Thursday 20 April 2023

Hunting For NDBs In CLE291

ZSJ-258 Sandy Lake, ON (

This coming weekend brings CLE 291. This is a challenge for all NDB hunters, both new and old 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.
With the number of targets slowly being decommissioned, the hunting grounds have been widened...this month the frequency range is for the NDBs whose published frequencies are between 240.0-259.9 kHz and 420.0 - 439.9 kHz.

A good target for all NA listeners is powerhouse ZSJ on 258 kHz, located at Sandy Lake, Ontario. Listen for its upper sideband CW identifier on 258.406 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 info:

Hello all,


This coming weekend we have another chance to enjoy a Coordinated Listening Event. All CLE logs will be very welcome, short or long.


Days:                   Friday, 21st April – Monday, 24th April

Times:                 Start and end at midday, local time at the receiver

Searching for:    NDBs in the ranges

240.0 - 259.9 kHz   and   420.0 - 439.9 kHz

BOTH frequency ranges are for ALL listeners.

REU and RNA show that the number of NDBs, each

of them heard by at least 10 or more listeners in the

last 12 months, was:


240-259.9 kHz   420-439.9 kHz

REU                      30                         116

RNA                      54                         54


Please log the NDBs you can identify that are listed in the ranges, plus any UNIDs that you come across there.

You can find details, lists and maps of the beacons in those ranges, if you go to


Send your final CLE log to  ndblist'at'  with “CLE291” and

“FINAL” in the email Subject.

Please show on EVERY LINE of your log:


  #   The full Date (or Day no.)  e.g. ‘2023-04-21’ (or just ‘21’)

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

  #   kHz (the beacon's nominal published frequency if you know it)

  #   The Call Ident.


Other optional details - Location, Distance, etc. - go LATER in the same line (or in footnotes).  Please make your log useful to old and new members alike by ALWAYS including your own location (and 6-character Locator if you know it) and brief details of the equipment and aerial(s) that you were using.   


We will send an 'Any More Logs?' email at about 20:00 UTC on Tuesday evening so you can check that your log has been found OK.

To be included in the combined results  your log must have arrived by 09:00 UTC on Wednesday 26th April at the very latest.

We hope to complete making the Combined Results within a day or two.

 Good listening

Joachim and Brian

(CLE coordinators)

If you would like to try some remote listening - you could use any one remote receiver for your loggings, stating its location (and with the owner’s permission if required).

A remote listener may NOT also use another receiver, whether local or remote, to make more loggings for the same CLE.


CLE's provide 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!