D. R. Evans (N7DR)

2026-04-16

Most-Logged Stations in CQ WW CW and SSB Contests: 2025, and the decade from 2016 to 2025

The public CQ WW CW and SSB logs allow us easily to tabulate the stations that appear in the largest number of entrants' logs. For 2025, the ten stations with the largest number of appearances in CQ WW SSB logs were:

Callsign	Appearances	% logs
CN3A	15,582	68
ES9C	15,242	67
UA7K	12,765	58
CR3A	12,508	62
P33W	12,248	58
M6T	12,194	58
LZ9W	11,953	56
V26B	11,752	55
II9P	11,353	57
RU1A	11,261	57

The first column in the table is the callsign. The second column is the total number of times that the call appears in logs. That is, for example, if a station worked V26B on six bands, that will increment the value in the second column of the V26B row by six. The third column is the percentage of logs that contain the callsign at least once.

Similarly, the ten stations with the largest number of appearances in CQ WW CW 2025 were:

Callsign	Appearances	% logs
TK0C	15,843	74
CN3A	15,363	75
CR3A	13,457	70
CR3W	13,147	67
ES9C	13,013	67
PJ4K	12,694	66
ZF5T	12,400	61
M6T	11,982	65
9A1A	11,639	66
PJ2T	11,508	57

I find it interesting to see which stations have had the most long-term activity on the contests. For the ten years from 2016 to 2025 on SSB we find:

Callsign	Appearances	% logs
CN3A	99,447	52
LZ9W	99,238	55
M6T	88,198	52
DF0HQ	87,426	52
YT5A	78,696	47
PJ2T	76,333	41
P33W	75,148	45
K3LR	70,681	45
V26B	70,490	40
CR6K	68,342	42

And for the same years on CW:

Callsign	Appearances	% logs
CR3W	116,962	66
LZ9W	106,651	65
M6T	96,631	57
PJ2T	95,867	52
YT5A	92,472	59
TK0C	91,591	52
9A1A	89,480	53
CN3A	82,187	43
LN8W	81,036	52
DF0HQ	78,816	52

Similar tables from last year may be found here.

2026-02-10

CQ WW video maps: 2005 to 2025

I have updated the complete set of CQ WW video maps on my youtube channel (channel N7DR).

The videos are created with time steps of ten minutes; when playing the video, each time step is displayed for five seconds. The videos are presented as animated GIF files, so they should display correctly without any specialised video software installed on your computer.

The videos assume that all communication is via the great-circle short path route, and include only inter-zone contacts. The width of the arcs is an absolute measure of the number of QSOs taking place over that path in the particular 10-minute segment. The colour of the arc reflects the relative number of QSOs taking place over the path. Each separate image (i.e., 10-minute segment) is normalised so that the path with the greatest number of QSOs is rendered in white. Paths with fewer QSOs are in progressively darker colours. Thus, arc colour should not be compared from one still image to another; arc width, however, is meaningful from one image to another. The width of an arc in pixels is one plus the natural logarithm of the number of QSOs represented by the arc.

2026-01-11

Cleaned and Augmented Logs (including RBN data) for CQ WW CW and SSB Contests, 2005 to 2025

Cleaned and augmented versions of the logs for the CQ WW CW and SSB contests are now available for the period 2005 to 2025.

Links to the cleaned and augmented logs may be found in this directory (look for "clean" or "augmented" in the filenames).

The cleaned logs are the result of processing the QSO: lines from the entrants' submitted Cabrillo files to ensure that all fields contain valid values and all the data match the format required in the rules. Any line containing illegal data in a field (for example, a zone number greater than 40, or a date/time stamp that is outside the contest period) has simply been removed. Also, only the QSO: lines are retained, so that each line in the file can be processed easily. All zones are rendered with two digits, so as to further simplify processing by scripts or programs.

The augmented logs contain the same information as the cleaned logs, but with the addition of some useful (derived) information on each line. In addition to the actual logs, two additional sources of information are used when appropriate:

AD1C has made accessible historical cty.dat and associated files. These allow us to use callsign-based multiplier lists as they would have existed at the time of each contest.
From 2009 onwards, the Reverse Beacon Network (RBN) has been available for the CW contests. This allows us to include the time since a station was last posted by the RBN (see below for details).

The information added to each line of the augmented logs comprises:

A sequence of four characters that are the same for each entry in a particular log:

a. letter "A" or "U" indicating "assisted" or "unassisted"
b. letter "Q", "L", "H" or "U", indicating respectively QRP, low power, high power or unknown power level
c. letter "S", "M", "C" or "U", indicating respectively a single-operator, multi-operator, checklog or unknown operator category [ the contest organisers have stated that checklogs are not made public, but in fact at least some of them from the early years have been, hence the need for the "C" category ]
d. character "1", "2", "+" or "U", indicating respectively that the number of transmitters is one, two, unlimited or unknown

A four-digit number representing the time if the contact in minutes measured from the start of the contest. (I realise that this can be calculated from the other information on the line, but it saves subsequent script-based processors of the file considerable time to have the number readily available in the file without having to calculate it for each QSO.)
Band
A set of fourteen flags, each -- apart from column k and column n -- encoded as T/F:
- a. QSO is confirmed by a log from the second party
- b. QSO is a reverse bust (i.e., the second party appears to have bust the call of the first party)
- c. QSO is an ordinary bust (i.e., the first party appears to have bust the call of the second party)
- d. the call of the second party is unique
- e. QSO appears to be a NIL
- f. QSO is with a station that did not send in a log, but who did make 20 or more QSOs in the contest
- g. QSO appears to be a country mult
- h. QSO appears to be a zone mult
- i. QSO is a zone bust (i.e., the received zone appears to be a bust)
- j. QSO is a reverse zone bust (i.e. the second party appears to have bust the zone of the first party)
- k. This entry has three possible values rather than just T/F:
  - T: QSO appears to be made during a run by the first party
  - F: QSO appears not to be made during a run by the first party
  - U: the run status is unknown because insufficient frequency information is available in the first party's log
- l. QSO is a dupe
- m. QSO is a dupe in the second party's log
- n. RBN information (see below)
If the QSO is a reverse bust, the call logged by the second party; otherwise, the placeholder "-"
If the QSO is an ordinary bust, the correct call that should have been logged by the first party; otherwise, the placeholder "-"
If the QSO is a reverse zone bust, the zone logged by the second party; otherwise, the placeholder "-"
If the QSO is an ordinary zone bust, the correct zone that should have been logged by the first party; otherwise, the placeholder "-"

RBN Information

In the CW contests from 2009 onwards, the RBN was active, automatically spotting the frequency at which any station calling CQ was transmitting. To reflect possible use of RBN information, the augmented files now include a fourteenth flag. For the sake of uniformity, this column is present in all the augmented files, regardless of whether the RBN actually contributed useful information to a particular contest.

Each QSO has one of several characters in the fourteenth column of flags. These characters should be interpreted as follows:

'-'
No useful RBN-derived information is available for this QSO.

'0'
The worked station (i.e., the second call on the log line) appears to have begun to CQ on this frequency within (roughly) 60 seconds prior to the QSO.

'A' to 'Z'
For the nth letter of the alphabet: the worked station appears to have been CQing on this frequency for (roughly) n minutes prior to the QSO.

'+'
The worked station appears to have been CQing for more than 26 minutes on this frequency.

'<'
Because the the RBN is distributed, and because each contest entrant station has its own clock, there is generally a skew between the reading of the clock of the station making the QSO and the timestamp from the RBN at which it believes a posting was made (indeed, it's unclear from the RBN's [lack of] documentation exactly how the timestamp on an individual RBN posting is to be interpreted). If the character '<' appears in the the RBN column, it indicates that the raw values of the clocks suggest that the QSO took place up to two minutes before the RBN reported the worked station commencing to CQ at this frequency. When this occurs, the most likely interpretation is that there is non-negligible skew between the two clocks, and the station was actually worked almost as soon as a CQ was posted by the RBN. This character also appears if the RBN erroneously posts the worked station as CQing at this frequency shortly after the QSO. But it might also mean that the entrant was simply lucky and found the CQing station just as it fired up on a new frequency.

Notes:

The encoding of some of the flags requires subjective decisions to be made as to whether the flag should be true or false; consequently, and because CQ has yet to understand the importance of making their scoring code public, the value of a flag for a specific QSO line in some circumstances might not match the value that CQ would assign. (Also, CQ has more data available in the form of check logs, which are generally not made public.)
I made no attempt to deduce or infer the run status of a QSO in the second party's log (if such exists), regardless of the status in the first party's log. This allows one cleanly to perform correct statistical analyses anent the number of QSOs made by running stations merely by excluding QSOs marked with a U in column k.
No attempt is made to detect the case in which both participants of a QSO bust the other station's call. This is a problematic situation because of the relatively high probability of a false positive unless both stations accurately log the frequency as opposed to merely the band. (Also, on bands on which split-frequency QSOs are common, the absence of both transmit and receive frequency is a problem; I confess that I have never understood why Cabrillo was not designed to report both transmit and receive frequencies -- or even to define clearly which frequency is to be reported. I digress.) Because of the likelihood of false positives, it seems better, given the presumed rarity of double-bust QSOs, that no attempt be made to mark them.
The entries for the zones in the case of zone or reverse zone busts are normalised to two-digit values.

2025-08-06

Station and QSL Manager non-respondents to direct QSL requests

Several QSL managers, and a handful of non-manager stations, operate "online QSL request systems" that allow one to pay for a direct QSL via Paypal. This assures the requester of the QSL that the money has correctly been received by the intended recipient (unlike, for example, when physical money is sent via the international postal system). For the most part, these OQRS exchanges work well. Unfortunately, though, I have found there to be a small number of cases in which the funds, although correctly transferred, have not resulted in the arrival of the corresponding QSL.

Below is a table showing my experience with stations that received the required funds for a direct QSL, as confirmed by a receipt from Paypal, but for which the corresponding card was never received by me. Note that this does not include requests that were sent via the Clublog OQRS, which are the subject of a separate post. The table lists requests made through the end of 2024, and for which the requested card has not been received as of early August, 2025.

Year of Request	Callsign	QSL Manager, if any
2019	Z31NA
2023	TL8AA	I2YSB
2024	TJ2TT	I2YSB
2024	HI3CC	EB7DX
2024	HI3AA	EB7DX
2024	HI3Y	EB7DX
2024	HI0LT	EB7DX

2025-08-05

Clublog OQRS non-respondents to direct QSL requests

This post updates an earlier post.

Clublog offers a service, known as OQRS (for "online QSL request service"), whereby one can send a direct request for a QSL to those stations that are willing to accept such requests. As part of the process of sending the request, Clublog automatically connects to Paypal so that the requester can pay the fee that the recipient of the request demands. This can be very useful: it makes requesting, and paying for, direct requests relatively quick and easy.

However, a very few people offering direct QSLs appear to take advantage of the system to collect the money from Paypal without sending the requested QSL.

Generally speaking, when someone whose QSL I desire does not respond to such a request within six months, I will send a polite follow-up e-mail, giving details of the QSO(s), the amount paid and the transaction ID of the Paypal transaction that transferred the money. If I hear nothing after a further three months, I repeat this exercise, but send this last e-mail from a different account, in case the account from which the first e-mail was sent is, for some reason, blocked by the recipient or some intermediate party.

After all this, there is a handful of stations who, in my direct experience, have neither sent the requested (and paid-for) QSL, nor responded to any of the e-mails.

These are the stations that, by my direct experience, have failed to fulfil the obligation to send a responsive QSL (with dates of the request up to the end of 2024):

Year of request Call

2020 D3AM
2021                     7X3IOTA
2021                     HC90IARU
2021                     PY0F/PP1CZ*
2021                     5X8C**
2021                     PY0FW
2022                     OH0T
2022                     TI9/3Z9DX***,†
2023                     CT3MD
2024                     EA7KW
2024                     OF9X
2024                     EA7X
2024                     CT8/S51TA
2024                     9X5RU‡
2024                     3D2CR†
2024                     3D2CCC†
* The Paypal payment was reversed by the recipient a couple of months after payment was made. No explanation was forthcoming from the recipient of the money (despite my questioning him via e-mail), and no QSL was ever received.
** A discussion did take place via e-mail, and it was agreed that the QSOs in question had indeed taken place, but there was some doubt as to who was responsible for sending out the requested card. Despite assurances that the issue would be dealt with, no card was ever received.
*** I did receive a responsive e-mail to this request, stating that the QSL would be sent at some future (unspecified) date; as of August, 2025, however, it has not yet been received. Were it to arrive, I should gladly remove the relevant call from the above list.
† I note that these entries all seem to be the responsibility of k38dom@gmail.com; sadly, I have never received any QSL in response to any money sent to that address. I continue to hope that that will change, and would be glad to hear from anyone who has had a more positive experience after sending a Clublog OQRS direct request to one of these calls. It would be marvellous were I to receive the requested cards and so be able to remove these calls from the above list.
‡ In April, 2025, I received an e-mail saying that a QSL had been sent to me in September, 2024. Unfortunately, no QSL was received. In response to my query, a second QSL was mailed to me (in April, 2025); but as of August, 2025, neither QSL had been received. I hope that this situation might change by the time I make the next update here.

I wish to emphasise that the great majority of stations faithfully respond to direct Clublog OQRS requests in a timely manner, and I thank such stations for offering this easy way to obtain their QSLs. This post is made merely so that those experiencing the disappointment of requests that have gone unanswered may see the stations that have likewise disappointed me.

2025-08-03

State-by-state activity tables in ARRL DX

Using the public logs from ARRL DX CW and SSB over the past few years, we can generate the following band-by-band activity tables for the continental U. S.