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Author Topic: 6993 khz, 1258 UTC 2-1-2018, Bizarre CW transmission  (Read 539 times)

Offline BoomboxDX

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6993 khz, 1258 UTC 2-1-2018, Bizarre CW transmission
« on: February 02, 2018, 0832 UTC »
I was testing my Radio Shack 200629 Synthesised World Receiver (RS's ATS505 -- I figured out how to keep it from sounding like a theremin -- it doesn't like mono SW EXT antenna plugs in the SW EXT stereo jack) and I tuned through the utility sections of the SW band, something I don't usually do. 

With this radio, it's more fun to tune through the utility bands because it doesn't chuff, and tuning through a swath of HF spectrum is like tuning an analog radio.

Anyway, I came across a bizarre CW transmission on 6993 kHz (it may have been a kHz or two off -- the RS 200629 has a BFO with clarifier, and I may have had it tuned off by a kHz or two). It was sent by hand, because the characters varied in speed, with small breaks sometimes between them. Signal strength also varied, starting at around S3 and ending up between S0 and S2.

Here's an example of what I heard. The dots are breaks where it faded out. Spaces are where there were short pauses:

NR091 KN CCK35180201 ... (fade)... RMKSC7 ... (fades) (speeds up during fadeup)... N65 5t6 2 tu7... 3... N.... 5
CRTTN72UM05....

...it went on, and then stopped around 0106UTC.

Very strange. I'm guessing it was somebody messing with CW out of band, for the fun of it, or possibly a spy operation. Or maybe a military or government station testing by just sending out junk? I have no idea.

Doing a search, I guess some other HFU people have heard other stuff on 6993. Any one hear CW? I'm sure it wasn't an image. The sending was too bizarre for a ham or ship transmission.
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Offline digitalmod

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Re: 6993 khz, 1258 UTC 2-1-2018, Bizarre CW transmission
« Reply #1 on: February 18, 2018, 0103 UTC »
 8) Same was heard around 6925 on 17th Feb and a day earlier. Sending is bizarre as if looking code up in a chart?
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Offline Token

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Re: 6993 khz, 1258 UTC 2-1-2018, Bizarre CW transmission
« Reply #2 on: February 18, 2018, 1510 UTC »
There is not really enough of the CW there to be sure, but it looks a bit like the Chinese military M89 station format.  And they have been known to use both 6992 and 6995 kHz, however they use pretty random freqs, so I would not place too much on that.  Also, the time was right for it to be Asian.

Just a starting point guess.

T!
T!
Mojave Desert, California USA