FT8 DXpedition Mode: How to Work Fox and Hound Stations

When a rare entity comes on the air with FT8, the waterfall fills with hundreds of callers within minutes. Ordinary FT8 handles that badly: one QSO at a time, several transmit periods per contact, and a pileup that keeps calling on top of the station it wants to work. FT8 DXpedition Mode, better known as Fox and Hound, was designed to fix exactly that. The DXpedition (the Fox) runs the pileup with a special set of rules, and the callers (the Hounds) follow a matching set of rules so that contacts are completed quickly and with very little wasted airtime.

This guide is written for the chaser. It explains how the mode works, what is different from normal FT8, how to configure WSJT-X as a Hound, where to transmit, what to do when the Fox answers, and the mistakes that most often cost a QSO. The details below follow the FT8 DXpedition Mode User Guide written by Joe Taylor, K1JT, and the WSJT-X User Guide. Where the exact behaviour depends on your software version, check the documentation that ships with the version you run.

Why FT8 DXpedition Mode Exists

Standard FT8 was built for one-to-one contacts. A typical QSO takes several 15-second sequences: a call, a report, a roger with report, and a final RR73 or 73. Multiply that by a pileup of several hundred stations and the hourly rate of a DXpedition becomes painfully low, which means fewer people get the new one before the team packs up.

The DXpedition mode changes the arithmetic in two ways. First, QSOs between the Fox and a Hound can be completed with as little as one Fox transmission per QSO, because the Fox combines the RR73 for one station with the report for the next. Second, an authorised Fox can transmit up to five signals at the same time, each carrying a different QSO. According to K1JT’s guide, this allows rates of up to about 500 QSOs per hour in ideal conditions.

The mode is intended for rare-entity DXpeditions and similar unusual operations, not for everyday use. The guide is explicit that it must not be used in the conventional FT8 sub-bands, because the program controls transmit frequencies in a way that would be anti-social in a shared segment. That is why DXpeditions announce a separate dial frequency for their Fox operation.

Fox and Hound: The Basic Roles

The names describe the situation well. One Fox, many Hounds. The Fox is the DXpedition station; the Hounds are everyone trying to work it. Each side has a fixed role, and WSJT-X enforces much of that role automatically once the correct mode is selected.

What the Fox does

The Fox transmits at audio frequencies between 300 and 900 Hz. Its operator does not answer callers one by one in the classic way. Instead, WSJT-X builds a sorted list of calling Hounds, and the operator moves callsigns from that list into a QSO queue. The software then calls the queued stations, sends reports and confirms completed QSOs, using several simultaneous signals if the Fox is configured to do so.

What the Hound does

The Hound makes its initial calls anywhere between 1000 and 4000 Hz. The Fox will not respond to Hounds that call below 1000 Hz. When the Fox calls a Hound, the Hound replies with its “R+report” message at the same frequency where the Fox called it, nominally in the lower part of the Fox range. Once the Fox receives that roger, it sends RR73 and logs the QSO.

The key point for a chaser is that you never need to work out the low-frequency reply yourself. WSJT-X moves your transmit frequency for the R+report automatically. Your job is to call in the right place, at the right time, and to leave the rest to the software.

Fox and Hound Compared With Normal FT8

The table below summarises the main practical differences a chaser notices. Values come from the FT8 DXpedition Mode User Guide.

Setting Up WSJT-X as a Hound

Most failed Fox and Hound attempts come from configuration, not propagation. Set things up before the DXpedition is on your band, not while the pileup is running. If your basic FT8 station still needs work, start with our guide to a WSJT-X and FT8 setup that works the first time, then come back to the Hound-specific steps below.

Version and CAT control

Everyone involved, Fox and Hounds alike, must use a WSJT-X version that supports DXpedition Mode; the feature arrived in WSJT-X 1.9.0, so any current release qualifies. The guide also asks everyone to use CAT control with Split Operation, set to either Rig or Fake It on the Settings | Radio tab. Split matters because your audio transmit frequency may change across a wide range during the QSO, and split keeps the actual audio tone in a comfortable part of your transmitter’s passband.

The guide also asks users to check “Monitor returns to last used frequency” on the Settings | General tab, so that the program comes back to the DXpedition frequency after you stop and restart monitoring.

The dial frequency

DXpeditions publish their Fox frequencies in advance. If the frequency is not already in your Working Frequencies table on the Settings | Frequencies tab, add it: right-click the table, choose Insert, select FT8 as the mode and type the frequency in MHz.

Selecting Hound

On the Settings | Advanced tab, under the special operating activity options, select Hound. Do not try to work a Fox in normal FT8 mode. The two sides only fit together when both use the matching modes.

Transmit messages and Tx frequency

On the main window, use the first tab for transmitted messages and set the Tx frequency somewhere between 1000 and 4000 Hz. You can also Shift+Click on the waterfall to pick it. K1JT notes that frequencies above 3000 Hz can be attractive because they usually carry less QRM. Select Tx1 as the next message.

The guide also recommends checking “Double-click on call sets Tx enable” on the Settings | General tab, so that one double-click on the Fox’s decode starts your call.

DX Call and the waterfall

Enter the Fox’s callsign as DX Call. If the DXpedition uses a compound callsign, enter all of it. The grid locator is optional, but adding it shows short-path azimuth and distance, which helps if you turn a beam.

Configure the Wide Graph so that the low end of the displayed spectrum reaches 200 Hz or lower; the Fox signals sit between 300 and 900 Hz, and you need to see them. Setting the upper end to 4000 Hz makes it easy to place your own Tx frequency and to see where other Hounds are calling.

Decoding range

In Hound mode WSJT-X normally ignores signals above 1000 Hz, because that is where the other Hounds are, not the Fox. If you want to watch the whole pileup, check Rx All Freqs.

Calling the Fox: Step by Step

With the station configured, the actual operating is simple. The difficult part is discipline. The sequence below follows the Hound instructions in the official guide.

1. Listen first. Toggle Monitor on and wait until you decode the Fox. Do not call if you are not receiving the Fox’s transmissions. Calling blind only adds QRM.
2. Respect directed CQs. If the Fox sends “CQ EU”, “CQ 7” or similar and your continent or numerical call area does not match, do not call. The Fox software ignores non-matching callers anyway, so calling out of turn gains nothing.
3. Call. After you have copied the Fox calling CQ or working someone, double-click its decoded message. Your Tx1 call goes out on your chosen frequency between 1000 and 4000 Hz.
4. Keep calling sensibly. You may keep calling until the Fox answers, and you can move your Tx frequency to find a clearer spot with Shift+Click on the waterfall. WSJT-X requires you to re-activate Enable Tx (or press Enter) at least once every two minutes, to make sure an operator is present.
5. Let the software reply. When the Fox sends you a report, WSJT-X automatically sends Tx3, your R+report, at the frequency where the Fox called you. If it needs to send the R+report more than once, later transmissions move 300 Hz higher or lower.
6. Log on RR73. When the Fox receives your R+report, it answers with RR73, logs the QSO and moves on. When you receive RR73, log it too.

If you miss the RR73, WSJT-X repeats your R+report. The Fox software answers repeated R+report messages with RR73 up to three times, so a single missed decode does not usually cost the contact.

What a Fox Pileup Looks Like on Screen

The messages are compact. A typical exchange in the K1JT guide, with a Fox signing a compound call, runs like this: the Fox calls CQ; several Hounds call it with their callsign and grid; the Fox sends one Hound a report; that Hound replies with “R” and its report; the Fox then sends RR73 to that Hound and, in the same transmission, a report to the next Hound. That combined message is the trick that allows one Fox transmission per QSO.

Because the Fox may be running several slots, you will often see two, three or more Fox decodes in the same period, each to a different station. Do not be surprised if your callsign appears in a decode alongside another Hound’s RR73.

The Fox side also uses a “three strikes” approach. According to the guide, the Fox calls a specific Hound up to three times while waiting for an R+report, and an attempted QSO is limited to three minutes in total. If you are called but do not answer in time, the software moves on. Watching the waterfall closely while you are calling is therefore more important than calling more often. If you are new to busy DX openings in general, our article on working a pileup from both sides covers the human side of the same problem.

Power, QRM and Why the Loudest Station Does Not Always Win

FT8 is a weak-signal mode, and the DXpedition mode keeps that character. The guide points out that contacts can be made reliably with signals well below the audible threshold, and that FT8 provides reliable decoding at signal-to-noise ratios down to about -20 dB.

The Fox operator also has a tool that changes the usual pileup logic: a Max dB setting that limits the displayed callers to those no stronger than a chosen level. A Fox can use it to work weaker stations deliberately and so discourage a high-power arms race. In practice that means:

• An amplifier is often unnecessary. The guide says that in many cases you will not need, and should not use, one.
• A clean calling frequency matters more than raw power. Moving to a less crowded part of the 1000 to 4000 Hz range is often the best thing you can do.
• Over-driven, distorted transmissions do not help. A clean FT8 signal with correct audio levels decodes better at the Fox than a loud but dirty one.

If your radio’s transmit filter cuts off around 2700 Hz, the guide’s answer is the same as above: use split operation. With split, WSJT-X keeps your actual transmitted audio tone within a narrow, comfortable range while the rig’s dial frequency moves, so you can still use the full 1000 to 4000 Hz calling range.

Common Mistakes That Cost the QSO

Most Hound failures are avoidable. The list below collects the mistakes the official instructions specifically warn against and a few that follow from them.

• Working the Fox in normal FT8 mode. Without Hound selected, your station does not behave the way the Fox software expects.
• Calling below 1000 Hz. The Fox will not respond to initial calls there, and you interfere with its own signals.
• Calling without copying the Fox. If you cannot decode the Fox, the QSO cannot be completed, no matter how often you call.
• Ignoring directed CQs. A non-matching call is simply ignored and adds QRM.
• Leaving the station unattended in Hound mode. The guide warns that WSJT-X will send your R+report automatically if the Fox calls you, even if Enable Tx is off and even if you stopped calling several sequences ago. If you step away from the rig, quit WSJT-X or disable Hound mode first.
• Forgetting to switch back. After the DXpedition, return to normal FT8 before you operate in the regular sub-bands. Hound mode is not meant for everyday contacts.

Finding the Fox Before Everyone Else

Fox and Hound operations are usually announced well ahead of time, including the planned bands and dial frequencies. The NG3K Announced DX Operations calendar is a long-standing independent listing of upcoming DXpeditions, and most teams publish their own frequency plans on their websites.

The harder part is knowing when the Fox is actually on your band. FT8 DXpeditions are spotted heavily on the DX clusters, so a callsign alert that watches the clusters for you is the most reliable way to catch a short opening. Our guide to automating DX spot alerts explains how to set that up, and the broader article on how to work a DXpedition covers planning, propagation and logging around the operation itself.

Once you have the alert, the configuration work you did in advance pays off: select the band, choose the Fox dial frequency from your Working Frequencies table, confirm Hound mode is active, and start monitoring.

Notes on Software Versions and Other Programs

The DXpedition mode has been part of WSJT-X since version 1.9, and later releases have refined it. The release notes for WSJT-X 2.7 mention more convenient handling of the two callsign queues on the Fox side, a Fox Log window with recent QSO rate statistics, and proper handling in Hound mode of multi-streamed messages transmitted by the MSHV program. Some DXpeditions run MSHV rather than WSJT-X on the Fox side, which is why that compatibility matters to chasers.

The safest habit is simple: run a current release from the official WSJT-X website, read the DXpedition’s own operating notes before calling, and follow any specific instructions they publish. For a neutral overview of the FT8 protocol itself, the FT8 article on Wikipedia is a reasonable starting point.

The Bottom Line

FT8 DXpedition Mode turns a chaotic FT8 pileup into an orderly, high-rate operation, but only if the Hounds play their part. Select Hound in WSJT-X, use CAT with split, set the published dial frequency, call between 1000 and 4000 Hz, and only call when you can decode the Fox and a directed CQ includes you. Let the software send your R+report where the Fox called you, log the QSO when RR73 arrives, and never leave the station unattended in Hound mode. Prepare the configuration before the DXpedition starts, keep an alert running for its callsign, and a clean, modest signal will often get you into the log faster than a big amplifier.

Frequently Asked Questions

What is FT8 DXpedition Mode?

It is a special operating mode in WSJT-X, also called Fox and Hound, that lets a DXpedition (the Fox) work FT8 pileups at high rates. QSOs can be completed with one Fox transmission per QSO, and an authorised Fox can send up to five signals at once.

Where should a Hound call the Fox?

Make your initial calls anywhere between 1000 and 4000 Hz audio on the dial frequency announced by the DXpedition. The Fox will not respond to initial calls below 1000 Hz, and its own signals are between 300 and 900 Hz.

Do I need to change my frequency when the Fox answers?

No. In Hound mode WSJT-X automatically sends your R+report at the frequency where the Fox called you. If it has to repeat the message, it moves 300 Hz higher or lower.

Can I work a Fox in normal FT8 mode?

You should not. The official guide says not to try working the Fox in normal FT8 mode. Select Hound on the Settings | Advanced tab before calling.

Do I need an amplifier to work an FT8 DXpedition?

Usually not. FT8 decodes well below the audible threshold, and a Fox can limit its list to weaker callers. A clear calling frequency and a clean signal usually matter more than extra power.

Why does WSJT-X keep asking me to re-enable Tx?

In Hound mode you must re-activate Enable Tx, or press Enter, at least once every two minutes. This makes sure an operator is present and paying attention while calling the Fox.

Is it safe to leave WSJT-X running in Hound mode?

Not unattended. WSJT-X will send your R+report automatically if the Fox calls you, even with Enable Tx off. Quit the program or disable Hound mode before leaving the station.