05/2022
contacto@amsat-ea.org

eb1ao@amsat-ea.org

MAY

Translation by Fernando EC1AME

Plantsat
PlantSat (Satellite of the Universityof Chile for the aerospace research)is a
CubeSat 3U satellite,built by students andengineers from the University of Chile. Its
main mission is to monitor the behavior of aplant in a microgravity environment andunder extreme solar radiation conditions.
Its objective is to study in a low orbit thegrowth of a plant, replicating the conditions
that will experience life on the surface ofMars. These conditions include low force ofgravity and high solar radiation.
Plantsat is a joint project between the
researcher Mr. Matthew Lehmitz, who leads
the scientific mission, GomSpace ,a danish
company that kindly provide the satellite
platform, the University of Chile that leads
assembly, integration, testing and loading
utility of the biosphere and Rocket Lab.
The 3U CubeSat satellite, provided
by GomSpace, consists of two units
containing the satellite systems (based on
SUCHAI 2) and a unit consisting of the
payload of the biosphere. The type of plant
proposed for PlantSat is Tillandsia. This is a plant that can be found throughout
the neotropics, high in the Andes mountains and near the shores of the
Atacama desert. Its strength and versatility makes it an excellent candidate forsurviving in harsh environments.

A launch from a plane was originally planned, but later the mission moved
to the ION-SCV 005 tug to be launched on a Falcon-9 v1.2 (Block 5) in April 2022.
Telemetry Downlink Frequency 437.240 FSK Ax100
More info:

URESAT-1 (Satellite Modules)
EA4GQS - Felix (Amsat-EA CEO)In this newsletter we are going to talk about the architecture ofmodules/functional units of our URESAT satellite, which are the following:
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Solar panels
EPS - Electric Power System
Control processor (OBC – On Board Computer)
Receiving system (RX)Transmitter
Antenna system
Mechanical structure
Orientation Control System (ADCS)
Thermal control system

Solar Panels and Power System (EPS)
Up to six satellite faces +X+Y+Z-X-Y-Z will be equipped with solar panels.
Panels with opposite faces are connected to the same MPPT circuit. The MPPT
(Maximum Power Point Tracker) circuit is a chip that makes the panel work at its
optimal point, allowing to extract from it the maximum possible energy. It has
two control loops. When the panel lighting varies, 1) modifies the working
current-voltage point maximizing the extracted power, and at the same time, 2)
keeps the output voltage stable.
One or several panels can be illuminated simultaneously. MPPTs areconnected to the main power bus. A high-density battery and low weight isconnected to the main power bus through a circuit switch.
The EPS battery charge control system monitors that the battery is notovercharged, or discharged below a limit.

Control Processor (OBC)
The microprocessor monitors different facts of the satellite (voltages,
current, temperatures, counters) and generates periodic telemetry packets forobservation by control operators.
The 32-bit control microprocessor includes capabilities of 1) baseband
signal processing from the analog FM demodulator 2) telecontrol packet
decoding. This microprocessor implements a rudimentary store-and-forward
system, allowing read/write to non-volatile Flash memory using packets ofremote/telemetry.

AMSAT-EA 05/2022

2 of 12Receiver (RX) and transmitter (TX) system
The receiving system is based on an ad-hoc SDR. The SDR allows to
implement different communications services and navigation without
modifying the satellite. Allows to transmit and receive simultaneously (FULL
DUPLEX operation) or remain in reception waiting for signals. Different
waveforms (modulation/protocol) are possible to implement both in thereceiving and transmitting chain replacing the software elements.

Antenna system and mechanical structure
The implemented antennas are very simple: a monopole for VHF andanother for UHF made of tape measure, a very practical material because it
conducts and therefore it serves as an antenna and because it recovers its
position when it is released.
The metal structure uses additive manufacturing techniques andmachinery in steel. It has the necessary robustness for the loads that appear
during the launch and rise. The mechanical structure, determination/control ofOrientation and thermal control are passive and do not consume electricalenergy.

Orientation Control System (ADCS)
An orientation system based on magnets and diamagnetic materials has
an important impact on the signal footprint on the earth's surface by theradiation pattern of the antenna. Having a single stabilized axis forces the useof low directivity antennas. The amplitude of precession is estimated in 30
degrees.

Thermal control system
The thermal control system makes sure that the satellite works in areasonable temperature range. It is a complex issue that requires a lot of
studies.

AMSAT-EA 05/2022

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Calculation of QRG in a linear LEO satellite contact sked
EA1PA - Salva

After a long time without writing an article for the AMSAT-EA
newsletter,I take the opportunity to participate again with these lines. My
intention is to describe a practical situation we encounter often when we
have a sked with another station and, in addition, the duration of the passand the mutual sat footprint is very small.
First, I have to admit that I
don´t like doing skeds with others t at i o n s. I p re fe r ra n d o mcontacts. But , I couldn´t reject a
proposal from Joe, KE9AJ.
Simply couldn't say no and we
did it as a personal challenge.
Most difficult part for Joe since
the possible contact meant he
had to work the satellite withpractically zero or even negative
elevation. I had it easier with a positive elevation, less than a degree, butwith a few trees in that direction that could disrupt everything planned. So, I
couldn't let him down, I had to be there to try.
Joe was in the state of Colorado and moved to the top of a nearby
mountain, "Genesee Mountain" - DM79iq, to try to take advantage of its
exceptional horizon to the east. On my side, I addressed myself to my usual“satellite” spot, “Monte de Tariego” - IN71sv, not far from my QTH in Venta
de Baños, and which has good visibility, without major obstacles except thetrees I mentioned before that could compromise my LOS.
Joe was going to make the great effort to climb up there with all thelogistics, set up the installation, battery, antenna, … and more things ordetails to have into account for an ephemeral pass of a few minutes;
Honestly, I didn't care about the new locator or the new state, my ultimate
goal was for Joe to get the contact done to reward his work, dedication,
time and radio spirit that he shows in his outings with any of us.
Finally, the day marked on the calendar arrived: Sunday, May 15,
satellite AO-07, mode B and we still had to decide the strategy. Consists
mainly in establishing a meeting frequency, specifying who deals withcalling CQ first on that QRG and, of course, "crossing your fingers" to beprepared for any unexpected change.
The QRG chosen for the appointment was 145.955 MHz as thereception frequency on Joe's rig. I would take care of calling CQ first to“reserve” frequency in advance so that when his AOS arrives, it would
coincide with my LOS, Joe could answer my call as fast as possible.
AMSAT-EA 05/2022

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The next step would be to estimate my QRG equivalent to that of Joe's
rig, 145.955 MHz, to meet us at the correct frequencies on both sides.
Namely, calculate the RX frequency of my equipment that I would have totune to hear myself on the way down and be heard in Colorado on thefrequency set by Joe.
It is a bit confusing to explain in words, so I will explain it below. There
are no mysteries, it's eas. I go step by step:
1.The initial or starting data is defined with the location of both
stations:

2.Doppler calculation using SATPC32 software.
ŸŸŸ

AMSAT-EA 05/2022

2.1 Pass seen from IN71sv:
The coordinates, latitude and length, corresponding toIN71sv.

The pass for the AO-7 is simulated considering that the QSO
will happen at 18:43 UTC on May 15. Access through the menu
“Tracking” -> “Preview”.

5 of 12Ÿ

The following data (downlink Doppler) is extracted:

The receive frequency on IN71sv would be 145948.938 kHz foran tx frequency on the satellite of 145950 kHz.
145948.938 – 145950 = -1.062 kHz
The satellite is moving away since the predicted “Doppler shift”
has a negative value.

2.2 Pass seen from Dm79iq:

AMSAT-EA 05/2022

ŸRestart the program to enter the coordinates corresponding toDM79iq.

ŸThe pass for the AO-7 is simulated at the same time as before
from IN71sv. Again we go to “Tracking” -> “Preview”.

6 of 12ŸIn the screen above we check that the data is ok and we we lookat the frequencies of the “Downlink”:

Now the receive frequency on DM79sv would be 145951.001 kHz
for a satellite tx frequency of 145950 kHz.
1459951.001 – 145950 = +1.001 kHz

The satellite is approaching as the predicted Doppler has apositive value.
2.3 Collecting the Doppler data in RX in both stations , for asatellite frequency of 145950 kHz, we can get the following
sketch:3.QRG estimation in IN71:
Now travel the path towards my position. Remember that the
input data is the receive frequency of 145955 kHz on Joe's side.
So, we have it following:

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145955 kHz on DM79 is equivalent to 145953.999 kHz on the sat
1459955 - 1.001 = 145953.999 kHz
145953.999 kHz on the sat its equivalent to 145952.937 kHz on IN71
1459953.999 - 1.062 = 145952.937 kHz

Therefore, if I have not made any mistake, we can estimate that
145952.937 kHz is the approximate receive QRG for me to tune so Joe canhear me on the agreed-upon frequency of 145955kHz. Consequently, once
my equivalent reception QRG is defined , I will adjust my transmission for
the uplink until I hear me clearly on that frequency calculated for my rig.
At first glance, and in VHF, the difference does not seem to be toomuch and the frequencies between the two stations are relatively close,
only slightly more of two kHz, but if we apply it to a satellite with mode J of
operation, the Doppler is practically multiplied by 3. If we add to that a passin which the maximum elevation is considerable and we intend to adjust to
the limits of the trace with the other correspondent, the differences are
already very substantial. So, I consider the calculation to be quite critical,
and that is the key for a good contact under the circumstances described.
Going back to the story of the scheduled contact with Joe, witheverything set and in position, the moment of truth arrived. As planned,
place, time and QRGs, we managed to establish contact with relatively
good signals. Was a special and exciting moment, a mixture of sensations
when imagining the path traveled by the radio waves, back and
AMSAT-EA 05/2022

8 of 12forth,through an "oldie bird " put into orbit in the 1970s, simply Awesome.
Suddenly Joe's voice came out like a magical melody, like coming fromdeep space, clearly recognizable above the noise level and the typical"crackles" of the transponder. The exchange of reports was correct andwe could tell we were really satisfied. Joe, thank you very much for givingme that moment, congratulations on your operation and performance insuch conditions.

Let me highlight that our friend José, EB1AO, was waiting for our QSO
to finish. He kindly patiently allowed the culmination of our QSO to later
work Joe. Congratulations José, thanks to you also for your help and theevidence event audio.
As soon as I finished hearing José I stopped receiving thetransponder, the pass ended for me. It all faded away despite my attempts
to stretch and get on my feet trying to avoid the obstacles and rush the passas much as possible. Anyway, it was short but very intense. It was time to getback home till the next weekend.. I still remember the way back to my QTH
with a smile on my face and accompanied by a beautiful sunset on the local
horizon.
I don't want to end the article without mentioning Juan Antonio,
EA4CYQ, for teaching us how this matter of the QRG is calculated,sincerely the conferences in Iberradio Ávila 2019 marked me deeply. I hopeeverything is ok, and I apologize in advance for any mistakes, oversights, oromissions.
And finally, also thank Philippe, EA4NF, his encouragement andwisdom advice from an operator with plenty of experience, anunquestionable reference of portable operation on all types of situations.

Greetings to all. See you soon,

AMSAT-EA 05/2022

9 of 12AMSAT-UK at EMFCamp 2022
Amsat-UK

June 2 to 5 2022 will takeplace the popular electromagnetic
field event (EMFcamp) at Eastnor
Castle Deer Park, Herefordshire,UK.
Imagine camping withelectricity and high speed internet
access in a crowded village full ofcreators and enthusiasts of thetechnology. The expect visitors fromall over ready to learn, share andchat.
The EMF camp will feature a full program of talks and workshops and there
will be both an Amateur Radio Village GX1EMF and an AMSAT-UK Village GB4EMF.
Among the scheduled talks we can find:ŸŸ Hacking the radio spectrum with GNU Radio by Dave Rowntree

M0IEG.
Ÿ Reception of satellite beacons by Damian Bevan G4WPO.
Ÿ Launch of a rocket suspended by a balloon by Dave Johnson

G4DPZ.
Ÿ Inside Datatrak: Resurrecting a Radio Navigation Network by

Phil Pemberton M0OFX
Ÿ 2500 nerds, one pathetic robot by Chris Stubbs M6EDF
Ÿ Astro Pi Mark II: How to ship a Raspberry Pi from a factory inWales to the International Space Station by Richard Hayler

More information about the event:AMSAT-EA 05/2022

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SAT Frequency Tables
EA1PA - SalvaSATELLITE

LOTW IDUPLINKCTCSS

DOWNLINKMODE

SATELLITE

AO-27 (Eyesat-1)

AO-27

145.850 MHz-

436.795 MHz

FM

AO-07 Mode A(AMSAT-OSCAR 7)

LOTW ID UPLINK BW

TYPE

145.850 MHz

DWNLINK BW

BAND
WIDTH

BEACONTELEMETRY

100 kHz29.502 MHz-

50 kHz145.975 MHz-

100 kHz 435.795 MHz-

29.400 MHz
Normal145.950 MHz

29.500 MHz

432.125 MHz

145.975 MHz

AO-7

ISS Crossband Repeater

ARISS

145.990 MHz

67 Hz

437.800 MHz

FM

AO-07 Mode B(AMSAT-OSCAR 7)

FO-29 (JAS-2)

SO-50 (SaudiSat-1C)

SO-50

145.850 MHz

67 Hz

436.795 MHz

FM

CAS-3H (LilacSat-2)

CAS-3H

144.350 MHz-

437.200 MHz

FM

Reverse432.175 MHz

145.925 MHz

145.900 MHz

435.900 MHz

FO-29

Reverse146.000 MHz

435.800 MHz

435.130 MHz
AO-73 (FUNcube-1)

AO-73

145.970 MHz
Reverse435.150 MHz
435.030 MHz
XW-2A (CAS-3A)

IO-86 (Lapan A2)

IO-86

145.880 MHz

88.5 Hz435.880 MHz

FM

CAS-2T?

145.925 MHz-

435.615 MHzFM

XW-2B (CAS-3B)

XW-2C (CAS-3C)

XW-2A

XW-2B

145.665 MHz

435.090 MHz

145.750 MHz
Reverse435.110 MHz

145.730 MHz

435.150 MHz

145.815 MHz

XW-2C

AO-91

435.250 MHz

67 Hz

145.960 MHz

FM

ReverseXW-2D

AO-92 (Fox-1D) Mode L/V

XW-2E (CAS-3E)

67 Hz

145.880 MHz

XW-2E

FM

1267.350 Mhz

XW-2F (CAS-3F)

PO-101 (Diwata-2)

PO-101437.500 MHz 141.3 Hz

145.900 MHz

FM

UVSQ-SATUVSQ

145.905 MHz-

437.020 MHz

FM

SO-114 (EASAT-2)

SO-114145.875 MHz-

436.666 MHz

FM

LO-87
(LUSEX-OSCAR 87)

LO-87

EO-88 (Nayif-1)

EO-88

145.915 MHz

435.330 MHz

146.000 MHz
Reverse435.350 MHz

145.980 MHz

435.935 MHz

145.965 MHz
Reverse435.965 MHz

CAS-4B (ZHUHAI-1 02)

SO-115145.925 MhHz-

436.888 MHz

JO-97 (JY1Sat)

JO-97

145.860 MHz

435.270 MHz

145.935 MHz
Reverse435.290 MHz

145.915 MHz

435.100 MHz

145.875 MHz
Reverse435.120 MHz

This is a reduced version of
the table of frequencies and data of
the current satellites. Can download
the full table here:

FO-99

RS-44 (DOSAAF-85)
AO-109(RadFxSat-2 / Fox-1E)

AO-109XW-3 (CAS-9)
Hope-OSCAR 113

HO-113145.915 MHz

145.935 MHz

435.670 MHz
Reverse145.995 MHz

435.610 MHz

145.860 MHz

435.790 MHz
Reverse145.890 MHz

145.975 MHz

145.955 MHz

30 kHz145.900 MHz-

30 kHz-145.940 MHz

20 kHz145.855 MHz 145.835 MHz

20 kHz145.910 MHz 145.890 MHz

20 kHz-145.840MHz

30 kHz--

20 kHz145.910 MHz 145.890 MHz

60 kHz435.605 MHz-

30 kHz-435.750 MHz

435.760 MHz

145.855 MHz

435.195 MHz
Reverse145.885 MHz

20 kHz145.935 MHz
Reverse435.290 MHz
RS-44

145.910 MHz 145.890 MHz

435.880 MHz

435.270 MHz
TO-10820 kHz435.910 MHz
Reverse145.930 MHz
TO-108 (CAS-6)

145.855 MHz 145.835 MHz

145.855 MHz

145.900 MHz
FO-99 (NEXUS)

20 kHz145.880 MHz
Reverse435.230 MHz
CAS-4B

FM

145.790 MHz 145.770 MHz

145.960 MHz

435.210 MHz

SO-115 (HADES)

20 kHz145.990 MHz
Reverse435.045 MHz
CAS-4A

145.725 MHz 145.705 MHz

145.935 MHz

435.015 MHz

CAS-4A (ZHUHAI-1 01)

20 kHz145.935 MHz
Reverse435.290 MHz
XW-2F

145.660 MHz 145.640 MHz

145.860 MHz

435.270 MHz

435.350 MHz
AO-92

20 kHz145.880 MHz
Reverse435.230 MHz

AO-92 (Fox-1D) Mode U/V

145.935 MHz

145.795 MHz

435.210 MHz
XW-2D (CAS-3D)-

145.685 MHz
Reverse435.050 MHz

435.170 MHz

AO-91 (RadFxSat / Fox-1B)

20 kHz145.950 MHz

30 kHz435.575 MHz 435.725 MHz

435.165 MHz

PORTABLE STATION OF THE MONTH - (DK9JC- John)AMSAT-EA 05/2022

11 of 12AMSAT-EA products in the URE store
For several weeks you have at your disposal several
products of AMSAT-EA personalized with your callsign on the
URE website.

Don´t hesitate
Support AMSAT-EAAMSAT-EA 05/2022

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