Fox and Hound Mode: FT8 DXpedition Operating Explained

You're scanning 14.090 and suddenly see a callsign you've been chasing for months — let's say 3Y0J from Bouvet Island. Hundreds of stations are calling. But something looks wrong: the DXpedition's signal appears way down at the bottom of the waterfall (300 Hz), and they seem to be answering multiple stations simultaneously. Welcome to Fox and Hound mode.

If you don't understand how F/H works, you'll waste hours calling into the void. Let me break it down.

What Fox and Hound Mode Is

Fox and Hound (F/H) is a special operating protocol in WSJT-X designed specifically for DXpeditions to maximize their contact rate. Standard FT8 can handle maybe 15-20 QSOs per 15-second period on a single frequency. F/H mode enables a single DXpedition station (the "Fox") to work multiple Hounds simultaneously.

The Fox transmits on a fixed low frequency (typically 300-900 Hz audio), while Hounds call on higher frequencies (1000-4000 Hz). The Fox can respond to up to 5 Hounds in a single transmission by generating a multi-signal compound message.

Rate improvement: A skilled Fox operator can sustain 150-200+ QSOs per hour on a single band. Standard FT8 maxes out around 60-80/hr for the most active stations. For a DXpedition with limited time and massive demand, that rate difference decides how many people get in the log.

How It Works: The Protocol

Fox Side (DXpedition)

1. Fox transmits CQ on a fixed audio frequency (e.g., 300 Hz)
2. Fox's software decodes all calling Hounds
3. Fox selects up to 5 Hounds to respond to simultaneously
4. Fox transmits compound messages — multiple signal reports in one TX period, each at a different audio offset
5. Fox confirms RR73 to completed exchanges and starts new ones

In classic Fox and Hound the Fox's signals sit between 300 and 900 Hz, 60 Hz apart, at the bottom of the passband (a SuperFox sends one wide signal instead; see below). Each sub-signal carries a message to one specific Hound.

Hound Side (That's You)

1. You enable Hound mode in WSJT-X
2. You see the Fox's CQ and their responses to others
3. You call on a frequency ABOVE 1000 Hz (software handles this)
4. You watch for your callsign in the Fox's response
5. When the Fox sends you a signal report, you send R+report back
6. When the Fox sends RR73, you're in the log

Timing

Like standard FT8, F/H uses 15-second transmission periods. The Fox transmits on even or odd sequences (the DXpedition chooses which). Hounds must transmit on the opposite sequence.

Configuring WSJT-X as a Hound

Step-by-Step Setup

1. Open WSJT-X (use the current release, 3.0.2 at the time of writing; SuperFox needs 2.7.0 or later)
2. Go to File → Settings → Advanced
3. Check "Special operating activity"
4. Select "Hound"
5. Click OK

Now your interface changes:

• TX frequency is forced above 1000 Hz
• You can only call stations transmitting below 1000 Hz (the Fox)
• Auto-sequencing works slightly differently
• The Band Activity window shows decoded Fox transmissions

Important Settings

TX frequency: WSJT-X will pick a random TX frequency between 1000-4000 Hz. If you're not getting answered after several attempts, try changing your TX frequency. The Fox's software may have your current frequency in a busy/QRM zone.

Auto-sequence: Enable it. The exchange in F/H mode is rapid and predictable. Manual sequencing means you might miss your window.

Hold TX frequency: Leave this ON. Don't let the software jump your TX frequency around — that makes it harder for the Fox to find you again on a subsequent period.

Calling CQ frequency: Don't set anything here. In Hound mode, you don't CQ. You only respond to the Fox.

Strategy for Working the Fox

Patience is the Primary Strategy

A DXpedition on a rare entity might have 5,000-10,000 stations trying to work them. Even at 200 QSOs/hour, that's 25-50 hours of continuous operation to clear the pileup. You will likely need multiple sessions before getting through.

Timing Matters

When to call:

• Early in the DXpedition (smaller pileup, operators still fresh)
• During off-peak hours (3-6 AM local time for the DXpedition's target audience)
• When the band is marginal (fewer callers, but you need a decent signal yourself)
• Band openings that favor your path specifically

When NOT to call:

• Peak propagation windows when every station on the continent is calling
• If you can't decode the Fox at -15 dB or better (if you can barely hear them, they can barely hear you)

Signal Quality

The Fox's software ranks callers by decode quality. A clean, strong signal gets answered faster than a marginal one. This means:

• Ensure your transmitter is NOT overdriving (zero ALC action)
• Use the best antenna you have for that band
• Run enough power for a clean, decodable signal; the WSJT-X DXpedition guide notes that in many cases you will not need an amplifier
• Keep your computer clock within ±1 second of UTC, as WSJT-X requires

Frequency Selection

Your TX frequency (the audio offset where you call) matters:

• Avoid frequencies where you see many other Hounds calling (check your waterfall)
• Frequencies around 1500-2500 Hz are typically less congested than 1000-1200 Hz
• If you're not getting answers after 10 minutes, shift by 100-200 Hz
• Don't change every TX period — the Fox needs to find you at a consistent frequency

Calling Discipline

Only call when you can decode the Fox. If you can't hear them, they can't hear you (the path is reciprocal within a few dB). Calling blindly just adds QRM for everyone.

Don't call on the Fox's frequency (below 1000 Hz). This creates QRM that degrades the Fox's CQ and responses. It's the F/H equivalent of calling on the DX frequency in a phone pileup.

What You'll See in the Band Activity Window

Decoded messages in F/H mode look like:

0730  -5  0.3  300  ~  3Y0J CQ
0730  -8  0.1  350  ~  W1ABC 3Y0J -12
0730  -7  0.2  450  ~  JA7XYZ 3Y0J -18
0730  -9  0.1  550  ~  DL4ABC 3Y0J RR73

The Fox's CQ is at 300 Hz. Responses to individual Hounds appear at different offsets (350, 450, 550 Hz). You can see who's being worked and what signal reports are being exchanged.

When you see YOUR callsign with a signal report, immediately acknowledge. The auto-sequencer handles this, but verify it's working.

Common Problems

"I can decode the Fox but they never answer me"

• Your signal may be too weak at their end
• You might be in a frequency zone with heavy QRM from other Hounds
• Time sync may be slightly off (verify with GPS or network time)
• Try different times of day for different propagation paths

"I see the Fox working others but their CQ is missing"

• The Fox's CQ at 300 Hz may be below your receiver's passband if you've set a narrow filter
• Widen your receive bandwidth to at least 200-3500 Hz
• Check that you haven't accidentally set a narrow IF filter

"The exchange started but didn't complete"

• QSB (fading) took your signal out mid-exchange
• The Fox's software timed out waiting for your response
• Try again — partial exchanges aren't logged by either side

"WSJT-X won't let me enable Hound mode"

• Verify you're running a current WSJT-X release (2.7.0 or later)
• Hound mode only works when FT8 mode is selected
• Some special contest modes conflict — disable any other special activity first

SuperFox Mode (New in WSJT-X 2.7+)

Recent DXpeditions have started using "SuperFox" mode, an evolution of the original F/H protocol. SuperFox can work up to 9 Hounds simultaneously and uses a more efficient encoding scheme.

For Hounds: Select Hound as the special operating activity, then also tick SuperFox mode on the Settings Advanced tab (and OTP if you want WSJT-X to verify the Fox). Without the SuperFox box ticked you will not decode a SuperFox. The SuperFox user guide lets Hounds call anywhere from 200 to 3000 Hz, and you should stay on your calling frequency.

Requirement: Make sure you're running the latest WSJT-X version. SuperFox Hound support was added in 2.7.0; versions before that cannot decode a SuperFox at all.

Etiquette and Community Norms

Don't Multi-Call

Don't run multiple instances of WSJT-X calling the same Fox on different frequencies. This is considered bad practice and may get your callsign blacklisted by the DXpedition operators.

Don't Call If You've Already Worked Them on That Band

Duplicate contacts waste the Fox's valuable time and deprive other operators of the chance. Most DXpedition logging software flags dupes, but it still wastes a TX cycle.

Accept Your Fate

Some DXpeditions, you won't work. The propagation might not favor your path, the pileup might be too deep, or the timing might not align with your schedule. That's okay. There'll be another expedition eventually.

Checking the Log

Most DXpeditions post their logs online (usually on Club Log) daily. Check whether your QSO was logged rather than calling again "just to make sure." If it's in the log, you're confirmed. If it's not after 24 hours, try again.

The Bigger Picture

Fox and Hound mode transformed DXpedition operating. Before F/H, DXpeditions on digital modes were frustratingly slow — standard FT8 rate-limited what was already a time-constrained operation. Now, digital pileups clear at rates competitive with CW.

The downside is that it added complexity for the casual operator. You need to know the mode exists, configure your software correctly, and understand the protocol's rhythms. But once you've done it successfully once, it becomes second nature. Your DXCC count will thank you.