Wednesday 25 May 2022

Hunting For NDBs in CLE280


It's CLE time once again. This is a challenge for all newcomers to NDB listening and the ultimate test of your medium frequency receiving capabilities. Can you meet the challenge?

'CLE's are 'Co-ordinated  Listening Events, and NDB DXers around the world focus their listening time on one small slice of  the NDB spectrum.
It's back to an 'almost normal' activity but with a slightly wider frequency span: 350.0 - 369.9 kHz.

When tuning for NDBs, put your receiver in the CW mode and listen for the NDB's CW identifier, repeated every few seconds. Listen for U.S. NDB identifiers approximately 1 kHz higher or lower than the published transmitted frequency since these beacons are modulated with a 1020 Hz tone approximately.

For example, 'AA' near Fargo, ND, transmitted on 365 kHz and its upper sideband CW identifier was tuned at 366.025 kHz while its lower sideband CW ident could be tuned at 363.946 kHz. Its USB tone was actually 1025 Hz while its LSB tone was 1054 Hz.

Often, one sideband will be much stronger than the other so if you don't hear the first one, try listening on the other sideband.

Canadian NDBs normally have an USB tone only, usually very close to 400 Hz. They also have a long dash (keydown) following the CW identifier.

All NDBs heard in North America will be listed in the RNA database (updated daily) while those heard in Europe may be found in the REU database. Beacons heard outside of these regions will be found in the RWW database.

From CLE organizers comes the following CLE info:

Hello all

Our 280th Co-ordinated Listening Event is almost here.

Can new 'listening eventers' join in too?   YES, PLEASE! 

Joachim and I are always pleased to help first-time CLE logs through the harvester program.


     Days:     Friday 27 May - Monday 30 May

     Times:   Start and End at midday, your LOCAL time

     Range:   350.0 - 369.9 kHz   


Please log all the NDBs you can identify that are listed in this range (it includes 350 kHz but not 370) plus any UNIDs that you come across there.

You can find full information to help you, including seeklists made from REU/RNA/RWW, by going to the CLE page and clicking on  CLE Seeklist  there.


Please send your 'Final' CLE log to the List, if possible as a plain text email and not in an attachment and - important - with 'CLE280' and 'FINAL'

in its title.

Please show the following main items FIRST on EVERY line of your log:


  #   The full Date (e.g. 2022-05-27) or just the day (e.g. 27)

         and UTC (the day changes at 00:00 UTC).

  #   kHz - the beacon's nominal published frequency, if you know it.

  #   The Call Ident.


Optional details such as Location and Distance go LATER in the same line.

Please always include details of your own location and brief details of the receiver, aerial(s), software  and any other equipment you were using.


Joachim or I will send the usual 'Any More Logs?' email at about 20:00 UTC on Tuesday so you can check that your log has been found OK.

Make sure that your log has arrived at the very latest by 08:00 UTC on Wednesday 1 June.   We hope to make all the combined results within a day or so.


Good listening



From:      Brian Keyte G3SIA        ndbcle'at'

Location:  Surrey,  SE England       (CLE coordinator)



(Reminder:  If you wish you can use a remote receiver for your loggings, stating its location and owner -  with their permission if required.

A remote listener may NOT also use another receiver,  whether local or remote, to obtain further loggings  for the same CLE)

These listening events serve several purposes. They

• determine, worldwide, which beacons are actually in service and on-the-air so the newly-re-vamped Rxx online database can be kept up-to-date

• determine, worldwide, which beacons are out-of-service or have gone silent since the last CLE covering this range

• will indicate the state of propagation conditions at the various participant locations

• will give you an indication of how well your LF/MF receiving system is working

• give participants a fun yet challenging activity to keep their listening skills honed

Final details can be found at the NDB List website, and worldwide results, for every participant, will be posted there a few days after the event.

The NDB List Group is a great place to learn more about the 'Art of NDB DXing' or to meet other DXers in your region. There is a lot of good information available there and new members are always very welcome. As well, you can follow the results of other CLE participants from night to night as propagation is always an active topic of discussion.

You need not be an NDB List member to participate in the CLEs and all reports, no matter how small, are of much value to the organizers.

Remember - 'First-time' logs are always VERY welcome!

Reports may be sent to the NDB List Group or e-mailed to CLE co-ordinator, Brian Keyte (G3SIA), whose address appears above. If you are a member of the group, all final results will also be e-mailed and posted there.

Please ... give the CLE a try ... then let us know what NDB's can be heard from your location! Your report can then be added to the worldwide database to help keep it up-to-date.

Have fun and good hunting!