Very wideband FSK(?) on 40m

HB9TMC · June 17

It appears to be 2x2 carriers, pretty powerful signal.

G8JNJ · June 18

Well done on the TDoA, especially as it doesn't work too well on CW or FSK. I made several TDoA runs during grey line propagation, and initially thought it was from Germany. I should have known better. I used two separate browser instances with my KiWi, with the frequencies offset to produce a composite, but much narrower shift FSK signal, that I could attempt to read with an external decoder. However, the data is encrypted, as you would expect for a military signal.

The pair on 7043/7050 kHz shift to 7041.5/7048.5 kHz

The pair on 7063/7070 kHz shift to 7061.5/7068.5 kHz

Reports and discussion suggest it's a Russian FSK transmission, with some reports suggesting it's coming from somewhere in the Urals or the heart of Siberia, but one more detailed report suggests that the source is in the Crimea near Sevastopol ( https://youtu.be/zRho2iFfBCE )

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Sevastopol; Extremely powerful two channel 20b/7000 Hz FSK paired signals re-appear from Apr 23rd on 40m band ~ 7045cf and 7065.5cf, each channel seems to be 7 kHz from mark and space, chosen for it's immunity from being easily jammed, at times the pair will shift frequency; originating from Eastern EU / Western RU region, now Crimea with transmitters near Sevastopol. The modulation rate of 20b with a shift of 7000 Hz.

-The signal frame is 17 bits, the first of which is a 0.

-The superframe is 15 frames (255 bits) and is constantly repeated so it does not appear to carry any useful information

Military encryption 5N1 use in related signal connection to the conflict between Ukraine and Russia is likely. Contributor ANgazu thank you for your analysis!

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This link has a similar discussion and explanation as to these signals:

https://reflector.sota.org.uk/t/some-weird-cw-found-on-40m/38289?u=iu1kgs