Re: Mystery mode


Roughly speaking where are you located? Are there military or protest sites anywhere near you? That definitely looks like some form of covert comm.


On 20220709 08:05:18, Ken Sejkora wrote:

Thank you, Gary.  The signal is not there all the time; it was there yesterday, Fri:08-Jul around 11:30 UTC, but wasn’t there several times when I checked this morning, Sat:09-Jul.  As stated in my original post, I usually notice it when I tune into WWV at 15 MHz, or when I’m listening to the upper part of the 20-meter band and see the blips in the waterfall above 14.5 MHz.  Given the frequency, I don’t believe it to be local to New England (Kriss up in NH often sees it as well), and is likely propagation from somewhere more distant, although CHU on 14670 kHz was coming in when I took the screenshot yesterday.  Next time I notice it, I’ll check what regions are ‘skipping’ in on 20-meters, and also check WWV and other commercial stations to get a sense of propagation while I’m seeing the mystery signal.


If it is some type of frequency-hopping communication mode, I’m impressed that it is spanning a frequency range of about 700 kHz.  That’s pretty big at HF frequencies, but maybe not so up in the VHF and UHF bands.


By the way, my monitoring here is with SDR Console, Airspy HF+ Discovery, fed from a random longwire coupled through a 9:1 unun.


Thanks again.  Have a great weekend.




Sent: Saturday, July 9, 2022 09:46 AM
Subject: Re: [SDR-Radio] Mystery mode


After enlarging the screen shot I see what you are talking about. I’ve actually been monitoring 14 MHz lately and have never noticed that phenomenon before here in Central, IL. I am using  SDR Console, Airspy HF+Discovery and a Wellbrook Loop antenna. I will watch for it though,




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