AmateurRadio.com

This coming weekend will see the 'Barn Door' CLE, mentioned in a previous blogspot here. Listeners are required to challenge themselves by listening on a receiver using a wide enough bandwidth that several kHz worth of signals can be heard at once.




The 'immersive' effect this wider bandwidth mode provides is much different than when listening with narrow filters and can make digging out IDs a lot more challenging. Throwing in some mid-summer lightning noise makes it even tougher, but if it were easy, it just wouldn't be much fun!

Many, including myself, will be using homebrew single MOSFET regenerative receivers, often called a '1AD' since they normally use just one active device. I've just finished testing my own version and have been able to hear some night time DX so hopefully the band will be quiet enough to hear some signals during the CLE.

From CLE organizer Brian Keyte, here are the details explained ... and good luck to all participants!

Hi all

It is an opportunity to bring back to life basic kinds of receiver - anything with low selectivity which allows you to hear NDBs on several frequencies simultaneously - leaving the barn door wide open!

Listening with 'back to basics' equipment often gives very satisfying and unexpected results.  It can also show us ways of improving our listening when operating more normally.

Our last Barn Door CLE was No. 209 in July two years ago.

Here comes our fifth 'Barn Door' CLE.  Between us there will be a great variety of different receiver types in use.

    Days:      Friday 27 to Monday 30 July 2018
    Times:    Start at  ## 11 a.m. on Friday 27th, your LOCAL time
                   End at   ## 3 p.m. on Monday 30th, your LOCAL time
    Frequencies:   Centred on 360 kHz (see below)
    NDBs:     NOT MORE than 100 'normal' NDBs including any UNIDs
                   (That is not intended to be a target to reach)

We are all asked to listen with NON-SELECTIVE receivers - i.e. with a WIDE
filter or NO filter.  Your 'barn door' should be open wide so you could
hear, at the same time, any NDBs 2 kHz away on both sides of your receiver
setting - E.g. NDBs on 348, 349, 350, 351 and 352 kHz with the receiver set
to 350 kHz.

## The extra daytime hours on the first and the last day might help some of
us planning to listen out of doors.

You could listen with:

1. A simple home-made receiver, such as a single transistor set with regen.
    (e.g. based on the sets used by Mike, Finbar and others).

2. OR - an Ultralight receiver, maybe one converted to cover the NDB
    frequencies with a modified aerial.

3. OR - an 'antique' receiver (e.g. Eddystone, R1155, Scott, etc.)
    Perhaps you have something you've not switched on for many years?

4. OR - a normal receiver but with NO filtering, or using a WIDE FILTER,
    (not less than about 2 kHz and no selection of an audio filter).

You choose how wide a RANGE of frequencies you will listen in, CENTRED ON
360 kHz.  You could choose 350-370 kHz or 330-390 kHz or 260-460 kHz, etc.
   (This allows each of us to choose a +/- range with enough NDBs to
   match our equipment's capability.  It will also allow our loggings to
   be compared in the Combined Results, at least around 360 kHz).

Logs should show NOT MORE THAN 100 NDBs please (if more than 100, the
harvester program will 'drop' the loggings furthest from 360 kHz).

There are several extra targets you could set yourself - maybe the wide
bandwidth, the centre frequency of 360 kHz and the 100 loggings limit do not
challenge you enough!

You could listen only in daytime and/or away from home.
Or how about NDBs on 360 +/- 10 kHz or even +/- 5 kHz?
The Twente remote receiver in Holland could be interesting to use for the
whole of your (only) CLE log.
( Go to http://websdr.ewi.utwente.nl:8901/ and read the advice there:Select AM and 'MAX IN', enter e.g. 354.7 in the frequency box and change the
filter's limits to 2 or 3 kHz from the centre frequency on both sides )

We’ll summarise everyone's equipment on the first page of the combined
results, so please describe:
The RECEIVER/AERIAL you used and the FILTER(s) selected, if any.
If homebrew, please quote:  the total number of active devices used –  e.g.
1 for a single transistor stage ( 1AD ) -  the transistor/valve types,
whether using regen.,  etc.

All the usual procedures for making logs apply:

Send your CLE log to NDB List, if possible as a plain text email and not in
an attachment.

Please show on EVERY LINE of your log:
    # The full date (or Day No.) and UTC (the day changes at 00:00 UTC).
    # kHz - the beacon's nominal published frequency, if known.
    # The Call Ident.

Show those main items FIRST on each line, before other optional details
such as Location, Distance, etc.  Please send your complete log with
CLE234 and FINAL  in the Subject line.

Whether you are a first time CLE-er or a regular, make your log interesting
to everyone by showing your own location and your equipment details.
Do feel free to share any comments you have on this unusual event.

Joachim or I will send the usual 'Any More Logs?' email at about 17:00 UTC
on Tuesday 31st so that you can check that your log has been found OK.
Make sure your log has arrived on the List at the very latest by 08:00 UTC
on Wednesday 1 August.   We hope to complete making the combined
results a day or so later.

However you choose to take part, we hope you will find your 'back to basics'
listening enjoyable and worthwhile.


P.S.   NOT FOR YOU?

Listening without narrow filters is not going to revolutionise our hobby!
But there ARE some unexpected benefits and advantages:

1. Hearing several beacons on a few adjacent frequencies at the same time
becomes easier as you get practice at recognising them by listening to their
very different audio tones. At first, when listening to a random frequency
setting, you may hear just one or two beacons. But after listening for a
little while you realise that there are three - - four, maybe more, all of
them audible without altering any of the receiver controls.
It is a skill that gives satisfaction as you improve.

2. Hearing multiple beacons like that can be useful because, with no extra
tools, you can hear NDBs over a wide frequency range much more quickly than
usual, perhaps spotting the arrival of new UNIDs or the return of occasional
beacons.  (To protect your hearing, keep your receiver gain controls fairly
low, except on very quiet frequencies).

3. With normal listening it is easy to miss any NDBs that have abnormal
carrier frequencies or non-standard offsets.  With 'Barn Door' listening
they won't escape because everything is let through.

4. When using a wide filter, you may be surprised by hearing some Broadcast
Station signals (e.g. harmonics) among the NDBs and you will be able to
identify them.
With a narrow filter, often you may not recognise an AM signal as audio
- it just sounds like nondescript 'hash' affecting a wide range of
frequencies around the central carrier.


Maybe listeners will report some other good things about their barn door
listening during the CLE - and probably some bad things too!

Do join in if you can.

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

Don't forget that help and chat regarding NDB DXing can be had on the ndb group list here.

Alfred Morgan 1 Tube Regen courtesy: KC9KEP

The next CLE event will be the "Barn Door" listening activity which requires listeners to use receivers without the usual narrow filters. Some of the older tube radios can do this easily as can most homebrew receivers ... especially the regens!

If you've never listened to the NDB band with a wide bandwidth, it is a fascinating experience! If conditions are normal, you can typically hear a half dozen or more signals, all at various pitches, vying for your attention. It's almost as if you have plunked yourself down in the middle of the NDB forest of signals, and they are coming at you from all directions.

Many choose to use one of their homebrew receivers for this event, often as simple as a '1AD' or a '1 Active Device' circuit. A recent posting to the ndblist group from CLE organizer Brian Keyte (G3SIA), described just how much fun can be derived from such a simple radio. I'll let Brian's words speak for themselves below:

Recently I've had a few requests to provide details of my 1-transistor receiver, as used on my recent Scotland holiday and back in April 2009 for our first CLE for simple receivers. (There's still time to try making something for our next CLE145).
Here goes:

In March 2009 I was tempted to try following in the footsteps of Mike Tuggle and Finbar to see if I, as a complete D-I-Y beginner, could make a very simple 1-transistor NDB receiver. The story of making and using my own '1AD' (single active device) may help anyone also wondering whether to try some simple D-I-Y construction for CLE145, our second Listening Event for basic receivers.

I started by rounding up some likely old radios and a TV from my junk box and tried to see what I had in them that might be useful for a 1-transistor regen. receiver. From a list of the transistor types that I'd found, Mike identified a BF362 as probably the only suitable one. It is a 'normal' N-P-N silicon transistor (a BJT - bipolar junction transistor - as opposed to a field effect transistor like the MOSFETs) and is intended for low power high frequency applications. My background in making anything using transistors was just about nil and I knew almost nothing about them. The first challenge was removing the BF362 from its circuit board (a small board designed to amplify incoming UHF TV signals). Trying to play safe, I sawed round a big chunk of the actual board having snipped off most of the other components. A bit of brute force was needed as well as the hacksaw. Tests with a meter then showed that I should be able to solder to Collector, Base and Emitter without overheating the transistor. (Google helped when I entered ' BF362 data sheet ').

From the discarded MW / LW receivers there were several 2-gang variable capacitors and their tuning coils wound on ferrite rods - and of course lots of fixed capacitors and resistors. Many years ago a friend had passed to me the result of his construction of a basic amateur receiver (Heathkit RA1). That was useful because of the lack of a circuit board - the components were just soldered to lugs, most with still usefully-long wires. It also had a full list of parts and simple advice on construction. One of the old portable receivers I'd found had a plastic case that looked suitable for housing things (about the right size and shape, easy to drill, etc.).

First I tried a lash-up of the basic components on-the-bench (i.e. on the dining room table!) using the simplest transistor circuit without any regen. Trying my normal aerials, including a 100 metre long wire, I could weakly hear a few broadcast stations in the LF part of the MW band. Complete silence where there should have been NDBs - and my nearest, 316 EPM, is only 5 km away. When I tried adding regen. it proved to be an uncontrollable beast - stray capacitance effects due to all the loose connecting wires, etc. (I had made no use of a soldering iron yet!).

It seemed there was nothing for it but to start mounting the main components in the case - something I had wanted to do only after getting some real results. I had to try and guess where to site the components for likely best performance, ease of operation, etc. With no metal casing, it seemed to be a good idea to put a grounded copper wire as a 'busbar' round part of the case. That might help reduce any hand capacity effects and it would be useful for making the several ground connections including the '-' side of the little PP3 9v battery. Where possible the metal cases of the potentiometers were grounded to it too. 


I had only just started fixing components in the case when Sue and I needed to move up to Lincolnshire for 5 days. That turned out to be good, as I would be well away from temptations to continue the component searches for 'something a bit better' and I could concentrate on what should be the fun part. There was a good ground connection there but I was limited to a 30 metre long wire aerial. With regen. working, that proved to be long enough to get some results from Broadcast stations, though still not loud. I was making slow progress by trying out different component values etc. and by the time came to come back home I had only heard TWO beacons. One, 338 FNY Doncaster/Sheffield International (Robin Hood Airport), only 15 miles away, was faint but fairly easy to find. The other, 365 KIM Humberside and also about 15 miles away was very faint and I only managed to hear it once. Listening during the evenings didn't add any more NDB loggings at all. I was very disappointed and ready to give up the project, but Sue reminded me I had said that if I heard just one NDB during the 5 days I would consider it a success!


Returning to Surrey my luck changed. Without making any alterations, I tried the set using my 100 metre long wire - and it was transformed! During a few minutes at dusk I heard about 25 beacons, mostly weak but clear - the 30 metre aerial in Lincolnshire must have been the problem. Listening briefly again later that evening, several European countries were there - and to my surprise I suddenly stumbled on OZN 372 (Greenland) among the loudest and clearest. That made me wonder if a Canadian beacon was possible, so I tried for DF 350 more or less at random as one of the more likely ones. Setting the receiver to 350 kHz could be difficult with no frequency markings yet, but then I noticed that it would be halfway between my locals FOS 348 and WOD 352, both of whose idents could be heard at the same time. But no luck!

Then, at about 01.15 and just before bed, I tried again. After a minute or two there appeared a weak intermittent carrier and then - sure enough - about 5 cycles of a definite 'DF' before it faded and was gone. Can you imagine my delight? Ten days after starting as a complete D-I-Y beginner, a 1-transistor device made entirely of a few junk box components was getting me Deer Lake, almost 4,000 km away (2,500 miles) in Newfoundland. After that I thought the set justified having a name, so it was christened 'Max' (contradicting its minimal design!).

The next morning I took Max to try it out when genuinely portable using a long fence not far from here. Midday conditions this time but, with the necessary short aluminium rod pushed into the ground, it gave around 25 beacons in about 10 minutes, including Wales, Belgium, Guernsey and France. Another advantage of a simple portable receiver - there are lots of places with very long ungrounded wire fences that I've noted on our walks. Then at the end of the month Sue and I had a week's holiday at a self-catering cottage on the Isles of Scilly, 50 km into the Atlantic off the far South-West of England. Travelling by train and ship (no car), my AR7030 receiver and power supply couldn't make it into my rucksack but Max did, a fraction of the weight, together with about 100 metres of light wire to drape on the hedgerows beside the cottage. Listening mainly at daytime I heard over 100 NDBs. Again, the signals were mostly quite weak, but crystal clear.

Back home I made a few overdue improvements - replacing most of the remaining twisted wires with soldered connections, fitting a terminal block for the aerial and earth, adding a little switch to select one or both of the capacitor gangs and changing connections in the output transformer giving a considerable increase in volume. I had wondered whether my reception of DF had really happened, despite the detailed notes that I had made at the time. Then early one morning there was DF again, much louder than before and it persisted for several minutes.
I used the set of course for our first 'Barn Door' listening event for basic receivers, CLE116, during Easter weekend 2009. I chose to listen only within two hours of midday using a long wire or one of my fixed passive loops and I just managed to reach 100 NDBs. 14 of the loggings were of beacons over 400 km away.
In June this year, with CLE145 coming at the end of July, Max needed to be re-awakened and tested before taking it with us to Scotland. It had always suffered a little from hand capacity effects - touching some parts caused minor changes in frequency, as did the aerial being blown about by strong winds, etc. I discovered that one of my old PC keyboards had a big metalised screen under the keys. This cured all those problems merely by placing it (fixed with rubber bands!) over the front of the receiver. It also stops an occasional 'fizzing' kind of interference if I slide the first few inches of the headphone lead under the rubber band to hold it against the screen (see picture). I assume that problem was caused by some kind of RF getting through to the 'phones.


The attached pictures show Max's front view, the inside view with the back cover unscrewed and the circuit diagram.


In the front view the main tuning knob is at the top right hand side, still with primitive frequency markings on it! (35 = 350 kHz, etc.).
The regen. control is just visible at the bottom left hand side.
The top right hand switch extends the tuning range below 300 kHz by adding the second half of the variable capacitor.
(The top central switch is a refinement that allows the tuning to cover just the Medium Wave broadcast stations by using a different winding). 


 In the inside view, the main components are:

The transistor on its hacked bit of white circuit board which can be seen centre right.
The windings on the ferrite rod at the top are, left to right, the original main tuning coils, aerial coupling and the regen. coil.
The bottom right potentiometer is the regen. control.
The 'floating' pot. is the base bias control.
The large top left knob is main tuning, (I tried adding a fine tuning capacitor in parallel, but it added operating complication without any advantage and I removed it)
The bottom left pot. (still as in the original set) is spare, but it incorporates the battery ON/OFF switch.
The battery, wrapped in plastic in case it shorts things, can be changed using the hinged flap.
(However the battery drain is about 1 mA, so the battery would last for many months if I listened for an hour every day!)
The output matching transformer is next to the battery. 


As you can see, my approach has been very 'Heath Robinson' and a real hit-and-miss affair, so don't put much reliance on it. The set does work pretty well, but I'm sure circuit design experts will see lots of things than could be improved - and not just the quality of the soldering! Others are likely to use different transistor types and component values and some connections may be different. A MOSFET would be expected to perform better.

In case you haven't used a regeneration set before, the regen. control allows feedback of some of the RF signal to the main tuning circuit. As the regen. knob is increased from zero it increases the apparent signal strength considerably. Broadcast stations get much louder and a very local NDB would just be heard from its audio ident (a 400 Hz or 1020 Hz Morse tone). Turning the regeneration control up further continues to increase the signal strengths until suddenly beat notes start to be heard when you tune across any carriers. Now you hear the NDB signals much as 'real' receivers would when using their CW setting and no filter (or a very wide one).
The regen. could be increased even further, but eventually the set starts to fizz or wail loudly and becomes a 'dirty' transmitter - not useful!

If you have read as far as this you must have already built a simple set or are at least a bit tempted to!
If you have a little spare time, do give it a try. It really is a fun project and when you start to get results it is like reliving all over again those early days when you were delighted by your first DX loggings - only this is even more satisfying!

I'm grateful to Mike and Finbar for their encouragement and suggestions. I sent details of their sets to the List on 10th June in my email introducing the 'Barn Door CLE145' in late July. It would be good to hear details from any others with working sets or who are well on their way to having them.


Good listening!
Brian

Now if this is something that might interest you, filling a log page of NDBs heard on your own little creation, then there is still plenty of time to whip something together. If you prefer 'modern', then Mike and Brian's circuits might be a good place to begin experimenting or you could just grab one of your old Handbooks and check out the simple regenerative circuits described ... from the '30s on up! Just beef up the L and C values enough to get you down below the broadcast band and you're in business.

There is also a ton of stuff on the web via the vintage magazine and book collection available at the American Radio History website here, with enough info to keep you at the workbench for a long time.

courtesy: American Radio History

Here is the CLE info, direct from Brian:

Our 233rd Coordinated Listening Event is only just over, but Joachim and I
want to tell you a little about something special coming for our next CLE,
27th - 30th July.

For CLE234 we’ll have one of our occasional ‘Barn Door’ CLEs.
It will be an opportunity to bring back to life basic kinds of receiver -
anything with low selectivity which allows you to hear NDBs on several
frequencies simultaneously – “leaving the barn door wide open!”.
Our last Barn Door CLE was No. 209 in July two years ago.

Listening with 'back to basics' equipment often gives very satisfying and
unexpected results. It can also show us ways of improving our listening
when operating more normally.

To take part, you could use any one of the following:

1. A simple home-made receiver, such as a single transistor set with regen.
(e.g. based on the sets used by Mike Tuggle, Finbar and others).

2. OR - an ultralight receiver (maybe one converted to cover the NDB
frequencies with a modified aerial).

3. OR - an 'antique' receiver brought back to life (e.g. Scott,
Eddystone, R1155, etc.). Most of those are anything but ultralight!

4. OR - a normal receiver but with NO filtering, or using a WIDE FILTER,
(not less than about 2 kHz and with no selection of an audio filter).

Your 'barn door' should be open wide enough for you to hear any NDBs
on at least five adjacent frequencies all at the same time - E.g. NDBs on
348, 349, 350, 351 and 352 kHz with the receiver set to 350 kHz.
Listening to one NDB and ignoring several others of different pitch can be
quite a challenge - but it is very satisfying when you find how quickly it
becomes easier to do.

It may take a while to prepare for some of those ways of listening,
especially the first - hence this ‘Early Warning’!
The attached guide *** (click here) from the past by Mike Tuggle may help you if you are thinking of using a basic D-I-Y receiver.

The ‘Early Advice’ and ‘Final Details’ for the CLE will follow about 9 days
and 6 days before the event, earlier than usual to help you to get ready.


Good Listening!
Brian
-----------------------------------------------------------------
From: Brian Keyte G3SIA ndbcle'at'gmail.com
Location: Surrey, SE England (CLE coordinator)
----------------------------------------------------------------

YLD - 335kHz courtesy: http://www.ve3gop.com/

This coming weekend will see another monthly CLE challenge. This time the hunting grounds will be 335.0 - 349.9 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 YLD - 335, located in Chapleau, Ontario.

'YLD' runs just 100W into a 100' vertical but is well-heard throughout North America and many parts of Europe under the right conditions. Listen for its upper-sideband CW identifier (with your receiver in the CW mode) on 335.415 kHz.

Summer lightning storms may provide additional listening challenges but today's lightning map of North America looks surprisingly quiet ... maybe we will get lucky. It can't however, be any worse than last month's CLE, where widespread lightning was reported by almost every participant.!

courtesy: http://thunderstorm.vaisala.com/explorer.html

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 and compare against what others in your area might be hearing.

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.

From CLE organizer Brian Keyte, G3SIA, comes the details:


Hello all

Here are the full details for this weekend's co-ordinated listening event.
It is open to everyone including CLE new-comers:

Days: Friday 22 June - Monday 25 June
Times: Start and end at midday, your LOCAL time
Range: 335.0 - 349.9 kHz

Wherever you are, please join us and log the NDBs that you can positively
identify that are listed in this busy frequency range (it includes 335.0 kHz
but not 350 kHz) plus any UNIDs that you come across there.

Send your CLE log to the List, preferably as a plain text email
(not in an attachment) with "CLE233 - FINAL Logs" at the start of its
subject line.

Please show on EVERY LINE of your log:
# The date ( e.g. 2018-06-22 or just the day no. 22 ) and UTC
(the day changes at 00:00 UTC).
# kHz (the beacon's nominal published frequency, if you know it)
# The Call Ident.

Show those main items FIRST on each line, before other optional details
such as Location, Distance, Offsets, Cycle time, etc.
If you send any incomplete logs to the List during the event, please also
send your 'FINAL', complete one.
Please always make your log interesting to everyone by showing your
own location and brief details of the receiver and aerial(s), etc., that
you were using.

We will send the usual 'Any More Logs?' email at about 17:00 UTC on
Tuesday so that 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 27th June.
We hope to complete making the combined results on that day.

You can check on all CLE-related information from the CLE Page
http://www.ndblist.info/cle.htm
It includes a link to seeklists for the Event from the Rxx Database.

Good listening
Brian
----------------------------------------------------------
From: Brian Keyte G3SIA ndbcle'at'gmail.com
Location: Surrey, SE England (CLE coordinator)
----------------------------------------------------------

(REMINDER: You could use any one remote receiver for your loggings,
stating the location and owner - with their permission if required.
A remote listener may NOT also use another receiver, whether local
or remote, to obtain further loggings for the same CLE). 
-------------------------------------------------------------------

courtesy: https://sdr.hu/

In a previous blog I described the amazing KiwiSDR network of online receivers. A quick check of the network as I write today's blog shows that there are presently 207 active online receivers distributed throughout the world!

Over the past year, there has been a growing interest in using many of the online receivers during the monthly CLE NDB listening events, all focused on the medium frequency (MF) part off the spectrum just below the AM broadcast band. Some use the SDRs to search for unlogged beacons while others use them because their home locations have become too noisy to hear anything using their own radios, a growing problem for listeners everywhere.

One ardent NDB DXer, Dan Petersen, W7OIL, (located in Vancouver, WA) has become a regular Kiwi network user as well as a regular contributor to the very valuable RNA / REU / RWW list of worldwide beacon activity. Over the past year, Dan has been keeping careful notes on not only what he has been hearing but also on how well many of the online radios perform on the MF NDB band.

As it turns out, many receivers perform very well on the HF bands but are dreadfully inadequate when it comes to the medium wave frequencies. Many are plagued with high noise levels, switching power supply signals, intermod or inadequate antenna systems, making them unusable for weak signal DX work below the broadcast band.

Other receivers however, are superb performers, as evidenced by their quiet low noise locations and well engineered antennas, providing the ideal opportunity to conduct some serious medium wave weak signal detection.

Dan has now produced the start of an ongoing guide, mainly focusing on the various Kiwi Network receivers that he has tested, rating them with regard to sensitivity and local noise, when used in the 200 - 500 kHz range only.

His SDR EVALUATION LIST (in .pdf form) can be downloaded from here, and will be updated periodically, as other online receivers are evaluated.

If you are plagued with local noise on the MF band yet would like to do some weak signal DXing, especially during the monthly NDB CLE activities, the online SDRs may be of interest to you. With Dan's helpful groundwork already giving you a leg up, hopefully you can give them a try sometime soon!

                          *********************************

Speaking of monthly CLEs ... the recently completed weekend event (CLE232), was a rough one, with worldwide lightning noise as well as an active geomagnetic field hampering reception for all participants. In North America, all three nights were terribly noisy and propagation was poor.

As is so often the case, Friday night was the 'best' of the three nights but only 18 stations were heard here. My log is shown below.

It was nice to hear POA in Pahoa, Hawaii, still going strong as it is located close to the present volcanic eruptions.

All signals were heard on a Perseus SDR feeding an inverted-L antenna, resonated to 300kHz.

26 09:00 325.0 YJQ Bella Bella (Campbell Island), BC, CAN
26 09:00 326.0 YQK Kenora, ON, CAN
26 10:00 326.0 DC Princeton Municipal Apt, BC, CAN
26 06:00 328.0 YTL Big Trout Lake, ON, CAN
26 09:00 328.0 LAC 'Lacomas' Fort Lewis, WA, USA
26 09:00 328.0 5J Coronation, AB, CAN
26 06:00 329.0 YHN Hornepayne, ON, CAN
26 09:00 329.0 YEK Arviat, NU, CAN
26 09:00 329.0 X2 Athabasca, AB, CAN
26 10:00 329.0 PMV Plattsmouth, NE, USA
26 09:00 329.0 PJ Robinson (Whitehorse), YT, CAN
26 09:00 330.0 0O UNID, XUU
26 09:00 332.0 XT Terrace, BC, CAN
26 09:00 332.0 WC White Rock (Abbotsford), BC, CAN
26 10:00 332.0 VVV Ortonville Municipal Apt, MN, USA
27 09:00 332.0 VT Buffalo Narrows, SK, CAN
26 12:00 332.0 POA Pahoa - Hawaii Island, HWA
26 06:00 334.0 YER Fort Severn, ON, CAN

YEK - 329kHz courtesy: www.ve3gop.com/

This coming weekend will see another monthly CLE challenge. This time the hunting grounds will be 320.0 - 334.9 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 Arviat NDB, located in Nunavut on the western shores of Hudson Bay. 

'YEK', on 329 kHz runs 500W into a 100' vertical and it's well-heard throughout North America and many parts of Europe under the right conditions. Listen for its upper-sideband CW identifier (with your receiver in the CW mode) on 329.421 kHz.

Propagation has been very good on the MF band recently but at this time of the year, good listening is often hampered by a lot of lightning activity. Hopefully that will not be the case this coming weekend but today's map shows what we may be up against!

courtesy: http://thunderstorm.vaisala.com/explorer.html

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 and compare against what others in your area might be hearing.

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.

From CLE organizer Brian Keyte, G3SIA, comes the details:

Hello all

Our next Co-ordinated Listening Event is less than a week away.
It is an ideal one for new listeners as well as for regulars:

Days: Friday 25 May - Monday 28 May
Times: Start and End at midday, your LOCAL time
Range: 320.0 - 334.9 kHz

It's straightforward - just log the NDBs that you can identify having their
nominal frequencies in the range, plus any UNIDs that you come across
there. We last concentrated on these frequencies during CLE216 in
February 2017.

We'll be near the DGPS beacons range and some of us, especially in North
America, may hear a few, but please don't report them in this CLE.

73
Brian
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From: Brian Keyte G3SIA ndbcle'at'gmail.com
Location: Surrey, SE England (CLE coordinator)
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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. A remote listener may NOT also use another receiver, local or remote, to make further loggings for the same CLE.

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Last weekend's CLE 230 overall results have now been tabulated. Reports from European NDB hunters and those from North America and the rest of the world may all be found here at the NDB List info website.


If you have joined the NDB List group, a copy of these will have already been sent to your mailbox.

It seems that compared to the last time these same frequencies were searched (CLE 213 Nov '16), my results were a little poorer, with 36 beacons heard this time versus 52 for the previous effort.

Propagation varied over the three night event depending upon what part of the world you were listening from and as usual, when there has been some recent coronal hole induced geomagnetic disturbance, the further away from the auroral zone you were, the better the prop seemed to be. The third and final night saw summer-like lightning noise for most North American listeners and the next several CLE weekends will be  lucky to escape these rising levels until late in the fall ... but don't give up as there can be some great propagation in the summer and those quiet nights do come around when you least expect them.

In spite of the poor propagation here, there were some unusual quirks. Many of the 25 watt, normally easy NDBs from the central and southern states, were missing in action ... yet on all three nights, both FIS in Key West, Florida and SQT, up the coast on Florida's central eastern shoreline, were easy copy for several hours.

I can only guess that the reason for this is that both of these are 'big' beacons ... big antennas and power in the 300W plus class. They just managed to power through in spite of the poor propagation.

FIS - 332 kHz Key West, Florida (aka: The 'Fish Hook' beacon)

SQT - 257 kHz Melbourne, Florida

The other surprise was a loud signal on all three nights from FS in Sioux Falls, South Dakota, yet there was not even a hint of many of the other regular midwestern stations. Its reported 300W and 60' vertical is no doubt the reason. 

FS - 245 kHz Sioux Falls, South Dakota

How DD in Columbus, Ohio managed to sneek through is a bit of a mystery but it looks like her 50W and classic 'T' was enough to do the trick.

DD - 253 kHz Columbus Ohio

I managed only 36 stations but spent little time on Friday since conditions were truly dreadful.


25 04:00 240.0 BVS Burlington, WA, USA
25 08:00 241.0 YLL Lloydminster, AB, CAN
25 04:00 242.0 ZT Port Hardy, BC, CAN
25 04:00 242.0 XC Cranbrook, BC, CAN
25 07:00 244.0 TH Thompson, MB, CAN
25 05:00 245.0 YZE Gore Bay, ON, CAN
25 13:00 245.0 HNS Haines, ALS
25 06:00 245.0 FS Sioux Falls, SD, USA
25 08:00 245.0 CB Cambridge Bay, NU, CAN
25 08:00 245.0 AVQ Marana, AZ, USA
25 06:00 246.0 ZXJ Fort St. John, BC, CAN
25 07:00 248.0 ZZP Queen Charlotte Is, BC, CAN
25 04:00 248.0 WG Winnipeg, MB, CAN
25 07:00 248.0 QL Lethbridge, AB, CAN
25 07:00 248.0 QH Watson Lake, YT, CAN
25 09:00 248.0 PQF Mesquite, TX, USA
25 10:00 250.0 FO Flin Flon, MB, CAN
25 04:00 251.0 YCD Nanaimo, BC, CAN
25 11:00 251.0 OSE Bethel, ALS
25 04:00 251.0 AM Amarillo, TX, USA
25 07:00 253.0 GB Marshall, MN, USA
25 09:00 253.0 DD Commercial Point, OH, USA
25 09:00 254.0 ZYC Calgary, AB, CAN
25 09:00 254.0 SM Fort Smith, AB, CAN
25 09:00 254.0 EV Inuvik, NT, CAN
25 06:00 256.0 LSO Kelso, WA, USA
25 08:00 256.0 EB CFB Edmonton, AB, CAN
25 04:00 257.0 XE Saskatoon, SK, CAN
26 06:00 257.0 SQT Melbourne, FL, USA
25 04:00 257.0 LW Kelowna, BC, CAN
25 04:00 257.0 HCY Cowley, WY, USA
25 04:00 258.0 ZSJ Sandy Lake, ON, CAN
25 09:00 420.0 FQ East Chain, MN, USA
26 06:00 421.0 VLY McKenney, TX, USA
26 06:00 426.0 EN Council Bluffs, IA, USA
25 07:00 428.0 POH Pocahontas, IA, USA

As usual, my receiver of choice was the Perseus SDR in combination with my MF inverted-L, tuned to 300kHz.

The very active NDB Group.io List 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.