Hi Don,
That looks very much like the signal I'm seeing. I'm pretty sure it's
some kind of comm system, as I can see what looks like modulation of the
broad sidebands. They vary both in amplitude and spacing to the central
cluster.
I am seeing the signal only on 20 meters, and it's not nearly as strong
as the one you and Mike saw, so it might be much further away.
Were you and Mike ever successful in finding the source?
73,
Scott K9MA
On 7/31/2024 9:45 PM, Don Kirk wrote:
Hi Scott,
I never like to guess but take a look at this video showing RFI we
tracked down last year at W9RE and you will see similarities to what
you are seeing and you might also gain some info/insight on other
characteristics to look for in the demodulated audio spectrum.
https://youtu.be/yD7U-nH-AAg?si=Xrb7JPAByTj4NNKg
73,
Don wd8dsb
On Wed, Jul 31, 2024 at 5:31 PM K9MA <k9ma@sdellington.us> wrote:
This RFI source has appeared recently:
https://sdellington.us/hr/RFI/24.07.31.png
It appears to be harmonics of about 78 kHz. However, unlike most SMPS
RFI, it is very stable. It disappears at night, suggesting a solar
system, but it persists, weakly, an hour or so after sunset. Maybe a
solar system comm link, with a supercapacitor? However, I'm not
aware of
any new solar systems nearby. Anyone seen anything like this before?
Needless to say, I'll be out tracking it soon.
73,
--
Scott K9MA
k9ma@sdellington.us
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Scott K9MA
k9ma@sdellington.us
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