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.
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