Scott,
We had an invisible dog fence with buried perimeter wire. It showed primarily
on 80m and spikes were about 10 khz apart. It was at our house, not the
neighbors.
- turned down the power level, it was set higher than necessary.
- used snap on chokes on the fence wire, type 31, with about 1/2” ID, wound it
about 6 times, then shut and secured with zip ties.
- used an FT240-31 on an extension cord to the squelch the wallwart.
- added additional FT240-31 chokes on coax at feedpoint and entrance
- This brought it down to “barely detectable”.
A couple months later the fence stopped working. The “transmitter” which
drives the fence wire was dead and the dogs got loose. I suspect the chokes on
the fence wire overloaded and burnt it out. We got a different brand of fence
with new dog collars. Choked that on the AC side but not the fence wire, and
this one is quiet.
Hope that helps. Start with the chokes on feedline to antenna.
Joe K1VW
> On Dec 17, 2025, at 12:22 AM, K9MA <k9ma@sdellington.us> wrote:
>
> A new source has just shown up:
>
> https://sdellington.us/hr/RFI/25.12.17%200454Z.jpg
>
> The harmonics are about 8 kHz apart, which is awfully low for a SMPS, though
> that's what it looks like. I'm only hearing it on 80. It's not coming from my
> house, but I have many nearby neighbors. It's definitely local. So far, I
> haven't been able to detect it with a portable receiver, but I need to do
> some more tracking. Any ideas on what this might be?
>
> 73,
> Scott K9MA
>
> --
> Scott K9MA
>
> k9ma@sdellington.us
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|
