HFU HF Underground
Loggings => Utility => Topic started by: KMD3HR on May 15, 2015, 0043 UTC
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Can someone tell me what I am hearing..It seems to be thier alot. Especially when the free radio stations come up. FSK very fast? Can anyone decode it? Just wondering
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Normally there is not FSK present on this frequency, but rather some other kind of digital signal, such as Link 11. Several nights recently there has been FSK present.
The center frequency is 6947 kHz, not 6948 kHz. The tuned frequency would be about 6946 or 6945 kHz (varies depending on what you want the audio tones to be at), as you tune this signal in USB.
Without a recording I cannot tell what the signal was when you posted, however at this time it is STANAG 4481 FSK, it is KG-84c encrypted and you cannot decode it.
T!
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FWIW, It came on at 2244z yesterday. It was there all last night on the SDR recordings, generally with an S9+20 signal.
It is still audible now at 1143z but weaker, 4 or so. Based on propagation I would assume it is very roughly 500-1000 hundred miles from my QTH?
Curiously, I did not observe any obvious bit reversals or KG-84 headers when checking the waterfalls of the SDR recordings.
There's another FSK transmission around 6942 as well, it also looks like 850/75.