Wednesday 25 January 2023

Hunting For NDBs In CLE288

YNE - 207 Norway House, MB (tnx

Yes! 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 a two-parter this time:

The first part is hunting for the NDBs whose published frequencies are between 190 - 239.9 kHz. With NDBs closing down at a rapid rate, this wider range will offer listeners more targets.

The second part is hunting for the NDBs whose carrier frequencies are 'half-way'. 

E.g. 282.5 RT (AUI), 284.5 MH (TUA), 312.5 KML (SYR), 328.5 EGT (NIR), 400.5 COD (ITA).

A good target for all NA listeners is powerhouse YNE on 207 kHz in Norway House, Manitoba. Listen for its upper sideband CW identifier on 207.405 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,

Do try not to miss our 288th co-ordinated listening event - it starts this Friday at midday.  This could be an ideal CLE to try out for the first time, but everyone is welcome, as always, of course!


    Days:  Fri. 27th - Mon. 30th January, Midday-Midday, your local time

    NDBs  on frequencies from 190 - 239.9 kHz

    PLUS:  normal NDBs with carriers on 'half-way' frequencies ( nnn.5 kHz )

                from 190.5 - 999.5 kHz


So for all of us it is a CLE in two parts - the first part is hunting for the NDBs whose published frequencies are lower than 240 kHz.

The second part is hunting for the NDBs whose carrier frequencies are 'half-way'. 

E.g. 282.5 RT (AUI), 284.5 MH (TUA), 312.5 KML (SYR), 328 EGT (NIR), 400.5 COD (ITA).

The seek list below includes the ones that are more likely to be logged.


(Europe listeners will hear few or none from part 1, while the

listeners away from Europe will hear few or none from part 2)


Please send your final CLE log to the List, if possible as a plain text email and not in an attachment, showing 'CLE288' and 'FINAL' in its title.

(Loggings from both parts can be shown in the same list)

Please include on EVERY line of your log:


  #  The date (or just the day 'dd') and UTC (days change at 00:00 UTC).

  #  kHz - the beacon's nominal frequency.

  #  The Call Ident.


It is important to show those main items FIRST - any other optional details such as Location, Distance, etc., go LATER in the same line.


Don't forget to give your OWN location (your 6-character Locator if you know it please) and details of your receiver and aerial(s), etc.   Others will be interested to know, especially new members - and old ones with failing memories like mine!

Listening around the 'half-way' frequencies means we might also catch some interesting non-CLE beacons – you can tell us about those too, but in a separate list. 


Joachim and I will be processing the incoming logs as usual - please look out for our 'Any More Logs?' email at about 19:00 UTC on Tuesday evening, with a list to let you check that your own log has been found OK.

Do make sure that your log has arrived on the NDB List at the very latest by 08:00 UTC on Wednesday.


Good listening

   Brian and Joachim

  (CLE Coordinators)


If you wish you could 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, local or remote,

to make further loggings for the same CLE.


For your full seek list in the 190-240 kHz range just go to Rxx ( for your part of the World.

Below is the seek list which includes the ‘nnn.5’ NDBs that are more likely to be heard.

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!

Wednesday 11 January 2023

Topband's Poor Winter Performance

A recent discussion on the Topband mailing list regarding the exceptionally poor propagation this fall and winter, especially on the polar path, brought forth some interesting opinions as to the reason. The rapid growth of solar Cycle 25 and its seemingly continuous flaring was the prime culprit ... but what was the exact mechanism? 

One of the best and clearest explanations was posted by Frank, W3LPL, who, with 317 countries confirmed on 160, knows a thing or two about propagation on topband! His comments are particularly relevant for stations in the northern regions of the US as well as for all regions in Canada. 

 "There's some confusion about the effects of increasing solar activity on 160 meter DX propagation.

160 meter DX propagation is often badly affected by nighttime propagation degradations, especially as Solar Cycle 25 becomes much more active from now through solar maximum in about 2024-2025 and as it slowly declines to current ionization levels through about 2027-2028.

Solar flares have no known impact on 160 meter DX propagation. Solar flares produce electromagnetic radiation that travels from sun to Earth at the speed of light - in about 8 minutes. Solar flare electromagnetic radiation (mostly X-rays) affects only the sunlit side of the earth and ionosphere. There are no known physical processes that extend solar flare effects into the night time ionosphere. 

While solar flares have no relevance to 160 meter DX propagation, solar flares often occur coincident with (but are not caused by) coronal mass ejections that can cause severe post-midnight absorption in the D region on propagation paths that cross the auroral oval (e.g., North America to northern Europe and Asia). CMEs cause the auroral oval to dip to much lower latitudes causing post-midnight increased D region absorption on propagation paths crossing lower latitudes.

Unrelated to CMEs, coronal hole high speed stream effects also cause increased D region absorption in the post-midnight auroral oval and occur very frequently compared to geo-effective CMEs (thankfully most CMEs never strike the Earth or its magnetosphere, they usually miss our tiny planet). 

But what about 160 meter absorption usually present much earlier in the night, from sunset through midnight and later? 

The E region usually retains enough ionization to degrade 160 meter night time propagation especially during the more active years of the solar cycle. The ionized night time E region causes increased absorption at the bottom of the E region (just above the D region) and blankets propagation that would otherwise pass through the E region to the F region. Blanketing causes many shorter hops that suffer increased loss from multiple lossy passes through the ionized E region. 

 73 Frank W3LPL"

I found Frank's comments regarding the auroral zone (highlighted in RED) particularly interesting as it confirms behaviors I have noted for several decades while operating from SW British Columbia ... particularly when it comes to the MF NDB band (200 - 530kHz). Time and time again while propagation on these frequencies has been severely degraded, stations just a few hundred miles (often less) to my south or south-east enjoy almost normal propagation. I've long-suspected that the AU zone has temporarily slipped this far south while my not too far away neighbours have escaped its unwelcome reach.

I have ALWAYS associated these poor conditions with signal absorption by a heavily-ionized D layer that has not dissipated after darkness but it seems a second factor may also be in play, that being from the E-layer as explained by Frank (highlighted in BLUE). 

Although CMEs and flares can cause a lot of disruption, the big culprit for the past few years has been an almost continual barrage of high speed coronal hole streams that have regularly killed nightime propagation on 80 and 40m as well.

With Solar Cycle 25 really starting to ramp up (three X-flares in the past two days!) it's very likely we will see poor propagation on topband as well as on the lower HF bands for the next few years. Some relief may be in store during the downslope ride as there is generally less flare and streaming activity during this period than on the ride up.

None of this eliminates periods of quiet geomagnetic conditions at any time, producing worthwhile propagation, particularly on the non-polar paths ... so don't turn off your radios!