[Spooks] UNID digital signal at 5241 kHz (possible MFSK)

[Curt Rowlett]

While tuning around on a Web SDR located in Vihti, Finland, I discovered
this signal. It was fading in and out and I tried tuning it in on other Web
SDRs located all through Northern Europe. (It was soon apparent that the
Finland Web SDR gave the best signal, so I recorded what I was hearing).

Video recording here: https://youtu.be/Nsx3PBIIc2g

Just over halfway through the video, I changed from USB to LSB (around the
7:20 mark) as I was not sure that I had the proper frequency and mode for
this.

I have no idea exactly what this is (do you?), but it may be some form of
MFSK (Multi-Frequency Shift Keying) mode. I checked through the *Signal
Identification Guide* and the closest thing that I could find that
resembles this signal is here:
https://www.sigidwiki.com/wiki/Unidientified_%22MFSK-13%22

UTC time and date visible in the UTC widget seen running at the top right
of the video.

Regards to all,

Curt / W9SPY