Hunting For NDBs In CLE269


AP-378 Active Pass, Mayne Island

It's CLE time! '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 another normal one again with a 15kHz window -- the hunting ground is 370.0 - 384.9kHz.

Propagation on MF has been both hot and cold for the past few weeks, seemingly depending on where you live and the amount of geomagnetic activity affecting your region. Thankfully the Sun has ended, for now, its Coronal Hole Streams toward earth which had been causing so much disruption.

A 'challenge target' for listeners in North America is AP - 378kHz on Mayne Island, BC ... just a 1/2 mile down the beach from me! It's a super-pest for me but will be a great target for you. Its been heard as far east as Ohio ... can you beat the record and become famous? Listen for AP's upper sideband on 378.412 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, transmits on 365 kHz and its upper sideband CW identifier is tuned at 366.025 kHz while its lower sideband CW ident can be tuned at 363.946 kHz. Its USB tone is actually 1025 Hz while its LSB tone is 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. These databases have recently been re-vamped and are slicker than ever before!

From CLE organizers comes the following CLE info:

Hi all,

Please join us in our 269th Coordinated Listening Event which starts this Friday.

The CLE is open to everyone including new-comers.

It’s not a contest - but enjoy taking part and you will be a winner:


    Days:            Friday 25th June - Monday 28th June

    Times:           Start and end at midday, LOCAL TIME at the receiver

    Frequencies:     370 - 384.9 kHz


Wherever you are, please join us and log all NDBs that you can positively identify with their nominal (listed) frequencies in the range (it includes 370 kHz but not 385 kHz) plus any UNIDs that you come across there.

Very short logs are as welcome as very long ones!

Please Send your CLE log to the List, preferably as a plain text email (not in an attachment) with ‘CLE269 FINAL’ at the start of its subject line.
Show on EVERY LINE of your log:


    # The date       (e.g. 2021-06-25, etc., or just 25)

    # UTC            (the date changes at 00:00 UTC)

    # kHz            (the nominal published frequency, if known)

    # The Call Ident.


Show those main items FIRST - other optional details such as Location and Distance go LATER in the same line.

If you send interim logs, please also send a 'FINAL’ (complete) log!

As always, tell us your own location and brief details of the equipment that you were using during the weekend.

We will send the usual 'Any More Logs?' email at about 19:00 UTC on Tuesday 29th June - you can then check that your log has been found OK.

All logs must arrive on the list at the very latest by 08:00 UTC on Wednesday 30th June.   

We hope to complete making the combined results within a few days.

To help you to plan your listening, seeklists and maps for your part of the World are available via the CLE page

You can also access listings, seeklists, maps and export-files via REU/RNA/RWW by clicking on the “CLE” menu-item.

We last used this frequency range for CLE252 in January 2020.

Good listening - enjoy the CLE.

Joachim & Brian    



If you wish you can use any one remote receiver for your loggings,

stating the location and owner and with their permission if required.

A remote listener may NOT also use another receiver, whether local

or remote, to make further loggings for the same CLE.


If you are interested in some remote listening - maybe due to local difficulties - you could use any one remote receiver for your loggings, stating its location and with the owner's permission if required.( e.g. see ) A remote listener may NOT also use another receiver, local or remote, to make more 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!
Steve McDonald, VE7SL, is a regular contributor to and writes from British Columbia, Canada. Contact him at [email protected].

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