[RFI] Powerline noise question

[Jim Brown]

First, figure out if it's impulse noise or electronic noise.

Others on this reflector have far more experience than me on impulse 
noise, but a technique that has worked goes like this. I have two 
VHF/UHF FM rigs with wideband RX and AM detection. One is a talkie, the 
other a conventional mobile rig. I've programmed both with a half dozen 
frequencies, beginning at 160 MHz up to the upper limit of their 
coverage around 550 MHz. I drive around listening on 160MHz, and as it 
gets stronger, I switch to the higher frequencies.

When I get close, I get out of the car with the talkie, holding it 
against my chest, giving it a half-space directivity. And when I get 
REAL close, I remove the duck.

73, Jim K9YC

On 12/29/2022 7:15 PM, Richard Karlquist wrote:
> I have a powerline noise coming from about 2 miles away, which is
> nevertheless quite strong at my QTH.
> 
> Here are the symptoms:
> 
> 1.  A 120 Hz noise burst at regular intervals, about 0.9 seconds apart.
> 
> 2.  The noise goes away after a rain; then comes back after things dry
> out.
> 
> 3.  Can be heard from 500 kHz up to a few MHz.
> 
> 4.  The noise is very strong along a road for a few miles.  There is a
> 
> power line that follows the road.  I haven't been able to localize it
> better than
> 
> that so far.  From my QTH, though, it is definitely coming in at a
> specific azimuth
> 
> which is consistent with the noisy road a few miles away.  (Using a loop
> antenna
> 
> for DF'ing).
> 
> Any help appreciated.
>