HFU HF Underground

Loggings => HF Mystery Signals => Topic started by: alleycat on July 16, 2021, 0413 UTC

Title: Amateur mode 3596 kHz - FSK?
Post by: alleycat on July 16, 2021, 0413 UTC

I'm seeing several frequencies in the 80 meter band with nearly 2 kHz-wide bursts that appear to be some sort of FSK (although none of the sources I'm familiar with, such as SigIdWiki, seem to identify an FSK variant with this wide a bandwidth). Audio clip at https://www.lutins.org/temp/radio/3596.mp3 (https://www.lutins.org/temp/radio/3596.mp3) with waterfall as depicted below. Any ideas? Thanks!
(https://www.lutins.org/temp/radio/3596.jpg)

Title: Re: Amateur mode 3596 kHz - FSK?
Post by: CoryD81 on April 12, 2022, 0042 UTC

Link to audio not working. Waterfall pics are also a huge help if you're able to get any.

Title: Re: Amateur mode 3596 kHz - FSK?
Post by: alleycat on April 29, 2022, 0209 UTC

After over 6 months without a reply I deleted the audio file. I had originally included a waterfall image in my post; that too got deleted.

Title: Re: Amateur mode 3596 kHz - FSK?
Post by: Josh on May 04, 2022, 1937 UTC

I show a few CIS fsk modes with a 2kc shift;
CIS_98.8_2000, 98.8 baud
CIS_100_2000, 100 baud, listed as REA4 Russian AF HQ Moscow
Both listed shifts might be the same modem running different encryption and/or framing, dunno.

Next closest shift in wcode hf table;
BAUDOT F7B, 1550 shift, 250 baud, listed as UKR (Ukraine) FSK encrypted via T207 modem