Wednesday 24 August 2022

Hunting For NDBs In CLE283

Time marches on and once again, it's CLE time. This is an opportunity for you to discover the KIWI SDR online network and to put it to use for hunting NDBs ... either close to you or on the other side of the world!

'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.
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 

Here are the final details for our special 283rd listening event which 
starts this coming Friday.  

Joachim and I are grateful for the questions, suggestions and help in the last few days.   Thanks also to Martin, who has made some changes that improve the way RWW handles logs that have been made at remote receivers.


  Days:    Friday 26 August - Monday 29 August

*Midday on Friday to *Midday on Monday,

                   local time at your chosen REMOTE RX
  QRG:    Normal LF/MF frequencies (190 - 1740 kHz)

  NDBs:   A MAXIMUM of 100 normal NDBs (not DGPS, Navtex, Amateur, .. )
                (That’s not intended to be a target to reach!)

Please check that you will be following the help given in the Early
Advice, sent last Saturday, and in the later contributions to the List.

Send your CLE log to the List, preferably as a plain text email (not in an attachment) with ‘CLE283 FINAL’ in its subject line.

    Please show on EVERY LINE of your log:

       #  The date (e.g. '2022-08-27' or just the day no. '27')
 and UTC*

       #  kHz  (The beacon's nominal published frequency)

              If you don’t know it, please visit where you will find all the details.

       #  The Call Ident.


           *UTC  is the same everywhere of course - but

           *Midday local time can always be checked from your browser by entering e.g. time timbuktu  (try it now!)

Show those main items FIRST on each line, before other optional
details such as Location, Distance, etc.  If you send any interim logs during the event, please also send your 'FINAL', complete one.

Please make your log interesting to everyone by giving details of the listening location and brief details of the receiver there thatyou were using.

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

Do make sure that your log has arrived on the List at the very latest by 08:00 UTC on Wednesday 31 August.   We will then hope to
 complete making the combined results within two or three days.

Good listening


   Brian and Joachim

   (CLE Coordinators)


Here is additional information to help you in CLE283:

CLE283 – further guidance

Please be aware that, because most of the available Web-SDRs can be shared with a number of other users, there may occasionally be a need to wait your turn to use a particular one.

If you plan to participate in our upcoming CLE, you can use any one remote receiver for your loggings, stating its location (and web-address if possible) and with the owner’s permission if required.

You may NOT also use another receiver, to make further loggings for the same CLE.

Here’s a list of what can be found on the internet and there are definitely many more.

Kiwi receiver map :  

The KiWi-receivers are amongst the most popular web-controlled remote-receivers and there are many of them to explore all over the world.

Simply select a receiver from the map and it will start playing.

The KiWi-software is easy to use. For beacon hunting I found that it is best to switch to CW mode, fully zoom in and set the bandwidth to about 40 Hz by dragging the left and/or right side of the bandwidth indicator until the bandwidth suits your needs.

Type “h” or “?” to see a list of keyboard shortcuts. Also a right-click in the waterfall or frequency scale will bring up a Kiwi-specific menu.


WebSDR receiver List and map :

You can select a receiver from the list by clicking on the displayed link. However, you should make sure it supports the desired frequency band by observing the information in column “Frequency Range” because not all receivers do support the NDB-Band.

However, the wide band web-sdr at the University of Twente does and it is, by far, the most popular receiver using the websdr-software.

There’s also a search box near the top of the page allowing you to specify the frequency range.

To access the receivers-map, you have to scroll all the way down to the bottom of the web page.

Clicking on the icon for a particular receiver displays an info-box which shows the available frequency ranges as well as a link to start the receiver.


GlobalTuners :

GlobalTuners provides access to remotely controlled radio receivers all over the world.

You can tune the receivers to listen to any desired frequency band.

Be aware that this webpage requires a login to access any of the available receivers.

Also, for most of the receivers, listening time has been limited by the operators.


SDR-Console :

You can use Simon Brown’s marvelous software SDR-Console to listen to a huge number of remote receivers.

Simply download SDR-Console from  and install it on your PC.

Once the radio selection screen is displayed upon start of the software, select tab “Server”, click on button “Definitions”, click on “Search” and select “V3 Server”.

Then click on button and select a receiver from the list.


Perseus SDR :

Each Perseus Receiver comes with a server module which allows sharing of  this Rx via the internet.

You can select those receivers via the Perseus server-map :

However, this requires a Perseus SDR and the Perseus Software to be installed on your pc.

Please be aware, that listening to a Perseus server needs some forwarding of TCP/UDP-Ports in your firewall.

  1. Forwarding port 8014 (UDP Protocol) to your computer (if you are behind a router);
  2. “Unblocking” the Perseus software in Windows Firewall (automatically requested by Windows o/s at the first run)

Please refer to the manual (Client-Server Perseus Software Reference - EN02.pdf) which comes with the Perseus software for more information.

This webpage provides a good start if you are searching for a web-receiver.

You can search by selecting

  1. a preview page
  2. a table showing information of the available bands and location info as well as the type of receiver
  3. a map
  4. the receiver type (Kiwi-receivers, WebSDR receivers and OpenWebRX receivers)

              OpenWebRx is a clone of the “Kiwi SDR-Software” and allows to put all kinds of SDR receivers on the internet using a small Linux PC like the RaspBerry Pi.

Here is some additional advice from Martin Francis, the designer of the RWW database:

And remember, if you are using a radio in Australia for example - choose RWW as your system; if your receiver is in Europe REU will be your choice; if it's in the Caribbean, you will choose RNA.

You can use the filtering capabilities in the RXX system to give you likely targets - so if that remote radio is in New Zealand, you can show signals that have been heard IN New Zealand.

And if the radio you choose is already in the RXX system, you can go to 'Personalise' and select that actual radio to see distances and bearings to each station in your targets list.


If you submit logs from a location NOT already listed in RXX, please include as much info as you can to help our admins get your logs uploaded and create a new profile for that location.

Please include the specific URL (website address) used to access the radio, together with the receiver owner's callsign if they have one, and the town, state / province (if it has one), country, timezone and Grid square.

Also include the location YOU remotely operated the radio from (YOU are the OPERATOR in this scenario), especially if you haven't submitted a log before.

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!