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Old May 20th 08, 02:30 PM posted to rec.radio.amateur.antenna
John Livingston John Livingston is offline
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First recorded activity by RadioBanter: May 2008
Posts: 3
Default 1Hz click external noise? - HF Radar ?

Lumpy wrote:
Any guesses as to the origin of the mystery
noise bugging me this morning would be apprec.

I'm hearing an S9 "click" at just about
once per second, everywhere on 20meters
where there's not a powerful station's
signal. It clicks for maybe 3-5 seconds
then stops for a few seconds. Not always
symmetrical (3 sec noise ~ 10 sec no noise).

Click sounds like what I'd imagine a charging
and regularly discharging capacitor might do.

Freq independant, it's everywhere on the 20m phone segment.

S9+ stations seem to override the click.
S7 stations don't override, the click
comes right through and clobbers reception.

Station is "backyard remote", battery powered,
asymmetrical wire dipole.

I found some recordings of electric blanket
noise via k0bg's site. It sounds very much
like those recordings. Both of the elec blankets
in my home are off and unplugged. Neighbor elec
blankets? They would be probably 100' away from
the closest point to my antenna.

Noise just started this morning. No new elec
or mechanical devices running at my home.
Turned off the A/C, fans, elec fence, light
dimmers, pool filter etc. Three computers
run inside the house, as they have for
years.


Anyone have a guess at this 1 Hz click noise?
TIA -

Craig 'Lumpy' Lemke

www.n0eq.com


Everyone seems to assume this is local RFI - but I've heard something
very like this recently - in the UK (I guess you're in US?). It's not
electric fences or heating igniters - I am pretty familiar with what
they sound like ....

I can't remember the exact time or frequency, but 20m is probable. I
clearly remember that it wasn't on other bands, and it was in groups of
1Hz pulses, with quiet spells.

My guess is it could be some sort of OTH radar. I often hear OTHR pulses
in the UK, but at a higher PRF. These are usually assumed to originate
from the Cyprus or Middle East area.

John