FT8 DXpedition Mode
User Guide
Joe Taylor, K1JT — May 16, 2018

WSJT-X Version 1.9 introduces special operating features that enable DXpeditions tomake FT8 QSOs at very high rates. The following instructions explain how to use these
new features. The instructions are intended for users already familiar with program WSJTX and the FT8 protocol. If necessary, refer also to the WSJT-X User Guide, accessible
from the WSJT-X Help menu.
Basic Operation and Frequency Conventions
In FT8 DXpedition mode, QSOs between the DXpedition (“Fox”) and calling stations(“Hounds”) can be completed with as little as one Fox transmission per QSO. Moreover,authorized Foxes can transmit up to five signals simultaneously, thereby allowing QSO
rates up to about 500 per hour in ideal conditions.
Please note these restrictions and prerequisites:
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FT8 DXpedition mode is intended for use by rare-entity DXpeditions and otherunusual circumstances in which sustained QSO rates well above 100/hour are
expected. Do not use the multi-signal capability if you do not satisfy thisrequirement.
DXpedition Mode must not be used in the conventional FT8 sub-bands. If you arecontemplating operation as Fox in DXpedition Mode, find a suitable dial frequency
consistent with regional band plans and publicize it for the operators you hope towork. Remember that on-the-air signal frequencies will be higher than the dialfrequency by up to 4 kHz.
Everyone, including Fox and all Hounds trying to work Fox, must use WSJT-X
Version 1.9.0 or later.
Everyone should use CAT control with Split Operation, either Rig or Fake It on
the WSJT-X Settings | Radio tab:

Everyone should check Monitor returns to last used frequency on the Settings |General tab.

Fox transmits at audio frequencies between 300 and 900 Hz. When transmitting multiple
simultaneous signals, the signals are spaced at 60 Hz intervals.
Hounds make initial calls anywhere in the range 1000 – 4000 Hz. Fox will not respond to
Hounds initially calling below 1000 Hz. Hounds acknowledge having been called and send
their “R+rpt” messages at the same frequency at which they were called by Fox, nominally1

in the range 300 – 540 Hz. If a Hound needs to send “R+rpt” more than once, subsequenttransmissions will be moved 300 Hz higher or lower. These frequency conventions are
enforced and orchestrated semi-automatically by WSJT-X.
When Fox is running a pileup the standard messages look something like the following,where Fox is signing KH1/KH7Z:
Fox
1.
2.
3.
4.
5.
6.
7.
8.

CQ KH1/KH7Z
K1ABC KH7Z -13
K1ABC RR73; W9XYZ <KH1/KH7Z> -17
W9XYZ RR73; G4AAA <KH1/KH7Z> -09...

Hounds________________________________
KH7Z K1ABC FN42, KH7Z W9XYZ EN37, ...
KH7Z K1ABC R-11
KH7Z W9XYZ R-16

Note that Hounds use Fox’s base call, not his full compound callsign.
Hounds that must use a compound callsign should enter their compound callsign in theusual place, in the My Call box on the Settings | General tab. WSJT-X will detect thecompound callsign and will call Fox by omitting the locator and sending DE followed by thecompound call: for example DE W2/G4XYZ or DE K1ABC/7. We recommend using theoption Full call in Tx5 only.
Detailed Instructions for Hounds
1. Start WSJT-X in FT8 mode and select the desired band and pre-arranged dialfrequency. If this frequency is not already present in the Working Frequencies
table on the Settings | Frequencies tab, you should add it there. Right click on the
Working Frequencies table, choose Insert, then select Mode = FT8 and enter thefrequency in MHz. You can do this for any number of bands and frequencies.

22. Select Hound under FT8 DXpedition mode on the Settings | Advanced tab. Do not
try to work the Fox in normal FT8 mode.

3. Select Tab 1 on the main window for transmitted messages, and set Tx nnnn Hz toa Tx frequency between 1000 and 4000 Hz. You can also select a Tx frequency byusing Shift+Click on the waterfall display. You may find frequencies above 3000
Hz are desirable because they have less QRM. Select the “Tx1” message under
Next. (WSJT-X 2.3.0 and later has only two tabs here, rather than three.)

4. On the Settings | General tab, check Double-click on call sets Tx enable.

35. Enter Fox’s callsign as DX Call. If Fox is using a compound callsign, be sure toenter all of it. The grid locator is optional but provides the advantage of displaying
the short-path azimuth and distance from your location.

6. Configure Wide Graph (the waterfall window) suitably for your system. It shouldlook something like the screen shot below. Signals from Fox are expected at audio
frequencies between 300 and 900 Hz, so be sure that the low-frequency end of yourdisplayed spectrum goes down to 200 Hz or lower. You may want to set the highfrequency end of the waterfall to 4000 Hz, to make it easy to set your Tx frequency
with Shift+Click on the waterfall. Doing so also makes it easy to see thefrequencies of other Hound signals as you monitor the band.

7. Toggle the Monitor button on the main window to green, to start receiving.
8. Note that in Hound mode, WSJT-X is normally configured to ignore signals above
1000 Hz. If you wish to decode signals over the full range of the waterfall, to keep
closer track of the pileup, check the box Rx All Freqs.
9. Please do not call Fox if you are not receiving his transmissions. Do not call
Fox if he issues a directed CQ (“CQ EU”, “CQ 7”, …) and your continent or
numerical call area does not match the requested one. Calling out of turn only
creates QRM, and will certainly not get you a QSO.
10. Remember that FT8 is a weak-signal mode. Contacts can be made reliably withsignals well below the audible threshold. The Fox operator may explicitly decide toanswer only calls with signal strength below some limit, for example S/N = –10 dB.
In many cases you will not need and should not use an amplifier. It’s more
important to find a calling frequency free of QRM.
11. After you have copied Fox calling CQ or working someone else, double-click on his
decoded message to call him. You may keep calling until he answers, perhaps
changing your Tx frequency in the hope of finding a frequency clear of interference.
Use Shift+Click on the waterfall to change your Tx frequency — the red “goal4posts” marker on the waterfall scale. You will need to re-activate Enable Tx (or hit
Enter on the keyboard) at least once every two minutes. (This restriction is toensure that an operator is present and paying attention.)
12. After you receive a signal report from Fox, WSJT-X will automatically send yournext transmission as message Tx 3 (“R+rpt”) at the same frequency at which Fox
called you. If you need to send “R+rpt” more than once, subsequent transmissions
will be moved 300 Hz higher or lower. Note that WSJT-X will send this message
even if Enable Tx is disabled, and even if you have not called Fox for several Tx
sequences. If you have stopped calling Fox because you will be leaving the rig
unattended, you should quit WSJT-X or disable Hound mode in order to avoid thepossibility of unwanted transmissions.
13. When Fox receives your “R+rpt” message he responds with “RR73”. At this point
he considers your QSO complete and logs it. When you receive “RR73” you should
log it, too !
14. If for some reason a Hound fails to copy an RR73 sent by Fox, that Hound will
repeat his transmission of Tx 3 (“R+rpt”). Fox will respond to such “R+rpt”
messages by sending “RR73” up to three times.
Detailed Instructions for Fox
1. Start WSJT-X in FT8 mode and select the desired band and pre-arranged dialfrequency. If this frequency is not already present in the Working Frequencies
table on the Settings | Frequencies tab, you should add it. Right click on the
Working Frequencies table, choose Insert, select Mode = FT8, and enter thefrequency in MHz. Check Show DXCC entity and worked before status on the
Settings | General tab.
2. Select Fox on the Settings | Advanced tab. This choice will enforce that Tx
even/1st and Auto Seq (on the main window, see next page) are checked.

53. Configure the Wide Graph (waterfall window) as shown for Hounds on page 4.
Hounds make their initial calls at audio frequencies 1000 – 4000 Hz; after being
called they acknowledge and send their report at a frequency between 300 and 900
Hz. Be sure to configure the Wide Graph so that your waterfall extends at leastfrom 200 to 4000 Hz.
4. Select Tab 3 (Tab 2 for WSJT-X 2.3.0 and later) for Tx messages. Set Tx 300 Hz,
and check Hold Tx Freq.

5. To evade QRM you can choose another Tx frequency in the range 300 – 600 Hz.
Alternatively, you can uncheck Hold Tx Freq and WSJT-X will randomly choose astarting frequency in this range for each transmission.
6. In Fox mode the left text panel on the main window is labeled “Stations calling
DXpedition …”. When Hounds are calling Fox, this window will be filled with asorted list of callsigns and associated information, as shown below. By using thedrop-down list at the top right you can choose to sort the list by Call, Grid, S/N,
Distance, or Random order. The Age parameter tells how many Rx sequences
ago each Hound was most recently decoded. Hound callsigns are dropped fromthe list if their Age exceeds 4 sequences. If your most recent CQ was directed to aparticular continent, only calls from that continent will be displayed.

7. N List sets the maximum number of sorted callsigns that will be displayed in the lefttext panel.
68. You can limit displayed callsigns to those no stronger than Max dB. As Fox you
can use this feature to work weaker stations, thereby discouraging Hounds fromengaging in a high-power “arms race”. Remember that FT8 is designed as a weaksignal mode. It provides reliable decoding at signal-to-noise ratios down to about –20 dB.
9. N Slots sets the maximum number of Fox signals transmitted simultaneously. Fox
can conduct as many as N Slots QSOs in parallel.
10. The CQ drop-down list offers a selection of CQ messages directed to a particular
continent or numerical call area. If you have selected one of these options, nonmatching calls from Hounds will be ignored. You should probably call CQ for
several sequences after changing this selection, to make sure everybody gets themessage.

11. Click on Fox Log on the View menu to display an optional window showing QSOs
logged in the current WSJT-X session. This window also displays the number of
decodable Hounds found to be calling, the number of QSOs in progress, thenumber logged in the current session, and the hourly QSO rate.

12. To send logged QSOs directly to N1MM Logger+, go to Settings | Reporting,check Enable logged contact ADIF broadcast, and enter the IP address and port
number used by N1MM.

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You must also configure N1MM to accept logging data from WSJT-X. Go to Config| Configure Ports, … | Broadcast Data … and check the box near the bottom thatenables WSJT and JTAlert connections
13. The Fox operator’s main task is to select Hounds to be called and worked. The
rectangular text box on Tab 3 holds the QSO queue: a list of Hound calls to beworked and the signal reports they will be sent. Hit Enter to select the top callsign
from the sorted list and enter it in the QSO queue. Alternatively, you may doubleclick on any call in the list to move it to the QSO queue.
14. Double-click on a callsign in the QSO queue to delete it from this queue.
15. The Reset button clears all queues, thereby ensuring that Fox will call CQ at thenext opportunity.
16. The right text window (labeled “Rx Frequency”) displays decodes of signals below
1000 Hz (by default these are highlighted in red) and Fox’s own transmissions(highlighted in yellow). The red messages will be those containing “R+rpt”,
signifying that a Hound is awaiting the concluding “RR73” from Fox.
17. To start a run, activate the Enable Tx button. If a Hound call is available in the
QSO queue, that station will be called in Fox’s next transmission. If the QSO
queue is empty, Fox will call CQ. If N Slots is greater than 1 and more Hounds areavailable in the queue, Fox will call more than one Hound.
18. After receiving “R+rpt” from a Hound previously called, Fox will send “RR73” to that
Hound and log the QSO.
19. WSJT-X maintains several queues in a manner that allows difficult QSOs to becompleted while keeping the overall QSO rate high. We use a “3 strikes and you’reout” rule. Fox will call a specific Hound up to 3 times, waiting for an “R+rpt”
response. If a Hound repeatedly sends an “R+rpt” message, Fox will send RR73 up
to 3 times. Finally, the total timespan of an attempted QSO is limited to 3 minutes.
When any of these timeouts is exceeded, the QSO is aborted.
20. Fox is programmed to call CQ in a single slot (and thus at maximum signal power)
at least once every 5 minutes.
21. You can transmit short messages to instruct the pileup by using one of the Tx
message boxes (say Tx 5) on Tab 1, or the Free msg box on Tab 2. Examples
might be “NOW 15 M” or “QSY 21.067”.
22. If you have plenty of Hound callers and you’re tending to work Hounds with S/N = 10 dB or higher, you can speed up the decoding by choosing Normal rather than8

Deep on the Decode menu. Don’t forget to return to Deep when working weakersignals.
Important Note for Fox Operators: When using N Slots > 1, your transmitted signal will
not have a constant envelope. To avoid producing unwanted sidebands you must ensure
good linearity throughout your Tx system. One way to get things about right is to use the
WSJT-X Tune button to generate an unmodulated carrier. Configure your transmitter andPA as required for the desired peak output power, say P0. Then pull the Pwr slider(bottom right of the WSJT-X main window) down until your output power decreases by
about 10%. Use this audio level setting for all your Fox transmissions. If you are using N
Slots signals, your average transmitted power will be P0/(N Slots) and the power in eachsignal will be P0/(N Slots)2. Thus, for N Slots = 1, 2, 3, 4, and 5 the average power per
signal will be down from P0 by about 0, 6, 9.5, 12, and 14 dB, respectively.

Answers to Frequently Asked Questions
1. Why should FT8 DXpedition Mode be used only by DXpedition stations and thosetrying to work them?
a. In FT8 DXpedition mode, Tx frequencies of Fox and Hound stations are
sometimes controlled by the program rather than by the operator. This behavior
is undesirable for general use, and would be extremely anti-social if used in theconventional FT8 subbands.
b. Stations other than legitimate DXpeditions should not “hog the spectrum” bygenerating multiple simultaneous signals.
2. Can FT8 DXpedition Mode be used for Field Day, QSO parties, and othercontests? No. This new mode is explicitly designed for the many-to-one situation of apileup trying to work a rare DX station, exchanging reports. It is not suitable for events
where everybody works everybody, exchanging other specified information.
3. Can the new program version be used for normal FT8 operation? Yes, and also
for operation in all the other modes supported by WSJT-X v1.8.0.
4. The Tx filter in my rig cuts off at 2700 Hz. How can I make use of the full
frequency range 1000 – 4000 Hz allocated for Hounds? You should be using Split
Operation, so that your Tx audio always stays in the range 1500 to 2000 Hz. See Section
4.2 in the WSJT-X User Guide.
5. I can’t use CAT control; can I still work the Fox? With some extra effort andinconvenience, yes. Select your initial Tx frequency somewhere in the range 1000 –4000 Hz where you know you can transmit. When Fox sends you a signal report,
immediately change your audio Tx frequency to something below in the range 300 –900 Hz, and send your Tx3 message there.
96. My big antennas and legal limit amplifier make me loud, and I'm used to working
DX before everyone else. Why can't I make a contact with Fox? The DXpedition
operator may have the Max dB filter set, and you're being ignored because your signal
is too strong. FT8 is a weak-signal mode. Try reducing your power output.
7. How does the new message format work? Standard JT-style structured messages
include two callsigns and a locator or report. Normally the two callsigns are those of theaddressed and transmitting stations. The new message format used by Fox (e.g., lines
5 and 7 near the top of page 2) is flagged by setting one of the three extra bits in the
75-bit FT8 payload. Upon reception, the two callsigns are then interpreted as those of
two different Hounds: one whose QSO is acknowledged as complete, and one now
invited to send a report. The 16-bit field normally used for a locator or report is instead
used for a 10-bit hash of Fox’s callsign and a signal report.
8. Are you trying to kill CW as a mode? No. CW is a highly flexible general-purpose
mode with good weak signal performance and good spectral efficiency. FT8 has evenbetter weak signal performance and spectral efficiency, but it is a special-purpose
mode designed specifically to optimize reliable, minimal QSO exchanges.

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