select one of the mixers “Collective 

pitch”, “Ch1  throttle” and “Ch1  tail” as well as 

“Channel 1 curve” from a list, either individually or in 

any combination. 

To do this, use the selection keys on the left or right 

four-way button to change to the desired value field. 

Then briefly tap the center SET key of the right fourway button ...

SEL

Lv1

Mixer

–––

–––

––– None

None

None

PH

L 1

P

L

L

L

1

1

1

None

... and select the desired mixer with the selection 

keys of the left or right four-way button, for example:

SEL

Lv1

Mixer

–––

–––

––– None

None

None

PH

L 1

P

L

L

L

1

1

1

Pitch

Another tap on the center SET key of the right fourway button or the ESC key of the left four-way button 

will conclude the entry. This procedure is the same for 

the other lines.

A tap, at the same time, on the  or  selection 

keys of the right four-way button (CLEAR) will reset a 

field displayed in inverse video back to “None”.

mc

 

16 20
Program description - Profi trim | Helicopter models 235

3. Column “P” (Point)

The lines of the column “Mixer” were used to select 

one or mixers. Now, in the “Point” column, the reference points to be trimmed will be set. 

To do this, use the selection keys on the left or right 

four-way button to move to the desired value field. 

Then briefly tap the center SET key of the right fourway button ...

SEL

Lv1

Mixer

–––

–––

––– None

None

None

PH

1

P

L

L

L

1

1

1

Pitch 1

If a undefined point is selected–in the basic version, 

only points “L” and “H” are set–the respective regulator will remain ineffective.

The point offset (in a maximum range of about ±12%) 

for the selected mixer will simultaneously be displayed in the curve diagrams of the respective »Helicopter mixer« or »Channel 1 curve« menu so that 

the offset can also be checked visually.

4. Column “PH” (Phase)

The rightmost column is used, if desired, to determine 

which programmed flight phase the given regulator 

is to be active. The number preceding flight phase 

names, in the example “1” (Normal)”, are based on 

the phase numbers as found in the »Phase assignment« menu on page 158:

SEL

Lv1

Mixer

–––

–––

––– None

None

None

P PH

L

L

L

1

1

1

Pitch 1 2

However, the current position of the regulator will 

be–contrary to the corresponding fixed-wing program–set to a new zero point when ...

• ... by a change of flight phase, individual or all trim 

controls become active or

• ... the given trim control is erased or

• ... meanwhile the function assigned in the “Mixer” 

column is to be changed.

In all of these cases, the current regulator position will 

be stored and automatically overridden, i.e. adopted 

into the curve characteristic, by the pre-programmed 

curve points specified by the »Channel 1 curve« and 

»Helicopter mixer« menus. In this manner it is possible to simultaneously optimize up to four arbitrary 

curve points during the flight.

The memory storage option described here is, for 

example, useful during the first test flights of a new 

model as this permits the “flown” flight corrections to 

be immediately recorded in the program.

However, in order to have a clearly defined reference 

point prior to the first time a store is done, it is important to put all regulators into their middle positions. 

But always be careful that, after repeated stores, 

servo travel is not too severely restricted on one side. 

Check and correct the control linkage if necessary.

Sometimes, despite an optimal basic setting for the 

model, it becomes necessary to temporarily change 

reference points, for example, when the weather has 

changed and the motor requires a short-term correction or even when the muffler gets a leak unexpectedly, etc. Of course, in all of these cases, the corrected settings should not be stored via the Profi trim 

option. Storage can be prevented by ensuring that the 

regulator is in its middle position before activation or 

deactivation.

Note:

Yet another point, independent of this, can be regulated via the “Trim point function” through use of the 

selection keys. This is described in detail along with 

the programming of 6-point curves in section »Channel 1 curve« on page 141.
236 Program description - Trim memory | Winged models

Trim memory

Storing the current trim position

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Trim 

memory« menu option in the Multi-function menu:

Tx. output swap

Telemetry

Fail-safe adjust

Profi trim

Teacher / pupil

Trim memory

Open this menu option with a tap on the center SET

key of the right four-way button:

Trim memory

AILE

ELEV

RUDD

0% 0%

0% 0%

0%

POS SET

CH1 0% 0%

0%

This menu permits selective storage of the given 

current position for the four digital trim controls in 

order to return them afterward to their visual middle 

points. This makes the last stored trim positions in the 

respective middle positions of trim levers for control 

functions 1 ... 4 available again following a model 

memory location change or after long flight pauses.

This memory store process is effective on a flightphase specific basis for the currently active model 

memory location and is not to be stored globally. 

Therefore, as soon as flight phases have been defined in the »Phase settings« and »Phase assignment menus, the given active flight phase will be 

displayed on the screen’s bottom line. For example:

Trim memory

AILE

ELEV

RUDD

0% 0%

0% 0%

0%

POS SET

CH1 0% 0%

0%

normal

Storing trim positions

The model has been flight tested and trimmed during the test flights. Current trim positions are now 

displayed in the column “POS” located approximately 

in the middle of the display. (The trim range is about 

±30% of total control travel.) The right column displays trim memory content, currently filled uniformly 

with 0% because values have not yet been stored. 

Therefore, the display appears like as follows:

Trim memory

AILE

ELEV

RUDD

+5% 0%

+3% 0%

–7%

POS SET

CH1 0% 0%

0%

normal

Now use the selection keys on the left or right fourway button to move to the line where a trim value is 

to be written into trim memory, e.g. the elevator trim 

value:

Trim memory

AILE

ELEV

RUDD

+5% 0%

+3% 0%

–7%

POS SET

CH1 0% 0%

0%

normal

The trim value is stored in the trim memory when you 

press the central SET button of the right-hand fourway button; the setting is displayed in the right-hand 

column:

Trim memory

AILE

ELEV

RUDD

+5% 0%

0% +3%

–7%

POS SET

CH1 0% 0%

0%

normal

Now, if desired, change the flight phase and repeat 

the procedure. Perform the same procedure for the 

other control functions, as necessary.

Erasing stored trim positions

Use the selection keys on the left or right four-way 

button to move to the line where a trim value is to be 

erased from trim memory, e.g.:

Trim memory

AILE

ELEV

RUDD

+5% 0%

0% +3%

–7%

POS SET

CH1 0% 0%

0%

normal

Simultaneously tap on the  or  selection keys 

of the right four-way button (CLEAR) reset the value 

field again back to “0%”.

Trim memory

AILE

ELEV

RUDD

+5% 0%

0% 0%

–7%

POS SET

CH1 0% 0%

0%

normal

However, if you do not erase a trim memory before storing a new value, the new value will be 

added to the stored value. 

Although this an “elegant” way to effectively offset 

servo throw beyond the normal trim range of about 

±30%, do keep in mind that excessive offsets for 

servo travel can lead to anomalies including onemc

 

16 20
Program description - Trim memory | Winged models 237

sided restriction. It is then prudent to check control 

linkages and make corrections as necessary. 
238 Program description - Trim memory | Helicopter models

This option is available as standard on 

both transmitter types.

Use the selection keys of the left or right 

four-way button to scroll to the »Trim 

memory« menu option in the Multi-function menu:

Tx. output swap

Telemetry

Fail-safe adjust

Profi trim

Teacher / pupil

Trim memory

Open this menu option with a tap on the center SET

key of the right four-way button:

Trim memory

Roll

Nick

Tail

0% 0%

0% 0%

0%

POS SET

PT/thr 0% 0%

0%

This menu permits selective storage of the given 

current position for the four digital trim controls in 

order to return them afterward to their visual middle 

points. This makes the last stored trim positions in the 

respective middle positions of trim levers for control 

functions 1 ... 4 available again following a model 

memory location change or after long flight pauses.

This memory store process is effective on a flightphase specific basis for the currently active model 

memory location and is not to be stored globally. 

Therefore, as soon as flight phases have been defined in the »Phase settings« and »Phase assignment menus, the given active flight phase will be 

displayed on the screen’s bottom line. For example:

Trim memory

Roll

Nick

Tail

0% 0%

0% 0%

0%

POS SET

PT/thr 0% 0%

0%

normal

Storing trim positions

The model has been flight tested and trimmed during the test flights. Current trim positions are now 

displayed in the column “POS” located approximately 

in the middle of the display. (The trim range is about 

±30% of total control travel.) The right column displays trim memory content, currently filled uniformly 

with 0% because values have not yet been stored. 

Therefore, the display appears like as follows:

Trim memory

Roll

Nick

Tail

+5% 0%

+3% 0%

–7%

POS SET

PT/thr 0% 0%

0%

normal

Now use the selection keys on the left or right fourway button to move to the line where a trim value is 

to be written into trim memory, e.g. the elevator trim 

value:

Trim memory

Roll

Nick

Tail

+5% 0%

+3% 0%

–7%

POS SET

PT/thr 0% 0%

0%

normal

The trim value is stored in the trim memory when you 

press the central SET button of the right-hand fourway button; the setting is displayed in the right-hand 

column:

Trim memory

Roll

Nick

Tail

+5% 0%

0% +3%

–7%

POS SET

PT/thr 0% 0%

0%

normal

Now, if desired, change the flight phase and repeat 

the procedure. Perform the same procedure for the 

other control functions, as necessary.

Erasing stored trim positions

Use the selection keys on the left or right four-way 

button to move to the line where a trim value is to be 

erased from trim memory, e.g.:

Trim memory

Roll

Nick

Tail

+5% 0%

0% +3%

–7%

POS SET

PT/thr 0% 0%

0%

normal

Simultaneously tap on the  or  selection keys 

of the right four-way button (CLEAR) reset the value 

field again back to “0%”.

Trim memory

Roll

Nick

Tail

+5% 0%

0% 0%

–7%

POS SET

PT/thr 0% 0%

0%

normal

However, if you do not erase a trim memory before storing a new value, the new value will be 

added to the stored value. 

Although this an “elegant” way to effectively offset 

servo throw beyond the normal trim range of about 

±30%, do keep in mind that excessive offsets for 

servo travel can lead to anomalies including oneTrim memory

Storing the current trim position

mc

 

16 20
Program description - Trim memory | Helicopter models 239

sided restriction. It is then prudent to check control 

linkages and make corrections as necessary. 
240 Program description - Telemetry

Telemetry

Read-in and settings for telemetry data

This option is available as standard on 

both transmitter types.

The receiver’s settings, as well as optional 

telemetry sensor settings, can be called 

up and programmed in real-time by way of the »Telemetry« menu. Communication with the transmitter 

is accomplished over the return channel built into the 

HoTT receiver.

A maximum of four sensors can be connected to the 

Telemetry sockets of the following receivers, using 

Y-leads where necessary: GR-12S HoTT (Order No. 

33505), GR-12 HoTT (Order No. 33506), GR-16 (Order No. 33508), GR-24 HoTT (Order No. 33512) and 

GR-32 DUAL (Order No. 33516), provided that they 

feature the current firmware.

The update capability of these and future receivers, 

which can be performed by the user, will keep the 

respective »Telemetry« menu up to date with the 

latest version and ensure enhancement with future 

functions or languages.

Note:

After registering your product at https://www.graupner.de/en/service/product_registration.aspx you are 

automatically informed of new updates. 

Important notices:

• This manual is based on the functions available at 

the time of revision of this manual.

• As already mentioned in the section entitled “Binding multiple receivers” on pages 87 and 95, it 

is also possible to bind more than one receiver per 

model if required. The software of mc-16 HoTT 

and mc-20 HoTT transmitters is capable of directly managing a maximum of two receivers, and 

the menu system can also be used to distribute 

up to twelve transmitter control channels between 

these two receivers in any configuration you wish.

However, only the receiver selected in the line 

“TEL.RCV” of the “Telemetry” menu is able to 

establish a telemetry connection to the transmitter! 

TELEMETRY

SETTING & DATA VIEW

SENSOR SELECT

RF STATUS VIEW

VOICE TRIGGER

TEL.RCV. RCV CH1

However, that also means the inverse, that only 

this receiver can be addressed through the »Telemetry« menu! If necessary, therefore, the selection must be changed before settings can be 

made on a specific receiver.

• When adjusting the settings of the remote control, make absolutely sure that the transmitter 

antenna is always far enough away from the 

receiver antennae! To be on the safe side, keep 

them at least one meter apart. Otherwise there 

is a risk of a faulty connection to the return 

channel and malfunctions will result.

• When operating a powered tug for aero-towing,

ensure that the receiving systems and the 

aerials in the two models are always at least 

50 cm apart; we recommend the use of satellite receivers in such situations. If you neglect 

this, there is a chance of interference from the 

downlink channel. 

• Since the telemetric data between transmitter and 

receiver is only exchanged after the fourth data 

package, the data transmission requires a certain 

amount of time for technical reasons, so the reaction to the operating keys and changes to settings 

take place with a delay. Therefore, the delay is not 

due to an error.

• Programming on the model or on sensors may 

only take place if the model is on the ground. Only 

carry out the settings with the motor switched off 

and the battery disconnected! Otherwise, undesired programming cannot be ruled out.

For example, a servo test initiated accidentally could cause the model to crash and cause personal injury and/or property damage. Observe the 

safety instructions on pages 4 ... 9 of this 

manual and the respective separate manuals.

• All settings (such as fail-safe, servo direction reversal, servo travel, mixer and curve settings, etc.) 

made through the »Telemetry« menu are stored 

only in the receiver and therefore are adopted 

along with it if it is implemented as a receiver in 

another model. Therefore, to be on the safe side, 

re-initialize your HoTT receiver if you want to use 

the receiver in a different model; see “Reset” on 

page 54.

• Only program the servo direction reversal, servo travel, mixer and curve settings through the 

respective transmitter’s standard menus »Servo adjustment« page 112, »Dual Rate / Expo« 

page 130 or page 134, »Channel 1 curve« 

page 138 or 141, and so on. Otherwise, the settings superimpose one another, which can lead to 

complexity or even problems in the later operation.

• The channel assignment function, called “Channel 

mapping”, integrated into the »Telemetry« menu 

of the mc-16 HoTT and mc-20 HoTT transmitters can also freely distribute control functions 

over multiple receivers or even distribute a single control function over multiple receiver outputs, 

such as two servos per aileron instead of only one 

individual servo, etc. We also recommend exercising extreme during the programming.

mc

 

16 20
Program description - Telemetry 241

Telemetry

The menus gathered under the heading »Telemetry« 

can be called up from the mc-16 HoTT and mc20 HoTT transmitter’s basic display with a tap of 

about one second duration on the center ESC key of 

the left four-way button. The same menus can, like 

other transmitter menus, also be opened in the multifunction menu with a tap on the center SET key of the 

right four-way button:

Tx. output swap

Profi trim

Teacher / pupil

Trim memory

Telemetry

Channel sequence

Basic operation

Operating the »Telemetry« menu is essentially the 

same as for the remaining mc-16 HoTT and mc20 HoTT transmitter menus. The few differences are 

described in the following:

The  selection keys of the left or right four-way 

button can be used to switch between individual 

pages of the Telemetry menu. Corresponding directional indicators can be found at top right of each 

display page in the form of angled brackets ( ), refer 

to the figures below. If only one angled bracket is visible, you are on either the first or last respective page. 

In this case, changing pages is only possible in the 

indicated direction.

Menu lines in which parameters can be changed are 

identified with the aforementioned angled bracket ( ). 

The “ ” pointer will jump a line forward or back with a 

tap on the  selection keys of the left or right fourway button. Lines to which a jump cannot be made 

are unalterable.

In order to change a parameter, briefly touch the 

center SET key of the right four-way button (the parameter will be displayed in inverse video), change 

the value within the permissible adjustment range via 

the selection keys of the right four-way button and 

adopt the value with another tap on the SET key. A 

brief tap on the center ESC key of the left four-way 

button will cause a return to the starting position 

again.

Now use the  selection keys of the left or right 

four-way button to pick the desired sub-menu. However, if the message ...

CAN‘T

RECEIVE

DATA

O K

... appears instead of the desired sub-menu after 

touching the center SET key of the right four-way 

button then no connection has been established with 

a receiver. Therefore, switch on your receiver system 

or, if applicable reconnect the addressed receiver 

as described on page 87 or 95 or activate it as 

described under “Important Notices” on the previous 

page.

On the first display page of the sub-menu “SETTINGS 

& DATAVIEW” of the »Telemetry« menu, overwritten 

with ...

RX DATAVIEW

TELEMETRY

SETTING & DATA VIEW

SENSOR SELECT

RF STATUS VIEW

VOICE TRIGGER

TEL.RCV. RCV CH1

... no settings can be made. This page is only provided for information:

RX DATAVIEW

S–STR100% R–TEM.+28°C

L PACK TIME 00010msec

R-VOLT :05.0V

L.R-VOLT:04.5V

S–QUA100%S–dBM–030dBM

SENSOR1 :00.0V 00°C

SENSOR2 :00.0V 00°C

Value Explanation

S-QUA Signal quality in%

S-dBm Reception power in dBm

S-STR Signal strength in%

R-TEM. Receiver temperature in°C

L PACK 

TIME

Indicates the time in ms in which the 

longest data package is lost during the 

transmission from the transmitter to the 

receiver

R-VOLT Current operating voltage of the 

receiver in volts

L.R-VOLT Lowest operating voltage of the receiver 

since it was last turned on, in volts

SENSOR1 Indicates values of optional telemetric 

sensor 1, in volts and °C

SETTINGS & DATAVIEW
242 Program description - Telemetry

SENSOR2 Indicates values of optional telemetric 

sensor 2, in volts and °C

Signal quality (S-QUA)

The signal quality (S-QUA) is sent “live” over the 

receiver’s return channel to the transmitter and indicates the signal quality in %.

Reception power (S-dbm)

Reception power (S-dbm) is indicated with negative 

values, which means a value of zero is the maximum 

value (= best reception) and the lower the values are, 

the poorer the reception power! The range test before 

operation, among other things, is important for this.

Note:

With negative numbers the evaluation of a number is 

reversed: The higher the number following the minus 

symbol, the lower the value is. Therefore, a reception 

power of -80dBm, for example, is poorer than one of 

-70dBm.

Perform the range test as described on page 91 or 

99 before each flight and, in doing so, simulate all 

servo movements which also take place during the 

flight. The range must be at least 50m on the ground 

with the range test activated. At this distance, the 

value shown under “S-dBm” in the “RX DATAVIEW” 

display may not be greater than -90dBm in order to 

guarantee safe operation. The model should never be 

operated with a lower value (e.g. -95dBm). Check the 

installation of the receiver system and the position of 

the antenna.

The reception power should not drop below -90 dBm 

during operation. Otherwise, reduce the distance of 

the model. Normally, however, the acoustic range 

warning (peep tone interval 1s) is triggered before 

this value is reached in order to guarantee safe operation.

Signal strength (S-STR)

The signal strength (S-STR) is displayed in %. In general, an acoustic range warning (peep tone interval 

1s) is issued as soon as the receiver signal becomes 

too week in the return channel. However, since the 

transmitter has a significantly higher transmission 

power than the receiver, the model can still be safely 

operated. For the sake of safety, the distance to the 

model should be reduced until the warning tone goes 

silent again.

Receiver temperature (R-TEM.)

Make sure the receiver remains within the permissible 

temperature range during all flight conditions (ideally 

between -10 and 55°C).

The receiver temperature limit, at which a warning 

is issued, can be adjusted in the sub-menu »RX 

SERVO TEST« under “ALARM TEMP+” (50 ... 80°C 

and “ALARM TEMP-” (-20 ... +10°C). When the value 

is under-run or over-run, an acoustic signal sounds 

(continuous peep tone) and “TEMP.E” will appear at 

the top right of all “RX” receiver sub-menus. Additionally, the parameter “R-TEM” will be displayed in inverse video on the »RX DATAVIEW« display page.

Data packages (L PACK TIME)

Indicates the longest time span in ms in which data 

packages are lost in the transmission from the transmitter to the receiver. In practice, that is the longest 

time span in which the remove control system has 

entered into fail-safe mode.

Receiver operating voltage (R-VOLT)

Always check the operating voltage of the receiver. 

Never operate or even start your model if the operating voltage is too low.

The receiver low voltage warning can be adjusted between 3.0 and 7.5 volts in “ALARM VOLT” of the »RX 

SERVO TEST« sub-menu. If this range is under-run, 

an acoustic signal is sounded (repetitive double peep 

tone (long/short)) and “VOLT.E” will appear at the top 

right of all »RX ...« receiver sub-menus. In addition, 

the parameter “R-VOLT” will be displayed in inverse 

video in the »RX DATAVIEW« sub-menu.

The current receiver battery voltage is also displayed 

in the main display, see page 28.

Minimum receiver operating voltage (L.R-VOLT)

“L.R-VOLT” indicates the minimum operating voltage 

of the receiver since the last time it was switched on.

If this voltage should deviate significantly from the 

current “R-VOLT” operating voltage, the receiver battery may be too heavily encumbered by the servos. 

The consequence is voltage drops. In this case, use 

a more powerful voltage supply in order to achieve 

maximum operational safety.

Sensor 1 + 2

Indicates the values of optional telemetric sensors 1 

and 2, if present, in volts and °C. 

RX SERVO

RX SERVO

REVERSE : OFF

CENTER : 1500μsec

TRIM : –000μsec

LIMIT– : 150%

OUTPUT CH: 01

LIMIT+ : 150%

PERIOD : 20msec

It is very important that you read the notices on page 

240 before doing any programming on this display 

page.

Value Explanation Possible

settings

OUTPUT 

CH

Channel selection 1 ... depending 

on receiver

REVERSE Servo reversal OFF / ON
Program description - Telemetry 243

Value Explanation Possible

settings

CENTER Servo center in μs if active 

(inverse), 

dependent on 

control position

TRIM Trim position in μs 

deviating from the 

CENTER position

-120 ... +120μs

LIMIT– Travel limit on the "–" 

side of servo travel in 

% servo travel

30 ... 150%

LIMIT+ Travel limit on the "+" 

side of servo travel in 

% servo travel

30 ... 150%

PERIOD Cycle time in ms 10 or 20ms

OUTPUT CH (channel selection)

If applicable, select the line “OUTPUT CH” with the 

selection keys. Touch the SET key of the right fourway button. The value field is shown highlighted. Now 

set the desired channel (e.g. 01) with the selection 

keys on the right four-way button. The following 

parameters are always based on the channel set 

here.

Reverse (servo reversal)

Set the rotational direction of the servo connected to 

the selected servo channel: ON / OFF

CENTER (servo center)

For the control channel selected in the “OUTPUT CH” 

line, the “CENTER” line displays the currently stored 

pulse width for “servo centre” in μs. The default channel pulse width of 1500 μs represents the standard 

centre position, and corresponds to the usual servo 

centre setting.

In order to change this value, select the “CENTER” 

line then tap the SET key of the right four-way button. 

The Value field is highlighted. Now move the respective transmitter control, stick and/or trim lever to the 

desired position and store the current control’s position with another tap on the SET key. This position is 

saved as the new neutral position. 

The–new–value now displayed varies according to 

the current setting of the transmitter control which affects this control channel, and the position of its trim.

TRIM (trim position)

In the “TRIM” line” you can carry out the fine adjustment of the neutral position of a servo connected to 

the control channel selected in the “OUTPUT CH” line 

using the selection keys of the right four-way button in 

1 μs increments. The value in the “CENTER” line can 

be adjusted by the TRIM value set here in a range of 

±120μs. 

Factory setting: 0 μs.

LIMIT–/+ (side dependent travel limit –/+)

This option is provided for the adjustment of a sidedependent limit (limiting) of the servo travel (rudder 

throw) of the servo connected to the control channel 

selected in the “OUTPUT CH” line. 

The settings for both directions are separate but both 

are in a range of 30 ... 150%.

Factory setting: 150% each.

PERIOD (cycle time)

In this line you determine the time interval of the individual channel impulse. This setting is adopted for all 

control channels.

With the use of only digital servos, a cycle time of 

10ms can be set.

In mixed operation or with use of only analog servos, 

20ms should absolutely be set, because the latter 

can otherwise be “over-strained” and react with “shaking” or “quivering” as a result.

RX FAIL SAFE

RX FAIL SAFE

INPUT CH: 01

MODE : HOLD

F.S.POS. : 1500μsec

DELAY : 0.75sec

OUTPUT CH: 01

FAIL SAFE ALL: NO

POSITION : 1500μsec

The description of this menus necessitates a few 

words of warning in advance:

“Do nothing” is the absolute worst thing to be done in 

this regard. “HOLD” is prescribed in the base setup 

model of the HoTT receiver.

In the event of a failure, in the best case scenario the 

model flies straight ahead for an indefinite amount of 

time and then hopefully “lands” somewhere without 

causing significant damage! However, if something 

like this happens in the wrong place at the wrong 

time, the model may become uncontrollable and “tear” 

across the flight field completely out of control, putting 

the pilot and spectators at risk.

Therefore, it would obviously be beneficial to program 

the the function “Motor off” at the very least, in order 

to prevent such risks. If necessary, seek the advice of 

an experienced pilot in order to find a “logical” setting 

for your model.

And then another brief notice regarding the three 

possible versions of the mc-16 HoTT and mc-20

HoTT transmitters for the setting of Fail Safe:

The easiest, and recommended, way to fail-safe settings is the use of the »Fail Safe« menu, which can 

be reached from the multifunction menu, see page 

220.

Similarly, in order to achieve the same result somewhat more laboriously, the “FAIL SAFE ALL” option 

described on the following pages is also available.

In addition, there are the relatively elaborate methods of the individual adjustment using the options 
244 Program description - Telemetry

“MODE”, “F.S.Pos.” and “DELAY”. The description of 

these variants begins with the “MODE” option further 

below.

Value Explanation Possible

settings

OUTPUT 

CH

Output channel 

(servo connection 

of the receiver)

1 ... depending 

on receiver

INPUT CH Input channel 

(channel 

coming from the 

transmitter)

1 ... max. 12

MODE Fail-Safe mode HOLD 

FAIL SAFE 

OFF

F.S.POS. Fail-safe position 1000 ... 2000μs

DELAY Reaction time 

(delay)

0.25, 0.50, 0.75 

and 1.00s

FAIL 

SAFE ALL

Save of the Failsafe positions of all 

control channels

NO / SAVE

POSITION Display of the 

saved Fail-safe 

position

Between approx 

1000 and 2000μs

OUTPUT CH (servo connection)

In this line you select the respective OUTPUT CH 

(servo connection of the receiver) to be set.

INPUT CH (selection of the input channel)

As already mentioned on page 240, the eight control functions of the standard eight-channel mc-16

HoTT transmitter, the twelve control channels of the 

mc-16 HoTT with twelve channels unlocked, and 

the standard twelve-channel mc-20 HoTT transmitter can be arbitrarily distributed to multiple receivers, 

if necessary, or even assigned to multiple receiver 

outputs with the same control function. For example, 

this might be used in order to be able to control two 

servers for each aileron flap or an oversize rudder 

with linked servos instead of an individual servo. 

Distribution to multiple HoTT receivers, in turn, offers the advantage of not having to use a long servo 

cable, e.g. for large models. In this case, bear in mind 

that only the receiver selected in the line “TEL.RCV.” 

through the »Telemetry« menu can be addressed!

The 8 respectively 12 control channels (INPUT CH) of 

the mc-16 HoTT or mc-20 HoTT transmitter can 

be appropriately managed through so-called “Channel Mapping” (channel assignment) whereby a different control channel is assigned to the servo connection selected in the OUTPUT CH line for the receiver 

in the INPUT CH line.

BUT CAUTION: If, for example, “2AIL” is specified in 

the transmitter on the “Aileron/camber flaps” line of 

the »Base setup model« menu then control function 

2 (Aileron) will already be assigned in the transmitter to control channels 2 and 5 for distribution to the 

left and right ailerons. The receiver’s corresponding 

INPUT CH, which must also be mapped, would be 

the channels 02 and 05 in this case; see the following 

example.

Examples:

• You would like to control each aileron of a large 

model with two or more servos. 

Assign one of the two standard aileron control 

channels 2 or 5 as INPUT CH to the corresponding OUTPUT CH (servo connections) depending 

on the left or right bearing surface. 

• You would like to control the rudder of a large 

model with two or more servos. 

Assign the same INPUT CH (control channel) to 

the corresponding OUTPUT CH (servo connections). In this case, this is the standard rudder 

channel 4.

MODE

The settings of the options “MODE”, “F.S.Pos.” and 

“DELAY” determine the behavior of the receiver in the 

event of a failure in the transmission from transmitter 

to receiver.

The setting programmed under “MODE” is always

based on the channel set in the OUTPUT CH line.

The factory setting for all servos is “HOLD”.

For each selected OUTPUT CH (servo connection of 

the receiver) you can choose between:

• FAI(L) SAFE

With this selection, in the event of a failure the corresponding servo moves to the position shown in 

the “POSITION” line for the remainder of the failure until the “Delay time” set in the “DELAY” line 

has lapsed.

• HOLD

With a setting of “HOLD”, in the event of a failure 

the servo maintains the last correctly received servo position for the duration of the failure.

• OFF

With a setting of “OFF”, in the event of a failure the 

receiver discontinues the retransmission of (temporarily stored) control impulses for the respective 

servo output for the duration of the failure. In other 

words, the receiver switches the impulse line “off”.

BUT CAUTION: Analog servos and even some 

digital servos no longer put up any resistance 

against the previous control pressure during the 

failure of the control impulse and are more or less 

pushed out of their position as a result.

F.S.POS. (Fail-safe position)

For each OUTPUT CH (receiver servo connection), 

set the position the given servo should assume in 

“FAI(L) SAFE” mode, i.e. in the event of a failure, via 

the “F.S.POS.” line. This is done by first activating the 

value field (inverse representation) with a tap on the 

SET key of the right four-way button then using the 
Program description - Telemetry 245

selection keys of the right four-way button to choose 

the servo position. The adjustment takes place in 10-

μs increments.

Factory setting: 1500 μs (servo center).

Important notice:

The function “F.S.POS.” has an additional meaning in 

all three modes, “OFF”, “HOLD” and “FAI(L) SAFE” 

in the event that the receiver is switched on, but (still) 

does not receive a valid signal. 

The servo immediately travels to the fail-safe position predefined in the “Position” line. In doing so, the 

landing gear, for example, is prevented from retracting of the receiver is accidentally switched on while 

the transmitter is switched off. In normal model mode, 

on the other hand, the corresponding servo behaves 

in accordance with the set “MODE” in the event of a 

failure.

DELAY (fail-safe reaction time or delay)

Here you adjust the delay time after which the servos 

should move to their predetermined positions in the 

event of a signal interruption. This setting is adopted 

for all channels and only pertains to the servos programmed to the “FAIL SAFE” mode. 

Factory setting: 0.75s.

FAIL SAFE ALL (global fail-safe setting)

This sub-menu allows servo fail-safe positions to 

be established at the “push of a button” in a similar 

manner to that described on page 220 for the »Fail 

Safe« menu.

Switch to the “FAIL SAFE ALL” line and activate the 

value field by touching the center SET key of the right 

four-way button. “NO” will be displayed in inverse 

video. Then adjust the parameter to “SAVE” with one 

of the selection keys of the right four-way button. 

Now, using the operating elements of the transmitter, move all servos to the desired fail-safe position 

you assigned or want to assign in the line “MODE” 

“FAI(L) SAFE”. The current position of the control for 

the channel which was just set is shown in the bottom 

“Position” line:

RX FAIL SAFE

INPUT CH: 01

MODE : FAI-SAFE

F.S.POS. : 1500μsec

DELAY : 0.75sec

OUTPUT CH: 01

POSITION : 1670μsec

FAIL SAFE ALL: SAVE

After a tap on the center SET key of the right four-way 

button, the display will change again, from “SAVE” to 

“NO”. The saved the positions of all servos affected 

by this measure and adopted them in parallel to the 

line “F.S.Pos.” and the display then immediately shows 

the following for the current OUTPUT CH (servo connection):

RX FAIL SAFE

INPUT CH: 01

MODE : FAI-SAFE

F.S.POS. : 1500μsec

DELAY : 0.75sec

OUTPUT CH: 01

POSITION : 1670μsec

FAIL SAFE ALL: NO

Switch off the transmitter and check the fail-safe positions based on the servo throws. 

“Fail Safe” in combination with “Channel Mapping”

In order to ensure that the mapped servos–that is to 

say servos which are controlled from a common control channel (INPUT CH)–react the same way even 

in the event of a failure, the corresponding settings of 

the INPUT CH determine the behavior of the mapped 

servos!!! 

Therefore, the servo connections 6, 7 and 8 of a 

receiver are mapped, for example, with one another, 

whereby the OUTPUT CH (servo connections) 06, 

07 and 08 are assigned as INPUT CH of the same 

respective control channel “04” ...

RX FAIL SAFE

INPUT CH: 04

MODE : OFF

F.S.POS. : 1670μsec

DELAY : 0.75sec

OUTPUT CH: 06

POSITION : 1670μsec

FAIL SAFE ALL: NO

RX FAIL SAFE

INPUT CH: 04

MODE : OFF

F.S.POS. : 1230μsec

DELAY : 0.75sec

OUTPUT CH: 07

POSITION : 1670μsec

FAIL SAFE ALL: NO

RX FAIL SAFE

INPUT CH: 04

MODE : HOLD

F.S.POS. : 1770μsec

DELAY : 0.75sec

OUTPUT CH: 08

POSITION : 1670μsec

FAIL SAFE ALL: NO

... the INPUT CH 04 determines the fail-safe behavior 

of these three servos connected to the control channel 4 completely independently of the individual settings of the respective OUTPUT CH: 

RX FAIL SAFE

INPUT CH: 04

MODE : FAI-SAFE

F.S.POS. : 1500μsec

DELAY : 0.75sec

OUTPUT CH: 04

POSITION : 1500μsec

FAIL SAFE ALL: NO

This is also the case, for example, if this is mapped 

with INPUT CH 01:
246 Program description - Telemetry

RX FAIL SAFE

INPUT CH: 01

MODE : FAI-SAFE

F.S.POS. : 1500μsec

DELAY : 0.75sec

OUTPUT CH: 04

POSITION : 1500μsec

FAIL SAFE ALL: NO

In this case, the servo connection 04 would, in turn, 

react according to the fail-safe settings of CH 01.

The reaction or delay time set in the “DELAY” line, on 

the other hand, always applies uniformly for all channels set to “FAI(L) SAFE”.

RX FREE MIXER

RX FREE MIXER

MASTER CH: 00

SLAVE CH : 00

S–TRAVEL–: 100

S–TRAVEL+: 100

MIXER : 1

RX WING MIXER

TAIL TYPE: NORMAL

Value Explanation Possible settings

MIXER Mixer selection 1 ... 5

MASTER 

CH

Signal source or 

source channel

0, 1 ... depending 

on receiver

SLAVE CH Target channel 0, 1 ... depending 

on receiver

S-TRAVEL– Admix negative 0 ... 100%

S-TRAVEL+ Admix positive 0 ... 100%

RX WING 

MIXER 

TAIL TYPE

tail type NORMAL, 

V-TAIL, ELEVON 

(vertical/horizontal 

mixer for delta and 

flying wing)

MIXER

Up to five mixers can be programmed simultaneously. 

Use “MIXER” to switch between mixers 1 ... 5.

The following settings in this display always for just 

the mixer selected in the “MIXER” line.

Important notice:

If you have already programmed mixer functions 

in the »Wing mixer« or »Free mixer« menus, make 

absolutely sure that these mixers do not overlap 

with those in the menu “RX FREE MIXER”!

MASTER CH (“from”)

According to the same principles described in the 

section “Free mixer” on page 204, the signal applied 

at the MASTER CH (signal source or source channel) 

is mixed to a variable extent to the SLAVE CH (target 

channel). 

Select “00” if no mixer should be set.

SLAVE CH (“to”)

The signal of the MASTER CH (source channel) is 

mixed proportionally to the SLAVE CH (target channel). The mix ratio will be determined by the percentages entered in the lines “TRAVEL–” and “TRAVEL+”.

Select “00” if no mixer should be set.

TRAVEL–/+ (proportion of the admix in %)

With the settings of these two lines the percentage 

of the admix is specified in relation to the MASTER 

signal separately for each direction.

RX WING MIXER TAIL TYPE (tail unit type)

The following model types are also available in the 

“Tail” line of the »Model type« menu, on page 104 

and should, preferentially, be preset there. In this 

case, always leave the TAIL TYPE set to NORMAL.

However, if you would prefer to use the mixer integrated in the receiver, you can select the already 

pre-adjusted mixer functions for the corresponding 

model type:

• NORMAL

This setting corresponds to the classic aircraft 

type with rear tail unit and separate rudder and 

elevator. No mixer function is necessary for this 

model type.

• V-TAIL (V-tail unit)

With this model type the elevator and rudder control functions are connected, so that each of the 

two tail unit flaps–each controlled with a separate 

servo–assume both the elevator and rudder function. 

The servos are normally connected to the receiver 

as follows:

OUTPUT CH 3: Left V-tail servo

OUTPUT CH 4: Right V-tail servo

If the servo’s direction of rotation is incorrect, 

please observe the notices on page 73.

• ELEVON (delta/flying wing models)

The servos connect at the outputs 2 and 3 assume the aileron and elevator function. The servos 

are normally connected to the receiver as follows:

OUTPUT CH 2: Left horizontal/vertical

OUTPUT CH 3: Right horizontal/vertical

If the servo’s direction of rotation is incorrect, 

please observe the notices on page 73.

RX CURVE (EXPO)

RX CURVE

 TYPE : B

CURVE1 CH : 02

 TYPE : B

CURVE2 CH : 03

 TYPE : B

CURVE3 CH : 04

Value Explanation Possible settings

CURVE1, 

2 or 3 CH

Channel 

assignment of the 

respective curve 

setting 

1 ... depending on 

receiver
Program description - Telemetry 247

Value Explanation Possible settings

TYPE Curve type A, B, C 

see figure

Expo = +100%

–100% +100% 0 –100% 0 +100%

Expo = –100%

TYPE A

–100% +100% 0 –100% 0 +100%

linear

–100% +100% 0 –100% 0 +100%

TYPE B

TYPE C

DR = 125% DR = 70% Servo travel

Control travel

Servo travel

Control travel

Servo travel

Control travel

Normally a non-linear control function, if applicable, is 

used for the aileron (channel 2), elevator (channel 3) 

and rudder (channel 4). These channel defaults also 

correspond to the factory settings. 

BUT CAUTION: This assignment only applies when, 

on the transmitter side, neither “2HRSv3+8” is specified in the “Tail type” line nor is “2AIL” or “2AIL 2FL” 

specified in the “Aileron/camber flaps” line of the 

»Model type« menu, page 130. Otherwise, assignments will have already been made in the transmitter for control function 3 (elevator), which will then 

be split between control channels 3 & 8, or control 

function 2 (aileron), which will then be split between 

control channels 2 & 5 for the left and right ailerons.

The corresponding control channels (INPUT CH) in 

the receiver would in both cases be channels 03 & 08 

or 02 & 05.

Therefore if, for example, “2AIL” has been specified 

on the transmitter side and the intent here is to utilize 

the RX CURVE option instead of the mc-16 HoTT 

or mc-20 HoTT transmitter’s individually adjustable 

»Dual Rate / Expo« menu, see page 130 or 134, 

then two curves must be set. Otherwise, the left and 

right ailerons have different control characteristics:

RX CURVE

 TYPE : A

CURVE1 CH : 02

 TYPE : A

CURVE2 CH : 05

 TYPE : B

CURVE3 CH : 04

With the RX CURVE function you can manage the 

control characteristics for up to three servos:

• CURVE 1, 2 or 3 CH

Select the desired control channel (INPUT CH) of 

the first servo.

The following setting in TYPE only pertains to the 

channel selected here.

TYPE

Select the servo curve:

A: EXPO = -100% and DUAL RATE = 125% 

The servo reacts strongly to movements of the 

stick around the neutral position. As the rudder 

throw increases, the curve becomes flatter.

B: Linear setting. 

The servo follows the stick movement linearly.

C: EXPO = +100% and DUAL RATE = 70%

The servo reacts weakly to the stick movements 

around the neutral position. As the rudder throw 

increases, the curve becomes steeper.

Note:

The control characteristics programmed here also 

affect the mapped receiver outputs.

5CH FUNCTION: “SERVO” or “SENSOR”

RX CURVE

 TYPE : B

CURVE1 CH : 02

 TYPE : B

CURVE2 CH : 03

 TYPE : B

CURVE3 CH : 04

5CH FUNCTION:SERVO

Some receivers have a specific servo connection 

which has been made switchable rather than an 

independent telemetry connection. Thus, for example, 

on the GR-12 receiver included with the mx-12 HoTT 

set, order no. 33112, servo connector 5 has an extra 

“T” mark and can be alternatively connected ...

Servo 

Sensor OR

... not only via an order no. 7168.6A adapter cable 

to upgrade the receiver but also connected to a telemetry sensor. 

However, in order for the receiver to correctly recognize the given connected device correctly, servo connection 5 (in this case) MUST be appropriately set for 

either “SERVO” or “SENSOR”.

This switchover is accomplished by moving the 

with the selection key of the left or right four-way 

button until the “ ” symbol is at the left margin of the 

bottom line then tapping on the center SET key of the 

right four-way button:

RX CURVE

 TYPE : A

CURVE1 CH : 02

 TYPE : A

CURVE2 CH : 03

 TYPE : B

CURVE3 CH : 04

5CH FUNCTION:SERVO

Now use one of the  selection keys on the right 

four-way button to select the alternative setting “SENSOR”.
248 Program description - Telemetry

RX CURVE

 TYPE : A

CURVE1 CH : 02

 TYPE : A

CURVE2 CH : 03

 TYPE : B

CURVE3 CH : 04

5CH FUNCTION:SENSOR

Another tap on the center SET key of the right fourway button will close the selection and, with appropriate repetitive taps on the center ESC key of the left 

four-way button, a return to the transmitter’s basic 

display is accomplished.

RX SERVO TEST

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

TEST : STOP

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

CH OUT TYPE:ONCE

Value Explanation Possible

settings

ALL-MAX Servo travel on the 

"+" side for all servo 

outputs for the 

servo test

1500 ... 2000μs

ALL-MIN Servo travel on the 

"-" side for all servo 

outputs for the 

servo test

1500 ... 1000μs

TEST Test procedure START / STOP

ALARM 

VOLT

Alarm threshold 

of the receiver 

undervoltage 

warning

3.0 ... 7.5V

factory setting: 

3.8 V 

ALARM 

TEMP+

Alarm threshold for 

excessively high 

temperature of the 

receiver

50 ... 80°C

Factory setting: 

55°C

ALARM 

TEMP–

Alarm threshold 

for excessively low 

temperature of the 

receiver

-20 ... +10°C

Factory setting: 

-10°C

CH 

OUTPUT 

TYPE

Channel sequence ONCE, SAME, 

SUMI, SUMO and 

SUMD

ALL-MAX (servo travel on the “+” side)

In this line you set the maximum servo travel on the 

plus side of the control travel for the servo test.

2000 μs corresponds to the full throw; 1500 μs corresponds to the neutral position.

Make sure that the servos do not overrun mechanically during the test routine.

ALL-MIN (servo travel on the “-” side)

You adjust the maximum servo travel on the minus 

side of the control path for the servo test in this line.

1000 μs corresponds to the full throw; 1500 μs corresponds to the neutral position.

TEST

You start and stop the servo test integrated in the 

receivers in this line.

A brief tap on the center SET key of the right four-way 

button will open the entry field:

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

CH OUT TYPE:ONCE

TEST : STOP

Now, with one of the selection keys of the right fourway button, select START:

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

CH OUT TYPE:ONCE

TEST : START

A brief tap on the center SET key of the right four-way 

button will now start the test run. The input field is 

shown as “normal” again:

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

CH OUT TYPE:ONCE

TEST : START

To stop the servo test, reactivate the entry field as 

described above, select STOP and confirm this selection with the SET key of the right four-way button.

ALARM VOLT (receiver undervoltage warning)

The receiver voltage is monitored through ALARM 

VOLT. The interval can be adjusted between 3.0 and 

7.5 Volt. If the set alarm threshold is undercut, an 

acoustic signal is issued (interval peep tone long/

short) and “VOLT.E” blinks in the top right of all »RX 

...« displays:

RX SERVO

REVERSE : OFF

CENTER : 1500μsec

TRIM : –000μsec

TRAVEL– : 150%

OUTPUT CH: 01

TRAVEL+ : 150%

PERIOD : 20msec

VOLT.E

The parameter “R-VOLT” is also represented inversely in the »RX DATAVIEW« display:
Program description - Telemetry 249

S–STR100% R–TEM.+28°C

L PACK TIME 00010msec

L.R-VOLT:03.5V

S–QUA100%S–dBM–030dBM

SENSOR1 :00.0V 00°C

SENSOR2 :00.0V 00°C

R-VOLT :03.7V

RX DATAVIEW VOLT.E

ALARM TEMP +/- 

(recommended temperature monitoring)

These two options monitor the receiver temperature. 

A lower threshold “ALARM TEMP-” (-20 ... +10°C) 

and an upper threshold “ALARM TEMP+” (50 ... 

80°C) can be programmed. When these specifications are exceeded or undercut, an acoustic signal 

(continuous peep tone) sounds and “TEMP.E” appears in the top right of all receiver displays. In addition, the parameter “R-TEM” is shown inversely on the 

“»RX DATAVIEW«“ display page.

Make sure that your receiver remains within the permissible temperature range during all flight conditions 

(ideally between -10 and 55°C).

CH OUTPUT TYPE (connection type)

Here you select how the receiver outputs are controlled.

• ONCE

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

TEST : START

CH OUT TYPE:ONCE

The servo connections of the receiver are controlled successively. This is recommended for 

analog servos. 

This setting automatically operates servos in a 

20ms cycle–or in a 30ms cycle for a 12 channel 

receiver (order no. 33512)–, regardless of what is 

set or displayed in the “PERIOD” line of the »RX 

SERVO« screen!

• SAME

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

TEST : START

CH OUT TYPE:SAME

The signals are passed to the receiver servo sockets in parallel blocks. For example, the control signals are sent simultaneously to the servos connected to sockets 1 to 4 and 5 to 8 of the GR-16 

receiver, and the servos connected to sockets 1 to 

4, 5 to 8 and 9 to 12 of the GR-24 receiver.

This is recommended for digital servos when multiple servos are used for one function (e.g. aileron), so that the servos can run absolutely synchronized.

When only using digital servos, we recommend 

setting the “PERIOD” line of the »RX SERVO« to 

10ms in order to be able to utilize the fast reaction 

of digital servos. With the use of analog servos or 

in mixer mode, 20ms must be selected!

With this setting, pay particular attention to the 

sufficient dimensioning of the receiver current 

supply. Since up to four servos can always operate simultaneously, the requirement is higher.

• SUMO (sum signal OUT)

A HoTT receiver configured as SUMO permanently generates a so-called sum signal from the control signals of all of its control channels and provides this by default in the case of the receivers 

supplied as standard in the sets:

GR-16 at servo socket 6

GR-24 at servo socket 8

On receivers whose right of “SUMO”, an additional 

two-digit number in the display appears ...

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

TEST : START

CH OUT TYPE:SUMO 08

... after confirmation of “SUMO” with a brief tap on 

the center SET key of the right four-way button, 

the active field changes to the right for channel selection. With this selection you specify the highest

of the transmitter channels contained in the SUMO 

signal:

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

TEST : START

CH OUT TYPE:SUMO 08

Either confirm the default with another tap on the 

center SET key of the right four-way button or use 

the selection keys to pick another channel between 04 and 16 and confirm that with SET. 

Receiver outputs will be controlled successively 

in a 20ms cycle (30ms with the GR-32 DUAL receiver, order no. 33516), even if 10ms is set in the 

“PERIOD” line of the the »RX SERVO« screen.

Primarily intended for the “Satellite mode” of two 

HoTT receivers, as described below, the sum signal generated by the SUMO-designated receiver 

can also be used, for example, to control of Flybar 

systems (provided they have an appropriate input) 

or to control flight simulators via an adapter cable, 

order no. 33310.

In ...
250 Program description - Telemetry

Satellite mode

... two HoTT receivers are connected to one another through a three-wire connecting cable (order no. 33700.1 (300mm) or 33700.2 (100mm)) 

at receiver-type-specific servo connections. Type 

GR-16 and GR-24 receivers, for example, are to 

be connected with one another at servo output 6 

respectively 8. More detailed information can be 

found on the Internet at www.graupner.de.

All the channels of the HoTT receiver configured 

as SUMO (or the channels selected in the “CH 

OUT TYPE” line) and designated satellite receiver, 

are passed constantly to the second HoTT receiver via this connection; this is the primary receiver, 

which is designated ...

• SUMI (sum signal IN)

... the designation for the main receiver. Therefore, 

the signal always goes toward SUMI:

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

TEST : START

CH OUT TYPE:SUMI

The receiver defined as SUMI, however, only uses 

the sum signal coming from SUMO in the event of 

a failure of receipt if at least one channel in SUMI 

is programmed to fail-safe. 

If the receiver programmed as the SUMO satellite 

receiver has a reception outage, the servos connected to this receiver assume the fail-safe positions which were programmed into the satellite 

receiver, completely independent of the main receiver.

On the other hand, if two receivers have a reception outage simultaneously, the fail-safe settings in 

the current receiver software at the time this manual went to revision (in principle, the SUMO’s failsafe settings) become effective. In the individual case, however, interactions cannot be ruled out, 

which is why we urgently recommend performing an appropriate test BEFORE commissioning a model.

This receiver combination is recommended if, for 

example, one of the two receivers is installed in 

the model at an unfavorable position for receiving 

or as a result of nozzles, carbon fiber material or 

the like, there is the danger that the receipt signal is weakened due to the flight position, so that 

interruptions of the range must be taken into account.

Therefore, make sure to connect the most important control functions to the main receiver programmed as SUMI, so that, in the event of a failure, the model remains controllable when the 

SUMO satellite receiver no longer receives a signal.

Telemetry data, such as the voltage of the onboard electricity supply, on the other hand, is only 

sent to the transmitter by the satellite receiver configured as SUMO. For this reason telemetry sensors must be connected to the satellite receiver 

(SUMO), and this receiver must also be defined as 

such in the “TEL.RCV.” line of the »Telemetry« 

menu (Bind 1 ... 2); see “Important notes” on page 

240. Each receiver should be connected with its 

own supply line from the common voltage supply. 

With receivers with a high current load, it may 

even be beneficial to connect them with two supply lines to the same current supply. .

On the other hand, if 

each of the two receivers 

should be supplied from 

its own voltage source, 

the center cable must be 

removed from one of the 

two plugs of the satellite 

red

1

2 3

cable; see figure. 

If you would like to carry out additional programming, such as fail-safe settings, disconnect the 

three-pole satellite connection between the two receivers and switch on only the relevant receiver. It 

may be necessary to also change the connection 

sequence.

• SUMD (digital sum signal)

A HoTT receiver configured as SUMD, as described above, constantly generates a digital sum 

signal from the control signals of a (user-defined) 

number of its control channels, and makes this 

available at the following receiver outputs (receivers supplied in the sets as standard):

GR-16 at servo socket 6

GR-24 at servo socket 8

At the time these instructions were revised this 

type of signal is exploited by a few of the latest 

electronic developments in the fields of flybarless 

systems, high-capacity power supply systems, etc. 

However, if you wish to use this facility it is essential to read and observe the set-up notes 

supplied with the device connected to the receiver, otherwise there is a risk that your model will be uncontrollable.

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

TEST : START

CH OUT TYPE:SUMDHD12

When you confirm “SUMD” by briefly pressing 

the central SET button of the right-hand four-way 

button, the active Value field moves to the right, 

where you can select one of three possible receiver responses in the case of reception failure (FailSafe):
Program description - Telemetry 251

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

TEST : START

CH OUT TYPE:SUMDHD12

• HD („hold“)

The signals last detected as correct are “held” 

at the output.

• FS (Fail Safe)

The signals stored previously as the Fail-Safe 

positions are passed to the output; see the section entitled “Fail Safe” on page 220.

• OF (OFF)

No signals are passed to the servos during the 

period of interference.

When you again press the central SET button of 

the right-hand four-way button, the active field finally moves to Channel Select: at this point you 

can determine the highest transmitter channel 

which is to be included in the SUMD signal:

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

TEST : START

CH OUT TYPE:SUMDHD12

Note:

In most cases a value higher than “12” is not 

required by devices likely to be connected to the 

system.

SETTING & DATAVIEW sensor(s)

If, in addition to a “receiver”, at least one sensor is 

selected in the »Telemetry« menu’s »SENSOR SELECT« sub-menu (described below) then its settings 

can be read in and changed in addition to the previously described receiver screens. 

However, to actually gain access to this data, the 

selected sensor/s must be connected to the receiver 

system and this receiver system must have an active 

telemetry connection. 

If, as described in the next section, there is at least 

one sensor activated which has the support of current 

firmware, then it is possible to directly switch between 

individual modules. However, if sensors with older 

firmware are in use, it may be necessary to select 

“etc.” instead of the direct sensor selection. 

In either case, tap the  or  selection key of the left

four-way button ... 

RECEIVER

VARIO

etc.

... then use the same keys to select up or down for 

the desired module, for example:

VARIO

GPS

RECEIVER

If the selected module, in this case a Vario module, is 

active then on the last receiver screen (“RX SERVO 

TEST”), at the top right there will also be an additional “ ” symbol pointing to the right. This symbol is 

located just to the right of the left-pointing “ ” symbol 

and is the visible indicator that additional display 

screens can be accessed:

RX SERVO TEST

ALL–MIN : 1000μsec

ALL–MAX : 2000μsec

ALARM VOLT : 3.8V

TEST : STOP

ALARM TEMP–:–10°C

ALARM TEMP+: 55°C

CH OUT TYPE:ONCE

Now use one of the  selection keys on the left or 

right four-way button to switch to the selected sensor’s displays and check or change its settings as 

described in the manual delivered with the sensor. 
252 Program description - Telemetry

SENSOR SELECT

Selecting sensors

After selection of the desired menu line with the 

selection keys of the left or right four-way button ...

TELEMETRY

SETTING & DATA VIEW

SENSOR SELECT

RF STATUS VIEW

VOICE TRIGGER

TEL.RCV. RCV CH1

... and a subsequent tap on the center SET key of 

the right four-way button, the selected sub-menu will 

open.

 SENSOR SELECT

RECEIVER

GENERAL MODULE

VARIO MODULE

ELECTRIC AIR.MOD

GPS

This menu option can be used to determine which of 

the graphic displays described on page 38, as well 

as those described previously for sub-menu »SETTING & DATAVIEW«, can be selected and which 

remain hidden. 

Activate ( ) or deactivate ( ) the display of respective sensors by selecting the desired lines with the 

 selection keys of the left or right four-way button 

then tapping on the center SET key of the right fourway button, e.g.:

 SENSOR SELECT

RECEIVER

GENERAL MODULE

VARIO MODULE

ELECTRIC AIR.MOD

GPS

You must make this selection in order to include the 

corresponding sensor in the “SELECT VOICE MESSAGE” sub-menu, see page 254, and to display 

telemetry data in the respective data displays, starting on page 38. 
Program description - Telemetry 253

After selection of the desired menu line with the 

selection keys of the left or right four-way button ...

TELEMETRY

SETTING & DATA VIEW

SENSOR SELECT

RF STATUS VIEW

VOICE TRIGGER

TEL.RCV. RCV CH1

... and a subsequent tap on the center SET key of the 

right four-way button will open the selected sub-menu. 

This provides a visualization of the quality of the connection of transmitter and receiver:

R100%

T –40

E 10

R –51

5.2VC

S 90%

4.9VM 0123456789ABCDE

Top row: Reception power of the channels 1 ... 

75 of the 2.4 GHz band in dBm coming from the receiver to the transmitter.

Bottom row: Reception power of the channels 

1 ... 75 of the 2.4 GHz band in dBm 

coming from the transmitter to the 

receiver.

Comments:

• Since reception power is measured and presented 

in dBm, reception power is increasingly worse the 

higher the bar is and vice versa; refer also to “Reception power (S-dBm)” on page 242 about this. 

• The points above the bars mark the poorest reception since switching on the transmitter or the 

last reset of the display with a simultaneous tap 

on the or  keys of the right four-way button 

(CLEAR).

RF STATUS VIEW

Additional figures are shown to the left of the graphic 

representation of the reception power. These mean:

Value Explanation

R Signal quality in % of the signal received 

from the receiver

S Signal quality in % of the signal received 

by the receiver

T Reception power in dBm

E Number of lost data packages of the receiver

R Reception power in dBM of the signal 

received by the receiver

VC Current operating voltage of the receiver 

in volts

VM Lowest receiver operating voltage since 

last startup, in volts
254 Program description - Telemetry

After selection of the desired menu line with the 

selection keys of the left or right four-way button ...

TELEMETRY

SETTING & DATA VIEW

SENSOR SELECT

RF STATUS VIEW

VOICE TRIGGER

TEL.RCV. RCV CH1

... and a subsequent tap on the center SET key of the 

right four-way button will open the selected sub-menu.

–––

–––

–––

AIR ESC

VOICE TRIGGER

REPEAT 10SEC

TRIG

TRANSMITTER

RECEIVER

VARIO

GENERAL MODULE

ELECTRIC AIR.MOD

VARIO MODULE

GPS

Note:

The sensors displayed here vary according to the 

information you have entered in the “SELECT SENSOR” sub-menu; see page 252. The screen-shot 

above shows the maximum number of options, corresponding to “all sensors selected”.

REPEAT

–––

–––

–––

VOICE TRIGGER

REPEAT 10SEC

TRIG

TRANSMITTER

RECEIVER

VARIO

In order to be able to start the voice output through 

the headphone connection, at the very least the “REPEAT” line must be assigned to a switch. The takes 

place as described in the section “Physical control, 

switch and control switch assignments” on page 68:

VOICE TRIGGER

REPEAT 10SEC

Move desired switch

to ON position

(ext. switch: SET)

–––

–––

VOICE TRIGGER

REPEAT 10SEC

TRIG

TRANSMITTER

RECEIVER

VARIO

7

With this switch you can have the last respective 

voice trigger repeated for the duration of the time 

set to the left of the switch, as long as the assigned 

switch is closed.

Simultaneously pressing the Select buttons  or 

 of the right-hand four-way button (CLEAR) resets 

the time value to “1 SEC.”.

TRIG

With a switch assigned to this line, preferably a pushbutton, switch the selected voice messages in rotation 

on to the next voice message for the below-described 

“TRANSMITTER”, “RECEIVER” and “SENSOR” options. 

8

7

–––

VOICE TRIGGER

REPEAT 5SEC

TRIG

TRANSMITTER

RECEIVER

VARIO

VARIO

If the “VARIO MODULE” line is activated ( ) in the 

»SENSOR SELECT« sub-menu, as described on 

page 252, a switch assigned to one of these lines 

can be used to call up vario-specific voice messages 

for the headset connection which are completely 

independent of other voice messages, i.e. voice 

messages triggered by altitude changes, such as the 

message “slowly ascend/descend”:

8

7

15

VOICE TRIGGER

REPEAT 5SEC

TRIG

TRANSMITTER

RECEIVER

VARIO

TRANSMITTER

After selection of the desired menu line with the 

selection keys of the left or right four-way button ...

8

7

15

VOICE TRIGGER

REPEAT 10SEC

TRIG

TRANSMITTER

RECEIVER

VARIO

... and a subsequent tap on the center SET key of the 

right four-way button will open the selected sub-menu.

TX VOLT:

MODELTIME:

BATTERYTIME:

TIMER(GE.)CENTER:

TIMER(GE.)TOP:

PHASE TIMER:

TIME:

Here, after selection of the desired line with the 

selection keys of the left or right four-way button and 

a subsequent tap on the center SET key of the right 

VOICE TRIGGER
Program description - Telemetry 255

four-way button, the selected voice message can be 

activated ( ) or deactivated ( ).

TX VOLT:

MODELTIME:

BATTERYTIME:

TIMER(GE.)CENTER:

TIMER(GE.)TOP:

PHASE TIMER:

TIME:

RECEIVER

After selection of the desired menu line with the 

selection keys of the left or right four-way button ...

8

7

15

VOICE TRIGGER

REPEAT 10SEC

TRIG

TRANSMITTER

RECEIVER

VARIO

... and a subsequent tap on the center SET key of the 

right four-way button will open the selected sub-menu:

TEMP:

STRENGTH:

RX VOLT:

LOWVOLT:

Here, after selection of the desired line with the 

selection keys of the left or right four-way button and 

a subsequent tap on the center SET key of the right 

four-way button, the selected voice message can be 

activated ( ) or deactivated ( ).

“Sensors”

These lines only appear if you have already activated 

at least one sensor in the “SELECT SENSOR” submenu of the »Telemetry« menu; see page 252. The 

method of selecting corresponding voice messages is 

as described in the previous sections.

Note:

The points you select here are entirely independent 

of the “VARIO” messages. 
256 Program description - Channel sequencer

Channel sequencer

Programming the motion sequences of up to 3 servos

This option is available as standard on the 

mc-20 HoTT transmitter only.

Use the selection keys on the left or right 

four-way button to scroll to the »Channel 

sequence« menu option in the multi-function menu: 

Tx. output swap

Profi trim

Trim memory

Telemetry

Channel sequence

Multichannel

Tap briefly on the center SET key of the right four-way 

button to open this menu option:

Channel

Channel

Channel

Channel sequenzer

channel SET

9

10

11

INACT

INACT

INACT

The »Channel sequence« menu option can be used 

to execute up to 9 exactly coordinated steps for up to 

three servos over a period of up to 30 seconds. Such 

a sequence can be triggered by a single switch and 

begin at an initial servo position which is freely adjustable. For example, this makes the opening of undercarriage doors, complete with subsequent extension 

of the retractable gear, just as simple to program as 

opening a wheel well with renewed closing of one 

undercarriage door once the landing gear has been 

lowered or to program the raising of a cockpit canopy 

with subsequent head turns and waving performed by 

the pilot. However, the prerequisite for all these actions is the “parsing” of the desired motion sequence 

into practical, individual steps.

Programming procedure

On this menu option’s first display page, see figure 

below left, either accept the three preset channels, 9, 

10 and 11, or select an available channel, 5 ... 12, for 

each line to form any other desired combination, e.g.:

Channel

Channel

Channel sequenzer

channel SET

10

11

INACT

INACT

Channel 12 INACT

With a simultaneous tap on the  or  selection 

keys of the right four-way button (CLEAR), the given 

channel is reset back to 5, 6 or 7.

The next step makes the control channels needed for 

the channel sequence available. This is done in the 

“SET” column by changing settings from “INACT” to 

“ACT” and thus making the individual channels “available” to the program for sequencing. Conversely, this 

also means that channels defined as “active” in the 

»Channel sequence« menu are not available for 

other purposes:

Channel

Channel

Channel sequenzer

channel SET

10

11

ACT

ACT

Channel 12 ACT

With a simultaneous tap on the  or  selection 

keys of the right four-way button (CLEAR), the given 

channel is reset back to “INACT”.

Once control channels and their activity statuses 

have been set, switch to the right column then tap 

on the center SET key of the right four-way button to 

reach the second page, the »Channel sequence« 

menu’s choreography page. Since the call-up of the 

second page in this example was issued from the 

“Channel 12” line, this servo remains the object of 

focus after the page change:

ST TIME POS

11

0 0% –––

10

12

The previous display page permitted the selection of 

participating servos and their incorporation into the 

sequence. This display page will now be used to establish the sequence of steps for participating servos, 

beginning with initial positions yet to be defined. The 

step number, from “0” to a maximum of “9”, will be 

shown in the column labeled “ST” near the bottom left 

of the display.

Step 0: Setting initial position

Keep the focus of attention on “(Cchannel) 12” or 

change to any other of the three servos by using the 

 keys of the left four-way button, e.g. upward to 

“(Cchannel) 10”:

ST TIME POS

11

0 0% –––

10

12

Use one of the  selection keys of the right fourway button, as necessary, to shift the marker frame 

to the right from the column “TIME” to the value field 

above the column labeled “POS” then, after a tap on 

the center SET key of the right four-way button, alter 

this value within a range of ±100% until the servo is 

in the desired initial position. For example:

mc

 

16 20
Program description - Channel sequencer 257

ST TIME POS

11

12

0 –––

10

+90%

Repeat this procedure as necessary for the other two 

servos.

With a simultaneous tap on the  or  selection 

keys of the right four-way button (CLEAR), the given 

position value will be reset back to”0%”.

Step 1 (first event)

Now that initial positions have been established, the 

first step can be set. This is a matter of defining what 

is to be done, or not done, first, following a certain 

span of time.

Do this by first using the  selection keys of the left

four-way button to select one of the servos. Now tap 

the  key of the left four-way button. The step number, which was previously indicated by a “0” is now 

replaced by a “1” and the value “0.0s” will appear in 

the field above “TIME”. Use the selection keys of the 

right four-way button as necessary to shift the marker 

frame to the “TIME” column:

POS

11

12

1 0.0s +90% –––

10

ST TIME

Now briefly tap on the center SET key of the right 

four-way button to set the activation time into the value field for the “TIME” column, e.g. 1.5s. The current 

position in time is represented in the graphic by the 

dotted vertical line. It will move to the right according 

to the time setting and, at the same time, the course 

of servo positions will be presented as dotted lines 

between time-point “0” and time-point “1”:

POS

11

12

1 +90% –––

10

1.5s

ST TIME

Now set the desired servo positions for the end of the 

first time span (with the same procedure as already 

described for “Step 0”) or leave one or more of these 

servos in the same position they were in for the previous step.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset the inverse 

video value displayed if the TIME field back to “blank” 

and erase the current sequence, in this example only 

Step “1”:

POS

11

0 +90% –––

10

12

ST TIME

Step 2 ...

Repeat the previously described procedure for every 

other step to be defined until the servos have reached 

their terminal positions.

Switch assignment

In conclusion, assign the sequence of events created 

to a switch (as described in the section “Physical control, switch and control switch assignments” on page 

68) with which the servos can be switched between 

their initial and terminal positions:

POS

11

12

8 0%

10

0.0s 2

ST TIME

As soon as this switch is closed, the servos’ sequence of movements can be followed in the graphic. 

The servo curves will be shown in inverse video 

according to the preset time windows. All movements 

will sequence in reverse when the switch is opened 

again.

Important notices:

• The sequence shown is only for demonstration 

purposes and is not at all representative of a real 

sequence of servo movements. 

• The settings made in the “POS” value field replace 

the otherwise “conventional” transmitter control 

signal. Therefore it is necessary, before programming such a sequence, to check in the »Servo 

display« menu to make sure none of the channels 

planned for the sequence are actuated by any other transmitter operating element. If this were to be 

the case, it could lead to unpredictable excursions 

in the motion sequence. 

• The settings made in the »Servo adjustment« 

and »Tx. output swap« menus are not affected by 

settings in this menu.

When preparing and creating a sequence, be absolutely sure the servos do not collide mechanically. If 

necessary, use the “Travel limit” option in the »Servo 

adjustment« menu. 
258 Program description - Multichannel

Use the selection keys on the left or right four-way 

button to scroll to the menu option »Multichannel« 

menu option in the multi-function menu:

Profi trim

Trim memory

Telemetry

Channel sequence

Multichannel

Ring limiter

... then open this menu option with a brief tap on the 

center SET key of the right four-way button. 

Here, in the second column from the left, each of the 

two multi-channel functions can be activated (“ACT”) 

or deactivated (“OFF”) as desired and in the third column the given function can be assigned to one of the 

transmitter channels, 5CH through 8CH, in a list:

MC1

MC2

Multichannel

SET SEL

OFF

OFF

MUL4CH

MUL4CH

5CH

SEL

6CH

Note:

When a changeover is made to the »Servo display« or if »Servo adjustment« is used to select the 

“- travel +” or “- lim +” columns for these previously 

set channels, their respective cells will flash to indicate that these channels have been activated in the 

»Multichannel« menu. The preset values of 100% or 

150% should not be changed.

Prior to channel selection, please observe the following notices:

1. Switch to the “SETTINGS/DISPLAYS” line of the 

»Telemetry« menu and tap on the center SET key 

of the right four-way button:

• on the “RX SERVO” page, select the “20ms”

setting in the last line “PERIOD”, see page 

243.

• On the “RX SERVO TEST” display page, select 

the “SAME” option for the last line “CH OUT 

TYPE”, see page 249.

2. The control channel used may not be used as an 

input nor as an output channel for any mixer! For 

example, if 5CH is selected, be sure that the “Aile/

flaps” line of the »Model type« menu is preset 

to “1AIL” or that the “Swashplate type” line of the 

»Helicopter type« menu is preset to “1 servo”.

3. The channel settings intended for NAUTIC control 

channel purposes in the »Control adjust« and 

»Servo adjustment« menus are to be left as they 

are or reset back to their original settings. Do not 

assign any transmitter control or switch to the respective input either. Also be sure that the servo’s 

direction of rotation is not reversed. Leave the servo middle at 0%.

In the next column to the right, make a separate 

channel count specification for each of the two multichannels; “MUL4CH” for the NAUTIC-Multi-Prop 

mini decoder, order no. 4142.N or “MUL8CH” for the 

NAUTIC-Expert switching module, order no. 4159, for 

example:

MC1

MC2

Multichannel

SET SEL

OFF

OFF

5CH MUL4CH

SEL

6CH MUL8CH

Afterward, use the right arrow symbol at the bottom 

line’s right end to switch over to the second page of 

settings for the »Multichannel« menu. On this second page you can now enter the individual settings 

separately for “MC1” (Multichannel 1” ... 

Multichannel

Channel multiplier for special functions

This option is available as standard on 

both transmitter types.

The transmitter mc-16 HoTT and mc20 HoTT has an integrated multi-function 

channel built into the transmitter’s software. This facility permits up to two control channels to be used for 

up to four or eight special functions. Every available 

switch (including the so-called expansion switches, 

see page 68) or transmitter control can be assigned on the transmitter side.

On the receiver side, the following modules are available as accessories, whereby at one time a maximum 

of two modules can be operated via the »Multi-channel« menu.

NAUTIC-Expert, switching module, order no. 4159

The NAUTIC-Expert switching module expands a 

servo’s functionality to 16 switched functions. By 

appropriately wiring the connecting cable, loads can 

either be operated from a common power supply or 

also separately by multiple power sources.

NAUTIC-Multi-Prop mini-decoder order no. 4142.N

The 1/4 C-NAUTIC-Multi-Prop mini-decoder expands 

a proportional function to four proportional functions.

Light module order no. 2381

A module for switching the light signals of rail, road 

and airborne vehicles with true authenticity.

Sound switch for vehicle models order no. 2382.F

start, stop and supplementary sounds as well as typical vehicle signals

Sound switch for ship models order no. 2382.S

start, stop and supplementary sounds as well as typical ship signals

Further information can be found in Internet at 

www.graupner.de. Use the search mask by entering 

the respective order no. Alternatively, contact or visit 

your local dealer.

mc

 

16 20
Program description - Multichannel 259

INPUT2

INPUT3

Multichannel 1

SEL offset

INPUT1

INPUT4

––– 0%

––– 0%

––– 0%

––– 0%

fr

fr

fr

fr

... and „MC2“ (Multichannel 2) ...

INPUT2

INPUT3

Multichannel 2

SEL offset

INPUT1

INPUT4

––– 0%

––– 0%

––– 0%

––– 0%

INPUT5 ––– 0%

INPUT6 ––– 0%

INPUT7 ––– 0%

INPUT8 ––– 0%

fr

fr

fr

fr

fr

fr

fr

fr

Column 2 “Control”

INPUT2

INPUT3

Multichannel 1

SEL offset

INPUT1

INPUT4

––– 0%

––– 0%

––– 0%

––– 0%

fr

fr

fr

fr

Use the arrow keys to move to the column over SEL. 

After completing the activation of transmitter control 

assignment by tapping the center SET key of the right 

four-way button, the message shown below will appear in the display:

IN

IN

Multichannel 1

SEL offset

IN

INPUT4

0%

0%

0%

fr ––– 0%

Move desired

control adj.

Erasing transmitter controls or switches

With transmitter control / switch assignment active, 

simultaneously pressing the  or  buttons of 

the right-hand four-way button (CLEAR)–see screenshots above–resets the corresponding input to “fr”

and “---”.

Column 4 “offset”

INPUT2

INPUT3

Multichannel 1

offset

INPUT1

INPUT4

0%

––– 0%

––– 0%

––– 0%

fr

fr

fr

3 2

The control center for the given control, i.e. its zero 

point, can be changed in this column. The adjustment 

range lies between -100% and +100%.

Simultaneously tapping on the  or  keys of 

the right four-way button (CLEAR) will reset the value 

displayed in inverse video back to its “0%” value.

Note:

Leave the offset setting at 0% while making switch 

assignments.

Column 5 „– travel +“

To adjust servo travel, move to the right, beyond the 

“Offset” column, following the right-pointing arrow in 

the bottom left-hand corner of the screen:

INPUT2

INPUT3

Multichannel 1

– travel +

INPUT1

INPUT4

+100%

+100%

+100%

+100%

+100%

+100%

+100%

+100%

Finally, transmitter control travel is set for both sides 

in the column “-travel+”. The range for this lies between -100% and +100%. This is accomplished by 

Now operate the transmitter control you wish to use: 

the information window closes, and instead the Value 

field displays the name of the transmitter control you 

have chosen. 

Note:

If you are using the Nautic-Expert switch module, 

Order No. 4159, any proportional controls you assign 

act like switches when close to their end-points.

Column 3 “Switch”

Multichannel 1

SEL offset

INPUT4 fr ––– 0%

Move desired switch

to ON position

(ext. switch: SET)

This column is used to assign each of the inputs 

used, 1 through 8 (maximum), to any switch available 

on the transmitter. These assignments are done as 

described in the section „Physical control, switch and 

control switch assignments“ on page 68:

Any controls which were previously assigned in the 

second column will be erased. In this case, instead of 

SEL, the switch symbol will be displayed at the 

bottom of the 2nd column such that now a second 

“normal” switch, or even a transmitter control switch, 

logical switch, ... can be assigned as needed from 

the group of “expanded switches”. In general it is sufficient to assign a simple switch or transmitter control.

INPUT2

INPUT3

Multichannel 1

offset

INPUT1

INPUT4

––– 0%

––– 0%

––– 0%

––– 0%

fr

fr

fr

2
260 Program description - Multichannel

M

6 (output: 5 ... 8)

5 (output 5 ... 8)

(Receiver power supply to the „B + -“ 

marked terminals)

Best. Nr. 4159

Max. 8 x 0,7 A

Batt 3 30V

NAUTIC - Expert

Schaltbaustein

2 - 16 K

Empfänger

1 H 2

1 G 2

1 F 2

1 E 2

1 D 2

1 C 2

1 A 2

1 B 2

Best Nr 4142 N

1/4 K NAUTIC Multi-PropMini-Decoder

RX

S 4

S 3

S 2

S 1

external powersupply 3 ... 30 V

- +

+

-

Current consumption of directly 

connected consumer units 

(but no electric motors) 

max. 0,7 A (total max. 8 x 0,7 A).

Wiring for direct connection of two consumer units at one output

3-pole cable with flat connector Order No. 3941.6 

red

brown

orange

consumer

unit

max. 0,7 A

consumer

unit

max. 0,7 A

additional modules e.g. ...

Switching module high voltage SXH Order No. 3970

Switching module multi function SXM Order No. 3971 

Switching module 

high voltage 

SXH Order No. 3970

Switching

module 

SXH

Switching

module 

SXM

Switching module

multi function 

SXM Order No. 3971 

Soundswitch

Order No. 2382

Light module 

Order No. 2381

7 (output: 5 ... 8)

8 (output: 5 ... 8)

additional servos, speed controller, 

sail winch, ... also on this side

The figure shows an example of the connectivity of the " 2-16 C NAUTIC 

Expert Switch building block ", " 1/4 K NAUTIC Multi-Prop Mini-Decoder ",

" light module " and " sound switch ". Two of these modules in parallel can 

be operated using the menu »Multi channel« on output 5 ... 8.

Before first time operation of the NAUTIC modules make the above described settings.

moving the associated transmitter control to the cen- Receiver Graupner|SJ HoTT GR-32 attachment example

tre–if you wish to set symmetrical travels–or in one 

direction or the other in order to set “travel” separately 

for each side of centre. 

If the assignment is for a switch, leave the setting at 

the default value of 100%.

Note:

Due to technical reasons, servos connected to a 

1/4 C NAUTIC Multi-Prop mini decoder may operate 

somewhat hesitatingly. This is not a fault.

Connection notes for the 

Nautic-Expert switching module, order no. 4159

As many as 16 switched functions can be controlled 

per switching module. 

Eight loads, like lamps, LEDs, etc.–but not electric 

motors–, with a load current of up to 0.7A each can 

be connected directly.

Two switch functions per connector socket are possible via the three conductor cable, order no. 3941.6 , 

see bottom right figure.

Electric motors and loads drawing substantial current 

should be connected by other means, e.g. via switching modules. Ask your dealer about this.
For your notes 261
262 Program description - Ring limiter

Ring limiter

Control of Voith Schneider propellers in model ships

This option is available as standard on the 

mc-20 HoTT transmitter only.

Scroll with the selection keys on the left or 

right four-way button to the menu option 

»Ring limiter« in the multi-function menu: 

Trim memory

Telemetry

Channel sequence

Multichannel

Ring limiter

MP3 player

Tap briefly on the center SET key of the right four-way 

button to open this menu option:

4

4

4

Ring limiter

Input SET

3

9

11

OFF

OFF

OFF

Output

X

3

3

3

Y Y

4

10

12

X

This »Ring limiter« menu point is available as 

standard on the mc-20 HoTT transmitter only, and 

is primarily intended for controlling a maximum of 

three Voith-Schneider power systems as employed 

in model boats. These are positioned beneath the 

ship where they are exposed to a free flow of water 

in all directions. The control of these drives and turning their vertically oriented propeller blades is done 

with two servos per Voith Schneider propulsion unit 

whereby, for mechanical reasons, the propellers of 

this type offered by Graupner under order nos. 2358

and 2358.BL have a maximum control travel limitation 

of 4mm each.

As long as the sticks for forward/reverse and left/

right are operated individually (see section “Column 

Input”) this is no problem because travel for the two 

servos can be appropriately adjusted, both mechanically as well as in the »Servo adjustment« menu. 

However, this becomes problematic when, for example, one stick is 100% forward and, at the same 

time, the other stick is pushed completely to the right 

to arithmetically produce a 141% sum for the two 

servo travel vectors. The mechanical controls of the 

Voith Schneider propellers will collide with their limits; 

in best case only drawing an unnecessary amount 

of electric current, in worst case causing damage or 

even bursting the linkage..

This problem can be circumvented by using “ring 

limiters”, which are featured as standard on the mc20 HoTT transmitter, and can be unlocked on the 

mc-16 HoTT transmitter as an extra-cost option. 

There are a maximum of three “ring limiters” available 

in the “SET” column of this option’s first display page 

(see figure at left) that can be switched “ON” or “OFF” 

individually. In the first line on the setting page for a 

given “ring limiter”, its maximum travel can then be 

set for a range of between 25 and 125%. The second 

line provides a setting for the size of limitation of overall deflection between:

 0% circular limit ()

100% no limit () 

(limitation is strictly a matter of the given stick’s 

mechanical stop)

Important notice:

When this function is used, leave the respective 

setting values in the »Dual Rate / Expo« and 

»Servo adjustment» menus at 0 and 100% or 

reset them back to their default values.

The adjacent sketch illustrates 

the effect for a 0% setting. The 

cross-hatched area of travel is 

curtailed and appears as a “dead 

zone”.

Column, “Input”

With the standard preset control mode 1, all three 

ring limiters are pre-assigned to inputs 3 (forward/reverse) and 4 (left/right) which are actuated by the left 

stick. However, this pre-assignment can be replaced 

anytime by any other transmitter control combination. 

Use the selection keys on the left or right four-way 

button to move the marker frame to the desired value 

field then briefly tap the center SET key of the right 

four-way button:

4

4

Ring limiter

Input SET

3

9

11

OFF

OFF

OFF

Output

X

3

3

3

Y Y

4

10

12

X

4

Select the desired control channel (1 ... 12 max.) 

for the value field now displayed in inverse video by 

using the  or  selection keys. However, do not 

forget that if a control channel in the range of 5 ... 12 

max. is selected, it must also be assigned to a control in the »Control adjust« menu, see page 118. 

Briefly tap the center ESC of the left four-way button 

or the center SET key of the right four-way button to 

conclude your entry.

In principle, the other inputs are to be handled in the 

same manner.

A tap on the  or  keys of the right four-way 

button at the same time (CLEAR) will reset the active 

value field back to its given default value.

Column, “Output”

The three ring limiters are pre-assigned to receiver 

outputs 3/4, 9/10 and 11/12 by default, whereby the 

outputs in column “X” are for the forward/reverse function and the outputs in column “Y” are for the left/right 

function. However, this preset combination of receiver 

outputs can be replaced as necessary by any other 

mc

 

16 20
Program description - Ring limiter 263

combination at any time. This is essentially done in 

the same manner as described previously under 

“Input”, for example:

4

4

Ring limiter

Input SET

3

9

7

OFF

OFF

OFF

Output

X

3

3

3

Y Y

4

10

6

X

4

Note:

Watch out for undesirable overlaps if you use one of 

the outputs within a mixer.

Column, “SET”

The SET column is used to determine just which of 

the ring limiters is to be “OFF” and which are to be 

“ON”, i.e. active. Use the selection keys on the left or 

right four-way button to move the marker frame to the 

desired value field in the SET column then briefly tap 

the center SET key of the right four-way button:

4

4

Ring limiter

Input SET

3

9

7

OFF

OFF

OFF

Output

X

3

3

3

Y Y

4

10

6

X

4

In the value field now displayed in inverse video, 

make a choice between the two options, “ON” and 

“OFF”, with the  or  selection keys then conclude the entry with a brief tap on the center ESC key 

of the left four-way button or on the center SET key of 

the right four-way button.

A tap on the  or  keys of the right four-way 

button at the same time (CLEAR) will reset the active 

value field back to its “OFF” default value.

„Settings page“

4

4

Ring limiter

Input SET

3

9

7

ON

ON

ON

Output

X

3

3

3

Y Y

4

10

6

X

4

Following a selection of one of the three lines with 

the selection keys, switch to the settings page for the 

selected ring limiter (1 ... 3) with a brief tap on the 

center SET key of the right four-way button:

0%

R.

max-X

0%

CH 4

100% 100%

CH 3

lim. 1

If, however, the small diamond at the center of the 

circle in the figure above (which represents the current stick position) is not visible ...

0%

max-X

0%

100% 100%

R.

CH 4 CH 3

lim. 1

... then the respective ring limiter is still switched 

“OFF”. In this case, switch back to the previous page 

with a brief tap on the center ESC key of the left fourway button then switch the respective ring limiter “ON” 

as previously described.

Programming procedure

The two upper value fields–labeled at the bottom left 

of the display as “max-X” or “max-Y”, depending on 

the position of the marker frame–are used to specify 

separate settings for each of the two control functions, “left/right” and “forward/reverse” within a range 

of 25 ... 

0%

max-X

0%

25% 100%

R.

CH 4 CH 3

lim. 1

... and 125%:

0%

max-X

0%

125% 100%

R.

CH 4 CH 3

lim. 1

In practice, the setting is made by changing the given 

value until the respective servos in the model just 

reach the point where they no longer move.

A tap on the  or  keys of the right four-way 

button at the same time (CLEAR) will reset the 

changed value in the active value field back to its 

“100%” default value.

In the next line down–labeled at the bottom left of the 

display as “<=>-X” or “<=>-Y”, depending on 

the position of the marker frame–the setting values, 

in a range from 0% and a maximum of 125%, affect 

the form of limitation between “circular” and “rectangular”, whereby a setting value here may never be 

greater than the value of the field above it.

0%

 -X

0%

100% 100%

R.

CH 4 CH 3

lim. 1
264 Program description - Ring limiter

 -X

0%

100% 100%

100%

R.

CH 4 CH 3

lim. 1

A tap on the  or  keys of the right four-way 

button at the same time (CLEAR) will reset the 

changed value in the active value field back to its 

“0%” default value.

When finished with these settings, switch back to the 

first display page for this option then repeat this procedure, as applicable, for the lines of ring limiter 2 or 

3.

Final note:

This option can, of course, also be used as necessary and applicable for fixed-wing models.
For your notes 265
266 Program description - MP3 player

MP3 player

Replay program for MP3 files, such as music files

This option is available as standard on the 

mc-20 HoTT transmitter only.

Scroll with the selection keys on the left or 

right four-way button to the menu option 

»Ring limiter« in the multi-function menu: 

Telemetry

Channel sequence

Multichannel

Ring limiter

MP3 player

Basic settings

Tap briefly on the center SET key of the right four-way 

button to open this menu option:

Vol:15 A00/00 T00/00

A

File not found

If the message “File not found” appears near the 

middle of the display when this menu option is called 

then the transmitter has been unable to find any suitable MP3 files on the SD card. If this should happen, 

use a PC or laptop to check the content of the “MP3” 

directory on the SD card and copy suitable MP3 files 

into this directory if it is empty.

Therefore, insert a SD card containing MP3 files in a 

directory named “MP3” and, after switching the transmitter on, open the »MP3-Player« menu option:

Vol:15 A00/00 T00/00

A

Briefly tap the  key of the left four-way button to 

start replay of the first MP3 file of album 1. The replay 

will start immediately, however, the display of data 

about the number of albums and titles as well as 

playing time for the current MP3 file–depending on 

the size of the MP3 file–will only appear after some 

delay.

Vol:15 A01/04 T01/04

A

Tra c k 0 1.

The automatic replay of album 1 will continue to run 

until it is stopped with a tap on the  key of the left 

four-way button ...

Vol:15 A01/04 T01/04

A

01.mp3

... or the transmitter is switched off.

During ongoing replay, the menu can be exited at any 

time and the transmitter can be used without restriction. 

Note:

If voice output is activated it will be blended in with 

the playing MP3 file.

Volume

You may need to use the Select buttons of the righthand four-way button to move to the left-hand Value 

field in the bottom line.

Activate the Value field by pressing the central SET

button of the right-hand four-way button, then use the 

Select buttons of the right-hand four-way button to 

adjust the playback volume in the range “0” (muted) to 

“30” (very loud):

A01/04 T03/04

A

.mp3

Vol:15

Album

Use the Select buttons of the right-hand four-way button to select the central Value field in the bottom line, 

and then press the central SET button of the righthand four-way button:

T05/21

A

ack05.mp

Vol:15 A02/04

Use the  selection keys of the right four-way button to select the desired album number (from 1 to 

a maximum of 10) in this value field. Briefly tap the 

center SET key of the right four-way button to confirm 

the selection.

Note:

The number of albums right of the slash (“/”) is a consequence of the number of files present in subdirectories of the “MP3” directory on the SD card, not the 

sum of album names which may be stored in identically named meta-data fields of the MP3 file.

Titel

Use the Select buttons of the right-hand four-way 

button to select the right-hand Value field in the bottom line, and then press the central SET button of the 

right-hand four-way button:

mc

 

16 20
Program description - MP3 player 267

A

05.mp3

Vol:15 A02/04 T05/21

Now select the desire title by using the  selection keys on the right four-way button. Briefly tap the 

center SET key of the right four-way button to start 

this selection.

A

Tra c k 0 9.

Vol:15 A02/04 T09/21

Notes:

• The title displayed will be the filename of the MP3 

file, not any identically named title which may be 

stored in the MP3 file as a meta-data field.

• The number of the title per album is a consequence of the number of MP3 files per directory.

MP3 player operator field

A

Vol:15 A02/04 T09/21

•

Analogous to corresponding keys on a MP3 and 

other players, jump one title forward or back for 

each tap on one of the  selection keys of the 

left four-way button.

• / 

Analogous to corresponding keys on a MP3 and 

other players, start and stop the MP3 player with 

a tap on the  selection keys of the left four-way 

button.

• A / 1 / 1

Switch between these three options with the  selection keys of the left four-way button:

A Replay of the selected album will repeat in 

an endless loop until it is either stopped or 

the transmitter is switched off.

1 Replay of the current title will repeat in an 

endless loop until it is either stopped or the 

transmitter is switched off.

1 Replay will stop automatically at the end of 

play for the current title.

A tap on the center ESC key of the left four-way 

button will exit the menu option without stopping 

any replay that may be running.
268 Program description - Basic settings

This option is available as standard on 

both transmitter types.

Use the selection keys on the left or right 

four-way button to scroll to the »Basic 

settings« menu option in the multi-function menu: 

MP3 player

Basic settings

Servo display

Servo test

Code lock

Info display

Tap briefly on the center SET key of the right four-way 

button to open this menu option:

Battery type

Battery warning

Touch Sense

Top LCD Contrast

Lith.

Display light

Region

2

3.60V

0

Euro

unlim.

Basic settings

Vario Vol

Beeps Vol

Power-on beep yes

Power on warn. unlim

BT Headset OFF

0/0

ID PAIR OFF

BT Volume 8

Voice Vol 5 –––

7 –––

7 –––

Own

Stick mode 1

Modulation HoTT

DSC Output PPM10

Pitch min back

Bottom LCD Contr.

0

SEL SEL

fr

fr

fr

Basic settings are made in this menu. Transmitterspecific settings, such as volume regulation for 

acoustic signals and voice messages output via the 

built-in speaker or headset connector, the owner’s 

name, country setting and even specifications for new 

model memories. The settings made in this menu on 

the lines ...

• “Stick mode”,

• “Modulation”,

• “DSC Output” and

• “Pitch min”

... therefore have no influence whatsoever on already 

existing model memories; instead, they are only 

defaults which are automatically adopted into newly 

initialized model memories and can be changed 

there individually at any time in the »Basic settings, 

model« and »Helicopter type« menus. A change 

to the “Pre-set” settings in value fields of this menu 

therefore only affects those model memories created 

new at a later time.

Note:

The settings in this menu are only specified once in 

the entire transmitter. Therefore, after opening this 

menu in another model memory, the last valid settings always appear.

Programming procedure

Select the desired line with the  selection keys 

of the left or right four-way button then tap the center 

SET key of the right four-way button. The value in the 

field now displayed in inverse video can be changed. 

After a change has been made, the entry can be 

concluded with another tap on the center SET key of 

the right four-way button or the center ESC key of the 

left four-way button.

Voice volume / Vario volume / Beeps volume

7 –––

3 –––

7 –––

SEL SEL

fr

fr

fr

Basic settings

Vario Vol

Beeps Vol

Voice Vol

Own

These three lines can be used to individually set the 

volume of the three groups of acoustic signals and 

voice messages. This involves selection from among 

a total of three variants, whereby the variants two and 

three offers option for individually regulating the volume even after leaving this menu.

Pre-setting a value

Use the selection keys on the left or right four-way 

button to move the marker frame to the desired value 

field in the column above the left SEL at the display’s 

lower edge then briefly tap the center SET key of the 

right four-way button. The desired volume for the selected group can be specified in increments between 

0 and 10 in the value field now displayed in inverse 

video by using the selection keys of the left or right 

four-way button. Another tap on the center SET key 

of the right four-way button or the ESC key of the left 

four-way button will conclude the process.

Following a simultaneous tap on the  or  keys 

of the right four-way button (CLEAR), the display will 

return to its “7” default value.

via proportional control

Use the selection keys on the left or right four-way 

button to move the marker frame to the desired value 

field in the column above the right SEL label at the 

display’s lower edge then briefly tap the center SET

key of the right four-way button. The message shown 

below will then appear in the display:

Basic settings

Basic transmitter settings

mc

 

16 20
Program description - Basic settings 269

–––

–––

–––

SEL SEL

Basic settings

Va 

Be 

Vo 

Own

Move desired

control adj.

Now move the desired control, for example, the right 

proportional slider Sl2. Afterward, this slider can be 

used anytime to incrementally regulate volume for the 

selected group between 0 and 10.

Following a simultaneous tap on the  or  keys 

of the right four-way button (CLEAR), the display will 

return to its “fr” default value.

via three position switch

Use the selection keys on the left or right four-way 

button to move the marker frame to the column above 

the switch symbol at the display’s lower edge then 

briefly tap the center SET key of the right four-way 

button. The message shown below will then appear in 

the display:

SEL SEL

Basic settings

 

 

 

Own

Move desired switch

to ON position

(ext. switch: SET)

Now, assign a switch as described in the section 

“Physical control, switch and control switch assignments” on page 68. Ideally a self-neutralizing three 

position switch, e.g. like that offered by Graupner

under order no. 33001.5. Afterward, this switch can be 

used anytime to incrementally regulate volume for the 

selected group between 0 and 10.

Following a simultaneous tap on the  or  keys 

of the right four-way button (CLEAR), the display will 

return to its “---” default value.

Own(er)

7 –––

3

7 –––

Cn5

Cn6

Basic settings

Vario Vol

Beeps Vol

Voice Vol

Own

2 3

Up to 15 characters can be used to specify the owner’s name. Change to the next screen page ( ) with 

a brief tap on the center SET key of the right four-way 

button:

!"#$%&’()�+,–./0123

456789:;

Owner H-J Sandb

FGHIJKLMNOPQRSTUVWX

YZ[¥]^_`ab cdefghijk

?@ ABCDE

Select the desired characters with the selection keys 

of the left four-way button. With a brief tap on the 

selection key of the right four-way button or its center 

SET key, move to the next position in which a character can be selected. A simultaneous tap on the 

or  keys of the right four-way button (CLEAR) will 

place a space character at the current position.

Positioning to any character position within the entry field can be done with the  keys of the right 

touch pad.

A brief tap on the center ESC key of the left four-way 

button will cause a return to the previous menu page.

(Pre-set) Stick mode

As a basic principle, there are four different ways to 

assign the four control functions, aileron, elevator, 

rudder and throttle or brake flaps for winged models 

as well as rolling, pitching, tail rotor and throttle/pitch 

for helicopter models to the two sticks. Just which of 

these options is chosen depends on the individual 

preferences of the individual model pilot:

Winged model stick mode

MODE 2 (Throttle at left stick)

elev. down

elev. up

left rudder

right rudder

full throttle

idle

left aileron

right aileron

full throttle

idle

left rudder

right rudder

elev. down

elev. up

left aileron

right aileron

elev. down

elev. up

left aileron

right aileron

full throttle

idle

left rudder

right rudder

full throttle

idle

left aileron

right aileron

elev. down

elev. up

left rudder

right rudder

MODE 1 (Throttle at rigth stick)

MODE 3 (Throttle at right stick) MODE 4 (Throttle at left stick)

Helicopter model stick mode

MODE 2 (Throttle at left stick)

pitch axis

pitch axis

tail rotor

tail rotor

throttle/pitch

throttle/pitch

roll

roll

throttle/pitch

throttle/pitch

tail rotor

tail rotor

pitch axis

pitch axis

roll

roll

pitch axis

pitch axis

roll

roll

throttle/pitch

throttle/pitch

tail rotor

tail rotor

throttle/pitch

throttle/pitch

roll

roll

pitch axis

pitch axis

tail rotor

tail rotor

MODE 1 (Throttle at right stick)

MODE 3 (Throttle at right stick) MODE 4 (Throttle at left stick)

Use the  selection keys of the left or right fourway button to select the “Stick mode” line. The option 

field will be framed.
270 Program description - Basic settings

3

7 Cn6 –––

Basic settings

Vario Vol

Beeps Vol

Own

2 3

H-J Sandbrunner

1

SEL

Stick mode

Tap on the SET key briefly. The currently displayed 

stick mode will be displayed in inverse video. Now 

use the selection keys of the right four-way button to 

select the variant, from 1 to 4, you most frequently 

use. In the future this will be used for newly initialized 

model memories, but can be changed on an individual basis for up to 20 respectively 24 model memories.

Following a simultaneous tap on the  or  keys 

of the right four-way button (CLEAR), the display will 

return to stick mode “1”.

With another tap on the SET key, the selection field 

will be deactivated again to permit a change to another line.

(Pre-set) Modulation

Standard equipment for the mc-16 HoTT and mc20 HoTT transmitters includes a HoTT transmitter 

module and, under the left front cover–as viewed 

from the front–a DSC jack and a DATA jack, see 

page 22. 

It is also possible to switch between three RF module variants in the “Module” line of the »Base setup 

model« menu–see pages 86 and 94–by selecting “HoTT”, “EXT.” or “SP.” for each model memory 

separately. The most frequently used variant should 

logically be selected for the “Pre-set modulation” line 

in the »Basic settings« menu. In the future this will 

be used for newly initialized model memories, but 

can be changed on an individual basis for up to 20 

respectively 24 model memories.

Briefly tap the center SET key of the right four-way 

button:

3

Basic settings

Beeps Vol

Own

2 3

H-J Sandbrunner

1

SEL

Stick mode

Modulation HoTT

Now use the selection keys of the right four-way button to select the variant from among “HoTT”, “EXT.” 

and “SP.”.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will return the display 

back to modulation “HoTT”.

With a brief tap on the SET or ESC key, the selected 

field is deactivated to permit a switch to another line.

(Pre-set) DSC Output

In the line with the same name in the »Basic settings, model« menu, page 92 or 100, a separate 

specification can be made from among the four available modulation types which is specific to each model 

memory and will then provided at the DSC socket. 

This choice primarily influences the maximum number of control channels which can be attached to the 

DSC (direct servo control) socket, and thus also available to a flight simulator or teacher/pupil system. By 

selecting “PPM10” this will be control channels 1 ... 5, 

for “PPM16” channels 1 ... 8, for “PPM18” channels 1 

... 9 and for “PPM24” channels 1 ... 12:

SEL

Rcv Ch Map R12 R08

Base setup model

RF transmit ON

RF Range Test 99sec

DSC Output PPM10

In a manner similar to “(Pre-set) Stick mode”, in this

»Basic settings« menu the selection made for the 

“(Pre-set) DSC Output” line will determine which of 

the four possible modulation types will be adopted 

as the default variant for a newly initialized model 

memory.

If necessary, use the  selection keys of the left or 

right four-way button to switch to the “DSC Output” 

line then, with a brief tap on the center SET key of the 

right four-way button, activate the value window:

Basic settings

Own H-J Sandbrunner

1

SEL

Stick mode

Modulation HoTT

DSC Output PPM10

Now a choice can be made from among the four possible modulation types: “PPM10”, “PPM16”, “PPM18” 

and “PPM24”, with the selection keys of the right fourway button. Another tap on the center SET key of the 

right four-way button will conclude the entry.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will reset this option 

back to “PPM10”.

(Pre-set) Pitch min 

(only relevant to helicopter models)

In a manner similar to the previously described options “Stick mode” and “DSC Output”, enter the preferred actuation direction for the throttle/pitch stick 

on this line so the choice will already be present by 

default for model memories newly initialized in the 

future. The functionality of all other helicopter program 

options (to the extent they affect throttle and/or pitch) 

are dependent on this setting; in other words the 

throttle curve, idle trim, Channel 1  tail rotor mixer, 

etc.

This means:

• “forwrd”

minimum front pitch setting, the pitch stick (C1) 

points away from the pilot.
Program description - Basic settings 271

• “back”

minimum rear pitch setting, the pitch stick (C1) 

points towards the pilot.

A simultaneous tap on the  or  keys of the 

right four-way button (CLEAR) will set this option to 

“back”.

Note:

The C1 stick’s control direction for “Throttle min front/

rear” in the fixed-wing program can be changed individually in the »Model type« menu.

LCD Contrast (upper display / lower display)

In assure optimal legibility of the transmitter mc-16

HoTT or mc-20 HoTT displays under all weather 

and temperature conditions, their contrast settings 

can be adjusted separately. 

mc-16 HoTT

The contrast of the front screen of the mc-16 HoTT 

transmitter–located between the switch boards–can 

be adjusted as follows: select the “LCD Contrast” line 

using the Select buttons of the left or right-hand fourway button, and then briefly press the central SET

button of the right-hand four-way button:

Basic settings

SEL

Modulation HoTT

DSC Output PPM10

LCD Contrast 0

Pitch min back

Now display contrast can be adjusted in the value 

field displayed in inverse video within a range of ±20 

by using the selection keys of the right four-way button:

Basic settings

SEL

Modulation HoTT

DSC Output PPM10

LCD Contrast

Pitch min back

–15

Basic settings

SEL

Modulation HoTT

DSC Output PPM10

LCD Contrast

Pitch min back

+15

mc-20 HoTT

Contrast for the forward display of the transmitter 

mc-20 HoTT, located between the switch panels, is 

adjusted by selecting the “Top LCD contrast” line with 

the selection keys of the left or right four-way button 

then briefly tapping on the center SET key of the right 

four-way button.

Basic settings

SEL

Modulation HoTT

DSC Output PPM10

Top LCD Contrast 0

Pitch min back

Now display contrast can be adjusted in the value 

field displayed in inverse video within a range of ±20 

by using the selection keys of the right four-way button:

RX–S QUA: 100%

RX–S STR: 100%

TX–dBm: –33dBm

RX–dBm: –33dBm

RX–VOLT:4.8V TMP

L–PACK: 10ms

R-LOW V:4.6V +22°C 

RX–S QUA: 100%

RX–S STR: 100%

TX–dBm: –33dBm

RX–dBm: –33dBm

RX–VOLT:4.8V TMP

L–PACK: 10ms

R-LOW V:4.6V +22°C

Contrast for the rear display, located between the 

four-way buttons, is adjusted by selecting the “Bottom 

LCD contrast” line with the selection keys of the left 

or right four-way button then briefly tapping on the 

center SET key of the right four-way button.

Basic settings

SEL

DSC Output PPM10

Top LCD Contrast

0

Pitch min back

0

Bottom LCD Contr.

Now display contrast can be adjusted in the value 

field displayed in inverse video within a range of ±20 

by using the selection keys of the right four-way button:

Basic settings

SEL

DSC Output PPM10

Top LCD Contrast

Pitch min back

–15

0

Bottom LCD Contr.

Basic settings

SEL

DSC Output PPM10

Top LCD Contrast

Pitch min back

+15

0

Bottom LCD Contr.

Simultaneously tapping the  or  selection keys 

of the right four-way button (CLEAR) will reset the 
272 Program description - Basic settings

inverse video field back to “0”.

Display light

This line determines how long the transmitter display’s backlight illumination is to remain on after 

switching the transmitter on or after the last activation 

of a transmitter operating element.

Available options are “unlim(ited)”, “30s”, “60s”, 

“120s” and “off”.

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) will reset the 

inverse video field to “unlimited”.

Power on/off beep

A power on/off beep for the transmitter can be 

switched on (“yes”) and off (“no”) in this line.

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) will switch this 

option shown in inverse video back to “yes”. 

Battery type

Basic settings

SEL

Bottom LCD Contr. 0

Battery type Lith.

Display light unlim.

Power-on beep yes

This line specifies whether transmitter power is provided by a four-cell NiMH battery or a single-cell LiPo 

battery. As a consequence of this setting, the next 

line will offer a suitable voltage range for the “Battery 

warning” threshold.

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) will switch this 

option shown in inverse video back to “Lith.”.

Battery warning (threshold)

Basic settings

SEL

Battery type Lith.

Display light unlim.

Power-on beep yes

Battery warning 3.60V

You can arbitrarily specify the warning threshold for 

the display ...

Batt. must

 be re-

 charged!!

...–contingent on the battery type selection in the 

line above–in increments of 0.01 volt between 4.50 

and 5.50V (NimH battery) or 3.40 and 4.20V (LiIo/

LiPo battery). Make sure that you do not enter a value 

which is too low, so that you still have sufficient time 

to safely land your model in the event of a battery 

warning.

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) will switch the 

field shown in inverse video back to its factory setting, 

4.70V (NiMh) or 3.60V (Lith.).

Power on warning

Basic settings

SEL

Battery type Lith.

Power-on beep yes

Battery warning 3.60V

Power on warn. unlim

In this line you can determine how long the transmitter should wait after the last actuation of an operating 

element until the activation of an optical and acoustic 

power-on warning ...

Power on warning

is active!

... before the transmitter switches off automatically 

one minute later.

The values “unlim(ited)”, “30s” and 1, 5, 10, 20, 30 

and 60 minutes are optional selections.

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) will reset the 

inverse video field to “unlimited”.

Touch Sense

Basic settings

SEL

Battery type Lith.

Battery warning 3.60V

Power on warn. unlim

Touch Sense 2

In this line you can select the touch sensitivity of the 

four-way buttons in a range from 1 to 10. The lower 

this number is, the more sensitive the four-way button 

will be to taps and vice versa.

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) will reset the 

field shown in inverse video back to “2”.

Region

Basic settings

SEL

Battery warning 3.60V

Power on warn. unlim

Touch Sense 2

Region Euro

The region is needed for compliance with various 

regulations (FCC, ETSI, IC etc.). In France, for example, the operation of a remote control is only permitted within a limited frequency band. Therefore, region 
Program description - Basic settings 273

MUST be changed to “France” for the transmitter 

whenever it is operated in France. In no case may 

the Universal/EURO mode be used in France!

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) will reset the 

field shown in inverse video back to “Euro”.

Note:

In July 2012 a new list of “Class 1 Devices” was published by the appropriate EU Commission, and at the 

same time the approved upper limit of the frequency 

band pertaining to 2.4 GHz radio control systems 

(“sub-class 22”) was extended from 2.400 to 2.485 

GHz, thereby eliminating the legal requirement for the 

earlier “France mode”. See also http://ec.europa.eu/

enterprise/sectors/rtte/files/rtte_subclass_july2012_

en.pdf.

BT headset and following lines

Notes:

• This menu point, and the menu points which follow 

it, are only relevant if you have installed the optional Bluetooth module, Order No. 33002.5, in your 

transmitter, and have initialised it as described on 

page 37.

• A detailed description of the Bluetooth module, Order No. 33002.5, and the method of operating the 

following menu points, can be found in the instructions supplied with every BT module, and also on 

the Internet at www.graupner.de. For this reason 

the following section only includes a brief description of the individual options:

The option ...

Basic settings

SEL

Power on warn. unlim

Touch Sense 2

Region Euro

BT Headset OFF

... is used to detect and couple Bluetooth devices. 

The same line can be used to select one of the two 

available transmission processes. It is also possible 

to remove all coupled BT devices again by simultaneously pressing the select buttons  or  of the 

right-hand four-way button (CLEAR) when the Value 

field is active.

The number of Bluetooth devices detected during a 

coupling procedure is displayed at far right in the next 

line down.

You can select the BT device (1 ... max. 9) you wish 

to use in the Value window to the left of this; its name 

is then displayed on the left of the same line; for 

example:

Basic settings

SEL

Touch Sense 2

Region Euro

BT Headset

BTH002 1/3

A2DP

In the line ...

Basic settings

SEL

Region Euro

BT Headset A2DP

BTH002 1/3

ID PAIR OK ON

... you can start and stop the connection to the selected BT device, and in the line ...

Basic settings

SEL

BT Headset

BTH002 1/3

ID PAIR

BT Volume 8

A2DP

OK ON

... you can adjust the volume of your BT device using 

the same procedure described earlier for adjusting 

volume for the “Speech volume”, “Vario volume” and 

“Button volume” options. 
274 Program description - Servo display

Servo display

Display of the servo position

This option is available as standard on 

both transmitter types.

Use the selection keys on the left or right 

four-way button to scroll to the menu 

option »Servo display« menu option in the multifunction menu: 

MP3 player

Basic settings

Servo display

Servo test

Code lock

Info display

Briefly tap the center SET key of the right four-way 

button to open this menu option.

The screen of the standard eight-channel mc-16

HoTT transmitter looks as follows: 

1

3

7

2

4

8

0%

0%

–100%

0%

0%

+100%

5 0% 6 +100%

... while the screen of the mc-16 HoTT transmitter with twelve channels unlocked, and the standard 

twelve-channel mc-20 HoTT transmitter, looks like 

this:

1

3

5

7

0%

0%

9

11

0%

0%

2

4

6

8

0%

0%

0%

10 0%

12 0%

–100%

+100%

+100%

However, the visual display of current servo positions can not only be opened by selecting this menu, 

but also–directly from the transmitter’s base screen 

as well as nearly all other menu positions–with a 

simultaneous tap on the  keys of the left four-way 

button. A brief tap on the center ESC key of the left 

four-way button will cause a return to the respective 

point from which it was called. 

The current position of each servo is displayed in a 

bar diagram between -150% and +150% of normal 

travel with consideration for the control and servo settings, the dual-rate/expo functions, the interplay of all 

active linear and curve mixers, etc. 0% corresponds 

precisely to the servo center position. This way, you 

can quickly check your settings without having to 

switch on the receiver. However, this does not absolve 

you from first carefully testing all program steps, as 

well as on the model, prior to the first operation of the 

model in order to eliminate errors!

For winged models the display takes place according to the following scheme:

Bar 1 Throttle/brake servo

Bar 2 Aileron or left aileron

Bar 3 Elevator

Bar 4 Rudder

Bar 5 Right aileron

Bar 6 Camber-changing flap (left) / free

channel

Bar 7 Camber-changing flap (right) / free

channel

Bar 8 Free channel / second elevator servo

Bar 9 Free channel / Left FL2

Bar 10 Free channel / Right FL2

Bar 11 Free channel / Left AI2

Bar 12 Free channel / Right AI2

... and for helicopter models::

Bar 1 Pitch or roll (2) or pitch (2) servo

Bar 2 Roll (1) servo

Bar 3 Nick (1) servo

Bar 4 Tail servo (gyro)

Bar 5 Nick (2) servo / free channel

Bar 6 Throttle servo or speed controller

Bar 7 Gyro sensitivity / free channel

Bar 8 Speed controller / free channel

Bar 9 Free channel

Bar 10 Free channel

Bar 11 Free channel

Bar 12 Free channel

Notes:

• However, please note that the servo display always refers to the original servo sequence, i.e. it 

does not take into account any changes you may 

have made to the output sequence in the »Tx. 

output swap« menu (which is available as standard on the mc-20 HoTT transmitter only, but 

can be unlocked on the mc-16 HoTT transmitter 

as an extra-cost option), or in the “Receiver output” sub-menu of the »Base setup model« menu.

• Please also note that, by default, bar diagram 

tracking is opposite to the left/right movements of 

a stick.

• The number of channels shown in this menu correspond to the control channels available in the respective transmitter. However, the number of actually usable channels depends on the receiver type 

as well as the number of servos connected to it 

and, therefore, may be considerably lower under 

certain circumstances.

• Use this display during the model programming, 

because you can immediately check all settings 

on the transmitter. However, this does not absolve 

you from first carefully testing all program steps, 

as well as on the model, prior to the first operation 

of the model in order to eliminate errors!

mc

 

16 20
Program description - Servo test 275

Servo test

Function test of Servo 1 ... 8

This option is available as standard on the 

mc-20 transmitter only.

Use the selection keys on the left or right 

four-way button to scroll to the menu option »Servo test« menu option in the multi-function 

menu: 

MP3 player

Basic settings

Servo display

Servo test

Code lock

Info display

Tap briefly on the center SET key of the right four-way 

button to open this menu option:

Servo test

act

off

1 2 3 4 5 6 7 8

0.5s

Any of the inputs 1 ... 8 can be activated for the servo 

test by selecting with the selection keys of the left 

or right four-way button and then briefly tapping the 

SET key of the right four-way button. As soon as you 

have set only one of the inputs 1 ... 8 to “active”, the 

following notice appears at the bottom of the display 

screen:

Servo test

act

off

1 2 3 4 5 6 7 8

CLR=act./deact. 0.5s

A simultaneous tap on the  or  selection keys 

of the right four-way button (CLEAR) would now start 

and stop, for example, a servo test of input “1” with a 

cycle time of 0.5s.

To change cycle time, select the loop symbol at the 

bottom right of the display with the selection keys of 

the left or right four-way button:

1 2 3 4 5 6 7 8

0.5s

Servo test

act

off

CLR=act./deact.

Once this value field has been activated with a brief 

tap on the center SET key of the right four-way button 

...

1 2 3 4 5 6 7 8

0.5s

Servo test

act

off

CLR=act./deact.

... the motion cycle can be changed for the value field 

shown in inverse video within a range of 0.5s and 

3.0s in 0.5s increments. Briefly tap the center SET

key of the right four-way button to finish time selection.

Important notice:

The shut-off of the transmitter does not automatically end an active servo test. Therefore, always 

stop a servo test manually BEFORE SHUTTING 

OFF the transmitter, because the servo test is 

otherwise restarted after switching on the transmitter again.

1 2 3 4 5 6 7 8

2.5s

Servo test

act

off

CLR=act./deact.

As soon as the servo test has been started by a 

simultaneously tap on the  or  selection keys 

of the right four-way button (CLEAR) a window will 

open:

1 2 3 4 5 6 7 8

2.5s

Servo test act.

Servo test

act

off

CLR=act./deact.

The “servo test” function automatically operates the 

servos as though the corresponding transmitter controls were being simultaneously and continuously 

moved back and forth between -100% and +100% 

during the preset time. All active mixing and coupling 

functions in the respective model memory, therefore, 

are effective and the servos move within the specified 

servo paths and servo delimitations.

Another tap simultaneously on the  or  selection keys of the right four-way button (CLEAR) will 

terminate the test.

mc

 

16 20
276 Program description - Code lock

Code lock

Locking the multifunction menu

This option is available as standard on the 

mc-20 transmitter only.

Use the selection keys on the left or right 

four-way button to scroll to the menu option »Code lock« menu option in the multi-function 

menu: 

MP3 player

Basic settings

Servo display

Servo test

Info display

Code lock

Tap briefly on the center SET key of the right four-way 

button to open this menu option:

Code lock

Desired (new)

secret number

(_ )

SET

1 2 3 4

Access to the multifunction menu can be locked 

against unauthorized use by a four-digit secret code 

comprised of the numbers 1 to 4. This code lock is 

entered by way of the selection keys of the left fourway button according to the scheme shown in the 

display, for example:

Code lock

Desired (new)

secret number

(123_)

SET

1 2 3 4

As soon as another tap of a left four-way button selection key occurs after the fourth number has been 

entered, the message shown below will appear in the 

display:

Code lock

De i 

 r

)

CLR

1 2 3

Memorise secret

number carefully

A brief tap on the center ESC key of the left four-way 

button will confirm the entered secret code and exit 

the menu.

On the contrary, a brief tap on the center SET key 

of the right four-way button will confirm the currently 

active CLR field at the bottom right of the display and 

thus erase the entered digits.

Make note of the secret code and keep it safe. 

Otherwise, the transmitter must be sent in to 

Graupner service for decoding.

The lock becomes active the next time the transmitter 

is switched on. However, the control remains ready 

for operation. However, a call-up of the multi-function 

menu, and thus also a model change, can no longer 

be accomplished without entering the correct number 

combination:

Code lock

Desired (new)

secret number

(_ )

SET

1 2 3 4

A renewed attempt following an incorrect entry is only 

possible after the lapse of a time-out:

Code lock

De i 

 r

)

CLR

1 2 3

Input error

Time lock

Deletion of the secret code

If the secret code is to be erased later on, tap twice

on the center SET key of the right four-way button 

right after calling up this menu option.

Code lock

Desired (new)

secret number

(1234)

CLR

1 2 3 4

The first activation of the center SET key of the right 

four-way button will erase the secret code (CLR):

Code lock

Desired (new)

secret number

(_ )

SET

1 2 3 4

And the second activation will confirm the empty 

entry field (SET). The message shown will appear in 

the display:

Code lock

D i 

 r

)

SET

1 2 3

Memorise secret

 none 

Now exit the menu with a brief tap on the ESC key of 

the left four-way button.

Leaving the menu without input of a secret code

To leave the menu opened out of curiosity or by accident when no other key has been touched. Therefore, 

the display appears as follows:

mc

 

16 20
Program description - Code lock 277

Code lock

Desired (new)

secret number

(_ )

SET

1 2 3 4

You can leave the menu by pressing the central ESC

button of the left-hand four-way button.

Tip:

If you generally want to dispense with a programming 

lock, that option should be removed from the multifunction menu by way of »Suppress menus«. This 

will prevent unauthorized persons from entering a 

secret code “on the sly”.
278 Program description - Info display

Info display

Transmitter ID, date, time and memory card

This option is available as standard on 

both transmitter types.

Use the selection keys on the left or right 

four-way button to scroll to the menu option »Info display« menu option in the multi-function 

menu: 

MP3 player

Basic settings

Servo display

Servo test

Code lock

Info display

Tap briefly on the center SET key of the right four-way 

button to open this menu option:

RFID

firmware ver.

date

time

SD-Card

available

1.234

0MB

0%

ABCDEF12

2012/07/01(SUN)

11:22:33s

0MB

Transmitter-specific information is shown in this menu 

and–insofar as necessary and beneficial–can also 

be changed.

Programming procedure

Select the appropriate line with the  selection 

keys of the left or right four-way button then briefly tap 

on the center SET key of the right four-way button. 

The given default value in the value field displayed in 

inverse video can now be changed–insofar possible 

and necessary–with the selection keys of the right 

four-way button followed by another tap on the center 

SET key to conclude the entry.

RFID

1.234

0MB

ABCDEF12

2012/07/01(SUN)

11:22:33s

RFID

firmware ver.

date

time

SD-Card

The RF identification number of the transmitter is 

shown in this line. It is transmitter-specific, is only 

issued once per transmitter and cannot be changed. 

During the connection process, this is sent to the receiver, among other things, so that it is always capable of identifying the radio signals of “its” transmitter.

Firmware version

1.234

0MB

ABCDEF12

2012/07/01(SUN)

11:22:33s

RFID

firmware ver.

date

time

SD-Card

The current version number of the transmitter software is shown in this line. 

At the time these instructions were revised, you can 

decide whether a current update of the transmitter’s 

operating system is available by comparing the number displayed here with the information offered on 

the Internet using the link http://www.graupner.de/en/

supportdetail/4d589f17-24b4-4e50-97d2-13a0f39bd13d. If the link does not work, the same information 

can be obtained by working through www.graupner.

de => “Service & Support” => “Update and revision 

history for Graupner|SJ HoTT components”.

If applicable, the version number is also required for 

inquiries with the service department.

Date

1.234

0MB

ABCDEF12

2012/07/01(SUN)

11:22:33s

RFID

firmware ver.

date

time

SD-Card

If necessary, select this line with the selection keys 

of the left or right four-way button and, as necessary, 

select the month or date field. After activating the 

respective value field with a tap on the center SET

key of the right four-way button, the year, month or 

day can be set with the selection keys of the right 

four-way button. Another tap on the center SET key 

of the right four-way button will close the given entry. 

Years ranging from 2000 through 2135 are available 

for selection.

The abbreviated day of the week to the right outside 

in brackets is automatically generated from the respective date.

Notes:

• If the transmitter is connected to a PC as described on page 50, the date and time can 

also be set through the PC program provided for 

the respective product via the Internet page at 

www.graupner.de.

• The date and time are protected against data loss 

due to power failure by a buffer battery for situations like a battery change, see page 18. 

mc

 

16 20
Program description - Info display 279

Time

1.234

0MB

ABCDEF12

2012/07/01(SUN)

11:22:33s

RFID

firmware ver.

date

time

SD-Card

If necessary, select this line with the selection keys of 

the left or right four-way button and, as applicable, the 

minute field. After activation of the respective value 

field by a tap on the center SET key of the right fourway button, the hour or minute can be adjusted with 

the selection keys of the right four-way button. Another tap on the center SET key of the right four-way 

button will close the given entry. 

In contrast, the seconds display cannot be set directly; it can only be restarted at “00” with a brief tap on 

the center SET key of the right four-way button.

Note:

• If the transmitter is connected to a PC as described on page 50, the date and time can 

also be set through the PC program provided for 

the respective product via the Internet page at 

www.graupner.de.

• The date and time are protected against data loss 

due to power failure by a buffer battery for situations like a battery change, see page 18. 

SD-Card

1.234

2048MB

ABCDEF12

2012/07/01(SUN)

11:22:33s

RFID

firmware ver.

date

time

SD-Card

In this line the memory capacity of a memory card inserted in the transmitter, if applicable, is shown in MB.

Depending on the memory capacity of the inserted 

micro SD or micro SDHC memory card, it may take 

several minutes until the correct value is shown after 

switching on the transmitter.

available

1.234

2048MB

2012/07/01(SUN)

11:22:33s

1234MB

firmware ver.

date

time

SD-Card

available

Display of the available storage space in MB.

As mentioned before, display of the available storage 

space–depending on the capacity of the inserted 

memory card–does not appear until some time has 

passed after switching on the transmitter.

The display of the available storage space in relation to the total memory capacity is shown in the line 

below:

2048MB

2012/07/01(SUN)

11:22:33s

1234MB

60%

date

time

SD-Card

available

As mentioned before, display of the available storage 

space–depending on the capacity of the inserted 

memory card–does not appear until some time has 

passed after switching on the transmitter.
280 Programming examples - Winged models

mc-16 and mc-20 HoTT programming

Preparatory measures based on the example of a winged model

Programming models in an mc-16 HoTT or mc20 HoTT transmitter ...

... is easier than it may appear at first!

The primary prerequisite for “clean” programming, 

and this applies not only to the mc-series but is 

also a principle for all programmable transmitters, is 

a mechanically correct installation of all remote control components in the model! Therefore, it should be 

ensured no later than on connection of the linkages 

that the servos are in their respective neutral position 

and their rudder lever is also in the desired position. 

Otherwise you should loosen the rudder and re-fasten 

it with an offset of a few lobes. If servos are positioned with the help of a servo tester, e.g. RC tester, 

order no. 2894.12, then the “correct” positions can be 

determined very easily. 

The possibility of changing the neutral position of a 

servo in practically every modern transmitter is only 

intended for fine-tuning. Greater deviations from “0” 

can result to further asymmetries in the course of 

the further signal processing in the transmitter. In the 

same manner: A car with a bent chassis does not get 

any straighter if only the steering wheel is trimmed to 

“straight”!

An additional important point is the adjustment of the 

rudder paths: This should take place through a corresponding adjustment of the steering points, insofar 

as possible. Ultimately this is far more efficient than 

extensive efforts with the path adjustments in the 

transmitter! In this case: Path adjustments serve first 

and foremost for to compensate for the manufacturerstipulated tolerances for the servos and their fine-tuning, and less for the compensation of carelessness.

If two separate aileron servos are used for a winged 

model, the ailerons, controlled through the corresponding activated wing mixer–see the following 

pages–can be assigned with both the flap function 

and raised with the brake flaps–however this would 

make more sense in a glider or electro glider than in 

a motor model.

In this case the rudder arms–starting from the neutral 

position–should be tilted forward one lobe, pointing 

toward the nose, set to the respective servo. 

The mechanical differentiation achieved through this 

asymmetric assembly contributes to the fact that the 

brake effect of the elevated ailerons increases with 

their deflection and, therefore, does normally require 

a greater path upward than downward.

Correspondingly, when planning to operated separately controlled flap servos, they should also be integrated into a crow system. Since the brake effect of 

this flap position referred to as a “crow position” is influenced less by the elevated ailerons than the downward deflection of the flaps, the rudder arms should 

be installed somewhat toward the rear in this case, 

tilted toward the trailing edge. As a result, there is a 

greater available path for the downward deflection. 

With such a combination of lowered flaps with raised 

ailerons, however, the latter should only be elevated 

moderately, because they have more of a stabilizing 

and controlling function than a braking function in this 

type of crow system.

A “tip” for seeing the brake effect in this connection: 

lift the flaps and look over and under the surface from 

the front. The greater the projected surface of the 

protruding rudder, the greater the brake effect.

Outboard ailerons

Inboard camber-changing flaps

(Similar asymmetric installation of rudder arms can 

be meaningful, e.g. for open-cowl flaps or landing 

flaps, even in a motorized model.)

If a model is completed and mechanically attuned 

in this respect, you can basically begin with the 

programming of the transmitter. The following examples, an attempt is made to follow the practice of 

first describing the general basic settings and then 

fine-tuning or specializing them in the subsequent 

steps. After the initial flight and over the course of the 

further flying in of a model, it may be necessary to 

occasionally adjust some of the settings. As a pilot’s 

experience increases, however, so does the desire for 

enhancements and expansions of settings. For this 

reason, the sequence of options is not always adhered to or some options are even mentioned multiple times.

Of course, just the opposite can also be the case, 

that not everyone of the described steps is relevant 

for a certain model, just as some users may miss the 

description of a certain step for their model ...

Whatever the case may be, you should consider a 

logical assignment of the control mechanisms before 

you begin with the model programming.

For models in which the emphasis is on the “motor”, 

regardless of whether it is powered by an electric 

or combustion motor, there should be no problem in 

this respect, because the assignment of the two stick 

units essentially lies in the four basic functions “Power 

regulation (= throttle)”, “Side”, “Altitude” and “Trans-
Programming examples - Winged models 281

verse”! However, in the menu ...

»Model type« (beginning on page 104)

Tail type

Motor at C1

Normal

None

Aile/flaps 1AIL

Model type

Brake Off +100% In 1

SEL

... you should determine whether you would like the 

minimum throttle position in the “front” or “rear”, because “none (motor)” is entered by the program in the 

creation of a model memory as a basic principle.

The difference between “none” and “idle front/rear” is 

not only the effect on C1 trimming, which covers the 

entire scope of stick travel with “none” but with “idle 

front/rear” only has an effect in the idle direction. In 

the process, the “effective direction” of the C1 stick 

is adapted accordingly, so that with a change from 

“front” to “rear” or vice versa, the rotational direction of 

the throttle servo or brake system do not have to be 

adapted as well. In addition, with an “idle front/rear” 

setting, a warning indication appears in the display 

for safety reasons and issues a warning beep, if the 

throttle stick is too far in the full-throttle direction:

#01

2:22h

Stp 0:00

0:00

0.0V

3.8

M

HoTT

Thr

 too

 high!

In any case, it will be necessary to give some thought 

to “special functions”. 

With electro gliders, on the other hand, it is only occasionally different. In this regard, one must ask how 

the drive and brake system are actuated. Certain 

solutions have shown to be practical and others have 

shown to be less practical.

For example, it is certainly less practical, if you have 

to release a stick for the approach of a glider model 

in order to be able to appropriately control the spoilers or a crow position using one of the other controls. 

It may be more advantageous to either design the 

function of the C1 stick to be switchable, see Example 

4, beginning on page 291, or to leave the control of 

the brake system at the stick and to control the motor through one of the other controls or even with a 

switch! Since this type of model does not normally 

have a motor, and just a “start assistance” function 

to either “lift” the model in the sky with full force or, in 

any case, to “tow” it with “half” force by a wind field, 

When this is also mounted in a convenient to grip 

location, the motor can be switched on and off without letting loose of one of the sticks–even during the 

landing approach.

If you do not decide immediately to have the threefunction stick switch, Order No. 33000.3, installed 

by a Graupner Service Centre, then we recommend 

that you use one of the three-position switches fitted 

as standard, and preferably the switch on the side of 

the transmitter away from the hand which holds the 

model when launching. In other words: If the model is 

started from the right hand, the motor switch should 

be mounted on the left side and vice versa.

The idea is the same for the control of flaps, regardless of whether only ailerons or flaps covering the entire wingspan (combinations) are raised or lowered. A 

3-position switch with a long grip generally suffices for 

control of camber flaps, preferably mounted outboard 

on the throttle/brake stick side There it is always accessible without having to let loose of the stick.

If everything is now in order, you can begin with the 

programming. 
282 Programming examples - Winged models

Initial steps for the programming of a new model

Example: Winged model with two ailerons and–initially–without motor propulsion

In the context of initial commissioning a new transmitter, in the selection menu ...

»Basic settings« (beginning on page 268)

Battery type

Battery warning

Touch Sense

Top LCD Contrast

Lith.

Display light

Region

2

3.60V

0

Euro

unlim.

Basic settings

Vario Vol

Beeps Vol

Power-on beep yes

Power on warn. unlim

BT Headset OFF

0/0

ID PAIR OFF

BT Volume 8

Voice Vol 5 –––

7 –––

7 –––

Own

Stick mode 1

Modulation HoTT

DSC Output PPM10

Pitch min back

Bottom LCD Contr.

0

SEL SEL

fr

fr

fr

... some basic information should be entered. This 

serves various purposes:

The first three lines of this menu can be used to 

individually regulate, in increments between 0 and 

10, the volume of voice and signal output emitted via 

the built-in loudspeakers or the transmitter’s headset 

connector. 

The fourth line of this menu is used to record the 

transmitter owner’s name and the lines “Stick mode”, 

“Modulation”, “DSC Output” and “Pitch min” are for 

the storage of pre-set values used as defaults for new 

models. These are then adopted on the activation of 

a new model memory in its basic settings, but can be 

changed there at any time.

The “LCD Contrast” or “Top / Bottom LCD Contrast” lines can be used to adapt the contrast of 

respective displays to ambient light conditions as 

necessary by changing the standard pre-set “0” in a 

range of ±20.

The setting in the “Display light” line determines 

how long display lighting remains illuminated after the 

transmitter is switched on or after the last activation of 

a transmitter operating element.

The selection of “yes/no” in the “Power-on beep” 

line determines whether the “recognition melody” is 

to sound when the transmitter is switched off or on 

again.

The “Battery type” line indicates to the transmitter whether its power comes from a four-cell NiMH 

battery or a single-cell Lith battery and the “Battery 

warning” line can be used to individually set the 

threshold for the battery warning. Make sure that you 

do not enter a value which is too low, so that you still 

have sufficient time to safely land your model in the 

event of a battery warning.

If necessary, the “Power on warning” line can be 

used to determine how long the transmitter should 

wait after the last activation of an operating element 

before issuing a visual and acoustic stick warning, 

followed about three minutes later by the transmitter 

switching itself off. 

On the other hand, the setting made in the “Touch 

Sense” line is merely a personal comfort setting. The 

lower this number is, the more sensitive the four-way 

button will be to taps and vice versa.

In contrast, the setting in the “Region” line is anything 

but a matter of taste and is determined by statutory 

regulations: Therefore, when in France, only commission the transmitter with the “France” setting. 

However, please observe the note on page 273 on 

this subject.

In contrast, the “BT Headset” menu point, and the 

lines which follow it, are only relevant if you have 

installed the optional Bluetooth module, Order No. 

33002.5, in your transmitter, and have initialised it as 

described on page 37. For more information on this 

please refer to the instructions supplied in the set.

This menu can be exited after completing “general 

settings” with a return to the multi-function menu by 

way of the center ESC key of the left four-way button.

To program a new model, now use the selection keys 

of the left or right four-way button to switch to the 

menu ...

„Model select“ (page 79)

..., and use the selection keys of the left or right fourway button to select a free model memory location:

1

BD1 BD2

Mod.name

Stick mode

module n/a

Base setup model

n/a

DSC Output PPM10

HoTT

Right after a tap on the center SET key of the right 

four-way button to confirm this selection, the type of 

model to be programmed will be requested:

Select model type

Since the objective is to work with a winged model 

in this section, the symbol for a winged model is to 

be confirmed with a tap on the center SET key of the 

right four-way button. The display switches back to the 

base screen.

Notes:

• Of course, you can also use the predefined default 
Programming examples - Winged models 283

“winged model” supplied with the receiver as model memory 01 for the programming of your first 

model.

• Once the “Select model type” option has been 

opened, the process can no longer be canceled! 

Even if you switch off the transmitter, this selection 

must be made! After a selection has been made, 

the selected model memory can only be made 

“free” again by erasing it subsequently from a different model memory; see page 80.

• If battery voltage is too low, the model switchover 

cannot be made due to reasons of safety. An appropriate message will appear in the screen:

not possible now

voltage too low

Once this first hurdle has been taken, the binding of 

the receiver built into the model to this model memory 

can be done in the menu ...

»Base setup model« (beginning on page 86)

To this end, switch to the line “module”:

Mod.name

Stick mode

module

1

n/a

Base setup model

n/a

BD1 BD2

DSC Output PPM10

HoTT

Note:

After confirmation of the model selection in the base 

screen, if you confirm the message appearing in the 

screen for a few seconds ...

BIND. N/A

OK

... with a tap on the SET key of the right four-way button, this line is accessed automatically.

In this line the binding process between model memory and receiver is initiated, as described in detail 

on page 87. Otherwise, you cannot address the 

receiver.

Afterward, use the  selection key of the left or right 

four-way button to move up to the first line and begin 

with the actual model programming in the “Model 

name” line:

Mod.name

Stick mode

module

1

n/a

Base setup model

n/a

DSC Output PPM10

HoTT

The “Model name” can now be entered here by a 

brief tap on the center SET key of the right four-way 

button to switch to the character table:

!"#$%&’()�+,–./0123

456789:;

Mod Name GRAUB

FGHIJKLMNOPQRSTUVWX

YZ[¥]^_`abcdefghijk

?@ ABCDE

The pre-sets for “Stick mode”, “Modulation” and 

“DSC Output” are adopted from data stored in the 

»Basic settings« menu and these should be reviewed and changed as necessary.

In the menu ...

Model type (page 104)

Tail type

Motor at C1

Normal

None

Aile/flaps 1AIL

Model type

Brake Off +100% In 1

SEL

... the principle arrangement of the servos in the 

model is selected and communicated to the transmitter. The following selections are available:

“Motor at C1”

• “none”

Trimming works independently of the stick position 

and the “Brake settings” sub-menu of the »Wing 

mixers« menu, beginning on page 170, is available without limitation.

The “Throttle too high” warning message, see 

page 33 and/or 104, and the “Motor stop” option, page 92, are deactivated.

• “(Idle) front or back“

C1 trimming is affected in the front or rear and the 

“Motor stop”, page 92, option is activated. 

If the throttle stick is too far in the full throttle direction when the transmitter is switched on, this will 

be indicated with the warning message “Throttle 

too high”.

In parallel with this, the “Brake settings” sub-menu 

of the »Wing mixers« menu, beginning on page 

170, will only then be available if the “Motor” column of the »Phase settings« menu, page 152, 

has the entry “none” for the currently active flight 

phase.

In the next two lines, the principle arrangement of the 

servos in the model is selected and communicated to 

the transmitter:

+100%

SEL

Tail type

Motor at C1

Normal

None

Aile/flaps 1AIL

Model type

Brake Off In 1

• Tail type

“normal”, “V-tail”, “Delt/fl.wing” or “2 Sv EL 3+8”
284 Programming examples - Winged models

• Aileron/camber flaps

1, 2 or 4 AIL servos and 0, 1, 2 or 4 FL servos

Since we want to actuate the brake system of the 

“Brake settings” sub-menu under the »Wing mixers« menu with the C1 stick, we will leave the outer 

right setting in the “Brake Offset” line with “Input 1”. 

With the “Offset value” to the left of this, you should 

only place the mixer neutral point at the point where 

the brake system is retracted or inactive. If, in the 

process, the offset is not place completely at the end 

of the control path, the rest of the path is “idle travel”, 

which means the mixer is not influenced in this range 

of the stick movement.

By now at the latest, servos should be plugged into 

the receiver in the standard Graupner’ish sequence:

Receiver power supply

Free or left aileron 2 or aux. function

Free or right aileron 2 or aux. function

Rudder

Aileron or left aileron

Elevator or 1st elevator

Free or 2nd elevator or aux. function

Receiver power supply

Airbrake or throttle servo

or speed controller (electric motor)

Right aileron or aux. function

Flap or left flap

Right flap or free or aux. function

Free or left flap 2 or aux. function

Free or right flap 2 or aux. function

Comments:

• If a V-tail unit should move incorrectly either “high/

low” or “left/right”, please observe the information 

in the table on page 73 in the right column. The 

same process applies for the ailerons and flaps.

• The settings described in the following are based 

on a model with “normal” tail unit and “none (motor)”. The settings are adopted for models with a 

V-tail with practically no changes at all. However, 

the transfer of this information is not so simple for 

delta/flying-wing models. Therefore, a special programming example for this model type is provided 

on page 310.

In the menu ...

»Servo adjustment« (page 112)

S1

S2

S3

Rev cent trv +

0%

0%

0%

100% 100%

100% 100%

100% 100%

0%

0%

100% 100%

100% 100%

S4

S5

... servos can now be adapted for appropriate “direction of rotation”, “neutral position”, “travel” and 

“limitation” to the requirements of the model.

In this sense, all settings which serve to compensate 

servos and make minor adaptations to the model are 

“necessary”.

Notes:

• The maximum possible throw of a Graupner servo is 150% per side, based on both mechanical 

and electrical reasons. For example, if the sum 

of the values of the column “Center” and one of 

both columns of “Servo travel” exceed this limit, 

the respective servo can no longer follow the control commands starting from this point. Therefore, 

please bear in mind that mixers and settings in the 

»Dual Rate / EXPO« menu also have an influence 

on servo travel. 

• The settings options provided in this menu for 

asymmetric servo travel do NOT serve for achieving differentiations for ailerons and/or flaps. There 

are options better suited for this purpose in the 

»Wing mixers« menu, page 172.

In the last column, “- limit +”, the basic settings of 

150% can, and perhaps should be, significantly 

reduced. 

The values entered in this position act as a “limiter”, 

whereby the setting is actually for which point of travel 

the respective servo may not exceed, so that it does 

not start up mechanically and thus unnecessarily 

draw current. In this case it is the end of available 

mechanical play on the servo, rudder and/or steering 

which is decisive for the value to be set.

An example of this would be the selection of a model 

with cruciform tail, with which the rudder moves in 

a wedge-shaped cutout of the elevator. In order to 

prevent the rudder on the elevator starting up and 

possibly blocking it, the travel is normally mechanically adjusted (at the linkage) so that the rudder does 

not start with the full throw of the stick. As long as the 

rudder is only controlled with the corresponding stick, 

there will not be any further problems with this. But at 

the moment, when in addition to the normal rudder 

signal a mixer also influences the rudder, such as an 

“AIL  RUD” mixer (aileron to rudder), it is possible 

that the two signals can sum to an excessive extent. 

A correctly set limit of travel intercedes precisely at 

this point and thus reliably prevents the mechanical starting of the rudder. The limit of travel should, 

however, not be too small, so that the rudder throw is 

permanently and excessively limited.

Of course, the travel on both sides could also be 

reduced, so that a start-up would not even occur with 

an addition of the maximum values. With this method, 

however, the prevention of an occasionally occurring 

event would result in a permanent reduction of the 

normal rudder throw.

The following menu, which is only available as standard on the mc-20 HoTT transmitter, is not just of 

interest to model aircraft specialists: 
Programming examples - Winged models 285

»Stick mode« (page 114)

Ch.1

Aile

Elev

Tr time +

4

4

4

0.0s

0.0s

0.0s

Rudd 4 0.0s

0.0s

0.0s

0.0s

0.0s

GL

PH

PH

PH

St

In addition to the generally interesting adjustment 

of the increments in the column “Tr” (number of trim 

increments for each “trim lever click”) for digital trimming–separate adjustments for each of the four trim 

lever–in the case of the (later) programming of flight 

phases in the second column of this menu you can 

select whether the trimming of transverse, altitude 

and side should operate “GL(obally)” in equal measure over all flight phases or separately in each 

(flight) “PH(ase)”.

The “Time” column, on the other hand, is not of interest for this initial programming.

The settings made up to this point are sufficient to 

permit basic flight of winged and motorized models–though the latter does require a correctly set 

idle stick direction in the “Motor on C1” line of the 

»Model type« menu. However, the “fine-tuning” is still 

missing. The fine-tuning certainly adds to the enjoyment of flying over the course of time. Therefore, if 

you can already fly your model safely, you should 

delve into the menu...

»Wing mixer« (beginning on page 170)

... where various options are available, depending on 

the specifications made in the »Model type« menu, 

page 104.

Since this section deals with a model having only 2 

servos in the wings, the Multi-flap menu beginning on 

page 181 is not shown.

Aile.diff.

Brake settings

0%

AI 0%

Wing mixers

EL AI 0%0%

–––

–––

RU

Therefore, we begin with the “Brake settings” submenu:

Brake settings

OFF

If this display appears, your model is equipped with a 

motor, contrary to the assumption of this section, and 

therefore you have selected “front/back” instead of 

“none” in the line “Motor on C1” of the »Model type« 

menu, page 104. Therefore, change this setting 

temporarily or change the “yes” entry in the “Motor” 

column of the »Phase settings« menu, page 152, 

to “no” for the currently active flight phase–Phase 1 in 

this case.

Pha1

Pha2

Pha3

Name motor

Pha4

Pha5



–

–

yes

yes

yes

yes

no

–

–

...

Elevat curve

Brake settings

AILE

Crow

D.red

0%

0%

After this statement about mutual dependencies, back 

to the topic:

If the ailerons are to be elevated for braking, an appropriate value is entered into the “Crow” line after 

activating the “AILE” column’s value field. In addition, 

a value should always be entered in the line below it, 

“D.red” (differentiation reduction), which corresponds 

to the value you entered or would like to enter on 

the first page of the »Wing mixers« menu in the line 

“Aile.diff.” (see figure above)! With this entry, on actuation of the brake stick, the set aileron differentiation 

is hidden again proportionally in order to increase the 

downward the throw of the raised ailerons and thus 

significantly improve its effect in the braking phase.

A setting of the “Elevat. curve” mixer is then only 

necessary if the flight speed of the model changes 

too dramatically on actuation of the brake system. In 

any case, you should try out the setting at a sufficient 

and readjust, if necessary, whereby you should focus 

less on the flight position than on maintaining the 

“normal” flight speed of the model. Otherwise there 

is the risk that the model plunges when engaging 

the brake system, because it became too slow in the 

meantime:

Input

Output

Point 1

–19%

–6%

–7%

Brake

normal

EL

Curve on

After exiting the “Brake settings”, the “Aileron differ-
286 Programming examples - Winged models

entiation can be set:

This serves to eliminate the negative torque. The 

downward deflected aileron normally generates a 

higher level of resistance during the flight than when 

deflected upward the same distance, whereby the 

model is pulled to the “wrong” side. In order to prevent 

this, with the input of a differentiation of the travel of 

the respective servo deflected downward is reduced 

accordingly. A value between 20 and 40%, in this 

case, seldom arises, however, the “correct” setting 

must be sought.

The option “AI  RU” (aileron  rudder) also serves 

a similar purpose, as well as for the comfortable control of a model. A value of about 50% is a practical 

initial value. However, this function should be made 

switchable with the assignment of a switch if you 

ever have aerobatic flight ambitions. (The author, for 

example, switches off this mixer “automatically” when 

switching to the “Speed” flight phase, in which he assigns both options to the same switch accordingly.)

The last option in the »Wing mixers« menu, the 

“El  Fl” mixer, is not yet of interest at the moment.

If the model-specific settings were made thus far, the 

initial start can be considered. If course, at first you 

should perform a “dry run”, meaning you should carefully check all the settings once again on the ground. 

Incorrect programming can damage more than just 

the model! In case of doubt, ask the advice of an 

experienced model pilot.

If you should find during the testing that one or multiple settings must be made for the adjustment of 

the rudder effects to your control habits, the control 

throws are too long or short on the whole, you should 

adjust this in the ... 

»Dual Rate / Expo« (page 130)

... to your own requirements and habits.

“Dual Rate” establishes a relationship between stick 

travel and control travel, see page 130:

100%

100%

100%

Ail

Ele

Rud

DUAL

–––

–––

–––

SEL

On the other hand, if the maximum throws are OK 

and only the reactions around the center position are 

to strong for more sensitive controls, then the “exponential” functions comes (additionally) into play: 

0%

0%

0%

EXPO

–––

–––

–––

SEL

Ail

Ele

Rud

If a switch is also assigned, switching can even take 

place between two dual-rate/expo settings during the 

flight.

This is similar for the option ...

»Channel 1 curve« (page 138)

Input

Output

Point ?

0%

0%

0%

Ch1 curve

Curve off

With this option, one or multiple points of the control 

curve of the throttle/brake stick can be influenced in 

such a way that a pleasant or even purposeful behavior is guaranteed.

An example of this would be the “dead” travel of spoilers. The flaps first pass through this after a certain 

“idle travel” of the brake stick from the wing. With a 

corresponding “bending” of the curve, the “dead’ travel 

is covered more quickly. The spoilers come out from 

the wing earlier and then the remaining travel can be 

controlled with greater sensitivity. (This also applies 

for the control of a motor in the same manner, which 

can be controlled through C1 as an alternative.)

Finally, the receiver’s behavior in the event of a failure 

should certainly be established in the menu...

»Fail safe« (page 220)

Fail-safe adjust

Pos

hold

1 2 3 4 5 6

 DELAY : 0.25s STO

... because “doing nothing” is the worst thing which 

can be done for a winged model.

In the transmitter’s home position, “Hold” is specified and “Hold” means that the receiver continuously 

sends the last correctly recognized control impulse to 

the servos in the model. In the best case scenario the 

model flies straight ahead for an indefinite amount of 

time and then hopefully “lands” somewhere without 

causing significant damage! However, if something 

like this happens in the wrong place at the wrong 

time, the model may become uncontrollable and “tear” 

across the flight field completely out of control, putting 
Programming examples - Winged models 287

the pilot and/or spectators at risk. Therefore, it would 

obviously be beneficial to program the function “Motor 

off” at the very least, in order to prevent such risks.

With electro gliders, on the other hand, the fail-safe 

setting “motor off” can also be used, for example, for 

outlanding, to reliably stop the motor or its propeller 

by immediately switching off the transmitter after the 

landing.

The author usually prefers a “braking finish” within 

eyeshot to floating off “somewhere else”.
288 Programming examples - Winged models

Integration of an electric drive into the model programming

An electric drive can be controlled in different ways: 

The simplest method to integrate one such drive into 

the model programming is with the use of a throttle/

brake stick (C1). However, since this is already specified for the brake system in the course of the model 

programming described above, either the switchable 

solution described beginning on page 291 or even 

the use of an alternative control is possible. 

As a suitable alternative, one of the two 3-position 

switches would be better than one of the proportionals controls. However, either one of the two side 

proportional rotary controls are also well suited to activation of a motor without having to let go of the stick. 

An alternative would also be one of the two-stage 

switches. Basically, whatever switch is used should be 

located where it is within convenient reach.

Before we turn to the individual examples, it is important must be noted that all inputs in the »Control 

adjust« menu can be selectively programmed as 

flight-phase specific (“PH” in the “type” column) or 

model memory specific (“GL” in the “type” column)!

However, since the drive should usually be available 

depending on the current flight phase, we recommend leaving the standard default “GL” (“global”) in 

the “type” column which your are using.

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8 –––

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

fr

SEL

A common option in the following examples 1 ... 5, 

the automatic tracking of the elevator trimming in the 

power flight, should also be mentioned at the beginning of this section:

If it becomes apparent after the initial power flights 

that the model must be continuously corrected with 

the elevator while the motor is switched on, this situation can be corrected by setting a free mixer and 

adjusting it accordingly. For this purpose, switch to the 

menu ...

»Free mixers« (beginning on page 205)

... and program one of the linear mixers, M1 ... 8, or 

even one of the curve mixers, C9 ... 12, from “channel controlling the motor” according to “EL”, for example:

ty fr to

M1

M2

M3

8 EL

M4

M5 ?? ??

?? ??

?? ??

?? ??

On its second screen page, the required–usually 

low–correction value is entered:

L.Mix 1

–100%

Offset

SYM ASY

8 EL

Mix input

+4% +4%

Note:

The adjustment of a curve mixer is described in 

detail in the section »Channel 1 curve« starting on 

page 138.

Example 1

Proportional control usage

If one of these controls is used, the connection is very 

simple. Only the motor controller (speed control) has 

to be connected to a free servo connection 5 ... 12 

max. of the receiver. 

Bear in mind that, depending on the model type and 

number of aileron and flap servos, the output 2 + 5 

and may be 6 + 7 are already linked. 

Therefore connect your speed controller to the next 

free input and assign the selected input–for example, 

“In8”–to one of the transmitter’s proportional controls, 

for example the left-side proportional rotary control. 

This is done in the menu ...

»Control adjust« (page 118)

Select the desired line with the  selection keys of 

the left or right four-way button. A tap on the center 

SET key of the right four-way button will activate the 

“Control assignment”. Now move the selected proportional control. After a short time, an entry, e.g. “Lv2”, 

will appear in the inverse video field:

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8 –––

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

Lv2

SEL

However, since propulsion must usually be available, 

independent of the current flight phase, leave the 

default value “GL” in the “type” column–as already 

mentioned earlier in this section.
Programming examples - Winged models 289

Note:

No delay is entered on the “OFF” side, so that the 

drive can be switched off instantly at any time. This 

does not additionally stress the drive, because it 

merely “runs down”.

The adjustment of the appropriate control travel and 

directions for the motor control (speed control) is normally carried out in the »Control adjust« menu in the 

“- trv +” column. Alternatively, these settings can also 

be made in the menu ... 

»Servo adjustment« (page 112)

S4

S5

S6

Rev cent trv +

0%

0%

0%

100% 100%

100% 100%

100% 100%

0%

0%

100% 100%

100% 100%

S7

S8

Example 2

2-way switch usage

This variant realizes a purely ON/OFF function.

On the receiver side, either a simple electronic switch 

or–if a gentle motor start-up, for example, is desired–an appropriate motor control (speed control) is 

required.

With the exception of assigning a different operating 

element, the settings required for this are essentially the same as those described under Example 1. 

Therefore, the same comments and recommendations also apply. 

Apart from the infinitely variable motor control under 

Example 1 and the two-stage motor control in this 

example, the selection of the two transmitter control 

types only has an effect on the type of timer control, 

see page 294.

Only the nature of the assignment and representation 

of the selected switch in the display of the menu ...

If you need to adjust the travels to suit the speed 

controller, use one of the arrow buttons to move right 

to the “- Travel +” column, following the right-pointing 

triangle at bottom left:

In5

– travel +

+100%

+100%

+100%

+100%

In6

In7

In8

+100%

+100%

+100%

+100%

This fields of this column can be use to set the travel 

required, even asymmetric if necessary.

A simultaneous tap on the  keys of the left fourway button now will switch over to the »Servo display« where the selected proportional control can be 

activated to watch the bars for channel 8 “wander” 

from one side to the other and back.

However, if the proportional control is moved too 

fast–in practice–the resulting sudden motor acceleration can briefly strain the entire drive train (too 

much). In this case, be sure to enter a value in the 

“- time +” column to counteract such a condition.

Therefore, using one of the selection keys, switch 

one column to the right, to the “- time +” column then 

move the selected control close to “full throttle” so the 

marker frame is only placed around one value field. 

Now enter a value of at least 1s ...

In5

– time +

0.0s

0.0s

0.0s

1.1s

In6

In7

In8

0.0s

0.0s

0.0s

0.0s

... with which a movement of the proportional control 

in the “ON” direction which is too fast is processes 

move gently, and you can check immediately this by 

switching to the »Servo display«.

»Control adjust« (page 118)

... differ. As in example 1, change over to the line of 

a free input, activate the “Switch assignment” in the 

second column as described on page 68, then 

move the selected switch, in this case for example 

switch 2, from the desired motor OFF position in the 

direction of motor ON:

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8 –––

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

2

Here again–as already mentioned earlier in this 

section–leave the standard default “GL” in the “Typ” 

column.

The setting of the appropriate control travel for the 

motor control (speed control) is made in the “- trv +”

column. If the motor should up gently with the use of 

a motor control (speed control), an appropriate delay 

time can be set–as described in Example 1–in the 

“- time +” column:

In5

– time +

0.0s

0.0s

0.0s

1.1s

In6

In7

In8

0.0s

0.0s

0.0s

0.0s

All other settings–as already mentioned earlier in the 

example–are made analogous to Example 1. Therefore, the same comments and recommendations also 

apply.

Note:

No delay is entered on the “OFF” side, so that the 

drive can be switched off instantly at any time. This 

does not additionally stress the drive, because it 
290 Programming examples - Winged models

merely “runs down”.

Example 3

3-way switch usage

This variant realizes a three-stage speed setting, 

such as Motor OFF, “half” and full power.

A corresponding motor control (speed control) is 

required on the receiver side.

The required settings are basically the same as those 

described under Example 1 and 2. Therefore, the 

same comments and recommendations also apply.

Apart from the infinitely variable motor control under 

Example 1 and the three-stage motor control in this 

example, the selection of the operating element only 

has an effect on the type of clock control, see page 

294, and the nature of the assignment.

Here again–as already mentioned earlier in this 

section–leave the standard default “GL” in the “type” 

column.

Put the desired 3-way switch into its middle position then activate the “Switch assignment” above the 

column with the switch symbol, as described on page 

68. Now put the selected 3-way switch forward, out 

of its middle position:

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8 –––

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

3

Now put the activated switch from its forward position 

back into its middle position.

Now move the marker frame to the left and into the 

column above the column now labeled with a second 

switch symbol instead of the previous label SEL. 

Reactivate the “Switch assignment” for this column 

then move the 3-way switch out of its middle position 

toward the rear:

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

2 3

The setting of the appropriate control travel for the 

motor control (speed control) is made in the “- trv +” 

column. The motor should rev up gently with a motor 

control (speed control), to this end a suitable delay 

time can be set–as described in examples 1 and 

2–in the “- time +” column:

All other settings–as already mentioned earlier in the 

example–are made analogous to Example 1. Therefore, the same comments and recommendations also 

apply.

Note:

By shifting the neutral position and subsequent adjustment of travel, the “half throttle position” can be 

influenced in the »Control adjust« menu by reducing travel from the offset value on the side to which 

the neutral point has been shifted and adding it to 

the other side. For example, an offset value of -20% 

results in +80% on the minus side of the travel setting 

and +120% on the plus side, and vice versa. 
Programming examples - Winged models 291

Tail type

Motor at C1

Normal

Aile/flaps 2AIL

Model type

Brake Off –90% In 1

SEL

front

STO

This idle path ensures that all brake settings remain 

at “neutral”, even with minor deviations from the limit 

of the brake flap control. At the same time, the effective control path is automatically spread to 100%.

For this reason, in the next step it must be ensured 

that the influence of the C1 stick on the motor can be 

influenced. For this purpose, switch to the menu ...

»Phase settings« (page 152)

... and assign a meaningful name, such as “Normal”, 

from the list for “Phase 1” after activation of the selection field in the “Name” column. The asterisk in the 

second column indicates which phase is currently active. As long as no phase switch has been assigned, 

this is always Phase 1. “Phase 2” can be given, appropriate to the example, the name «Landing».

In the “ph.Tim” column you can assign a so-called 

flight phase timer for the measurement of the motor 

running time and/or the gliding times as necessary for 

each phase. You could, for example, assign one of the 

“Timers 1 ... 3” to the “Normal” flight phase in order to 

measure the total motor runtime via the C1 stick:

Pha1

Pha2

Pha3

Name ph.Tim

Pha4

Pha5

normal

–

–

–

–

 Clk 1

Landing

Then the timer is controlled through a corresponding 

control switch to be defined on the C1 stick. As soon 

as you switch to the “Landing” flight phase, this flight 

»Model type« (page 104)

Here you first specify in the “motor” line whether the 

throttle minimum position (= Motor “OFF” position) 

should be at the “front” or “back”–as already discussed: In the following programming example, “Motor OFF” and “Brake OFF” are combined at “front”:

Tail type

Motor at C1

Normal

Aile/flaps 1AIL

Model type

Brake Off +100% In 1

SEL

front

Note:

With the selection of “Throttle min front/back” the 

trimming will then only have an effect in the “idle” 

direction of the motor and is not the same as with the 

“none” entry, having the same effect at every position 

of the C1 stick. Since the C1 trimming is not normally 

used with electric drives, however, this has no further 

relevance.

You adjust the “Tail type” according to your model, in 

this case “normal”.

In the “Aileron/flaps” line you enter the correct number 

of aileron and flap servos–in this example “2 AIL”.

In the last line you leave the standard entries for the 

selection of “Brake retracted = front”. On the other 

hand, if the preference is for “Brake retracted = back”, 

select the “Brake offset” line and define the offset 

point–as described on page 105–as “back”. In the 

process, if the offset point is not placed completely 

at the end of the control travel, the remainder of the 

travel is “idle” up to this limit.

Control E-motor and crow alternately with C1 stick

Example 4

Before we discuss the programming of this fourth 

example or turn to the expansion of the previously 

described basic programming, a few words should be 

said about the position of the throttle/brake stick with 

“Motor OFF” or “Brake OFF”. Normally the C1 control stick is moved forward for the throttle control and 

backward for the extension of the brake. However, if 

for this type of “traditional” assignment, for example, a 

switchover of the brake system is to take place for the 

“Motor OFF” condition (stick “back”) then a switchover 

to “full brake” would take place immediately after the 

pre-set switchover time specified in the »Phase settings« menu, and the opposite will take place when 

“brakes retracted” is switched over to propulsion 

causing the motor to switch over to “full power” within 

this time range ...

A “glider pilot” can make the best of this “Emergency”–normally with “brake retracted = front”–by 

switching to motor “ON” only if necessary so that 

power decreases, if applicable (and hopefully not 

forgetting to push the C1 stick “forward” again when 

switching back). A typical “motor pilot”, on the other 

hand, operates in the opposite manner, only switching 

to the brake if necessary, etc. You can also combine 

the “Zero point” of both systems to avoid confusion, 

whereby a “glider pilot” would tend prefer the “front” 

and a “motor pilot”, on the other hand”, would likely 

prefer the “rear”. 

Whichever the case may be, the mc-16 HoTT and 

mc-20 HoTT transmitters permits both variants. 

In the following text, however, the combination of the 

two “OFF” positions to “front” is assumed. However, 

if you have a different preference, it is not a problem: 

The only difference from the described version lies in 

the logical selection of “Throttle min rear/front” and, 

if applicable, of a corresponding brake offset in the 

menu ...
292 Programming examples - Winged models

»Brake settings« (page 183)

Elevat curve

Brake settings

AILE

Crow

D.red 0%

Landing

0%

... of the »Wing mixers« menu, set the desired throw 

of the ailerons by actuation of the C1 stick (“brake”) 

upward. Then, if applicable, switch to the “FL” column 

in order to specify the desired through of the flaps 

with C1 actuation downward (hidden in the figure 

above). This flap position is referred to as “Crow position” or “Butterfly; see also page 183.

In the line “D.red” (differentiation reduction), enter a 

value which corresponds to the value entered or want 

to enter on the first page of the »Wing mixers« menu 

in the “Aile.diff.” line.

With the “Elevat curve” mixer the normally occurring 

“Upward tilting” of the model on the raising of the 

ailerons can be automatically suppressed. The suitable correction values for the respective value must 

be tested out through flight. Set this mixer so that the 

flight speed of the model does not change too much 

with the brake system extended in comparison with 

the “normal” flight speed. Otherwise, there is the risk, 

among other things, that the model plunges when the 

brake system is retracted, e.g. for the extension of a 

landing approach which is too short.

If everything is correctly set so far, only the motor 

is controlled with the C1 stick in the “Normal” flight 

phase, whereas this should be switched off in the 

flight phase “landing” (Servo 1 in »Servo display« 

independent of “Throttle min front/rear” to -100% 

or adequately for a servo travel setting deviating by 

100%, if necessary). In this flight phase the C1 stick 

then only controls the raising of the ailerons and, if 

applicable, the lowering of the flaps with the neutral 

point in the C1 control position selected per offset.

»Phase assignment« (page 158)

Select the switch symbol under “C” with one of the selection keys. Following a brief tap on the center SET

key of the right four-way button, actuate the desired 

switch, e.g “2”.

Phase assignment

A B C D E F 

1 normal

2

prior combi

Both switch positions, in other words ON (I) and 

OFF ( ), are initially assigned at the bottom right of 

the display to phase «1 Normal». Select this value 

field with one of the selection keys then activate the 

phase selection list that was set up in the »Phase 

settings« menu with a brief tap on the center SET

key of the right four-way button. For example, you 

name the phase for the front switch position “normal” 

and “landing” for the rear position (or vice versa):

Phase assignment

A B C D E F 

2

prior combi

2Landing

These phase names then appear in all flight-phase 

dependent menus and, of course, also in the base 

screen of the transmitter.

Now switch to the «Landing» flight phase and in the 

“Crow” line of the sub-menu ...

phase timer is automatically stopped and hidden in 

the base screen. More about this can be found on 

page 166.

Now move the marker frame over the “ph.Tim” column to the “Motor” column to the right. Here you 

can decide with “yes/no” in which phase the motor 

is controlled by the throttle/brake stick and the brake 

system to be adjusted in the “Brake settings” submenu of the »Wing mixers« menu should be shut off 

(= “yes”) and vice versa (= “no”):

Pha1

Pha2

Pha3

Name motor

Pha4

Pha5

normal

–

–

–

–

 yes

Landing no

Now move the marker frame once more to the right 

and enter an appropriate switching time after activation of the value field of the “Sw.Time” column; for 

example:

Pha1

Pha2

Pha3

Name Sw.time

Pha4

Pha5

normal

–

–

–

–



Landing

1.1s

0.1s

0.1s

0.1s

1.1s

Then you must assigned these two flight phases to 

a switch with which you can switch between the two 

flight phases during the flight. In this case, a single 

switch is sufficient. It should be easy to reach, however, so that you can still switch between “motor” and 

“brake” during a landing approach, for example, without having to release a stick.

The assignment of the selected switch takes place in 

the menu ...
Programming examples - Winged models 293

C1-stick switchable between E-motor and spoiler

Example 5

If, contrary to the assumptions of the preceding Example 4, the model has additional spoilers or only 

spoilers, they can be incorporated into the control of 

the model by means of the following programming.

Do this by programming the menus »Model type«, 

»Phase settings« and »Phase assignment« in the 

same manner as described under Example 4. The 

settings described there in the “Brake settings” submenu of the »Wing mixers« menu are only then relevant if an additional crow system is to be employed 

in parallel with the spoilers.

With the settings described under Example 4, the 

control of the E-motor and, if applicable, that of a 

crow system will function as usual. Only the control 

of a spoiler connected to Output 8, for example, must 

additionally be programmed. For this purpose, switch 

to the menu ...

»Control adjust« (page 118)

... and switch into the «normal» flight phase.

Now use the selection keys to switch to the left into 

the “typ” column to set the parameter in this line, e.g. 

“In8” from “GL(obal)” to “PH(ase)”, so that the settings 

too follow become effective on a flight-phase specific 

basis.

In5

offset

0%

0%

0%

–––

0%

In6

In7

In8 –––

–––

–––

GL

GL

GL

typ

normal

fr

fr

fr

fr

SEL

PH

Afterward, switch to the “Offset” column and, following 

activation of the value field with a brief tap on the SET

key of the right four-way button, change the offset value for this Input 8 value field now displayed in inverse 

video until the spoilers are again “retracted”, e.g.:

In5

offset

0%

0%

0%

–––

In6

In7

In8 –––

–––

–––

GL

GL

GL

typ

normal

fr

fr

fr

fr

SEL

PH –95%

Confirm this setting with a brief tap on the center 

ESC key of the left or the center SET key of the right 

four-way button then switch to the left into the column 

above SEL. Now switch to the flight phase «Landing» then briefly tap on the center SET key of the 

right four-way button. The display shows the window 

...

In5

offset

0%

0%

0%

–––

In6

In7

In8

GL

GL

typ

Landing

fr

fr

SEL

95%

Move desired

control adj.

Now move the C1 stick. As soon as this is recognized, “Cn1” will appear in the display instead of “fr”:

In5

offset

0%

0%

0%

–––

In6

In7

In8 –––

–––

–––

GL

GL

GL

typ

Landing

fr

fr

fr

Cn1

SEL

PH –95%

Leave the offset value in this flight phase at “0%”. It 

may be necessary to change the leading symbol of 

the travel setting to reverse the control direction. Do 

this by switching the travel setting from +100% to 

-100% in the “trv” column.

Now we are practically finished. Check the programming in the »Servo display« menu, which you can 

reach from the base screen of the transmitter as well 

as nearly every other menu position with a simultaneous tap on  keys of the left four-way button. 

You will discover that “Servo 1” (motor control) is 

controlled in the “Normal” phase and in the “landing” 

phase only the spoiler is controlled at “Servo 8” and, 

if applicable the aileron and flap servos–just as we 

intended.
294 Programming examples - Timer confirmation with control or switch

SEL

0%

0%

0%

C1

C2

C3

C4 –––

Control switch

–85%

STO

–––

–––

Cn1 –––

SEL

Note:

Do not, however, set a switching point at a transmitter 

control’s travel end-point, since this makes reliable 

switching impossible.

In order to assign the control switch you just created 

to the desired timer, switch to the menu ...

»Timers (general)« (page 162)

... and select the line “Top” with the selection keys. 

This is the standard line assigned to the stopwatch. 

In this line, move the marker frame over the “Timer” 

column to the right, to the column above the switch 

symbol, using the appropriate selection key of the left 

or right four-way button. Now tap twice on the center 

SET key of the right four-way button: The first tap will 

activate the “Switch assignment”, the second tap will 

call up the list of “expanded switches”:

Model time

Alarm

0:34h –––

SEL

Control/Logic/fix sw

C2 C3 C4 FX

FXi L1 L2 L3 L4

C1

Now select the previously programmed control switch, 

C1 in the example, and assign it to the timer with a 

brief tap on the center SET key of the right four-way 

button:

Model time

Batt. time

Top :

Centr:Flight

Alarm

0:34h –––

1:23h

0s

0s

Stop C1

–––

SEL

The timer in the base screen now starts with movement of the C1 stick toward full throttle and stops if 

you pull the C1 stick back over the switching point. 

Example 1 of the preceding pages

If you have decided to continue with the model programming described on the previous pages in Example 1 on page 288, first switch to the menu ...

»Control switch« (page 145)

... and select the line of a control switch which has 

not been assigned yet with the selection keys. After 

activation of the control assignment with a brief tap 

on the center SET key of the right four-way button, 

the following window will appear:

SEL

0%

C1

C2

C3

C4 –––

Control switch

STO

–––

–––

–––

SEL

Move desired

control adj.

Now simply move the respective proportional control, 

e.g. the left side proportional rotary control from its 

motor “OFF” position toward the motor “ON” direction.

Thereafter, change to the column above STO by using the appropriate selection key, move the selected 

control near its motor “OFF” position then set the 

switch-point at the selected position with a brief tap 

on the center SET key of the right four-way button. 

The switch status is shown to the right of the control 

number:

Examples 4 and 5 of the preceding pages

If model programming is to be continued for Example 4, page 291, or Example 5, page 293, as 

described on previous pages or, completely independent of this example programming, the C1 stick 

(throttle/brake stick) is to be used for power regulation, then a control switch can be used to automatically start and stop the stopwatch. For this purpose, 

first switch to the menu ...

»Control switch« (page 145)

... and select the line of a control switch which has 

not been assigned yet with the selection keys. After 

activation of the control assignment with a brief tap 

on the center SET key of the right four-way button, 

the following window will appear:

SEL

0%

C1

C2

C3

C4 –––

Control switch

STO

–––

–––

–––

SEL

Move desired

control adj.

Now simply move the C1 stick (throttle/brake stick) 

from the motor “OFF” position in the motor “ON” direction.

Thereafter, change to the column above STO by 

using the appropriate selection key, move the C1 

stick close to its motor “OFF” position then set the 

switch-point at the selected position with a brief tap 

on the center SET key of the right four-way button. 

The switch’s state will be displayed at the right of the 

control number, e.g.:

Timer confirmation with control or switch
Programming examples - Timer confirmation with control or switch 295

SEL

0%

0%

0%

C1

C2

C3

C4 –––

Control switch

–85%

STO

–––

–––

Lv2 –––

SEL

Note:

Do not, however, set a switching point at a transmitter 

control’s travel end-point, since this makes reliable 

switching impossible.

C1 used in the example here should be “closed” 

in the “full throttle” direction and “open” below the 

switching point. 

Now switch to the menu ...

»Timers (general)« (page 162)

... and select the line “Top” with the selection keys. 

This is the standard line assigned to the stopwatch. 

In this line, move the marker frame over the “Timer” 

column to the right, to the column above the switch 

symbol, using the appropriate selection key of the left 

or right four-way button. Now tap twice on the center 

SET key of the right touch: The first tap will activate 

the “Switch assignment”, the second tap will call up 

the list of “expanded switches”:

Model time

Alarm

0:34h –––

SEL

Control/Logic/fix sw

C2 C3 C4 FX

FXi L1 L2 L3 L4

C1

Now select the previously programmed control switch 

“C1” then tap on the center SET key of the right 

touch pad:

Model time

Batt. time

Top :

Centr:Flight

Alarm

0:34h –––

1:23h

0s

0s

Stop C1

–––

SEL

The stopwatch in the basic display now starts with 

movement of the proportional rotary control toward 

full throttle and stops if it is turned back again over 

the switch-point. 

Examples 2 and 3 of the preceding pages

If you control your motor with a switch, on the other 

hand, you do not need the control switch described 

above. It is completely sufficient if you assign the 

same switch to the timer, so that it also begins to run 

when you switch on the motor.

Tip:

If the motor run time for an E-model is limited by the 

battery capacity, you can have the stopwatch count 

down. Enter the maximum permissible motor run time 

in the “Timer” column, e.g. “5min”, and shortly before 

expiration of permissible time, e.g. “30s” before, have 

the transmitter issue an acoustic warning signal:

Model time

Batt. time

Top :

Centr:Flight

Timer

12:34h –––

1:23h

0:00

Stop 5:00

Alarm

0:34h –––

1:23h

0s

15

–––

SEL

30s

Model time

Batt. time

Top :

Centr:Flight

Stop
296 Programming examples - Parallel operating servos

Parallel operating servos

A second servo running in parallel is often required, 

such as when brake flaps or spoilers installed in the 

wings or the left and right elevator or a double fin 

should be actuated by a servo or a large rudder flap 

should be simultaneously controlled by two servos 

due to high throw forces.

In principle, this task could also be solved by connecting the servos together on the model side using Ycable. However, the disadvantage here is that servos 

combined in this manner can no longer be adjusted 

individually and separately from the transmitter–thus 

negating the potential for finely tuning respective 

servos to one another with a computerized remote 

control system. A similar situation is given for the socalled “Channel mapping” feature of the »Telemetry« 

menu. Here too there are certain limitations involved 

when compared to the transmitter’s adjustment possibilities.

The first example, therefore, describes the coupling of 

two brake or spoiler servos, the second describes the 

operation of two or more throttle servos and the third 

describes the coupling of two elevator servos.

The “two rudder servos” example on the next page 

describes the coupling of two rudder servos, whereas 

Variant 1 is preferable for applications of this type 

because this solution is easier and quicker to program, using one of the »Dual mixer« menu, which is 

available as standard on the mc-20 HoTT transmitter only, but which can be unlocked on the mc-16

HoTT transmitter as an extra-cost option. In contrast, 

the second variant, also described on the next page, 

additionally permits asymmetric and/or non-linear 

curves through use of the »Free mixer« menu. 

Two brake or spoiler servos

In a situation where there is one installed servo for 

operation of brake flaps and/or spoilers in each wing 

half then the pre-set linear control characteristics for 

the »Channel 1 curve« menu should remain unchanged.

Then connect one of the two servos to Output 1, provided for this purpose by standard, and the second 

to an arbitrary free receiver connection 5 ... 12 max., 

such as Output “8”. Subsequently switch to the menu 

...

»Control adjust« (page 118)

... and, using the selection keys, assign “Control 1” in 

the Input 8 line :

In5

offset

0%

0%

0%

–––

In6

In7

In8 –––

–––

–––

GL

GL

GL

typ

fr

fr

fr

Cn1

SEL

GL 0%

Since the spoiler on Output 1 can normally only be 

operated on a flight-phase independent basis, it is 

strongly recommended that the “Typ” column for the 

input used is left at its “GL” default setting.

Also the remaining values should be left at their 

default settings. If necessary, carry out the required 

servo travel adjustments in the »Servo adjustment« 

menu. There you can also adjust the travel of servo 

1 and 8 to one another, if necessary. 

Multiple-motor aircraft

As described above, a model can also be operated 

with two or more motors.

The first throttle servo and/or the first motor control is 

connected as usual to (receiver) Output 1 and each 

additional throttle servo and/or each additional motor control is connected to a free (receiver) Output 6 

... 12 max. The inputs of respective assigned control 

channels are then each assigned to Control 1; for 

example:

In8

offset

0%

0%

0%

–––

In9

In10

In11 –––

–––

–––

GL

GL

GL

typ

Cn1

SEL

GL 0%

Cn1

Cn1

Cn1

The remaining values should be left at the default 

settings. If you need to adjust servo travels, it is better to use the »Servo adjustment« menu, where you 

can adjust the settings as required without having to 

switch menus.

Important notice:

Since the motor control unit should be available 

regardless of a currently active flight phase, make 

sure to leave the standard default “GL” in the “Type” 

column.

Two elevator servos

Two elevator servos should be switched in parallel. 

According to the receiver assignment plan, see page 

73, the receiver output 8 is intended for the connection of the second elevator servo.

This would be taken into account on the software side 

in the pre-configuration of a corresponding mixer. You 

can find this in the ...

»Model type« (page 104)

In this menu, switch to the “Tail type” line using the 
Programming examples - Parallel operating servos 297

selection keys, activate the value field with a brief tap 

on the center SET key of the right key pad then select 

the entry “2ELSv3+8”:

None

1AIL

+100%

SEL

Tail type 2ELSv3+8

Motor at C1

Aile/flaps

Model type

Brake Off In 1

Then do the fine-tuning for travel of the two servos “in 

the now familiar manner” in the »Servo adjustment« 

menu.

Two rudders

We want to switch two rudders “in parallel”. The second rudder is located at the free receiver output 8.

Variant 1

In the following menu, which is available as standard 

on the mc-20 HoTT transmitter only, but can be 

unlocked on the mc-16 HoTT transmitter as an 

extra-cost option ...

»Dual mixer« (page 218)

... select one of the dual-mixers and enter “8” and 

“RU” in its left and center value fields, as shown in the 

figure:

Diff.

Dual mixer

Mixer1

Mixer2

 8

Mixer3

Mixer4

?? ??

?? ??

?? ??

0%

0%

0%

0%

RU

The same deflection “ ”, which would take place 

through “Input 8” must not have an effect here. Therefore, you should make absolutely sure in the ...

»Control adjust« (page 118)

In5

offset

0%

0%

0%

–––

In6

In7

In8 –––

–––

–––

GL

GL

GL

typ

fr

fr

fr

fr

SEL

GL 0%

... menu, that “Input 8” “GL(obal)” is set to “free” so 

the control function is separate from the control channel over all flight phases.

Alternatively you can set Input 8 to “no transmitter 

control” for all flight phases in the »Mix-only channel« menu, which is available as standard on the 

mc-20 HoTT transmitter only, by setting channel 8 

to “Mix-only”.

MIX–only channel

only

normal

7 8 9 10 11 12

Note:

This menu can be unlocked on the mc-16 HoTT 

transmitter as an extra-cost option. 

Variant 2

This variant uses the ...

»Free mixers« (beginning on page 205)

... menu to set a mixer “Tr RU  8”. In the “ty(pe)” 

column, select the setting “Tr” so that the rudder trimming affects both rudder servos:

ty fr to

M1

M2

M3

RU 8

?? ??

M4

M5

?? ??

?? ??

?? ??

Tr

Afterwards, switch to the graphic screen and set a 

symmetric mix of +100%:

L.Mix 1

0%

Offset

SYM ASY

RU 8

Mix input

+100% +100%

Here too, “Input 8” should also be programmed–if 

applicable, for all flight phases–to “free” by way of 

the »Control adjust« menu. However, it is simpler 

to separate control function “8” from control channel 

“8” using the »Mix-only channel« menu–see page 

216. This applies to all flight phases, and is available 

as standard on the mc-20 HoTT transmitter only. 

MIX–only channel

only

normal

7 8 9 10 11 12
298 Programming examples - Using flight phases

Using flight phases

Up to 7 different flight phases (flight conditions) can 

be programmed with settings independent of one 

another within each the model memory.

Each of these flight phases can be called with a 

switch or a switch combination. This makes it possible to program different settings for various flight 

states, such as «Normal», «Thermal», «Speed», 

«Distance», etc., then make in-flight changeovers in 

a most convenient manner. However, with the flight 

phase programming you can also make slight modifications, e.g. of mixers, to try out by switching during 

the flight in order to find the optimal settings for each 

model more easily.

However, as owner of an mc-20 HoTT, or an mc16 HoTT with the »Stick mode« option unlocked, 

you really should think about the use of flight phases 

even before you start the actual programming procedure, and consider whether you wish to be able to 

adjust the digital trims for aileron, elevator and rudder 

separately in each flight phase–this is the default 

“PH(ase)” setting–or whether you want them to take 

effect in all flight phases–the alternative “GL(obal)” 

setting.

If you decide in favor of a phase-specific trimming of 

the rudder, for example, switch the menu ...

»Stick mode« (page 114)

... and change the standard “GL(obal)” default accordingly.

The same applies for the number of trimming steps in 

the “Tr” column:

Ch.1

Aile

Elev

Tr time +

4

4

4

0.0s

0.0s

0.0s

Rudd 4 0.0s

0.0s

0.0s

0.0s

0.0s

GL

PH

PH

GL

St

Example 1 ...

... continuing with the previous programming of 

an electric glider with 2 aileron servos.

AI

AI

EL

RU

Control of the electric motor is accomplished, independent of the C1 stick, with one of the two side 

proportional rotary controls or one of the two standard 3-way switches mounted into the switch panels. 

The motor’s speed control is connected to receiver 

output 8 as described on page 288 and continued 

in Examples 1 and 2. This is why “none” was selected for the “Motor on C1” line in the »Model type« 

menu. This not only causes the column “Motor” in the 

»Phase settings« menu to be unavailable but also 

allows all options to be available without restriction in 

the “Brake settings” sub-menu of the »Wing mixers« 

menu.

1st Step 

»Phase settings« (page 152)

Initially, one or more multiple flight phases are provided with a specific identification (“Name”) for the 

respective flight status. This identification has no influence on the programming of the transmitter; it only 

serves for an improved differentiation of the individual 

flight phases and is shown later in all flight-phase 

dependent menus and in the base screen.

The selection of the respective line, a name and the 

setting of the switchover time is done in the “usual” 

manner, with a tap on the appropriate key(s) of the 

two four-way buttons.

Pha1

Pha2

Pha3

Name ph.Tim

Pha4

Pha5



–

–

normal

Thermal

Speed

–

–

Launch

Note:

With the exception of Phase 1, which should always 

be assigned with the name “Normal” since it is always 

active, if the flight phases are deactivated, it is completely irrelevant which name is assigned to which 

phase!

In everyday use by a model pilot, three to a maximum 

of four flight phases are usually completely sufficient: 

• “Start” with the climb settings

• “Thermal” for “Flying high”,

• “Normal” for normal conditions and 

• “Speed” for high gear.

In the “Sw.time” column (switching time) ...

Pha1

Pha2

Pha3

Name Sw.time

Pha4

Pha5



+

+

normal

Thermal

Speed

+

–

3.0s

2.0s

4.0s

0.1s

Launch 1.0s

... a “blend-in” time can be established for the time in 

which a changeover from any other flight phase into 

this given flight-phase is to be accomplished in order 

to permit a “smooth” transition for different servo positions. Thus, an increased stress of the model under 

certain circumstances with a “hard” change of rudder or flap positions, for example, is prevented. The 

“Status” column shows you the currently active flight 

phase with an asterisk “”.
Programming examples - Using flight phases 299

2nd Step

In order to actually be able to switch between the individual flight phases, the assignment of one or multiple 

switches is necessary. Either one of the two threeway switches is ideally suited for switching between 

up to three flight phases.

Each of the two switch end positions starting from the 

center position will be assigned to one of the flight 

phase switches A ... F. The assignment of the switch 

takes place in the menu ...

»Phase assignment« (page 158)

First select “C” with the marker frame. Then briefly 

tap on the center SET key of the right four-way button 

and move the switch from its center position to one of 

its end-positions, for example, forward:

Phase assignment

A B C D E F 

1 normal

6

prior combi

Move the switch back to the center position and then 

select “D”, and after activation of the switch assignment, move the switch to the other limit position, for 

example, back:

A B C D E F 

1 normal

6 5

Phase assignment

prior combi

Now the 3-way switch is programmed. 

Now and additional switch could be assigned for the 

“start” flight phase, if applicable. In this case under 

“A”, so that the “start” phase is always switched to 

from every other flight phase in parallel to the switching-on of the motor: 

A B C D E F 

1 normal

7 6 5

Phase assignment

prior combi

The given switch positions must then be assigned 

to respective flight phases (names). Although some 

flight phases have already been assigned to names, 

the phase name «1 Normal» will always initially appear at the right in the display; see the figures above.

First move the 3-way switch to one of its limit positions, for example to the back, and switch with the 

marker frame in the display down to the right to set 

the flight phase name. Briefly tap on the center SET

key of the right four-way button to activate the entry field then select the desired flight phase for this 

switch position, in this example «2 Thermal», with the 

selection keys:

A B C D E F 

6 5

2 Thermal

7

Phase assignment

prior combi

Proceed in the same manner for the other switch limit 

position, which is assigned the name “3 Speed”.

If applicable move Switch 2 and assign this switch 

combination the name “4 Start”.

A brief tap on the center ESC of the left four-way button or the center SET key of the right four-way button 

will complete the phase name assignment.

The flight-phase dependent model settings made 

before the assignment of phase switches are now in 

the flight phase «1 Normal». This is the phase which 

is called with the open «Start» switch in the center 

position of the 3-way switch.

3rd Step 

In order to not have to carry out all previously made 

settings for the model in the “new” flight phase from 

the ground up, we recommend first copying the already tested programming of the flight phase “Normal” to the other flight phases. This is carried out in 

the menu ...

»Copy / Erase« (page 80)

=>

=>

=>

=>

Copy flight phase =>

Erase model

Copy model–>model

Export to SD

Import from SD

Here, select the “Copy flight phase” menu item with 

the selection keys then briefly tap the center SET key 

of the right four-way button.

In the window which now appears, “Copy from 

phase”, “1 Normal” is selected ...

7

Copy from phase:

3

5

2

4

6

1 normal Thermal

Speed Launch

... and a subsequent brief tap on the center SET key 

of the right four-way button will change the display 

to “Copy to phase”. Now the target is to be selected 

(initially “2 Thermal”) and confirmed by another tap on 

the center SET key of the right four-way button. After 

confirmation of the subsequent safety query, all settings are copied according to the selection.

Proceed in the same manner with the other two 

phases (“1 Normal” to “3 Speed” and “1 Normal” to 

“4 Start”).
300 Programming examples - Using flight phases

4th Step 

Now three or four phases are programmed, the 

settings are also copied and there is even a “soft” 

transfer, but ... there are still no flight-phase specific 

settings.

Now, if applicable, in order to adapt the flap positions 

to the different requirements of the individual flight 

phases, in the menu ...

»Phase trim« (page 160)

Starting from the “normal” flight phase, switch to one 

of the other flight phases, whose name will appear at 

bottom left in accordance with the switch position; for 

example, the «Thermal» phase.

Now move the marker frame to the “ AIL ” column, and enter any settings for the ailerons which 

differ from the “normal” flight phase. Both positive and 

negative changes to travel are possible. Enter these 

settings separately for each flight phase, for example:

Normal



0%

ELEV

Launch

0%

AI

Launch

Thermal

Speed

0% –7%

0% +5%

0% –11%

5th Step 

Any necessary phase-specific trimming of the elevator is made with the help of the digital trimming of the 

elevator stick. This is true provided that you have left 

at least the elevator trim at the standard “Phase” setting in the »Stick mode« menu, which is available as 

standard on the mc-20 HoTT transmitter only, as 

shown at the start of the programming example.

Alternatively, these settings can also be made in the 

»Phase trim« menu ...

Normal



0%

ELEV

Launch

0%

AI

Launch

Thermal

Speed

0% –7%

0% +5%

0% –11%

6th Step 

In the menu ...

»Wing mixers« (beginning on page 170)

... the flight phase name of the newly activated flight 

phase appears at the bottom edge of the display. If 

the switch position is now changed, the name of the 

flight phase selected with the switch appears, but with 

the previously copied settings of the flight phase “Normal”. Here you set your values phase-specifically for 

the aileron differentiation, the share of the mixture of 

transverse to side, and if applicable, also a mixture of 

altitude to transverse. (The latter increases the agility 

over the transverse axis when “Turning”.)

Aile.diff.

Brake settings

AI 55%

Wing mixer

EL FL 0%0%

–––

–––

RU

Thermal

33%

Note:

The list of displayed options depends on the number 

of servos entered in the “Ailerons/flaps” line in the 

»Model type« menu, in this example “2 AIL”. 

Now switch to the sub-menu ...

Elevat curve

Brake settings

AILE

Crow

D.red

+30%

+33%

normal

... and enter the raised height of aileron brakes for 

individual flight phases in the “Crow” line.

With “D.red” (differentiation reduction), you should enter the value previously set in the aileron differentiation line in order to suppress it again while breaking.

In the “Elevat. curve” sub-menu, enter a correction 

value for the elevator, see page 160.

Note:

The “Brake settings” sub-menu of the »Wing mixers« menu is switched “off” when: for the “Motor at 

C1 front/rear” column of the »Model type« menu, 

page 104, AND for the “Motor” column of the 

»Phase settings« menu, page 152, a “yes” is entered for the currently active flight phase. Change the 

flight phase, if applicable.
For your notes 301
302 Programming examples - Using flight phases

Example 2

Glider with four flap wings, two large flaps and 

tow coupling

AI

FL

FL

AI

EL

RU

The following example is based on the assumption 

that you have already mechanically pre-adjusted the 

model and you have already ensured the correct 

deflection of all rudders or checked this again in the 

scope of this programming and made adjustments, 

if applicable, through servo switching at the receiver 

and/or through the »Servo adjustment« menu.

This programming example is based on an assignment of the receiver connections in accordance with 

the following diagram:

Receiver power supply

Free or aux. function

Free or aux. function

Aileron or left aileron

Elevator or left rudder / elevator

2nd airbrake servo or 2nd elevator or aux. function

Receiver power supply

1st airbrake servo

Right aileron

Flap or left flap

Right flap

Aero-tow release or free or aux. function

Free or aux. function

Rudder or right rudder / elevator

Begin with the new programming of the model in a 

free model memory location. 

Essentially, the »Base setup model« menu, beginning on page 86, is used to bind the receiver to the 

transmitter. Enter a model name and select or review 

the selection of appropriate stick mode. Later on this 

menu will also be used to activate the range test 

before the start of flight operations.

In the menu ...

»Model type« (page 104)

...leave “Motor at C1” at “none”, and the tail type at 

“normal”. However, set “2 AIL 2 FL” in the “Aileron/

flaps” line.

In the “Brake offset” line program or leave “In1”, because the two brake or spoiler servos connected to 1 

+ 8 will eventually be controlled by the C1 stick, in addition to the butterfly (crow) braking system which is 

set up in the “Brake settings” sub-menu of the »Wing 

mixer« menu:

Tail type

Motor at C1

Normal

Aile/flaps 2AIL2FL

Model type

Brake Off –90% In 1

SEL

None

STO

The setting in the “Brake Offset” value field defines 

the neutral position of all mixers specified by the 

“Brake settings” sub-menu of the »Wing mixers« 

menu. Place this neutral point at approx. +90%, 

insofar as the brake system should be retracted in the 

front position of the C1 stick. The remaining path between +90% and the full throw of the sticks, +100%, 

is then assigned as idle travel. This assures that the 

rudders or flaps addressed by the mixers of “Brake 

settings” remain in their “normal” positions even for 

slight deviations from the limit position of the C1 

control. At the same time, the effective control path is 

automatically spread to 100%.

In the menu ...

»Control adjust« (page 118)

... assign a switch, for example In 9, to operate the 

aero-tow coupling. In order for this switch to work 

independently of the flight phase, leave the standard 

default “GL” in the “type” column of this input. With 

“– Travel +” you can adjust the control travel for the 

switching of the switch:

In6

offset

0%

0%

0%

–––

0%

In7

In8

In9

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

––– 8

With a simultaneous tap on the  keys of the left 

four-way button, the setting can be checked in the 

»Servo display«.

Since the C1 control should actuate Servo 8 simultaneously with Servo 1, establish this link by way of the 

»Control adjust« menu.

For this reason, also switch to the line before and assign “Control 1” to Input 8.

In6

offset

0%

0%

0%

–––

0%

In7

In8

In9

–––

–––

GL

GL

GL

GL

typ

fr

fr

Cn1

––– 8

SEL

However, please note in this connection, that a nonlinear control curve programmed in the »Channel 1 

curve« menu has as little effect on this input as brake 

offset set to less than 100%, which you can check 

very easily in the »Servo display« menu. You can 

reach this from nearly every menu position with a simultaneous tap on the  keys of the left touch pad:

Using flight phases
Programming examples - Using flight phases 303

The travel, and if applicable also the direction of rotation, for spoiler servo 1 as well as the second spoiler 

servo connected to Output 8 can be adjusted in the 

menu ...

»Servo adjustment« (page 112)

S1

S2

S3

Rev cent trv +

0%

0%

0%

100% 100%

100% 100%

100% 100%

0%

0%

100% 100%

100% 100%

S4

S5

In the Multi-flap menu of the ...

»Wing mixers« (beginning on page 170)

... you now enter the first mixer values for the four 

wing flaps; for example:

fl.pos 0%

AILE

Diff.

Ail-tr

AI +100%

+100%

+50%

fl.pos 0%

FLAP

Diff.

Ail-tr

AI +66%

+66%

+33%

Note:

The parameter values shown here are model-dependent and must be determined by test flights.

In the line...

• AI

... determines the percentage share with which 

the two flap pairs “AI” and “FL” are to respond to 

aileron steering. Also check whether the ailerons 

are deflected in the right direction during the adjustment of the parameter values.

The adjustment range from ±150% enables the 

correct throw direction adjustment regardless of 

the direction of rotation of the servos.

• AI-Tr.

... determines the percentage share with which aileron trimming should effect the AI and FL.

• Diff.

... the entry to specify aileron steering differentiation for AI and FL flaps is made here. Refer to 

page 172 about the significance of differentiation.

The adjustment range from ±100% enables the 

correct differentiation direction adjustment regardless of the direction of rotation of the aileron and 

flap servos.

• FL-Pos.

The flight-phase specific positions for all camber 

flaps present on the given model are set in this 

line. In the process, you can determine the positions the flaps assume for each flight phase.

Note:

The values appearing in this line are based on 

the same data set as in the comparable position 

in the »Phase trim« menu, which is why changes 

always take effect in both directions.

• FL

Since all inputs in the »Control adjust« menu are 

set to “free” by default, neither the ailerons nor the 

camber flaps can be operated with these default 

settings. In this respect, you also leave the default 

entry here.

However, if flap positions are to be varied with a 

switch or proportional control by the position specified in the “FL-Pos.” line, assign the desired control to Input 6 in the »Control adjust« menu and 

set the desired reaction to the movement of the 

control selected for this purpose by way of a percentage in this line.

• EL  FL

This mixer induces a partial reaction from aileron 

(AI) and camber flaps (FL) during elevator activation.

The mixing direction is to be selected so that all 

flaps are deflected downward with the elevator 

pulled up and deflected upward with the elevator 

pushed down (= hydroplane). The mix proportion 

is normally in the low double-digit range.

• EL  FL Off. 

In the “EL  FL” line you may have entered a value to amplify the effect of elevator commands in 

tight turns and aerobatics. In this “EL  FL offset” line you can enter an Offset value which determines the “onset point” of the flaps when elevator is applied:

• If you leave the Offset value at 0%, the flaps 

follow the travel of the elevator from the neutral 

point of the elevator stick, at the percentage 

rate set in the “EL  FL” line.

• If you set an Offset value other than 0%, the 

flaps only follow the travel of the elevator in 

the “down” and “up” direction after the elevator command has reached the selected Offset 

point.

Now, within the »Wing mixers« menu, switch to the 

“Brake settings” ...

Elevat curve

Brake settings

Crow

D.red

+44%

+77%

+66%

+55%

Note:

The “Brake settings” menu is switched “off” if: “Motor 
304 Programming examples - Using flight phases

on C1 forward / back” in the »Model type« menu, 

page 104, AND the “Motor” column of the »Phase 

settings« menu, page 152, are set to “yes” for the 

currently active flight phase. Change the flight phase, 

if applicable.

• Crow

Further above in this text section, the C1 stick was 

set for brake system steering.

In this line you determine the share with which 

the AI and FL should be included on actuation of 

C1 in the manner that both ailerons are deflected 

“slightly” upward and both flaps are deflected as 

far downward as possible.

Now with a simultaneous tap on the  keys of 

the left four-way button, a change to the »Servo 

display« menu can be affected for observation of 

servo movements and, in particular, to ensure that 

no influence on the flaps takes place above the 

adjusted brake offset, e.g. +90% and beyond to 

the throw limit of the C1 control (“Idle travel” of the 

C1 stick).

• D.red

The value previously entered into the aileron differentiation line should also be entered in this “Differentiation reduction” line to fade this out during 

braking.

• Elevat. curve

This line is used for the entry of any correction factor that may be required for the elevator, see page 

185.

Insofar as necessary, again check all flap throws and, 

by way of the »Servo adjustment« menu, adjust the 

servo center, the servo travel and the travel limit.

It may also be time to start the initial flight testing, 

insofar as all global settings–that is to say, all flightphase independent settings–are completed.

Two additional flight phases are now to be set up 

below, each of which requires a somewhat different flap position.

Therefore, switch to the menu ...

»Phase settings« (page 152)

... and activate the assignment of phase names in the 

“Name” column with a brief tap on the center SET key 

of the right four-way button:

Pha1

Pha2

Pha3

Name ph.Tim

Pha4

Pha5

–

–

–

–



Now give Phase 1–the “Normal phase”–that is also 

the phase which includes the previous settings, the 

name “Normal”, which you select from a list with the 

selection keys.

Phase 2 is given the name “Thermal” and Phase 3 is 

given the name “Speed”. Now conclude the entries 

with a brief tap on the ESC key of the left four-way 

button or the SET key of the right four-way button:

Pha1

Pha2

Pha3

Name ph.Tim

Pha4

Pha5

normal

Thermal

Speed

–

–

–

–



Now move the marker frame beyond the “ph.Tim” 

column to the right into the column “Sw. time” and set 

a “switching time” from any other phase into the given 

phase in order to avoid an abrupt phase change; in 

other words to avoid erratic changes of flap positions. 

Now try out different switching times. In this example 

we have specified 1s in each case:

Pha1

Pha2

Pha3

Name Sw.time

Pha4

Pha5



–

–

normal

Thermal

Speed

–

–

1.0s

1.0s

1.0s

0.1s

0.1s

Whether or not one of the phases 1 ... 7 currently has 

an assigned switch and the state of the switch can 

be seen in the “status” column at the second column 

from left:

Symbol Meaning

– No switch assigned

+ Phase can be called via switch

 Indicates the currently active phase

Since, except for phase 1, all other phases are still 

designated with a “–” symbol, now switch in the menu 

...

»Phase assignment« (page 158)

... and assign the previously defined flight phases 

to appropriate switches with which a selection from 

among three phases is possible.

Since there is no particular priority here, assign for 

example switch “C” in the display to one of the two 

end settings of one of the two 3-way switches. Afterward put the selected switch again into its middle 

position, activate the switch assignment under “D” 

then move the selected 3-way switch again out of its 

middle position and into the other end position, as 

shown below:

Phase assignment

A B C D E F 

1 normal

6 5

prior combi
Programming examples - Using flight phases 305

After the switch assignment is complete, use the selection keys to switch to the bottom right and activate 

the assignment of phase names with a brief tap on 

the center SET key of the right four-way button.

Now close for example switch “6” by moving the selected 3-way switch forward.

Assign the name “<2 Thermal>” to this switch position 

and leave the name of its “OFF” position as “<1 normal>”.

A B C D E F 

6 5

2 Thermalv

Phase assignment

prior combi

A B C D E F 

6 5

1 normal

Phase assignment

prior combi

Finally, move the 3-way switch to the rear toward 

“5”-position and assign this switch position the name 

“<3 Speed>”:

A B C D E F 

6 5

3 Speed

Phase assignment

prior combi

The phase names selected in the programming are 

now shown, depending on the switch status, in all 

flight-phase dependent menus, see the table on 

page 150.

Since we have already made some settings in flightphase dependent menus, such as in the »Wing 

mixers« menu, we will now copy these settings to the 

«Thermal» flight phase. For this purpose, open the 

menu ...

»Copy/Erase« (page 80)

... and switch to the “Copy flight phase” line:

=>

=>

=>

=>

=>

Copy flight phase

Erase model

Copy model–>model

Export to SD

Import from SD

All seven possible flight phases are listed in “Copy 

from phase”:

Select the flight phase to be copied, e.g. “1 Normal”.

7

Copy from phase:

3

5

2

4

6

1 normal Thermal

Speed

With a brief tap on the center SET key of the right 

four-way button, switch the window to entry of the 

target memory “Copy to phase”.

Select phase “2 Thermal” as the target:

7

Copy to phase:

3

5

4

6

1 normal

Speed

2 Thermal

Confirm the selection with a brief tap on the center 

SET key of the right four-way button.

A security query follows, who should be confirmed 

with “Yes”:

Phase to:

to be copied?

NO

1 Normal 2 Thermal

YES

Then repeat the process with flight phase “3 Speed”.

Now we will program the required settings in the 

flight phase “Thermal” as an example.

In order to vary camber flap positions in the «Thermal» phase, it is merely necessary to switch over to 

the menu ...

»Control adjust« (page 118)

... then change Input 6–as described beginning on 

page beginning on page 118–from “GL(obal)” to 

“PH(ase)” and finally assign it to an operating element. 

To do this, first use the selection keys to switch into 

the “typ” column for “In6” and change this setting from 

“GL” to “PH”:

In6

offset

0%

0%

0%

–––

0%

In7

In8

In9

–––

–––

PH

GL

GL

GL

typ

Thermal

fr

fr

Cn1

––– 8

SEL

Thereafter change one column to the right into the 

column above SEL ...

In6

offset

0%

0%

0%

–––

0%

In7

In8

In9

–––

–––

PH

GL

GL

GL

typ

Thermal

fr

fr

Cn1

––– 8

SEL

... and now assign this input, as described in the sec-
306 Programming examples - Using flight phases

tion “Physical control, switch and control switch assignments” on page 68, the left proportional slider 

in the middle console to, for example:

In6

offset

0%

0%

0%

–––

0%

In7

In8

In9

–––

–––

PH

GL

GL

GL

typ

Thermal

Lv1

fr

Cn1

––– 8

SEL

This control will allow the ailerons (2 + 5) and camber 

flaps (6 + 7) to be continuously adjusted (as camber 

flaps) with a mixer ratio yet to be set via the »Wing 

mixers« menu.

If you assign the still free second three-stage switch 

to Input 6 instead, you can call three different FL positions of the ailerons (AIL) and camber changing flaps 

(FL) as well as three elevator positions (Elev) in the 

“Thermal” flight phase, see the following page. (These 

three switch positions correspond to the center position and the two limit positions of the previously mentioned proportional rotary control.)

Note:

The FL and AIL flap positions in the two limit switch 

positions or in the switch center depend on the value 

set in the column “- trv +” as well as the offset value 

and the mixer proportion set in the “Multi-flap menu” 

of the »Wing mixers« menu, see further below.

Leave the (control) “- trv +” at its standard symmetric 

settings of +100% and the offset value at 0%. Specifying a symmetric or asymmetric time for smooth 

switching between the three switch positions–in the 

example “1.2s 1.2s”–in the column “- time +” is recommended:

In6

– time +

1.2s

0.0s

0.0s

0.0s

In7

In8

In9

1.2s

0.0s

0.0s

0.0s

Thermal

In the “Multi-flap menu” of the ...

»Wing mixers« (beginning on page 170)

... menu, subsequently change only the values for 

“FL.pos” and “FL” in the «Thermal» flight phase:

• FL.pos

It is here that AILE and FLAP positioning takes 

place during the «Thermal» flight phase in the 

event that the assigned control (proportional control or 3-way switch) is in its neutral or middle position:

fl.pos –9%

AILE

Thermal

Diff. +55%

Ail-tr

AI +100%

+100%

• FL

Enter in this line the share of influence for aileron and camber flap servos, when used as camber flaps, is to be produced by the selected control 

(see above) or 3-way switch. Be sure to set these 

values low enough that the flaps can be controlled 

with appropriate sensitivity, for example:

FL

–9%

+10%

fl.pos

+10%

AILE

Thermal

Diff. +55%

Ail-tr +100%

FL

–14%

+15%

fl.pos

+15%

FLAP

Thermal

Diff. +33%

Ail-tr +60%

A simultaneous tap on the  or  key combination of the right four-way button (CLEAR) will reset 

changed values back to their standard default values.

Note:

Due to the improved lift distribution, the degree of 

mix ratios should be set so that the camber flaps are 

slightly “lower” than the ailerons.

With a simultaneous tap on the  keys of the left 

four-way button, the reaction of the AILE and FLAP 

servos can be checked in the »Servo display« by actuation of the selected camber flap control. (Push the 

C1 stick to the front position so that the “AILE” and 

“FLAP” positions can be better followed on actuation 

of the corresponding control.) 

Caution:

With aileron actuation the bars of the »Servo display« move in the same manner, for camber flap 

actuation they will move in the opposite manner.

• In the control’s middle position, the–example’s–“FL-pos.” setting only has a -9% effect for 

the AI and -11% for the FL.

• In one transmitter control end-position, AILE and 

FLAP are again closer to the neutral position 

because the mix ratio specified in the example 

reduces the FL.pos setting, whereas ...

• ... in the other limit position, AILE and FLAP reach 

the maximum downward offset prescribed by the 

mixer percentage.

In order to set a–corrective–admix for the elevator, exit the “Multi-flap menu” and return to the base 

screen of the »Wing mixers« menu:
Programming examples - Using flight phases 307

Brake settings

AI 0%

Wing mixer

FL EL +5% +5%

–––

–––

RU

Multi-flap menu

Thermal

In the two limit positions of the three-stage switch the 

elevator is moved symmetrically in this example with 

+5% (true to side). If, on the other hand, you use a 

proportional control, the elevator is deflected according to the degree for the control position.

Then make the settings for the “Speed” flight phase in 

the same manner.

Notes:

• The digital trims for aileron, elevator and rudder 

are always “phase-specific” in operation at standard, regardless of these settings.

• The current positions of the INC/DEC buttons, 

CTL 5 + 6, which may be assigned to inputs 5 

...8 or 5 ... 12, are stored in accordance with your 

preference entered in the “Type” line, i.e. the positions are not lost when you switch flight phases, 

nor even when you change models.

The particular advantage of these two transmitter 

controls–which are fitted as standard to the mc20 HoTT transmitter only, but can be fitted to the 

mc-16 HoTT transmitter as an extra-cost option–lies in the fact that you can use one and the 

same INC/DEC button as trim controls in all the 

programmed flight phases, but–in contrast to a 

position-related proportional control–the trim values are retained even if you switch models.
308 Programming examples - Control of temporal processes

Control of temporal processes

using time delay and curve mixers

An interesting, but little known, facility included in the 

software of the mc-16 HoTT transmitter with optionally unlocked »MIX-only channel« and «Channel 

sequencer« options, and of the standard mc-20

HoTT transmitter, is the ability to set up virtually 

any servo movement to last up to 9.9 seconds via 

a switch, in addition to the features available in the 

»Channel sequencer« menu; see page 256.

The programming for this should be shown on the 

basis of some examples in the following. Additional 

applications can certainly be found once you become 

familiar with these capabilities.

The programming is begin in the menu ... 

»Control adjust« (page 118 or 122)

... and in order to be able to approach any point of 

the control curve during the programming, first assign one of the proportional controls to the desired 

control channel–in this example the side-mounted 

left proportional slider “Lv1” to the Input 9. However, 

leave the standard default “GL” in the “typ(e)” column 

so that this setting is effective for all flight phases 

analogously to the free mixers to be programmed in 

the following:

In6

offset

0%

0%

0%

–––

0%

In7

In8

In9

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

Lv1 –––

SEL

However, if necessary you can create phase-specific 

sequences using the “PH” option in the »Control 

adjust« menu, and the »Mix active / phase« menu; 

see page 215.

The input of a time delay in the “- time +” column most 

right should also be dispensed with initially:

Then in the menu ...

»Mix-only Channel« (page 216)

... of the selected control channel, “9” in this case, is 

set to “only”:

MIX-only channel

only

normal

7 8 9 10 11 12

It is mandatory that this is set to “only (MIX)”, because the control curves of the curve mixers described in the following example only function on the 

output of the same channel as desired if there is no 

direct connection between the control and output! 

Only then can the linear control signal be manipulated almost arbitrarily around a curve mixer and to the 

appropriate output.

Therefore, in the next step, switch to the menu ...

»Free mixers« (beginning on page 205)

... and program a curve mixer for the same channel, 

e.g. from “9” to “9”:

ty fr to

M8

C9

C10

?? ??

 9 9

C11

C12

?? ??

?? ??

?? ??

On this second screen the desired path of the control 

curve is then set, whereby the following examples 

should only be “food for thought” for the design of 

your own control curves.

For example, the control curve could be for ... 

... delayed lighting of a headlight after the beginning of the extension of the landing gear:

+50%

–100%

Input

Output

Point 1

C.Mix 9

Curve off

9 9

–100%

... the control of a landing gear flap which closes 

again after the landing gear is extended:

–100%

–100%

L

9 9

–100%

Input

Output

Point

C.Mix 9

Curve off

... a smooth motor start-up or the extension of a 

self-launch ...

–100%

–100%

L

9 9

–100%

on

Input

Output

Point

C.Mix 9

Curve

... triggered by the same switch, but with a delayed startup of the drive motor connected to 

Output 10:

–100%

–100%

Input

Output

Point L

C.Mix10

Curve

9 10

–100%

on
Programming examples - Control of temporal processes 309

The function you programmed functions as desired 

according to these suggestions–which you can verify 

at any time after switching to the »Servo display« 

by simultaneously pressing the keys  of the left 

four-way button–then to, complete the programming, 

an arbitrary switch, such as “SW 15” is assigned in 

the menu ... 

»Control adjust« (page 118 or 122)

... to the control channel used instead of the selected 

side-mounted proportional control–in these examples 

“Lv1” to channel “9”–and the desired symmetric or 

asymmetric time span is set in the “– Time +” column 

for the amount of time in which the function should 

ultimately take place:

In6

offset

0%

0%

0%

–––

0%

In7

In8

In9

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

––– 15

In6

– time +

0.0s

0.0s

0.0s

9.9s

In7

In8

In9

0.0s

0.0s

0.0s

9.9s

Notice:

In the course of the switch assignment, always bear 

in mind that you can also trigger multiple functions 

with one switch! For example, with the same switch 

a landing gear connected to Output 6 can be started 

and, as shown here as an example, the time-controlled landing gear flaps connected to Output 9 and/

or the headlight, etc.
310 Programming examples - Delta and flying wing

Of course, the general comments regarding the installation and the adjustment of the RC system to a 

model at the beginning of the wing model programming on page 280 also applies for delta and flying 

wing models! Similarly, the comments for test flying 

and fine-tuning the settings to the programming of 

flight phases also apply.

left

right

Delta and flying wing models differ significantly from a 

“normal” flight model due to their unique characteristic shape and geometry. The differences in the servo 

arrangement, on the other hand, are more subtle. For 

example, with “classic” delta/flying wing models, only 

two rudders are normally provided. They are responsible for both “transverse” and “height/depth”, like the 

side rudder/elevator function on a V-tail unit.

With more elaborate designs, on the other hand, it 

may be the case that one (or two) interior rudders 

have only an elevator function and the exterior ailerons only support the height/depth function, under 

certain circumstances. Even with a 4, or indeed up 

to 8, flap wing the use of camber flap functions and/

or even a crow system is nowadays entirely possible. 

In all these cases, however, the following assignment 

of the receiver outputs should be used, see also 

page 73. Unneeded outputs a simply left free: 

Receiver power supply

Free or aux. function

Free or aux. function

Left elevon

Right elevon

Free or aux. function

Receiver power supply

Airbrake or throttle servo

or speed controller (electric motor)

Free or aux. function

Free or left flap / elevator

Free or right flap / elevator

Free or aux. function or left flap 2 / elevator

Free or aux. function or right flap 2 / elevator

Free or rudder

According to the assignment of the receiver outputs, 

in the menu ... 

»Model type« (page 104)

None

2AIL

+100% In 1

SEL

Tail type Delta/fl

Motor at C1

Aile/flaps

Model type

Brake Off

... the necessary settings are made:

• “Motor an C1”

“None” or “Throttle min front/back”

• “Tail type”

“Delta/fl”

• “Aileron/camber flaps”

“2AIL” (appears automatically).

To the extent necessary–and if with the respective transmitter possible–expand default “2 AIL” by 

4 AIL or 1, 2 or 4 camber flaps (“1 FL”, “2 FL” or “4 

FL”).

• “Brake”

stays as is, only interesting for a delta wing or flying wing of type “2/4 AIL 1/2/4 FL”. In this case, reDelta and flying wing

fer to the text under “Brake offset” on page 105.

These model type specifying settings primarily affect 

the functions made available in the »Wing mixers« 

menu. Therefore, the options are discussed separately for two-flap and multi-flap models in the following: 

Delta/flying wing of the type: “2AIL”

+100%

SEL

Delta/fl

2AIL

None

In 1

Tail type

Motor at C1

Aile/flaps

Model type

Brake Off

By retaining the standard default “2 AIL” in the “Aileron/flaps” line, elevator and aileron control, including 

the trim function, are automatically mixed by percentage on the software side. However, on the transmitter 

side, the percentage effect of the elevator and aileron 

stick can be influenced in the »Dual Rate / Expo« 

menu, page 130.

Settings in the menu ...

»Wing mixers« (beginning on page 170)

... are, if need be, advantageous with the “AI  RU” 

mixers and are “played’ with a great deal of “feel” for 

flying behavior with minor differentiation values. 

Aile.diff

Brake settings

+10%

AI +50%

Wing mixers

RU –––

Due to the specific idiosyncrasies of this model type, 

additional settings lead to moments which cannot be 

compensated.
Programming examples - Delta and flying wing 311

0%

+100%

0% 0%

+100%

FLAP

0%

FL

fl.pos

EL FL

Diff.

0%

+100%

0% 0%

+100%

FLAP2

0%

FL

fl.pos

EL FL

Diff.

Note:

Contrary to the separately set aileron trimming, see 

below, the trimming is transferred proportionally to the 

set mixer value with the mixer “EL  FL”.

The following settings are model-specific and 

may not be adopted without checking that they 

are correct!

In the top line of this “Multi-flap menu”, analogous to 

“normal” four, six or eight flap wings, the effect of the 

aileron stick will be set to aileron (2), camber flap and, 

if applicable to FL2. One line below, in the line “Ail-tr.” 

line, will set the influence of aileron trimming on ailerons and camber changing flaps.

The setting of a differentiation is rather tricker due to 

the model type and should only take place based on 

a feel for the flight behavior of the model.

The line “FL” should then be set to the standard 

default of +100% in the “FLAP” (or “FL2”) column–as 

shown–to 0%, just to be safe:

Delta/flying wing of the type: “2 / 4 AIL 1 / 2 / 4 FL”

Tail type

Motor at C1 None

Aile/flaps

Model type

Brake Off +100% In 1

SEL

Delta/fl

2AIL4FL

With delta/flying wing constructions with more than 

two flaps, more moments can be compensated for. 

For example, the “lifting” moment caused by the 

raising of the ailerons (= elevator effect) can be compensated with camber changing flaps lowered correspondingly wide ( = hydroplane effect).

If you decide in favor of this model type and have 

assigned the receiver outputs in accordance with the 

connection plan shown above, the aileron function of 

the two (exterior) aileron servos will function correctly 

immediately, but not the elevator function of the two 

aileron servos and, if applicable, the (interior) camber 

changing flaps. 

This is only then achieved for “2/4 AIL 1/2/4 FL”

when, in the “Multi-flaps menu” of the ...

»Wing mixers« (beginning on page 170)

... menu, is set appropriately in the “HR  WK” line 

to “Aileron, camber flaps” or, if applicable, “Camber 

flap 2”: 

FL

0%

0%

fl.pos

EL FL 0% 0%

0%

AILE

Diff. 0%

0%

0% 0%

FLAP

0%

FL 0% 0%

fl.pos

EL FL

Diff.

0%

0% 0%

FLAP2

0%

FL 0% 0%

fl.pos

EL FL

Diff.

Even though all inputs are set to “free” by default 

in the »Control adjust« menu, should a control be 

assigned sometime by mistake ... then it will at least 

have no effect.

The last line, “EL  FL”, was explained at the beginning of this section.

In principle, the author of this manual had programmed a delta model years ago operated with the 

mc-20 of that time and a crow system as landing 

assistance ... entirely without tilting moments through 

correspondingly attuned wing mixers “Brake  Aileron” and “Brake  Camber flap”, whereby “Aileron” 

refers to the exterior rudder pair and “Camber flap” 

refers to the interior rudder pair. 

To achieve this now with todays mc-16 Hott or 

mc-20 HoTT also, switch to “Brake settings” in 

the ...

»Wing mixers« (beginning on page 170)

... menu, and enter the values for the ailerons to be 

raised and the “flaps” to be lowered in the “Crow” line 

so that the occurring moments compensate one another and the altitude of the model remains stable. In 

the process, however, you should leave the flaps with 

enough “play” for the elevator function!!! Therefore, do 
312 Programming examples - Delta and flying wing

not utilize the entire servo travel for the crow alone; 

for example:

Elevat curve

Brake settings

AILE

Crow

D.red

+55%

0%

–44% 0%

0% 0%

FLAP FLAP2

Normal

You can ignore all other settings in this menu.

Note:

The “Brake settings” menu is switched “off” if: “Motor 

on C1 forward / back” in the »Model type« menu, 

page 104, AND the “Motor” column of the »Phase 

settings« menu, page 152, are set to “yes” for the 

currently active flight phase. Change the flight phase, 

if applicable.

Similarly, a modern, tapered flying wing air craft can 

also be operated. With some of these models there 

are also interior and exterior rudders: The prior is in 

front of the center of gravity and the latter is behind. 

A downward throw of the central rudder(s) increases 

the ascending forces and has an elevator effect. An 

upward throw has the opposite effect. On the exterior ailerons, on the other hand, the effect is just the 

opposite: A downward throw shows an elevator effect and vice versa. With appropriate adjustment of 

the “leading” mixer to the setting of curve mixers in 

order to achieve a supporting effect from the external 

rudder pair with only extreme stick deflection in the 

height/depth direction, “everything” is possible here. 

The author of this manual uses a curve mixer for his 

model, which is defined by a total of four points:

0%

0%

Input

Output

Point

C.Mix 9

Curve

EL 5

0%

on

?

In this example the two interpolation points 1 and 2 

are each at 0% as well as the left edge point at +60% 

and the right edge point at -65%. In conclusion, the 

curve was rounded.

In this case: Regardless of which type of servo arrangement was selected, any type of differentiation 

should be set with caution! On a tail-less model, 

differentiations show a single-sided height/depth 

elevator effect, so we urgently recommend beginning 

at least the initial flights with a setting of 0%! Over 

the course of the further flight testing, under certain 

circumstances it may be advantageous to experiment 

with differentiations deviating from zero. 

With larger models, rudders in the winglets–the 

“ears” mounted on the wing ends–can be beneficial. 

If these are controlled with two separate servos, one 

of the mixers in the »Dual mixer« menu can be used; 

this is available as standard on the mc-20 HoTT 

transmitter only, but can be unlocked on the mc-16

HoTT transmitter as an extra-cost option. In this menu 

... 

»Dual mixer« (page 218)

... the rudder signal can be “split” very easily and 

even differentiated, whereby the second rudder servo 

is connected to one of the still free receiver outputs. 

For a model with a “Delta/fl” tail type, receiver output 

“5” should still be unoccupied and it can then be used 

as indicated below:

Diff.

Dual mixer

Mixer1

Mixer2

 5 RU

Mixer3

Mixer4

?? ??

?? ??

?? ??

0%

0%

0%

+66%

Differentiation is necessary in this case because, 

when flying curves, the respective exterior rudders 

will have a greater curve radius than the interior rudders, so this is comparable to the front wheel positions on a car when driving in curves.

Note:

The rudder can only be differentiated as programmed 

above!

If these two rudders are also to deflect outward upon 

actuation of a brake system with the C1 stick, this 

can be achieved, for example, by setting an additional 

mixer “C1  5” with an appropriate travel setting. Set 

the mixer’s offset according to personal preference, 

“front” (+100%) or “rear” (-100%), because the winglet rudder should deflect outward only for proportional 

extension.

Independent of this, finish up by uncoupling the “false” 

control function from the control channel to which 

the second servo was connected–even though all 

inputs in the »Control adjust« menu are “free” by 

default–or shift into the menu ... 

»Mix-only channel« (page 216)

... which applies to all flight phases, and is available 

as standard on the mc-20 HoTT transmitter only, 

in the interests of safety. In keeping with the above 

example, control channel 5 should therefore be set to 

“MIX only”.
Programming examples - Delta and flying wing 313

MIX-only channel

only

normal

1 2 3 4 5 6

Note:

This menu can be unlocked on the mc-16 HoTT 

transmitter as an extra-cost option.
314 Programming examples - F3A model

F3A model

F3A models are a part of the group of motor-driven 

winged models. They are powered by a combustion 

or electric motor. Electric-powered model aircraft 

are now becoming prevalent in the international F3A 

model aerobatic class as well as being eligible for the 

F5A electric aerobatic class. 

The basic comments and notices for the mechanical 

installation of a remote steering system, which was 

already referred to in the first programming example 

on page 280, also applies, of course, for F3A models and does not need to be mentioned here again.

Faultlessly constructed F3A models exhibit a largely 

neutral flying behavior. Ideally, they react with a good 

nature but precisely to control movements without the 

individual flight axes influencing one another.

F3A models are controlled with ailerons, elevator and 

rudders. Normally, each aileron is actuated by a separate servo. There is also the regulation of the drive 

output of the motor (throttle function) and a retractable landing gear in many cases. The assignment of 

the channels 1 to 5, therefore, do not differ from the 

previously described winged models. 

The additional “Retractable landing gear” function is 

to be provided on one of the auxiliary channels 6 to 8 

or 6 ... 12. It is best to actuate the landing gear with 

a switch without center position. In addition, another 

mix offset for the carburetor can–if necessary–be 

provided. You normally use one of the two proportional controls on the transmitter, which actuates one 

of the unassigned auxiliary channels.

Receiver power supply

Free or aux. function

Free or aux. function

Rudder

Aileron or left aileron

Elevator or 1st elevator

Free or 2nd elevator or aux. function

Receiver power supply

Airbrake or throttle servo

or speed controller (electric motor)

Right aileron

Free or aux. function (retracts)

Free or aux. function (mixture)

Free or aux. function

Free or aux. function

With the assignment of auxiliary channels at the 

transmitter, we recommend making sure that the 

operating elements required for this are easily within 

reach, because during flight–especially in competition–you have “very little time” to release the stick.

Programming procedure

Since the basic programming of the transmitter was 

already described in detail on pages 280 ... 287, 

only F3A-specific tips are added here.

In the menu ...

»Servo adjustment« (page 112)

S1

S2

S3

Rev cent trv +

0%

0%

0%

100% 100%

100% 100%

100% 100%

0%

0%

100% 100%

100% 100%

S4

S5

... the settings for the servos are carried out. Experience has shown that working with at least 100% servo throw is beneficial, because the control precision 

is significantly better if greater servo travel is used. 

This should already be taken into account during the 

construction of the model in the design of the rudder 

linkages. Check the servo’s direction of rotation. The 

servo center should be adjusted mechanically, insofar 

as possible. 

Any corrections can be made on the software side in 

the third column during the initial test flights. 

Through the menu ...

»Model type« (page 104)

... the idle trim is activated for Channel 1 (normally 

“back”, because full throttle is “front”). The trimming 

then only works in the idle direction:

Tail type

Motor at C1

Normal

Aile/flaps 2AIL

Model type

Brake Off +100% In 1

SEL

back

The remaining settings are made or left as shown in 

the figure.

After the model is test-flown and trimmed, we 

recommend reducing trim travel for the elevator and 

ailerons. The model has significantly less of a reaction 

to a movement of the trim lever. “Over-trimming” can 

be avoided, because with full trim travel, under certain circumstances, the movement by just one trimming step can have too strong of an effect: Therefore, 

the model which previously pulled slightly to the left, 

hangs somewhat to the right after the trimming. This 

is accomplished by moving to the ... 
Programming examples - F3A model 315

»Stick mode« (page 114)

... menu, which is available as standard on the mc20 HoTT transmitter only, and reduce the number of 

trim steps in the “Tr” column appropriately:

Ch.1

Aile

Elev

Tr time +

4

2

2

0.0s

0.0s

0.0s

Rudd 0.0s

0.0s

0.0s

0.0s

0.0s

GL

PH

PH

PH

St

2

Note:

This option can be unlocked on the mc-16 HoTT 

transmitter as an extra-cost option

It may also be necessary to assign appropriate operating elements and inputs for other model features, 

e.g. retractable landing gear, fuel-mix, etc. Make 

these assignments with the ...

»Control adjust« (page 118) 

... menu where a specific input can be assigned to an 

operating element, for example, the landing gear can 

be assigned to an ON/OFF switch on Input 6 and the 

fuel-mix can be assigned to one of the proportional 

sliders in the middle console, e.g. the side-mounted 

left proportional slider to Input 7. However, since it 

involves flight-phase independent settings, leave the 

standard default “GL” in the “typ” column:

0%

0%

0%

–––

––– 0%

–––

–––

GL

GL

GL

GL

fr

Lv1

fr

SEL

In5

offset

In6

In7

In8

typ

3

The control travel of the operating elements must be 

adapted and can also be reversed with a negative 

travel setting. 

Input

Output

Point 1

–50%

0%

0%

Ch1 curve

Curve on

Only three interpolation points, “L” at -100%, “H” at 

+100% and “1” at -50% give the control travel the 

rounded curve above.

Basic procedure:

• Move the C1 stick and, along with it the vertical 

line in the graph display, toward idle to about -50% 

of control travel then briefly tap on the center SET

key of the right touch pad.

• In order to attain the curve shape shown, raise this 

point with the selection keys to approx. 0% in the 

inverse video value field in the “Point” line.

• Finally, round the characteristic curve by moving 

the marker frame upward, select with a brief tap 

on the center SET key of the right touch pad then 

change the value from “Off” to “On” with the selection keys.

If additional interpolation points between the left (“L”) 

and right (“H”) end are necessary, repeat Steps 1 and 

2 analogously.

Since F3A models normally have two aileron servos, 

experience has shown that it is beneficial to move 

both ailerons upward somewhat when landing. In the 

process, the model usually approaches somewhat 

slower and, above all, more steadily for the landing. 

In order to do this it is necessary to program mixers 

through the menu ...

F3A models fly comparatively fast and thus react 

“harshly” to the control movements of the servos. 

However, since small control movements and corrections are not optically perceptible, because this 

results in inevitable point deductions in competition, 

we recommend setting an exponential control characteristic of the stick. For this purpose, switch to the 

menu ...

»Dual Rate / Expo« (page 130)

Experience has shown positive results with values of 

approx. +30% on the ailerons, elevator and rudders, 

which you set in the right column with the selection 

keys. In order to be able to control the F3A model to 

run smoothly and cleanly:

+33%

+33%

+33%

Ail

Ele

Rud

EXPO

–––

–––

SEL

–––

(Some experts even use up to a +60% exponential 

ratio.)

Since (some) combustion motors do not react linearly 

to movements of the throttle stick, through the menu 

...

»Channel 1 curve« (page 138)

... a “bowed” or, in other words, non-linear throttle curve can be set. Four-cycle motors with Roots 

pumps, in particular, such as OS Max FS 120, require 

a steep ascension of the curve in the lower speed 

range. However, the corresponding values must be 

adapted. The C1 control curve for the motor could 

appear as follows:
316 Programming examples - F3A model

»Free mixers« (beginning on page 205)

... accordingly.

The ailerons are extended as landing assistance 

depending on the position of the throttle stick, starting from approximately half throttle toward idle. The 

further the stick is moved toward idle, the more the ailerons deflect upward. Just the opposite applies when 

“throttling”; the ailerons are retracted again in order to 

prevent a sudden rise of the model. 

In order to prevent the model from climbing with the 

aileron landing flaps extended, the elevator must be 

mixed in somewhat.

For this purpose, set the two linear mixers shown 

in the following display. The activation of the mixers 

takes place with one and the same switch, such as 

“15”, to which both mixers must be assigned with 

identical switching direction.

ty fr to

M1

M2

M3

C1 5

C1 EL

M4

M5 ?? ??

?? ??

?? ??

15

15

Then switch to the second respective display screen 

in order to adjust the respective mixing degrees. In 

both cases the mixer neutral point is at the C1 control 

center.

Enter 0% above the control center after selection of 

the ASY field for both mixers and below the control 

center toward idle for:

MIX 1: -60%... -80% and

MIX 2: -5%... -10%.

Example Linear MIX 1:

L.Mix 1

0%

0%

Offset

SYM ASY

C1 5

Mix input

–30%

With this, the base setup model of an F3A model is 

concluded.

Compensation of model-specific errors

Unfortunately, there are nearly always minor modelspecific “errors” through the mixers of a computer 

remote control which must be compensated for. However, before you begin with these settings, it should 

be ensured that the model is faultlessly constructed, 

optimally balanced over the longitudinal and transverse axes and the down thrust and side thrust are 

correct.

Influence of longitudinal and transverse axes by 

the rudder

The actuation of the rudder often influences the behavior of the longitudinal and transverse axes. This is 

particularly disruptive in so-called knife-edge flying, 

in which the lift of the model with the rudder deflected 

should be created by the fuselage alone. In the process, the model can rotate and change directions as 

though it were controlled with the ailerons and elevator. Therefore, a correction over the transverse axis 

(elevator) and/or the longitudinal axis (ailerons) must 

be made, if applicable.

This can also be done easily with the »Free mixers« 

available in the mc-16 HoTT or mc-20 HoTT system. For example, if the model drifts away to the right 

over the longitudinal axis with the rudder extended in 

knife-edge flying, the aileron can be deflected slightly 

to the left with the mixer. Changes in direction over 

the transverse axis can be performed analogously 

with a mixer on the elevator:

• Correction over the transverse axis (elevator)

Linear MIX 3: “RU  EL”

Asymmetric setting. The appropriate values must 

be tested in flight.

• Correction over the longitudinal axis (aileron)

Linear MIX 4: “RU  AI”

Asymmetric setting. The appropriate values must 

be tested in flight.

Relatively small mixer values are usually sufficient 

in this case, the range lies below 10%, but can vary 

from model to model. With the use of curve mixers, 

the mix ratios can be adapted even more precisely 

to the corresponding throw of the rudder. Again, no 

values are indicated for this, because this would be 

model-specific.

Vertical ascent and descent

Some models have a tendency to deviate from the 

ideal line in vertical ascents and descents. 

In order to compensate for this, it is necessary to 

have a center position of the elevator dependent on 

the throttle stick position. If, for example, the model 

begins to hold off on its own in the vertical descent 

with a throttled motor, some elevator must be mixed 

in at this throttle position.

For this purpose, program a free mixer “C1  EL”. 

The corresponding mixer values are normally under 

5% and must also be tested in flight. 

Turning away over the longitudinal axis in idle

If the throttle is reduced, the model may begin to turn 

away over the longitudinal axis in idle. This can be 

counteracted with the aileron. 

However, the more elegant solution is to correct this 

effect with a free mixer “C1  AL”. 

The input values here are usually very low (approx. 

3%) and the settings should be made in calm weather. It often suffices to only use the mixer between 
Programming examples - F3A model 317

half throttle and idle. Therefore program the mixer 

asymmetrically, if applicable.

Turning away with the ailerons/landing flaps extended

If you move the ailerons upward for the landing, the 

result is often a turning away over the longitudinal 

axis due to various servo paths of the aileron servos 

or due to design precisions. Therefore, the model begins to automatically hang the left or right wing. This 

is also easy to compensate for with a mixer “C1 

AI” depending on the position of the ailerons/landing 

flaps. 

The mixer must be switched on and off with the same 

switch with which you can switch the aileron/landing 

flap function on and off (see previous page). Therefore, it only works with the aileron/landing flap function activated. The appropriate value must be tested 

in flight. 

One additional comment regarding ...

“FAIL-SAFE setting”

You utilize the safety potential of this option by programming at least the motor throttle position for 

combustion models to idle and the motor function for 

electrically powered models to stop for a Fail-Safe 

case. If interference should occur, the model is then 

less likely to fly off on its own and cause damage to 

property or even personal injury. If you additionally 

program the fail-safe positions of the rudders to that 

the model flies in gently sinking circles in the event of 

a failure, there is a good chance that the model even 

lands relatively gently on its own in the event of a 

continuing connection failure. You also have sufficient 

time to re-establish the connection if the entire 2.4 

GHz frequency band is temporarily disrupted. 

In the receiver’s condition as supplied, however, the 

servos maintain their last validly recognized position (“hold”) in the event of a fail-safe situation. As 

described on page 220, you can define a “Fail-safe 

position” for each receiver servo output (Fail-safe 

mode).

Summary

The settings described on this page are especially 

useful for the “expert” who would like to have an 

entirely neutral, precisely flying F3A model acrobatic 

model at his or her disposal. 

It should be mentioned this takes a lot of time, effort, 

instinct and know-how. Experts even program during the flight. To do this, however, is not suggested 

for an advanced beginner who ventures into an F3A 

acrobatic model. It would be best to turn to an experienced pilot and carry out the settings step by step 

until the model has the desired neutrality in its flight 

behavior. Then the pilot can begin to learn the not 

always easy to perform acrobatic figures with a model 

which flies faultlessly. 
318 Programming examples - Helicopter models

Helicopter models

With this programming example, you must have already covered the description of the individual menus 

and you must be familiar with the use of the transmitter. In addition, the helicopter’s mechanical construction should correspond exactly to the corresponding 

manual. The electronic capabilities of the transmitter 

should by no means be used to straighten out rough 

mechanical imprecision.

As is often the case in life, there are also various 

ways and possibilities to achieve a specific goal when 

programming the mc-16 HoTT or mc-20 HoTT 

transmitter. The following example should provide you 

with a clearer structure for logical programming. If 

there are multiple possibilities, the simplest and most 

clearly arranged solutions are recommended first. 

In order for the helicopter to function faultlessly later 

on, you are, of course, free to try out other solutions 

which may be better for you.

The programming example is based on the clockwiserotating STARLET 50 helicopter from Graupner with 

three pivot points each offset 120° of the swashplate 

type “3Sv(2 Roll)”, beginner adjustment without increased throttle curve; without heading-lock gyro system and without transmitter-side gyro influence of the 

“normal operating mode” and without speed regulator. 

This simple program was also consciously selected 

to demonstrate that a helicopter which flies really well 

can also be attained with relatively little (programming) effort. 

However, we do not want to dispense entirely with the 

enhancement possibilities: Therefore, after the basic 

description, you will find adjustment information for 

the gyro effect, the speed regulators and for the flightphase programming.

Note:

If you are not interested in the combustion helicopter described here, but a electric helicopter, please 

continue reading anyhow! With the exception of the 

omitted idle settings, you can practically adopt most 

of the settings described in the following unchanged.

In the scope of the initial commissioning of a new 

transmitter, in the selection menu ...

»Basic settings« (page 268)

Battery type

Battery warning

Touch Sense

Top LCD Contrast

Lith.

Display light

Region

2

3.60V

0

Euro

unlim.

Basic settings

Vario Vol

Beeps Vol

Power-on beep yes

Power on warn. unlim

BT Headset OFF

0/0

ID PAIR OFF

BT Volume 8

Voice Vol 5 –––

7 –––

7 –––

Own

Stick mode 1

Modulation HoTT

DSC Output PPM10

Pitch min back

Bottom LCD Contr.

0

SEL SEL

fr

fr

fr

... some basic information should be entered. This 

serves various purposes:

The first three lines of this menu can be used to 

individually regulate, in increments between 0 and 10, 

the volume of voice and signal output emitted via the 

built-in loudspeakers or the transmitter’s headset connector. The fourth line of this menu is used to record 

the transmitter owner’s name. Select the characters 

for this from an extensive character list on the second 

display screen, which can be reached via the 

symbol with a brief tap on the center SET key of the 

right touch pad:

!"#$%&’()�+,–./0123

456789:;

Owner H-J Sandb

FGHIJKLMNOPQRSTUVWX

YZ[¥]^_`ab cdefghijk

?@ ABCDE

The pre-set for “Stick mode” can be selected according to the criteria described on page 269.

The same applies to the pre-sets for “Modulation” 

and “DSC Output”, page 270.

The pre-set for “Pitch min” is a matter of personal 

control habits, page 109.

The pre-sets established here for “Stick mode”, 

“Modulation”, “DSC Output” and “Pitch forward/

back” will be initially adopted when a new model 

memory is created but they can also be freely 

changed within a given model memory location to any 

other available option.

The settings in the “Top/Bottom LCD Contrast” lines 

determine the legibility of the given displays under 

poor light conditions and the setting in the “Display 

light” line determines how long display lighting remains illuminated after the transmitter is switched on 

without any actuation of a control afterward or after 

the last control actuation.

The selection of “yes/no” in the “Power-on beep” 

line determines whether the “recognition melody” is 

to sound when the transmitter is switched off or on 

again.
Programming examples - Helicopter models 319

The “Battery type” line specifies whether the transmitter is supplied with current from a “NiMH or a “Lith.” 

battery, and the “Battery warning” line below it specifies the voltage at which the transmitter’s low-voltage 

warning should trigger. Do not enter a value that is 

too low here, so you have enough time to land your 

helicopter.

The setting made in the “Stick warning” line determines how long the transmitter will wait after the 

last actuation of an operating element before issuing 

visual and acoustic warning signals to indicate it is 

still switched on. Following the warning, you still have 

about three minutes to actuate the transmitter so 

the warning will abate. Otherwise the transmitter will 

switch itself off when this time expires.

The value set in the “Touch Sense” line is a matter 

of adapting the transmitter to personal preferences. 

And, in the event the transmitter is to be operated in 

France, the setting in the “Region” line is important: 

The legal regulations in France require that the 

“FRANCE” option is selected instead of the default setting “EURO”.

Note:

However, please observe the note on page 273 on 

this subject. 

Finally, if you are using a Bluetooth headset, you can 

bind and configure it as described in the instructions 

supplied with the optional Bluetooth module, Order 

No. 33002.5; see the section entitled “BT Headset”.

Once these settings have been taken care of, commissioning continues with the menu ...

»Model select« (page 79)

Use the selection keys to pick a free memory location ...

1

BD1 BD2

Mod.name

Stick mode

module n/a

Base setup model

n/a

DSC Output PPM10

HoTT

... and call it up with a brief tap on the center SET key 

of the right touch pad. In the display which then appears, use the  key of the left or right touch pad ...

Select model type

... to select the “helicopter” model type. The display 

immediately switches to the base screen if the selection is confirmed by a brief tap on the center SET key 

of the right touch pad. 

Notes:

• If the “Select model type” option has been opened, 

the process cannot be canceled. Even if you 

switch off the transmitter, this selection must be 

made! In any case, you can undo this by subsequently deleting the respective model memory.

• If the “Throttle too high” warning appears, it can be 

erased by turning the right-side proportional rotary 

control to its backward limit.

• If battery voltage is too low, the model switchover 

cannot be made due to reasons of safety. An appropriate message will appear in the screen:

not possible now

voltage too low

Once this first hurdle is cleared, the connection of the 

receiver built into the model at this model memory 

must be made in the menu ...

»Base setup model« (beginning on page 94)

To this end, switch to the line “module”:

Mod.name

Stick mode

module

1

n/a

Base setup model

n/a

BD1 BD2

DSC Output PPM10

HoTT

Note:

After confirmation of the model selection in the base 

screen, if you confirm the message appearing in the 

screen for a few seconds ...

BIND. N/A

OK

... with a tap on the SET key of the right touch pad, 

this line will be accessed automatically.

The line “module” initiates a binding process between 

model memory and receiver, as described in detail 

on page 94. Otherwise, you cannot address the 

receiver.

Afterward, use the  selection key of the left or right 

four-way button to move up to the first line and begin 

with actual model programming in the “Model name” 

line. Now give the model memory an appropriate 

name, ...
320 Programming examples - Helicopter models

Note:

More more information about the setting of this 

“emergency shutoff”, see further in this section.

Another tip:

Make a habit of giving all switches a common switchon direction; then a quick glance over the transmitter 

prior to the flight should suffice–all switches off. 

Setting options for the “Autorotation C1 position”, 

“Motor stop” and “Stick warning” are not yet of particular interest ...

... and you should only leave or set the “Auto timer 

reset” line to “yes” if you actually want the timers to 

be reset to the appropriate initial value every time you 

switch the transmitter on.

Additional settings specific to helicopters are made in 

the menu ...

»Helicopter type« (page 108)

In the “Swashplate type” line, select control for 

swashplate or pitch function. In this example: 

“3Sv(2rol)”.

The “Linearis. swashpl.” line is not yet of interest.

In the “Rotor direction” line, it is established whether 

the rotor–as viewed from above–turns to the right 

(clockwise) or left (counter-clockwise). In other words, 

whether it rotates counterclockwise or clockwise. In 

this example “right”. 

Check the default for “Pitch min”, which was adopted 

from »Basic settings«, to confirm that the entry 

“front” or “rear” is in keeping with personal preferences or should be changed:

3Sv(2rol)

SEL

Linear. swashpl.

Swashplate

no

Rotor direct right

Heli type

Pitch min. back

1

bind n/a

ST R ET

Rcv Ch Map R12 n/a

HoTT

Mod.name

Stick mode

module

Base setup model

... which must be assembled from characters available on the second page of the “Model name” line:

!"#$%&’()�+,–./0123

456789:;

Mod Name STARL

FGHIJKL MNOPQRSTUVWX

YZ[¥]^_`abcdefghijk

?@ ABCDE

After entering the “Model name”, the settings adopted from »Basic settings« for “Stick mode” and “DSC 

Output” are to be checked and changed as necessary for the given memory location.

Another option is to be activated in the “Autorotation” 

line. Even if you are not an advanced pilot, the autorotation switch should at least be set as an emergency 

shutoff switch for the motor. 

Do this by selecting the “Autorotation” line with a 

brief tap on the center SET key of the right touch 

pad, activate the switch assignment, assign a 2-way 

switch, e.g.“7”, and put it in its “ON” position:

99sec

PPM10

7I 

ON

DSC Output

Autorotation

RF transmit

Base setup model

RF Range Test

The selected switch should be in a location on the 

transmitter which is easily within reach–without letting loose of a stick–e.g. above the pitch stick. 

“Expo throttle lim.” in the bottom line of this display, 

are currently of no interest.

By now, the servos should be plugged into the receiver in the intended sequence:

Receiver power supply

Free or aux. function

Free or aux. function

Tail rotor servo (gyro system)

Roll 1 servo

Pitch-axis 1 servo

Free or speed governor or aux. function

Receiver power supply

Collective pitch or roll 2 or 

Pitch-axis 2 servo

Free or aux. function

Throttle servo or speed controller

Gyro gain

Free or aux. function

Free or aux. function

Note:

Please note that on the newer Graupner-mc- and 

mx- remote control systems, the first pitch servo and 

the throttle servo are swapped in comparison to some 

older systems.

Mix ratios and mix directions for swashplate pitch, roll 

and nick servos are already pre-adjusted to +61% in 

the menu ...

»Swashplate mixer« (page 220)

Swashplate mixer

Pitch

Roll

Nick

+61%

+61%

+61%

SEL

If the swashplate mixer should not follow stick movements properly, first change the mixing directions 

from “+” to “-” before changing servo directions in the 
Programming examples - Helicopter models 321

menu ...

»Servo adjustment« (page 112)

S1

S2

S3

Rev cent trv +

0%

0%

0%

100% 100%

100% 100%

100% 100%

0%

0%

100% 100%

100% 100%

S4

S5

This menu can also be used to adapt travel and 

direction for individual servos. However, one must 

attempt to retain 100% servo travel so as to achieve 

the best possible resolution and control accuracy. The 

direction of travel is determined with “Rev.” and, in the 

process, make sure that the direction is correct. The 

tail rotor servo must run so that the nose (!) of the 

helicopter follows the tail stick direction.

In the following menu, which is available as standard 

on the mc-20 HoTT transmitter only, but can be 

unlocked on the mc-16 HoTT transmitter as an 

extra-cost option ...

»Stick mode« (page 116)

Thr.

Roll

Nick

Tr time +

4

4

4

0.0s

0.0s

0.0s

Tail 4 0.0s

0.0s

0.0s

0.0s

0.0s

TL

PH

PH

PH

St

... the column “Tr” is used to set the increment size of 

each “click” on the digital trim keys. 

The C1 trimming only affects the throttle servo for 

the helicopter. At this point there is no need to go into 

the particulars of this trimming (“cut-off trim”) once 

again. Please read more about this on page 70. 

(Thanks to digital trimming, trim values can be saved 

automatically when a model change is affected. In the 

mc-16 HoTT and mc-20 HoTT systems these 

can even be stored automatically when a change of 

flight phase takes place.)

An additional setting which is specific to helicopters 

can also be made in this menu in which you determine which function the trim lever on the pitch stick 

should have. This is accomplished by selecting the 

“TL” setting in the “Thr(ottle)” line or leaving it as it is. 

This roughly corresponds to trim for the familiar idle 

trim function. If the trim indicator marker is moved all 

the way forward by “turning” the trim lever (remember: 

“pitch min rear” = “throttle forward”) the throttle limit 

will later take over the throttle limit for throttle enable 

seamlessly in the menu ...

»Control adjust« (beginning on page 122)

In5

offset

Thro

Gyro

Lim.

–––

–––

–––

Lv2

0%

0%

0%

0%

GL

GL

GL

GL

typ

fr

fr

fr

–––

SEL

... where input “Lim.” is assigned and all other inputs 

are “fr(ee)” by default.

This “Lim.” input serves as the throttle limiter. Its 

effect is exclusively on output “6”, where the throttle 

servo is connected. The throttle limiter is assigned by 

default to the right-side proportional rotary control.

Once again, as a reminder:

• With the use of the “throttle limiter” function, you 

do not have to program a flight phase “throttle preselection”. 

• The throttle limiter does not control the throttle 

servo; it only limits the travel of the throttle servo 

in the full throttle direction according to its position. 

The throttle servo is generally controlled from the 

pitch stick via »Helicopter mixer« menu setting/s 

for throttle curve/s, which is why input 6 must absolutely remain “free”. Refer to pages beginning on 

page 191 in this manual about this. 

• The C1 trimming also affects only the throttle servo for the helicopter. At this point there is no need 

to go into the particulars of this trimming once 

again. Please read more about this on page 70. 

(Thanks to the digital trimming, trim can be automatically saved values with a model changeover 

as well as with a change of the flight phase).

• A detailed description of the idle run base setup 

model and the adjustment of idle and throttle limit 

can be found beginning on page 127.

Then switch to the “travel” column with the  selection key of the left or right touch pad and increase 

the now inversely highlighted value from +100% to 

+125% with a fully opened throttle limiter with a brief 

tap on the center SET key of the right touch pad:

– travel +

+100%

+100%

In11 +100%

Lim.

+100%

+100%

+100%

+100% +125%

In9

In10

In doing so, it is assured that the throttle limiter releases the entire throttle travel with the pitch stick 

later during flight.

Adjustment notice for electric helicopters:

Since electric drive systems have no need for an 

idle setting, the basic configuration of settings for an 

electrically-powered helicopter merely involves making sure that the control range of the throttle limiter 

is both higher and lower than the adjustment range of 

the speed controller (usually -100% to +100%) by a 

safe margin. If necessary, therefore, the adjustment 

of the “travel” setting of the throttle limiter described 

above must be modified accordingly, for example, to 

symmetric +110%. The further adjustment, however, 

can take place analogously to the combustion helicopter described here.
322 Programming examples - Helicopter models

With this process, you have carried out the basic 

settings for the transmitter as they are needed again 

later for further model programming. 

The actual helicopter-specific settings take place 

primarily in the menu ...

»Helicopter mixer« (beginning on page 188)

C1

C1

Pitch

Throttle

Tail

Tail 0%

Roll 0%

Throttle

Roll

Throttle

Tail

Nick

Nick

Throttle

Tail

Swash rotation

Swash limiter

0%

0%

0%

0°

OFF

Gyro suppress 0%

Gyro gain 0%

The “Pitch” function appears right in the first line. A 

tap on the center SET key of the right touch pad will 

cause a switch to the corresponding sub-menu. The 

graphic representation of the pitch curve appears 

here; it is initially only defined by the points “L” and “H”:

Input

Output

Point ?

0%

0%

0%

Pitch

Curve off

Now place point “1” in the center with a brief tap on 

the center SET key of the right touch pad:

Input

Output

Point 1

0%

0%

Pitch

Curve off

0%

Always try to make due with these three points initially; more points can “over-complicate” the matter and 

are more of a burden at this point.

The reference point for the hovering should generally 

be the mechanical center position of the pitch stick, 

because this position comes closest to the normal 

control feel. Although the curve adjustment enables 

other settings, you must know exactly what you are 

doing. First set the pitch stick in the center. The servos which you had previously set according to manufacturer specifications have their levers at positioned 

perpendicularly to the servo housing (normally). A 

hovering pitch value of 4° to 5° is now mechanically 

set at the control rods to the rotor blades. In principle, 

all known helicopters fly with this setting. 

Then move the pitch stick towards maximum pitch 

until the limit position. (The vertical line shows you the 

current stick position.) Now change the pitch curve’s 

point “H” with the selection keys of the right touch pad 

such that the main rotor’s blades have a maximum 

pitch of about 9°. A value of +50% should be about 

right:

Input

Output

Point H

+100%

+50%

Pitch

Curve off

+50%

Note:

A rotor blade adjustment gage, such as the Graupner 

pitch gage, order no. 61, is quite useful for reading the 

angle. 

Now move the pitch stick toward the pitch minimum 

position until its limit position. Depending on the ability of the pilot, adjust the value of point “L” so that the 

blade angle of approach is 0 to -4°. Now a slightly 

pitched line arises at the hovering points, the socalled pitch curve, which can appear as follows:

L

–100%

–75%

Pitch

–75%

Input

Output

Point

Curve off

Now you can, if you like, move the marker frame 

upward with the selection keys to the “Curve” line 

and after activation of the value field with a brief tap 

on the center SET key of the right touch pad, set the 

curve function of the mixer to “on”.

L

–100%

–75%

Pitch

–75%

on

Input

Output

Point

Curve

If you now switch to autorotation phase–at the bottom left of the display the flight phase name “Autorot” 

appears–the “old” pitch curve is again:

?

0%

0%

0%

Pitch

Autorot

Input

Output

Point

Curve off

Now carry out the same setting as before in the normal phase. Only at point “H“–at maximum pitch–is it 
Programming examples - Helicopter models 323

possible to increase pitch angle by about 2°. In doing 

so, you will have somewhat more of an angle to catch 

the model later on (!).

After setting pitch curve, move the autorotation switch 

back then return to the helicopter mixer menu selection with a brief tap on the center ESC key of the left 

touch pad. In that display, change to the “C1  Thro” 

line to set the throttle curve.

The adjustment range for idle trim must first be 

matched to the throttle curve. Do this by putting the 

pitch stick into its minimum position then set point “L” 

to about +15%:

0%

+15%

C1 Thro

L +15%

Input

Output

Point

Curve off

With the throttle limiter closed and idle trim completely open, move the pitch stick back and forth somewhat at the minimum limit position. The throttle servo 

may not move with it in the process. No you have 

established a seamless transition from the idle trim to 

the throttle curve. The further settings along the throttle curve must be carried out later in flight. 

If you switch from this graphic to the autorotation 

phase for testing purposes, the following appears 

instead of the accustomed representation:

OFF

C1 Thro

Autorot

That means that this mixer is switched off and the 

throttle servo is switched to a fixed value, which can 

be adjusted as follows: 

Return to the menu list with a tap on the ESC key. As 

long as you are still in the autorotation phase, new 

sub-menus are listed; specifically:

Pitch

0%

Autorot

–90%

0%

Gyro gain 0%

Thr setting AR

Tailoffset AR

Gyro suppress

The line “Thr. setting AR” is important. Enter the value 

to the right, depending on servo direction, to either 

approximately +125% or -125%. 

0%

Autorot

0%

0%

–125%

SEL

Pitch

Gyro gain

Thr setting AR

Tailoffset AR

Gyro suppress

In doing so, the motor is safely switched off in the autorotation phase (in case of emergency). Later, when 

you have gained enough experience to practice the 

autorotation flight, a more stable idle can be entered 

here.

Adjustment notice for electric helicopters:

Since the motor must also be shut off for electrically 

powered helicopters in case of an emergency, this 

setting is to adopted without change. 

The further sub-menus are not important at the moment. By switching off “autorotation”, it returns to the 

first menu list.

Select the “C1  Tail” settings page in order to set 

static torque compensation for the tail rotor. In this 

case, also work with a maximum of three interpolation 

points; everything else is reserved for the experienced 

pilot. Do this by changing the heading-lock systems 

from their intended uniform pre-setting of 0% at point 

“L” (minimum pitch) to -30% and at the opposite end, 

at point “H” to +30% (maximum pitch). These values 

may have to be corrected in flight. It may also be necessary to set point “1” in the middle.

0%

0%

0%

C1 Tail

Input

Output

Point

Curve off

?

Now, for testing purposes, switch back to the autorotation phase. Here the setting is also deactivated; 

the tail servo no longer reacts to pitch movements 

(no torque usually arises when the main rotor is not 

powered). All additional interpolation points are not 

currently of importance yet.

If, contrary to the default setting, the gyro has a 

transmitter-side sensitivity setting, another free proportional control will be needed. This can be assigned 

in the ...

»Control adjust« (beginning on page 122)

... menu to “Gyro” input. Activate the control assignment with a brief tap on the center SET key of the 

right touch pad then move the selected control until 

its control number appears in the display: 

In5

offset

0%

0%

0%

–––

0%

Thro

Gyro

In8 –––

–––

–––

GL

GL

GL

GL

typ

fr

fr

fr

Cn6

SEL

Conclude this entry with a brief tap on the ESC key of 

the left touch pad then change to the column “- travel +” with the  selection key of the left or right touch 

pad. After a tap on the center SET key of the right 

touch pad, the gyro’s maximum sensitivity can be set 
324 Programming examples - Helicopter models

in the value field displayed in inverse video, e.g. to 

50%. To this end, move the selected control into its 

middle position or, if applicable also to the side, such 

that only one value field is displayed in inverse video:

In5

– travel +

+100%

+100%

+100%

Thro

Gyro

In8

+100%

+100%

+100%

+50% +50%

This produces a fixed value for as long as the control 

remains at the right limit position. The correct value 

must be adjusted in flight. 

In the process, however, always observe the adjustment instructions accompanying your gyro 

sensor, because your helicopter will not be able 

to fly otherwise!

To conclude this initial programming, a few words 

should be mentioned about the menu ...

»Channel 1 curve« (page 141)

Input

Output

Point ?

0%

0%

0%

Ch1 curve

Curve off

This function is a type of “convenient exponential 

curve” for the throttle/pitch stick and the mixer functions connected to it.

If ever, this curve should only be applied “cautiously” 

at the very end, when all adjustments have been 

made. It should never be used for the throttle/pitch 

adjustment! The over-lapping result in “nasty” effects.

With this, all helicopter-specific settings which can be 

made on the “workbench” are now completed. The 

further fine-tuning must take place in flight. The flighttested, (hopefully) minor (digital) trim settings are 

automatically saved. 

Larger deviations should first be mechanically adjusted or adjusted according to the previously discussed 

settings.

Further settings

Following this programming example, you have provided a helicopter with a basic adjustment for the 

hovering training and simple trips. Depending on your 

knowledge and experience as a pilot, additional functions can, of course, also be activated. 

If you want to fly at different speeds and with different 

trimming, you activate the so-called “flight phases”, 

which can be called with assigned switches as an alternative to the previously described “normal phase”. 

For this purpose, first open the menu ...

»Phase settings« (page 156)

... whereby the symbols appearing in the second 

column, sometimes only after a switch assignment in 

the »Phase assignment« menu, have the following 

meanings:

“–”: no phase switch present

“+”: phase switch present

“”: currently active phase

Pha1

Pha2

Pha3

Name ph.Tim.

Pha4

Autorot

–

–

–

Auto +



However, consider in advance whether these are to 

be implemented with individual switches or, more 

reasonably, with 3-way switches because as many as 

6 flight phases can be activated in addition to the autorotation phase. The latter possibility is more logical 

and usually more clearly laid out.

The “Autorot” line is already selected in the figure 

above. When activated, the autorotation phase always 

has precedence over any other phases you assign 

switches to. 

However, in the “Name” column you first assign 

“meaningful” names to Phases 1 to 3, which are 

adopted from a list. These identifications serve for the 

better differentiation and are shown later in the base 

screen and for all flight-phase dependent menus, see 

listing on page 150, for example:

Pha1

Pha2

Pha3

Name ph.Tim.

Pha4



+

+

Normal

Hover

–

–

Speed

Auto Autorot

Then, in the fourth column from the left, enter the 

switching time with which FROM phase should switch 

TO the next respective phase. Approximately 1s 

should suffice:

Pha1

Pha2

Pha3

Name Sw.time

Pha4



+

+

Normal

Hover

–

–

1.1s

1.1s

5.0s

Speed

Auto Autorot

1.1s

This value can also be adjusted later according to 

your personal preferences. Please observe in the 

process that TO the autorotation phase, whose name 

is defined as “Autorot”, is switched without a time delay. If necessary, enter the time with which a change 

FROM the autorotation phase to a different phase 

should be affected.

In order to be able to switch between the individual 

flight phases, the assignment of the individual switch-
Programming examples - Helicopter models 325

es or the three-stage switch is necessary.

The assignment of the switch takes place in the 

menu ...

»Phase assignment« (page 158)

Under “C” and “D”, for example, assign the one of the 

two standard 3-way switches mounted into the switch 

panels, e.g.:

Phase assignment

A B C D E F 

1 Normal

6 5

prior combi

Now the given switch position must be assigned to 

the respective flight phase in the »Phase settings« 

menu. Since these phases already have names, the 

name «1 Normal» will initially appear at the right in 

the display. If the already assigned autorotation switch 

was activated, the following warning message appears in the display:

Phase assignment

A B E F 

1 Normal

prior combi

Autorot

As a reminder:

The autorotation phase has absolute precedence.

Therefore, move the autorotation switch back again 

then put the selected switch, in the example the 

three-stage switch connected to switch plug-in locations 5 and 6, initially to one of its limit positions. Now 

use the selection keys to change to the bottom right 

and activate this entry field:

A B C D E F 

6 5

1 Normal

Phase assignment

prior combi

Now use the selection keys to select the desired flight 

phase for this–for example “2 Hover” ...

A B C D E F 

6 5

2 Hover

Phase assignment

prior combi

... and confirm this selection with a brief tap on the 

center SET key of the right touch pad or go ahead 

and put the switch into its other limit position and 

define the name for this new switch position, such as 

«3 Speed». 

A B C D E F 

6 5

3 Speed

Phase assignment

prior combi

The switch’s middle position then receives the name 

“1 Normal”:

A B C D E F 

6 5

1 Normal

Phase assignment

prior combi

Note:

Exchanged or different name assignments for the 

three switch positions are, of course, also possible. 

Thus, for example, implementation of a programmed 

speed controller (as described beginning in the next 

column) can make a sequence like “normal / hover / 

acro” quite logical.

The model settings made before the assignment of 

a phase switch are now in the flight phase “Normal”. 

This is the phase which is called after the above definition in the switch center position.

This normal setting, which was already tested in 

flight, can be copied to a different flight phase so that 

flying can take place in the same manner in every 

phase at first. For this purpose, use the menu ...

»Copy/Erase« (page 80) 

=>

=>

=>

=>

=>

Copy flight phase

Erase model

Copy model–>model

Export to SD

Import from SD

With the operation of the flight phases, it is possible 

to carry out changes in the phase-dependent menu 

for each individual phase. Since the mc-16 HoTT 

and mc-20 HoTT transmitters has digital trimming, in addition to the flight-phase dependent menu 

settings in the helicopter program, the trim positions 

of roll, nick and tail rotor stick can also be selected 

for storage on a flight-phase dependent basis, see 

»Stick mode« menu, page 116:

STARLET

#02

2:22h

Stp

Flt

 

0:00

0:00

5.5V

3.9V

M

HoTT
326 Programming examples - Helicopter models

Enhancement recommendation: 

Rotational speed regulator

At some point in time you may want to install a rotational speed regulator in the helicopter, in order to be 

able to fly with speeds automatically kept at a constant. In the process, it is logical to couple the individual rotational speeds with the flight phases so that 

further additional adjustments are possible.

It is mandatory for the transmitter-side programming 

that the rotational speed regulator was installed and 

programmed according to the manufacturer’s instructions. Of course, the mc-16 HoTT and mc-20

HoTT transmitters here too offers multiple possibilities 

to realize various speeds in individual phases. A practical proposal which retains the throttle limiter function 

can be found beginning on page 193.

If you have adjusted your helicopter according to this 

programming principle, it is not yet a competition helicopter, but it already permits sophisticated flying. 

You should only activate additional functions if the 

model flies faultlessly so that the (desired) improvements are also easy to follow. Insofar as possible, 

activate individual functions on an individual basis 

so that you can actually recognize and attribute the 

change. Bear in mind that it is not the quantity of functions used that distinguishes good pilots, but what 

they can do in terms of flying with relatively little input.
For your notes 327
328 For your notes
FCC-Information 329

FCC Information

Graupner|SJ mc-16 / 20 HoTT

FCC ID: ZKZ-MC-16

FCC ID: ZKZ-MC-20

FCC Label Compliance Statement

This device complies with Part 15C of the FCC Rules. 

Operation is subject to the following two conditions:

1. This device may not cause harmful interference.

2. This device must accept any interference received, 

including interference that may cause undesired 

operation.

WARNING:

Changes or modifi cations not expressly approved by 

the party responsible for compliance could void the 

user‘s authority to operate the equipment.

NOTE

This equipment has been tested and found to comply 

with the limits for a Class B digital device, pursuant to 

Part 15C of the FCC Rules. These limits are designed 

to provide reasonable protection against harmful 

interference in a residential installation. This equipment generates uses and can radiate radio frequency 

energy and, if not installed and used in accordance 

with the instructions, may cause harmful interference 

to radio communications. However, there is no guarantee that interference will not occur in a particular 

installation. If this equipment does cause harmful 

interference to radio or television reception, which can 

be determined by turning the equipment off and on, 

the user is encouraged to try to correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.

• Increase the separation between the equipment 

and receiver.

• Connect the equipment into an outlet on a circuit 

different from that to which the receiver is connected.

• Consult the dealer or an experienced radio/TV 

technician for help.

RF Exposure Statement

This device has been evaluated to meet the FCC 

RF exposure requirement when used in combination 

with the genuine Graupner|SJ HoTT accessoires and 

operated with a minimum distance of 20 cm between 

the antenna and your body.
330 Declaration of Conformity

Declaration of Conformity Konformitätserklärung gemäß dem Gesetz über Funkanlagen und Telekomunikationsendeinrichtungen (FTEG) und der Richtlinie 1999/5/EG (R&TTE) Declaration of Conformity in accordiance with the Radio and Telecomunikations Terminal Equipment Act (FTEG) and Directive 1999/5/EG (R&TTE) Graupner GmbH & Co. KG Henriettenstraße 94-96 D-73230 Kirchheim/Teck erklärt, dass das Produkt: declares that the product

Geräteklasse: 2Equipment classden grundlegenden Anforderungen des § 3 und den übrigen einschlägigen Bestimmungen des FTEG (Artikel 3 der R&TTE) entspricht. complies with the essential requirements of § 3 and the other relevant provisions of the FTEG (Article 3 of theR&TTE Directive).Angewendete harmonisierte Normen:Harmonised standards applied

EN 60950-1:2006+A11:

2009+A1:2010+A12:2011 

EN 301 489-1 V1.9.2EN 301 489-17 V2.1.1EN 300 328 V1.7.1 

 Health and safety requirements pursuant to § 3 (1) 1. (Article 3 (1) a)) Protection requirement concernig electromagnetic compatibility § 3 (1) 2, Artikel 3 (1) b)) Measures for the efficient use of the radio frequency spectrum § 3 (2) (Article 3 (2))

Kirchheim,07. August 2012 Stefan Graupner, Geschäftsführer 

Stefan Graupner, Managing Director

Graupner GmbH & Co. KG Henriettenstraße 94-96 D-73230 Kirchheim/Teck GermanyTel: 07021/722-0 EMail: info@graupner.de Fax: 07021/722-188

Gesundheit und Sicherheit gemäß § 3 (1) 1. (Artikel 3 (1)a)) Schutzanforderungen in Bezug auf elektromagnetische 

Verträglichkeit § 3 (1) 2, Artikel 3 (1) b))

Maßnahmen zur effizienten Nutzung des Frequenzspektrums 

§ 3 (2) (Artikel 3 (2))

mx-10 HoTT - No. 33110, mx-12 HoTT - No. 33112, mx-16 HoTT - No. 33116, mx-20 HoTT - No. 33124,mc-16 HoTT - No. 33016, mc-20 HoTT - No. 33020,mc-32 - No. 33032

0678

GR-12S HoTT - No. 33505, GR-12 HoTT - No. 33506, GR-16 HoTT - No. 33508, GR-24 HoTT - No. 33512, GR-32 HoTT - No. 33516
Warranty Certificate 331

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Set mc-16 HoTT

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Printed in China PN.QK-01 (V3de)

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