Charlie,
AS has been mentioned many times on this reflector, the most effective way
track down a source is: 1) Make certain it is not in or on your own property;
2) use DF techniques to locate its location if not on your property.
Another ham here in Iowa had an RFI source that was periodic in nature, much
like yours. I suggested to him, and now to you, that you power the radio
receiving the interference by battery, then turn of ALL power in your house.
If the noise goes away, it's source is with you. If it remains, then the
source is external and you will need to go hunt down its location.
The local ham was lucky - killing power in his house caused the noise to go
away. He then restored power one circuit breaker at a time. Success! The
problem was a battery charger that was trying to charge a defective battery
pack. May you be as lucky. BTW: When killing house power, kill the MAIN
breaker if you can. As others have noted, door bell transformers can sometimes
be the problem and they are often (as in my house) located right at the power
panel or hidden from sight. You MUST know for certain that the problem is in
your house.
There have been lots of postings here as to how to track down external RFI
sources. Yours does not sound as if it is power line noise, so it will be
easiest if it is something at your house.
You mention that your hand held can't hear the RFI. I presume that is because
it tunes VHF and/or UHF FM only. Be aware that some HTs have full HF AM
reception, the Icom IC-91A and 92A among them. (Yes, I can listen to WWV at 5
and 10 MHz with my HT as a time check.) Such an HT would be very helpful in
tracking down an external source.
73, Dale
WA9ENA
-----Original Message-----
>From: Charlie Gallo <Charlie@TheGallos.com>
>Sent: Sep 2, 2013 10:44 AM
>To: rfi@contesting.com
>Subject: [RFI] The Cable TV issue
>
>So, the tech came out today
>
>The voltage is gone (not the issue), and a loose ground block acting as a
>diode got rid of about 1/2 the signal, but then we were able to hear what was
>actually putting the initial RF buzz on the line
>
>My Motorola SURFboard SB6121 Cable Modem
>
>Just to let you know, this thing was putting out quite a bit of RF on the
>cable TV drop
>
>Now on to the next problem - On 80, there is a once ever 2 seconds (plus or
>minus, just counting Mississippi) pules of noise - Bip, Bip, Bip. 2 S units
>at my antenna. Problem of course is that the hand held can't hear it
>
>--
>73 de KG2V - Charles Gallo
>Quality Custom Machine-shop work for the radio amateur (sm)
>
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