UNID 7000 UNID Mode 0117 UTC 28 JUL 2022

[~SIGINT~]

UNID 7000.0 kHz Digital 01:17 UTC 28 JULY 2022

01:17 UTC - UNID; 3.2 kHz wide in UNID mode.



RSPduo | End-fed longwire antenna

[tiNG]

Hi SigInt.

Could be FUV - F Ny Djibouti, which has been reported on 7000,1 kHz in the past.

Also possible is the RUS Ny on 7000,0 (reportedly Kaliningrad) with AT3004D-modem PSK.

Hope this helps.

[~SIGINT~]

Thank you. I am going to place my bet on RUS Ny. Based on the information I found with regards to FUV, it definitely was not Morse nor RTTY.  The modem sound was unknown to me. I do have an I/Q recording of it if anyone wants to take a stab at it.

http://www.utilityradio.com/stations/africa/dji/dji-23.htm

[Charlie_Dont_Surf]

I noticed this on European SDRs starting about a week ago and is pretty much always active when I check but I have no idea if it is continuous.

For what it is worth, my TDoA results have been confusing and not very definite but there is some indication that it might be coming from central Asia, specifically Kazakhstan, Uzbekistan, or Kyrgyzstan.

The signal is pretty loud in Europe and I noticed that ham activity at the low end of 40 meters has been affected in Europe. CW operators were staying clear of the very lowest end of the band. I did not see anything about it on the RSGB or ARRL websites when I looked on the 23rd of July (I think). They will sometimes point out "intruders", especially if there was a complaint made.

[~SIGINT~]

I see what you mean about the signal being prevalent in Europe. Here it is from the University of Twente Wide-band WebSDR, a solid S+10. If you listen to the audio carefully for a long enough period you can pick out what seems to sound like 100 Baud FSK / fast RTTY.

I put it out on the UDXF. Will see what comes back.

[Charlie_Dont_Surf]

It switched off at 0643 UTC, 29 July. It didn't fade out; it went from 10 dB over S9 to gone in milliseconds.

[Edited the following paragraph for improved clarity]

Forgetting about TDoA for a second and just thinking about trying to locate it from pure propagation observations alone, I checked a few SDRs in Asia and eastern Europe before I started the TDoA work at around 0640 UTC, just to get "the lay of the land". At that time, around two hours after sunrise in western Europe, it was not nearly as strong in western Europe as it normally is in middle of the night. The signal at receivers in eastern Europe, where it was normally quite strong during darkness, had low or no signal. Another observation was that some kiwis in Finland and Sweden had a very strong signal.

I was starting to think that it maybe it is in Kaliningrad (per tiNG above) and was focusing the TDoA around that area. While setting that up, the TX switched off.  That's the end of that for tonight.

[~SIGINT~]

From the UDXF:

This is the typical picture of Russian CIS-12 also called AT3004D. It has 12 PSK + a carrier. That carrier is almost always on the right site (USB) I stopped counting but catched far over 250 frequencies so far between 2 and 17 Mhz.

Regards, Leon

[~SIGINT~]

01:44 UTC 31 JULY 2022 - It appears that this Russian operator has moved to 7060 kHz.

Here is a look via the University of Twente Wide-band WebSDR:

[Token]

Yes, this is CIS-12 / AT3x04D / Fire / whatever other name people have given it.  I say "AT3x04D" because both the AT3004D and AT3104D modems have this mode.  I have seen it on this frequency before.

An easy tell-tale (visually) is the 3300 Hz Doppler / Pilot tone, when combined with the rest of the signal.  This is the carrier like portion of the signal to the right of the data.  In this case (the last image you posted) the tuned frequency and mode would be 7058.0 kHz, USB mode.  This puts the Doppler tone right at 3300 Hz audio.  In the state your pictures show the 12 PSK data channels can be seen, but in other states it may look very different, and the Pilot tone will still be present.  There is also a 20 tone version, typically called CIS-20, that is from the same modem (I think only the AT3104D, not the AT3004D) and looks almost identical except for the 20, vs 12, PSK tones.

I know we don't use it much, and no one has added anything to it in years, but this signal is in this sites Signal Identification page:
https://www.hfunderground.com/wiki/index.php/File:CIS12.jpg

T!