[TowerTalk] Weird RFI at remote location

[Lux, Jim]

On 1/1/21 5:53 PM, Ignacy Misztal wrote:
> Happy New Year!
>
> I bought 26 ac of land with an old house for a remote station. The power
> company buried the last 300 ft of power line. Now, the location has 100ft
> tower with 40-10 beam, 4 sq on 80, with the tower is loaded for 160m. Also
> 7 beverages and a Spiderbeam. It was fun to have no man--made noise.
>
> A few months ago the first power line noise started only when wet. MFJ 3-el
> VHF sniffer was going off scale. No arc noise as measured by the ultrasonic
> dish. It turned out to be a new transformer. Then another transformer by
> the neighbor 600 ft away started making the identical noise. The power
> company has replaced both transformers.
>
> Now I have another powerline-like noise, strongest at 15m at S5 but heard
> on all bands 24h/day. NB blanks sometimes completely sometimes less
> complete.
> On a panadapter, the noise appears to have min and max every 300 KHz. On
> one beam the max is at 21.2 and on another one is at 21.0.
>
> The main power line is on a road 1500 ft away. The MFJ sniffer could not
> find anything really loud. I even tried 2m AM radio with 10 el beam, which
> indicated relatively small noise from an inaccessible pole. On 15m using a
> magnetic loop, I find strong noise by every pole. Strongest from a
> distribution pole where wires go to several other poles. It is about 270
> degrees from my QTH.
>
> The power company is lost with the new noise. They have no experience in
> RFI since there are no serious  active hams around.  They say that the
> noise may be coming from an electric fence.
>
> Any idea on where the noise could originated from? In the past, all my
> power line RFI occurred when dry and hot.
>
> Another question is how to deal with the power company that wants to help
> but can't and becomes frustrated? Should I try to hire someone from a
> nearby EMC that knows how to fix RFI?



You might get one of those $50 spectrum analyzers - seeing the RFI 
spectrum may give you some clues  - a loop antenna (untuned) will have 
distinct nulls. It's more "field compatible" than going around with your 
rig's panadapter.