[Boatanchors] Peristent, annoying, intermittent, elusive QRN problem: help please!

Tue, 12 Mar 2002 17:47:17 -0500

I had a very similar situation some years ago that was very
similar: persistent intermittent noise on/off like clockwork and
only at night.  I eventually traced it to a electric warming mat
with a bad bimetallic thermostat. Here is the story:

My wife likes to get a head-start on her garden by growing
seedlings in the house.  I rigged up an insulated box in the
basement that had a fluorescent light and warming mat.  The
light was on a timer and the warming mat was powered all of the
time.  The timer was set to mimic daylight, on in the morning,
off at night.

During the day the fluorescent lamp kept the plant box warm
enought so that the warming mat stayed off.  At night the light
would go off, the box would cool down and the heating mat would
cycle on and off.  Since the basement stayed at a relatively
constant temperature, the heating mat cycle also stayed
constant.

I had a devil of a time locating the source of the noise since
it was being radiated through the house wiring and so appeared
to be everywhere.

> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf
> Of Will White
> Sent: Tuesday, March 12, 2002 1:18 AM
> To: BA
> Subject: [Boatanchors] Peristent, annoying,
> intermittent, elusive QRN
> problem: help please!
>
>
> I have a local noise problem I am hoping someone can
> help me track down.  I hear
>
> S-6 or 7 loud, 'coarse' has on all HF bands, on all
> frequencies, though the
> intensity of noise diminishes somewhat on higher
> bands.  On 40M, my main band,
> it is all but intolerable, making QSOs with all but
> the loudest stations
> difficult, even at 12 WPM or so.
>
> The noise comes on for exactly 2' 15", and goes off
> for exactly 1' 25". Over and
>
> over. I have timed it many times over two weeks.  The
> noise is only there after
> dark. Aha! But I have searched and searched for an
> intermittent streetlight, to
> no avail. I have gone about three blocks in all
> directions from the house in
> this search, and also looked for automatic
> driveway/porch lights nearby, but
> can't find any. What the &*%$ can this be!??  I am
> really puzzled by the exact
> timing, since it would seem that a streetlight
> malfunctioning wouldn't do this,
> and a driveway light might stay ON for a specific
> time, but not off! HELP!
>
>
>
> --
> Will White, KD7BFX
> Seattle WA US
> King County, Grid CN87tq
> ITU Zone 6, CQ Zone 3
> ***************************************************
> "The wireless telegraph is not difficult to understand.
> The ordinary telegraph is like a very long cat.
> You pull the tail in New York, and it meows in Los Angeles.
> The wireless is the same, only without the cat."
>
> - Albert Einstein
> ***************************************************
>
>
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