Hunting For NDBs In CLE 224

"OO - 391" - Oshawa, Ontario

It's hard to believe but this coming weekend will see another monthly CLE challenge. This time the hunting grounds will be:  385.0 - 399.9 kHz.

For those unfamiliar with this monthly activity, a 'CLE' is a 'Co-ordinated Listening Event', as NDB DXers around the world focus their listening time on one small slice of the NDB spectrum.

A nice challenge in this one is to hear the Ottawa (Ontario) NDB, 'OO', on 391 kHz. 'OO' is an amazing 7-watter that has been heard on both coasts as well as in Europe!  Look for 'OO's CW identifier, repeated every 10.2 seconds, on 391.400 kHz with your receiver in the CW mode.

Usually the Fall season provides some excellent propagation as the summer thunderstorms quiet down but the recent warning of upcoming geomagnetic activity for the weekend may mean something else in store for us. Often these 'warnings' are not as dire as they might appear and MF propagation remains robust or even enhanced. 
If you are interested in building a system for the new (U.S.) 630m band, the CLE will give you the chance to test out your MF receiving capabilities.

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' in Fargo 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.

From CLE organizer Brian Keyte, G3SIA, comes the usual 'heads-up':

Hi all,

Our 224th Coordinated Listening Event is less than a week away.
The Northern Hemisphere summertime storms have subsided, the equinox
has passed and we can all hope for some good reception conditions.
Whether you are a keen propagation watcher or just a take-what-comes
listener, please join in.

    Days:    Friday 27 October - Monday 30 October

    Times:   Start and end at midday, your LOCAL TIME
    Range:   385.0 - 399.9 kHz

    (Most of us in Europe, will be altering our clocks this weekend – UTC time continues unaffected)

Please log all the NDBs you can identify that are listed in the range
(it includes 385 kHz but not 400 kHz) plus any UNIDs you find there.
Please send your CLE log to the List in a plain text email if possible
(not in an attachment) with 'CLE224' at the start of its title.

Show on each log line:

# The date (e.g. 2017-10-29, etc., or just 29) and 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.

To help your listening, seeklists and maps for your part of the World

are available via the CLE page

Good listening - enjoy the CLE

From:   Brian Keyte G3SIA           ndbcle'at'
Location: Surrey, SE England        (CLE coordinator)

These listening events serve several purposes. They:
  • determine, worldwide, which beacons are actually in service and on-the-air so the 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. If you are a member of the ndblist Group, results will also be e-mailed and posted there.

The very active Yahoo ndblist Group is a great place to learn more about the 'Art of NDB DXing' or to meet other listeners 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 ndblist member to participate in the CLEs and all reports, no matter how small, are of much value to the organizers. 

'First-time' logs are always VERY welcome!

Reports may be sent to the ndblist or e-mailed to either myself or CLE co-ordinator, Brian Keyte (G3SIA), whose address appears above.

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].

7 Responses to “Hunting For NDBs In CLE 224”

  • Dave, WD8CIV:

    Thanks for the regular reminders about the CLEs! I’m going to try to participate in this one, since I’m right across the lake from the OO beacon in Oshawa. (In your post you said Ottawa, but the caption on the photo is correct.)

  • Bob KK5R:

    These articles have given me an interest in listening to the beacons for another reason: They allow me to test my different antennas and radios to see which one or ones are the best combination. I also have learned that to find them is to use USB or LSB to detect the carrier and then to zero-beat the signal since this to me is more sensitive than to use AM. Also, it tells me to hear one signal instead of two that are overlapping in the AM passband. In my location, Eastern Kentucky, there are very few that I can hear but I have heard some in such places as Michigan, North and South Carolina and Tennessee. Some of them are school related, according to the list of stations I find on

    When in Africa many years ago, I had a Radio Shack DX-350 that had the Long Wave band on it and I heard a few long wave broadcasts, mostly from England and France. I found that these are no more, for the most part, and I have tried to receive some of them without success. Satellites have ended that era, apparently. Better remembered than currently experienced…!

    Bob — KK5R

  • ve7sl Steve:

    Oops! Thanks for the correction Dave. For some reason I had our nation’s capital in mind at the time.

    I hope you are able to participate and hopefully we will have passed the worst of this present geomagnetic disturbance. MF is really wiped-out here tonight.

    “OO” should be loud from there even with bad conditions. Good luck.

    Steve 73

  • Dave, WD8CIV:

    Thanks Steve. I had a bit of a chuckle because I was in Ottawa just two weeks ago, and my fiancee is from Oshawa. So both places are somewhat familiar.

    We’ll see what I can do in the CLE. My antenna farm is more like a potted plant (a short multiband vertical) and I’m not sure how well the FT-857 works at MF. But I have an SDR and an upconverter if the radio doesn’t work out, and plenty of trees I can string a wire through temporarily for an antenna. The good news is the path from here to Oshawa is virtually all over water. Fingers crossed!

  • ve7sl Steve:

    Dave – the PA0RDT active e-probe is easy to build and makes a great antenna for MF / LF receive.

    Bob – the best way to tune these ndb signals is with your rx in the CW mode and a narrow filter. Direct frequency readout will allow you to tune easily to either the upper or lower CW identifier signal. With rx in USB or LSB mode, your dial frequency can be confusing and filters won’t be as narrow.

  • Dave, WD8CIV:

    What’s a good, reasonably inexpensive receiver for CLEs? Looking at the specs for my FT-857D I see that while it will tune down to 100 kHz its sensitivity is 32 uV (as opposed to 2 uV above 1.8 MHz). I’m going to give it a go anyway but I’ll probably want something more suited to the band eventually.

  • ve7sl Steve:

    Yes…try and see what you find out. Try removing the antenna and if the noise level drops then you should be fine. You can always build a converter or a preamp for below the broadcast band.
    A superb rx for LF and MF, if you can find one, is the Icom R-75. Most Icoms and Kenwoods seem to work well on these frequencies but you will also need a proper antenna.

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