At 10:01 AM 12/31/97 -0800, Doug Brandon <dab@kaiwan.com> wrote:
>
>I've been plauged with some pretty bad local noise for quite a while now.
>It sounds like power line or some other sort of mechanically generated
>noise that shows up out of the blue and stays on at a constant high level
>for many days at a time. It doesnt just go away, but sort of "bleeds" off
>and slowly diminishes in strength over a few days until it completely
>disappears. Sometimes it is quiet for weeks, and other times it doesnt
>go away for weeks. The noise blanker in my 930S manages to chop it down
>from S8-S9 down to the S3-S4 level, but obviously strong adjacent signals
>cause the front end to chop like crazy. I've tried to keep a log of when
>it occurs to see if there is any sort of pattern, but I gave up since it
>seems to be pretty random.
>
>The noise doesnt peak in any direction when I turn my beam. I've also
>walked around the neighborhood with a transistor radio and was unable to
>find anything. The noise is strong on HF, VHF, UHF, and even causes
>sparkles on my cable TV. I have another ham friend who lives about a
>mile away and he doesnt experience this, so I know it's something in
>or near my neighborhood.
>
>
Before you do anything check your doorbell transformer! I was getting
random S9+ QRM on all bands and terrible lines on the TV even tho I am on
cable. I went around the neighborhood with my car radio, then walked the
house with a transistor radio. Putting the radio near the transformer
pointed to the problem. The noise stays on even when it is not causing TV
or radio RFI away from the transformer. I pulled the leads (after cutting
power to the transformer) and the noise went away. A replacement from Home
Depot was installed and I have had no problem since (except for the HV lines
1/3 mile away with S5 to 7 on 160 all the time).
Other possible sources....motor for an aquarium, faulty switch or control
for an electric blanket, any type of pump.
Check at home first .....
The JPS ANC-4 probably works for my HV line QRN but not for the type of
noise you have.
73, Dave K4JRB
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