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Author Topic: Numbers on 6852 Khz  (Read 3450 times)

Offline weaksigs

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Numbers on 6852 Khz
« on: March 02, 2012, 0000 UTC »
Numbers Station-  ???

I honestly know only a little about numbers stations however when l was looking for any
early pirate show transmissions this number (letter) sequence appeared steady and strong

I started to record at about 2215utc from here in central Florida.
Signal strength was extremely steady being S-9 to S-9+ 5 on the WinRadio Excalibur.
The antenna used during this logging was a 165 foot long wire terminated in a 9:1 torroid balun to the radio with a good rf ground. I must repeat this transmission exhibited almost no fading at all which was one thing that caught my attention.  ::)

The other thing that caught my attention was the fact that this MCW signal was constantly drifting down in frequency at what seemed a steady rate.

Start  Logging   2211 on  6852.75 Khz
End Logging      2228 on  6851.983 Khz

The transmission ceased at 2233 with the familiar  …-.-   sign off

Do these numbers station characteristically change frequency?
If they do I think this one was changing frequency at a predetermined rate, not merely like a drifting vfo from old tube days.

Very interesting strong signal that could easily been captured on most any portable as it was using MCW and signal strength was very good.

I did record a fair amount of this transmission and it can be found at this address;

http://dl.dropbox.com/u/65026409/numbers.mp3

Sorry about the constant blurps as I tried to compensate for the drifting. Trying to log time and frequency while keeping the signal at the same approximate pitch was next to impossible for me.

Let me know what you think as I don’t know much about these “numbers” or sequences, where they come from or if they could actually be local due to the constant signal strength.

Cheers

weaksigs
Central Florida
136' random wire for general HF,
Winradio Excalibur G31 & Kenwood TS-590

Peace!

Offline 4405486

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Re: Numbers on 6852 Khz
« Reply #1 on: March 03, 2012, 1841 UTC »
I did not listen to the whole thing; however, definately sounds like Cuban number station M8 to me.
Scroll down this message board and and click on keywords such as: Cuban Numbers, M8, 5800 Khz numbers etc. for information.
I did hear a recipient: TRDUN in "Cut Numbers". This is most likely one of two transmissions. The first or repeat transmission I can't tell. Typically both transmissions are an hour apart and are fairly close in frequency.
This site has a wealth of information; so much so, it takes time to assimilate it...especially the home page.
Thanks for the listing and recording, will see if I can observe it here on the west coast.
TNX VY 73..

Offline 4405486

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Re: Numbers on 6852 Khz
« Reply #2 on: March 03, 2012, 1849 UTC »
Excellent. Is not your listing on Feb. 9th: 6932 Khz 2115 UTC the first of two transmissions making this transmission the second repeat transmission?
Looks like it to me. Nice.

Offline weaksigs

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Re: Numbers on 6852 Khz
« Reply #3 on: March 05, 2012, 1428 UTC »
Thanks for your information 4405486!  ;)

I will be in a position very soon with more time to monitor my favorite
frequencies. So, I'll listen on some of the "numbers " freqs and try
to copy a few more.

Again I know only a little about this aspect of activity, but I can still
contribute a recording or two once in awhile.

Cheers!

weaksigs
Central Florida
136' random wire for general HF,
Winradio Excalibur G31 & Kenwood TS-590

Peace!

Offline Token

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Re: Numbers on 6852 Khz
« Reply #4 on: March 05, 2012, 1842 UTC »
Your recording is of Cuban numbers station M08a.

6854 kHz is a known M08a frequency in the 2200 UTC time slot (starts at 2200 UTC) on Wednesday and Thursday evenings.  This is a secondary or repeat schedule slot.  These would be repeats of the 2100 transmission on 6932.  The primary frequencies for this time slot (2200 UTC these nights) are on 7519 kHz on Wednesday night and 8009 kHz on Thursday night (repeats would be 2300 on 8009 and 8135 kHz).  The latest schedule for V02/M08/SK01 can be found in the latest Enigma Newsletter ( http://www.brogers.dsl.pipex.com/enigma2000/newsletters/CEN.pdf ), at this time Issue 69, March 2012, look near the end in the "Charts" section.

M08a uses either MCW or CW at various times.  When in MCW the station could be received in the AM mode on 6854 kHz or in the CW mode on 6853 and 6855 kHz (1 kHz CW tone in AM makes tones on either side of carrier).  When in the CW mode M08 is received on 6853 kHz, they normally use the transmitter in an LSB mode and modulated with a 1 kHz tone, creating tones 1 kHz down from the transmitter tuned freq.

The drifting nature of your reception is a bit interesting.  Of course, the Cuban numbers transmissions are known for their technical difficulties so nothing is really surprising, but normally the area the Cubans are pretty good in is stability.    So now the question has to be, was the transmitter shifting RF, or was the 1 kHz tone generator used to make the CW shifting audio frequency?

T!
« Last Edit: March 05, 2012, 1849 UTC by Token »
T!
Mojave Desert, California USA

Offline weaksigs

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Re: Numbers on 6852 Khz
« Reply #5 on: March 06, 2012, 0200 UTC »
Thanks for the ID TOKEN!  :)
I have caught these number stations at one time or another.
I just described to MT - They run a column on numbers.
Also, I appreciate your sharing the numbers station schedule posted earlier.
As I finally get on my time better (at the end of this month), I'll give a listen
once in awhile.

Very interesting hearing these mysterious stations the possibilities they represent!
 :o

Cheers!

weaksigs
Central Florida
136' random wire for general HF,
Winradio Excalibur G31 & Kenwood TS-590

Peace!

 

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