WW Digi DX Contest: FT4 and FT8 Rules, Scoring and Sub-Bands

The WW Digi DX contest is the one big HF contest in which nobody touches a key or a microphone. It is held on the last full weekend of August, it uses only FT4 and FT8, and the whole exchange is a four-character grid square that your software sends for you. That does not make it trivial. Choosing bands, managing a crowded waterfall, working out which grid fields you still need and keeping a clean log decide the result, and the rules contain some unusual details, such as a ban on autonomous operation and a log deadline of only 48 hours. This guide summarizes the rules published on the contest website on 27 October 2026, which describe the 2026 edition, and shows how to prepare for the next one.

Who Runs It and When It Takes Place

The official rules say that the contest is a collaboration between the World Wide Radio Operators Foundation and the Slovenia Contest Club. The 2026 event began at 1200 UTC on Saturday 29 August and ended at 1159 UTC on Sunday 30 August. The home page states that the contest is always held on the last full weekend of August, and lists the future dates: 28 and 29 August 2027, 26 and 27 August 2028 and 25 and 26 August 2029. The contest lasts 24 hours, there is no limit on band changes for single operators, and you may use any category of power from QRP to high power.

The objective is stated plainly: to contact as many other amateurs as possible in as many Maidenhead grid fields as possible, using the FT4 and FT8 modes. Because the focus is on fields, which are the first two characters of a locator, the contest has a strong worldwide flavor. There are only 324 possible grid fields in the world, so a good score needs contacts from every continent, not just a lot of contacts in nearby squares.

Six Bands, Two Modes

The contest uses six bands only: 160, 80, 40, 20, 15 and 10 meters, or 1.8, 3.5, 7, 14, 21 and 28 MHz. The WARC bands and 60 meters are not used. Only FT4 and FT8 are permitted, and a contact is scored once per band, whether it was made on FT4 or FT8. The rules recommend sub-bands for each mode, with FT4 just below FT8 on each band.

The rules tell you to set the radio dial at the bottom of the sub-band and work stations on audio frequencies within the radio passband, which is typically 2.5 to 4 kHz wide. If a sub-band becomes crowded, move the dial frequency up in 3 kHz steps, for example 7.080, 7.083 and 7.086 for FT4. There is a warning for 20 meters: 14.080 MHz is the standard everyday FT4 frequency, so to avoid confusion with non-contest stations it may be better to use 14.083. For Japanese stations on 80 meters, the sub-bands are 3.570 for FT4 and 3.573 for FT8. Note that the contest sub-bands are not identical to the normal operating frequencies used in WSJT-X, so you must change your dial frequency manually or create new entries in the frequency table. For basic setup, see our guide to a WSJT-X FT8 setup that works first time.

The Exchange and the Scoring

The exchange is your four-character grid square. The WSJT-X program has a special operating activity for this contest, and the exchange is built into the message sequence, so the program carries it out automatically. If you need help understanding locators, read our article on grid squares and the Maidenhead system.

The scoring has two parts. QSO points are one point plus one more for each 3,000 kilometers between the centers of the two grid squares; the rules give the example that 5,541 km is two points. Short-path distances are always used, whatever the real signal path was. The multiplier is one for each different two-character grid field contacted on each band. The final score is the sum of the QSO points across all bands multiplied by the sum of the grid fields across all bands. The rules give a simple example of 1,000 QSO points and 70 grid fields, for a score of 70,000.

That arithmetic changes your strategy compared with other contests. A contact across the Atlantic is worth two or three points rather than one, so nearby contacts are cheap and long ones are valuable. But the multiplier is the bigger lever: each of the 324 possible fields can be counted on each of the six bands. A station in Europe will find that fields in North America and Asia are the most valuable, and that fields in the Pacific, South America and Africa are the most difficult to come by. Check which fields you have on each band as the contest goes on, and prefer a new field to another contact in a field that you have already logged.

Entry Categories

Single-operator categories allow QSO finding assistance of any kind, so cluster spots and alerts may be used. The two main classes are Single Transmitter, called SINGLE-ONE, in which only one transmitted signal on one band is permitted at any time, and Multi-Transmitter, called SINGLE-UNLIMITED, which is all-band only and lets the six bands be active at the same time. Each comes in high power (up to 1500 watts), low power (up to 100 watts) and QRP (up to 5 watts) classes, and single-band entries are allowed for the first class.

• MULTI-ONE. Any number of operators, one transmitted signal at any time, with a maximum of eight band changes per clock hour.
• MULTI-TWO. A maximum of two transmitted signals on two different bands, each limited to eight band changes per clock hour, and the log must show which signal made each contact.
• MULTI-UNLIMITED. The six bands may be active at the same time.
• Checklog. An entry submitted to help the log checkers, with no score in the results.

All transmitters and receivers must be within a circle 500 meters in diameter, and antennas must be physically connected to them by transmission lines. Remote operation is allowed if all the transmitters, receivers and antennas are at the station location, and remote receivers outside the station location are not permitted.

Rules That Make This Contest Different

Two sentences on the home page set the tone: there are two important changes, a 48-hour log deadline and a prohibition on autonomous operation. The rules state that a human operator must initiate calling each QSO partner, and that autonomous systems or robots that emulate this action are prohibited. In other words, you may use auto-sequencing to carry a contact through, but you may not set the software to answer every call without you. Our article on FT8 operating etiquette describes good habits that are even more important in a contest.

Several other rules protect the integrity of the result. Self-spotting or asking to be spotted is not permitted. Alternating CQs on two or more frequencies on a band is not permitted. All requests for contacts, responses and copying of callsigns and exchanges must be done during the contest, using the mode and frequencies of the contest, and correction of logged callsigns and exchanges after the contest from a database, recordings or e-mail is not allowed. Unsportsmanlike conduct includes arranging contacts by telephone, the internet, chat rooms, VoIP, social media or web sites, changing times in the log to meet band-change rules, taking credit for excessive unverifiable contacts, and poor signal quality such as splatter, harmonics or excessive audio levels. An overdriven transmitter is easy to see on a wide waterfall, so keep ALC at zero.

A Sample Contact in FT8

To see how the exchange works in practice, imagine that you are in Lithuania in grid KO24 and you answer a station in Ohio. With the contest activity selected in WSJT-X, your transmissions are generated automatically. The other station calls CQ followed by its callsign and grid, you answer with both callsigns and your grid, the other station replies with its own grid and an R to confirm that it received yours, and you finish with RR73 or a final 73. Four short messages are enough, and the whole contact takes about a minute in FT8 and under half of that in FT4. Because the exchange is a fixed pattern, the program can decode it even when the signals are weak, and a contact that fails usually fails because one station did not hear the other’s grid rather than because of a long, complicated message.

FT4 is the faster mode, with a 7.5-second cycle compared with 15 seconds for FT8, and it is aimed at contesting. That speed is useful when the band is busy and signals are strong, but FT8 is more sensitive and works better when a band is marginal. Many operators keep both modes open and use FT4 on 20 and 15 meters during the daytime, switching to FT8 on the low bands at night.

Logs, Checking and Awards

Electronic logs are required, and the Cabrillo format is the standard. If your logging program cannot export Cabrillo, the contest provides an ADIF converter. U.S. and Canadian stations must show their operating location in the header, for example OH, and other stations enter DX. Web upload is the required method. All entries must be sent within 48 hours after the end of the contest, which in 2026 was 2359 UTC on 1 September; logs that arrive later may be listed but are not eligible for awards. Single-band entrants must include all contacts made during the contest, even on other bands, but only those on the band named in the header are scored. A good primer on the format is our article on Cabrillo logs and the UBN process.

The checking is done with custom software and human judgment. Duplicates and contacts with an incorrect exchange are removed without any penalty. Callsign errors and callsigns not in the other log are removed and carry a penalty equal to the QSO point value of the contact. Contacts that do not meet the band-change rules for multi-operator entries are removed without penalty. An entrant may withdraw a log within 30 days after the deadline. Everyone who submits a log by the deadline can download an electronic certificate, plaques go to top performers in many categories, and there is a club competition in which a club needs at least four logs to be listed.

Preparing for the Next Edition

Preparation matters more than hours in the chair. Three weeks before the contest, check the clock on your computer, because the decoder needs a very accurate time reference; our guide to FT8 time synchronization shows how. Create entries in WSJT-X for the contest sub-bands, and read the section on contest messages in the WSJT-X user guide. Make sure your logging program exports a Cabrillo file with the correct category and location fields. A test log made during a normal weekend, with the contest operating activity enabled, will reveal most of the problems.

On the day, plan your bands around sunrise and sunset at both ends of your paths. Low bands are best at night, and higher bands in the daylight hours, so a typical day starts on 10 or 15 meters, moves to 20 meters in the afternoon, and goes to 40, 80 and 160 meters at night. Keep your transmit power at a sensible level, because a clean signal will be copied more often than a loud one, and the rules penalize splatter. And remember that every band counts again for the multiplier: a field you worked on 20 meters is a new multiplier on 40 meters.

The Bottom Line

The WW Digi DX contest turns FT4 and FT8 into a proper radiosport event. It runs for 24 hours at the end of August on six HF bands, it is scored by distance and by the number of two-character grid fields, and it demands that a human starts every contact. The two rule changes to remember are the 48-hour log deadline and the ban on autonomous operation. With a computer clock set correctly, a clean transmit signal and a plan for grid fields, even a modest station can finish with a respectable score.

Frequently Asked Questions

When is the WW Digi DX contest?

On the last full weekend of August, starting at 1200 UTC on Saturday and ending at 1159 UTC on Sunday. The next listed dates are 28 and 29 August 2027.

Which modes and bands are allowed?

Only FT4 and FT8, on 160, 80, 40, 20, 15 and 10 meters. A contact counts once per band, on either mode.

What do I send in the exchange?

Your four-character Maidenhead grid square, for example JO65 or KO14. The first two characters are your grid field.

How are points and multipliers counted?

One point per contact plus one for each 3,000 km between grid-square centers, using the short path. The multiplier is the number of different two-character grid fields worked on each band.

Can I let my software answer calls automatically?

No. A human operator must start calling each QSO partner, and autonomous systems or robots that do this are prohibited.

What is the log deadline?

Forty-eight hours after the end of the contest, using the web upload of a Cabrillo file. Late logs may be listed but are not eligible for awards.