Mystery Morse Code Transmission On Medium Wave - UK Vintage Radio Repair and Restoration Discussion Forum

camtechman · 27th May 2010, 11:20 am

Hi All,

Whilst restoring a Dynatron Tourist TP14A and tuning around the medium wave band, at about 800KHz, I came across a regular & continuously repeated morse code transmission.

The transmission seems to go on 24/7 and appears to be two letters: C & U (dah dit dah dit & dit dit dah)

Here's the link to an audio clip of it, including pauses between transmission (note: once you've clicked on it, give it a few seconds to play):

http://www.plunder.com/Morse-Code-80...9ee079d938.htm

So, does anyone have any info on this?

Tony

Chris G0EYO · 27th May 2010, 12:02 pm

I read this as CIT but have no clue as to what it signifies

Chris G0EYO

cmjones01 · 27th May 2010, 12:10 pm

It sounds like an airport navigation beacon, though the ones I've heard have all been on lower frequencies than 800kHz.

Herald1360 · 27th May 2010, 12:41 pm

Have you tried a scan around the second channel frequency- for 800kHz that would be around 1740kHz (800+(2*470))?

Does it appear on another receiver at the same frequency? (Maybe the Tourist has a spurious oscillation somewhere?)

dominicbeesley · 27th May 2010, 12:45 pm

I thought it be one of the local airport beacons (possibly very strong) getting mixed with a multiple of the local oscillator? However after a bit of googling turned up this list for UK NDBs (non-directional beacons) used for airport navigation. http://navaids.nowindows.net/ndblist.htm

Cranfield is "CIT" on 850.0kHz - so there's your answer...yet another thing I can't pick up in this stupid valley!

Can you pick it up on any other set?

Dom

paulsherwin · 27th May 2010, 12:52 pm

MK isn't far from Cranfield.

camtechman · 27th May 2010, 3:59 pm

I've been able to receive the same transmission on several vintage radios: Dynatron Tourist, Bush TR114, Binatone Continental, Crosley 10-139 Repro & on several moderns, inc abrand new Lloytron Caplyso but, as my Roberts R309 on AM nudges up at 9KHz stages, it misses it.

I can't get it on any other frequency but that's not that surprising as the signal is pretty week, I had to amplify it after recording it to get a decent level.

Cranfield is nearby, as is Luton.

Here's a screen shot of the actual amplified audio trace and it looks like this:

Herald1360 · 27th May 2010, 9:45 pm

Interesting- looks like you can see the AGC on the receiver overshooting and recovering on the first da of the C. The noise in between the key down bits is then lower than it was when waitning for the signal to start.

Peter.N. · 27th May 2010, 10:30 pm

I made it 'CIT' I like that its slow enough for me to be able to read.

Heatercathodeshort · 27th May 2010, 10:38 pm

Norton would not let me open this file. Severe warnings about computer threats. All hell let loose! Most odd. J.

http://www.plunder.com/Morse-Code-80...9ee079d938.htm

Bumblebee · 27th May 2010, 11:34 pm

I have also heard this on my radio while going though the channels. I found it last year and now and again go back to see if it is still there, which it is.

All the best.
Mark.

dsergeant · 28th May 2010, 7:11 am

As mentioned, this is the Cranfield NDB (Non-directional beacon) and is on 850.0kHz. I can copy it here, but surprisingly weak for its distance, probably because I am using my 500kHz tuned vertical. The ident is CIT.

See the NDB list at http://navaids.nowindows.net/ndblist.htm - which shows all the NDB beacons in the UK. This site uses an Active X plugin and as such only works in IE (ughh..). Not sure why that one is the only one bang in the middle of MW.

See also the Wikipedia article on NDBs at http://en.wikipedia.org/wiki/Non-directional_beacon

As for your recording, no problems opening it here, but sending audio files as .wma file is a bit unusual, .mp3 would have been better

Dave

McMurdo · 28th May 2010, 8:58 pm

Around my neck of the woods (staffordshire) I get L-I-C right at one end of the dial which fascinated me as a child.

murphyv310 · 28th May 2010, 11:07 pm

Not a thing here using a wellbrook loop or long wire, into either a B40 or a Sait marine set.

Mike-repairman · 29th May 2010, 2:33 pm

Quote:

Originally Posted by Heatercathodeshort

Norton would not let me open this file. Severe warnings about computer threats. All hell let loose! Most odd. J.

http://www.plunder.com/Morse-Code-80...9ee079d938.htm

Scanned that file with Avast and Malwarebytes, both came back clean, so no problem with the file as expected. Norton is not the best of Anti-Viruses, some folk have no end of problems with it.

Mike.

Dave757 · 29th May 2010, 9:14 pm

Quote:

Originally Posted by McMurdo

Around my neck of the woods (staffordshire) I get L-I-C right at one end of the dial which fascinated me as a child.

Hi Kevin,

LIC is Lichfield aero beacon, and is on 545 kHz. Very strong
in Birmingham too.

Kind regards

Dave

Peter.N. · 30th May 2010, 8:40 am

Quote:

Originally Posted by Dave757

Quote:

Originally Posted by McMurdo

Around my neck of the woods (staffordshire) I get L-I-C right at one end of the dial which fascinated me as a child.

Hi Kevin,

LIC is Lichfield aero beacon, and is on 545 kHz. Very strong
in Birmingham too.

Kind regards

Dave

I didn't know that one was still going. My son learn't his first letters in morse from that while travelling along the A38, I was learning mine at the time and was converting number plates, road signs etc, must have been about 30 years or more ago. He insisted that it was sending 'LICE' as it had a dot on the end.

Peter

Dave757 · 30th May 2010, 12:10 pm

Hi Peter,

Just had a listen in case it had recently gone off, but
it's still there loud and clear. All the medium frequency
UK beacons you can hear now are aero beacons, the
marine ones having all been switched off some years ago.

Kind regards

Dave

27th May 2010, 11:20 am	#1
camtechman Nonode Join Date: Jan 2008 Location: Milton Keynes, Bucks. UK. Posts: 2,552	Mystery Morse Code Transmission On Medium Wave Hi All, Whilst restoring a Dynatron Tourist TP14A and tuning around the medium wave band, at about 800KHz, I came across a regular & continuously repeated morse code transmission. The transmission seems to go on 24/7 and appears to be two letters: C & U (dah dit dah dit & dit dit dah) Here's the link to an audio clip of it, including pauses between transmission (note: once you've clicked on it, give it a few seconds to play): http://www.plunder.com/Morse-Code-80...9ee079d938.htm So, does anyone have any info on this? Tony __________________ When I die, please don't let my Wife sell my collection for the amount I told her I paid for it!

27th May 2010, 12:02 pm	#2
Chris G0EYO Pentode Join Date: Dec 2008 Location: Redditch, Worcestershire, UK. Posts: 196	Re: Mystery Morse Code Transmission On Medium Wave I read this as CIT but have no clue as to what it signifies Chris G0EYO

27th May 2010, 12:10 pm	#3
cmjones01 Nonode Join Date: Oct 2008 Location: Warsaw, Poland and Cambridge, UK Posts: 2,681	Re: Mystery Morse Code Transmission On Medium Wave It sounds like an airport navigation beacon, though the ones I've heard have all been on lower frequencies than 800kHz.

27th May 2010, 12:41 pm	#4
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Mystery Morse Code Transmission On Medium Wave Have you tried a scan around the second channel frequency- for 800kHz that would be around 1740kHz (800+(2*470))? Does it appear on another receiver at the same frequency? (Maybe the Tourist has a spurious oscillation somewhere?) __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

27th May 2010, 12:45 pm	#5
dominicbeesley Octode Join Date: Nov 2004 Location: Hebden Bridge, West Yorkshire, UK. Posts: 1,885	Re: Mystery Morse Code Transmission On Medium Wave I thought it be one of the local airport beacons (possibly very strong) getting mixed with a multiple of the local oscillator? However after a bit of googling turned up this list for UK NDBs (non-directional beacons) used for airport navigation. http://navaids.nowindows.net/ndblist.htm Cranfield is "CIT" on 850.0kHz - so there's your answer...yet another thing I can't pick up in this stupid valley! Can you pick it up on any other set? Dom

27th May 2010, 12:52 pm	#6
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,970	Re: Mystery Morse Code Transmission On Medium Wave MK isn't far from Cranfield.

27th May 2010, 3:59 pm	#7
camtechman Nonode Join Date: Jan 2008 Location: Milton Keynes, Bucks. UK. Posts: 2,552	Re: Mystery Morse Code Transmission On Medium Wave I've been able to receive the same transmission on several vintage radios: Dynatron Tourist, Bush TR114, Binatone Continental, Crosley 10-139 Repro & on several moderns, inc abrand new Lloytron Caplyso but, as my Roberts R309 on AM nudges up at 9KHz stages, it misses it. I can't get it on any other frequency but that's not that surprising as the signal is pretty week, I had to amplify it after recording it to get a decent level. Cranfield is nearby, as is Luton. Here's a screen shot of the actual amplified audio trace and it looks like this: Attached Thumbnails __________________ When I die, please don't let my Wife sell my collection for the amount I told her I paid for it!

27th May 2010, 9:45 pm	#8
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Mystery Morse Code Transmission On Medium Wave Interesting- looks like you can see the AGC on the receiver overshooting and recovering on the first da of the C. The noise in between the key down bits is then lower than it was when waitning for the signal to start. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

27th May 2010, 10:30 pm	#9
Peter.N. Dekatron Join Date: Jul 2008 Location: Charmouth, Dorset, UK. Posts: 3,601	Re: Mystery Morse Code Transmission On Medium Wave I made it 'CIT' I like that its slow enough for me to be able to read.

27th May 2010, 10:38 pm	#10
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Mystery Morse Code Transmission On Medium Wave Norton would not let me open this file. Severe warnings about computer threats. All hell let loose! Most odd. J. http://www.plunder.com/Morse-Code-80...9ee079d938.htm

27th May 2010, 11:34 pm	#11
Bumblebee Pentode Join Date: Feb 2009 Location: Wolverley, Kidderminster, Worcestershire, UK. Posts: 102	Re: Mystery Morse Code Transmission On Medium Wave I have also heard this on my radio while going though the channels. I found it last year and now and again go back to see if it is still there, which it is. All the best. Mark.

28th May 2010, 7:11 am	#12
dsergeant Octode Join Date: Mar 2006 Location: Bracknell, Berkshire,UK. Posts: 1,175	Re: Mystery Morse Code Transmission On Medium Wave As mentioned, this is the Cranfield NDB (Non-directional beacon) and is on 850.0kHz. I can copy it here, but surprisingly weak for its distance, probably because I am using my 500kHz tuned vertical. The ident is CIT. See the NDB list at http://navaids.nowindows.net/ndblist.htm - which shows all the NDB beacons in the UK. This site uses an Active X plugin and as such only works in IE (ughh..). Not sure why that one is the only one bang in the middle of MW. See also the Wikipedia article on NDBs at http://en.wikipedia.org/wiki/Non-directional_beacon As for your recording, no problems opening it here, but sending audio files as .wma file is a bit unusual, .mp3 would have been better Dave

28th May 2010, 8:58 pm	#13
McMurdo Dekatron Join Date: Jun 2009 Location: Staffordshire Moorlands, UK. Posts: 5,274	Re: Mystery Morse Code Transmission On Medium Wave Around my neck of the woods (staffordshire) I get L-I-C right at one end of the dial which fascinated me as a child. __________________ Kevin

28th May 2010, 11:07 pm	#14
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Mystery Morse Code Transmission On Medium Wave Not a thing here using a wellbrook loop or long wire, into either a B40 or a Sait marine set. __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

30th May 2010, 12:10 pm	#18
Dave757 Heptode Join Date: Apr 2009 Location: Scratby, Norfolk, UK. Posts: 651	Re: Mystery Morse Code Transmission On Medium Wave Hi Peter, Just had a listen in case it had recently gone off, but it's still there loud and clear. All the medium frequency UK beacons you can hear now are aero beacons, the marine ones having all been switched off some years ago. Kind regards Dave Last edited by Brian R Pateman; 30th May 2010 at 2:09 pm. Reason: Quote not required.