While trying to impove my indoor loop on 40-80m (coil added in a middle makes a noticeable difference on both TX/RX!) I’ve came across those strange CW signals. Perhaps they are trying to emulate a mechanical key with no audio control (although a vertical wouldn’t sound like that) But what could be a purpose? Another weird thing is that those sigs are present on four frequencies simultaneously with S9+:
I’ve made that particular recording at 2327 UT, but hear them for at least couple of weeks. It resembles the old On The Beach film, where a Morse key was operated by a loose window frame
Hi Alex, I remember that scene, they set up a roller blind cord that was caught up on the straight key and when the wind blew through the partly open window the key would be operated. The film was made at the Melbourne (Australia) showgrounds. I was16 at the time and went daily to watch the filming.
I once noticed strange morse sounding signals up and down the 40m band. Although it seems to keep repeating, I couldn’t make much out, expect a few widely spaced e’s and a definite u. Mine turned out to be emissions from an unscreened cat 5 cable that ran from the house to the shed:-)
Good point. I’ll have a run through that later and see does anything match. For anyone hunting it down, it seems to be more regular iirc somewhere between the end of CW and start of FT8. Doesn’t sound like either in terms of tone.
Also heard these signals here in PA. When listening to some of them simultaneously on different receivers, there appeared to be some correlation between them. They were all very strong on 40m.
Hear them now, at 1600UT. Very weak, at a noise level on my indoor loop in Greystones. So it looks like they are here 24/7
Edit: much stronger now at 1700UT, around S3-4
At least it looks like it is not coming from EI or G
Edit 2: at 1730UT they are coming at S9 +20-30db on WebSDRs located in UA3-9, interesting how do they receive them during daytime?
And got this answer:- "It is a wide-band FSK mode, with the two tones on 7041.5 kHz and 7048.5 kHz . Can be heard in European afternoons and evenings these days."
“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! Recorded 12 June 2025 by Tyler Stampfli, KA0KA …”
