CQ WPX RTTY Contest: Serial Numbers, Prefixes and the 30-Hour Rule

In the middle of the northern winter, when the low bands are at their best, thousands of stations fill the RTTY segments for the CQ WPX RTTY contest. It is the winter companion to the autumn CQ WW RTTY event, but it is a different game: the exchange is a serial number, not a zone, the multiplier is the prefix of the callsign, and the points are weighted by band. It is also one of the contests in which a single operator may not stay on the air for the whole 48 hours, which changes the strategy completely. This guide follows the rules published on the contest website on 27 October 2026, which describe the 2026 edition, and explains how the scoring, the time limits and the categories work, so that you can plan an entry for the next February.

Dates, Bands and Time Limits

According to the official rules, the 2026 contest ran from 0000 UTC on Saturday 14 February to 2359 UTC on Sunday 15 February, a period of 48 hours. The objective is for amateurs worldwide to contact as many amateurs and prefixes as possible. Only five bands are used: 3.5, 7, 14, 21 and 28 MHz, and the organizers strongly encourage entrants to observe the established band plans.

The most distinctive rule concerns operating time. A single operator may operate 30 of the 48 hours, and the off times must be at least 60 minutes long, during which no contact is logged. Multi-operator stations may operate the full 48 hours. This is a stricter rule than in many other contests, and it makes planning your rest an important part of the strategy: you must decide which 18 hours to skip, and the usual answer is the times when your best bands are closed. For ideas, see our article on rest and time management in 24 and 48 hour contests.

The Exchange: RST and a Serial Number

The exchange is an RST report plus a progressive serial number that starts with 001 for the first contact. The report is almost always 599 in RTTY, so the number is the only thing that you really need to copy. There is one detail that catches new entrants: the Multi-Two, Multi-Unlimited and Multi-Distributed categories use a separate serial number sequence on each band, and the single-transmitter classes use one sequence for the whole log. If you operate in one of the multi-transmitter classes, check that your logging program is configured to do the same.

Copying serial numbers sounds easy, but it is a source of errors. A number that is repeated or mistyped is not accepted, and the log checker compares your received number with what the other station sent. RTTY decoders may show a wrong digit when the signal is weak, so ask for a repeat if the number is unclear. Our guide to RTTY contesting software, tuning and exchanges covers the macros and the settings that help you to copy correctly.

Scoring: Points by Band and the Prefix Multiplier

The final score is the total QSO points multiplied by the number of different prefixes worked. A station may be worked once on each band for QSO points. The points depend on the distance category and on the band: the lower bands pay double. The table gives the values from the rules.

The doubling on 40 and 80 meters rewards the effort of working on the difficult low bands. A single transatlantic contact on 80 meters is worth six points, the same as two on 20 meters. The prefix multiplier, on the other hand, counts each prefix only once, regardless of the band or the number of times the same prefix is worked. That makes the early hours of the contest very rewarding, since new prefixes come quickly, and it makes the later hours a hunt for stations from places that are less often active. Our article on how prefixes become multipliers in the CQ WPX contest explains the concept in detail for the CW and SSB version, and the same logic applies here.

What Counts as a Prefix

The rules define a prefix as the letter and numeral combination that forms the first part of the callsign. The examples given are N8, W8, WD8, HG1, HG19, KC2, OE2, OE25 and LY1000. Any difference in the numbering, the lettering or the order counts as a separate prefix, so LY1 and LY2 are two prefixes, and so are W8 and WD8. For portable operation, the portable designator becomes the prefix, provided that it is an authorized prefix of the country or call area of operation. A portable designator without a number is assigned a zero after the second letter, so PA/N8BJQ becomes PA0. Calls without numbers are given a zero after the first two letters; XEFTJW counts as XE0. Maritime mobile, mobile and designators such as /A, /E, /J and /P do not count as prefixes.

The rules also encourage special event, commemorative and other unique prefixes, provided that they are assigned by the licensing authority of the country of operation. Such stations, with unusual prefixes, are popular targets in this contest, because each one is a multiplier that many others will not have. The rules even use a Lithuanian example, LY1000, to show how a longer prefix is counted. If you want to hunt for such stations, a spot from the DX cluster or the Reverse Beacon Network is the quickest way to find them.

Categories and Assistance

The rules state that the use of QSO alerting assistance is permitted in all categories except the Single Operator Classic overlay. There is therefore no separate unassisted class for single operators in this contest. The single-operator classes are high power (up to 1500 watts), low power (up to 100 watts) and QRP (up to 5 watts), each for all bands or a single band, with no limit on band changes but only one transmitted signal at any time.

The overlay categories add variety. A single operator may also enter one of them by adding a CATEGORY-OVERLAY line to the Cabrillo header, and overlay entries are listed separately and scored as all bands.

• Tribander/Single Element (TB-WIRES). The entrant uses only one tribander with a single feed line for 10, 15 and 20 meters, and single-element antennas on 40 and 80 meters.
• Rookie. The operator has been licensed three years or less on the date of the contest and gives the date of the first license in the soapbox field.
• Classic. One radio, up to 24 of the 48 hours with off times of at least 60 minutes, no alerting assistance at all, and no receiving while transmitting.
• Youth. The operator was 25 or younger at the start of the contest.

Multi-operator entries are all-band only. Multi-One has one transmitted signal at a time and a maximum of ten band changes in any clock hour; a change from 20 to 40 and back to 20 counts as two. Multi-Two allows two signals on different bands, each limited to eight band changes per hour, with the log showing which transmitter made each contact. Multi-Unlimited allows up to five signals, one per band, and Multi-Distributed allows five signals from stations in different locations that are all in the same DXCC entity and CQ zone. For the planning of a team, our guide to contest band change strategy explains how to use the band changes that the rules allow.

Station Rules and Fair Play

As in other CQ contests, all entrants must obey a set of general rules. A different callsign must be used for each entry, and the power limit is measured at the output of the active amplifier. Self-spotting or asking to be spotted is not permitted. All operation must take place from one station location, and remote operation is permitted only if all the transmitters, receivers and antennas are at that single location, with remote receivers outside the location prohibited. Only one signal on a band is allowed at any time, and alternating CQs on two or more frequencies on a band is not permitted. Requests for contacts, answers and the copying of callsigns and exchanges must be completed during the contest, and logged callsigns cannot be corrected afterward from a database or a recording.

Unsportsmanlike conduct includes arranging contacts by non-amateur means during the contest, transmitting outside license limits, changing times in the log to meet band change or off-time rules and claiming unverifiable contacts. Operators must also be ready to supply details and photographs of their station on request. The checking is done by custom software and human judgment, and the penalties are straightforward: duplicates and contacts with an incorrect received exchange are removed without a penalty, while callsign errors or callsigns that are not found in the other log are removed and cost an additional penalty equal to the QSO point value of that contact.

Logs and Deadlines

Electronic logs are required, in Cabrillo format, by web upload only. The log must show the date and time in UTC, the frequency or band, the callsign of the station worked, and the exchange sent and received, and stations that compete for world and continent awards should provide accurate frequencies for every contact. A single-band entrant must include all contacts made during the contest, but only those on the band named in the header are scored. Entries must be submitted within 48 hours after the end of the contest, which in 2026 was by 2359 UTC on 17 February. Late logs may be listed in the results but are not eligible for awards, and extensions can be requested by e-mail before the deadline for a legitimate reason. For a guide to the file format and to the checking process, read our article on Cabrillo logs and the UBN process.

Every entrant who submits an on-time log can download an electronic certificate, and plaques are awarded for top performance in many categories. A club needs at least four logs to be listed in the club competition, and national organizations are not eligible. The Wikipedia article on radioteletype gives the background on the mode that the contest uses.

Planning Your 30 Hours

The 30-hour limit is the central strategic question. In February the high bands are open in the daytime and the low bands at night, so a plan for a European station often looks like this: start on 20 and 15 meters during the daylight hours of Saturday, move to 40 and 80 meters in the evening and the night, and keep the sunrise period for 40 and 80 meters again, since the paths to North America open then. Take your off periods in the hours when everything is quiet, in the middle of the afternoon on the second day, or in the early hours when you have already worked the available stations. Remember that each off period must be at least 60 minutes, so a few long rests are better than many short ones, and that the log does not count a contact in an off period.

Practice before the contest. Check that your decoder, your macros and your serial number counter work as expected, and test the exchange in a short sprint or a weekly RTTY event. Make a note of the prefixes that you need to work. A clean log with fewer contacts will beat a large log with errors, because each bad contact costs an extra penalty, and a plan that includes good rest will keep your copy accurate in the last hours.

The Bottom Line

The CQ WPX RTTY contest is a 48-hour February contest on five bands in which the exchange is a report and a serial number, the points are weighted toward the low bands, and the multiplier is the number of different prefixes. Single operators may use only 30 hours, so rest planning is part of the strategy, and the Tribander, Rookie, Classic and Youth overlays give extra ways to compete. The rules are firm about spotting, remote receivers and log accuracy. With a clean setup and a good plan for your 30 hours, it is an excellent winter contest.

Frequently Asked Questions

When is the CQ WPX RTTY contest?

In February. The 2026 edition ran from 0000 UTC on 14 February to 2359 UTC on 15 February.

What is the exchange?

An RST report and a serial number starting with 001. Multi-Two, Multi-Unlimited and Multi-Distributed entries use a separate serial sequence on each band.

How are points scored?

Three, two or one point per contact on 10, 15 and 20 meters, depending on distance, and six, four or two points on 40 and 80 meters. The total is multiplied by the number of prefixes.

How many hours can a single operator be on the air?

30 of the 48 hours, with off times of at least 60 minutes in which no contact is logged.

Can I use spotting assistance?

Yes, in all categories except the Classic overlay. There is no unassisted single-operator class in this contest.

When must the log be sent?

Within 48 hours after the end of the contest, by web upload in Cabrillo format. Late logs are not eligible for awards.