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Re: Topband: RFI

Subject: Re: Topband: RFI
From: Fred Moeves <>
Date: Thu, 25 Jun 2020 13:16:43 -0400
List-post: <>
Thanks everyone for the help/info.

The noise is there almost all the time the only time it stops is when it rains.
In my video the it just stopped raining and it was just getting going again.
I wanted to show the noise when it was not there too.

I know one of the guys who are involved in finding the pole.
I am working on the other two guys...I do have the main guy's cell so that's a step in the right direction.
And they do seem to care and want to solve the problem.

Thanks Tim for the graph and the good ideas.

 Don I thought I had it down to 2 different poles but they said it was not there.

I have 2 portable SW radios they will not receive the noise.
But if I connect my 40m full wave loop I can hear the noise.

So I think I have to come up with a good portable antenna maybe a small multi turn loop.
I have Hustler RM-40 resonator.
I hooked it up stood on my upper deck but can't hear it.

Well that's about it...73  and thanks


On 6/24/2020 7:03 PM, Tim Shoppa wrote:
Fred, I graphed the scope trace of your noise in the video you linked, it is definitely 120Hz impulse noise. Attempting to attach scope picture. Count 12 spikes in 0.1 seconds = 120Hz. Very likely the power line guys can find it if they come at a time when the noise is there.

Now if it's intermittent (like I hear) getting the power line noise experts to show up on a day when the noise is there is the magic. In the best world they have your phone number and call before they show up, and you have their phone number and can tell them if the noise is there for them to trace.

Sometimes intermittent noises burn themselves out but more likely it gets worse over time and become solid 24x7.

Most rigs have noise blankers that help in the face of 120Hz impulse noise and not-crowded bands. Noise blankers are harder to use effectively in thick dense signal environments like contests but progress has been made with advanced noise blanking techniques. There was a truly excellent article in NCJ by N2NC on advanced SDR techniques in contest situations.


Tim N3QE

On Wed, Jun 24, 2020 at 6:13 PM fmoeves < <>> wrote:

    Thanks Steve. I think my power line guys need some training.. I
    wish I could use their detector for an hour or so. They keep
    telling me my area is very clean. I'll drive around some more see
    what I can hear. Thanks Fred KB4QZH
    -------- Original message --------From: Steve Lawrence via Topband
    < <>> Date:
    6/24/20  5:21 PM  (GMT-05:00) To: fmoeves <
    <>> Cc: Top Band List List
    < <>> Subject:
    Re: Topband: RFI Look here. GL - Steve WB6RSESounds of RFI
    <>On Jun 24, 2020, at 1:44 PM,
    fmoeves < <>> wrote:Hoping
    someone can help me identify this noise.It's on 160 80 40...most
    times stronger on 40.I called the power company..they found
    nothing.The video is just after some rain. When it rains it goes
    Fred KB4QZH _________________Searchable Archives: - Topband
    Reflector_________________Searchable Archives: - Topband Reflector
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