snip

My neighbor used to have a chain link fence that generated electrical
noise when the wind blew. I didnt realize what was making all the pops
until the house sold and the new owner put up a wooden fence.

Oh, yeah!

This past summer I had occasion to haul some bundled antenna sections on
the
roof rack of my van. I was astonished at the BCB intermod that was
generated
with every vibration. I think the principal frequency intermoding was a
broadcast station about two miles from the start of my trip, since the
intermod got less and less as I got further away.

I'm familiar with intermods near transmit antennas, having dealt with EMI
on
USN ships for many years, but two miles?!?!?

Just like parasitic elements in a Yagi. Yes it does it on RX too. Not only
from the intended signal but chances are there are various closer sources
that can induce voltages in whatever junk is near your RX antenna too.

Very disconcerting to do the lab measurement and getting spurious down 70db
then measure 25db down off the air!?!