I worked on the offending electric fence and managed to get it to
quiet down. Started with an RFI filter on the primary, which was
no help at all. Then I re-mounted the transformer in its plastic
enclosure (it was flopping around in there, shorting to the contacts.)
This helped eliminate 80% of the noise. I also insulated the wire
from several wooden posts, and taped over the wire in areas where
contact with vegetation could not be avoided. The fence is no
longer generating any noise.
The QTH is now as quiet as ever in my 7 years here. I'm grateful to
the local power company folks who spent considerable time tightening
and replacing hardware on all the poles in the neighborhood.
In other words, I got off real easy this time, and I'm thankful.
The fence will probably require periodic maintenance, but I can
certainly live with that. Thanks for your comments and suggestions.
Administrative requests: rfi-REQUEST@contesting.com