I've found it helps to use higher frequencies. As you've discovered,
elevated wires re-radiate interference, so effective direction finding can
be impossible at low frequencies, leaving you to "round up the usual
culprits" and turn them off one at a time to find out where it's coming
However, power lines cease to be problematic radiators themselves at high
enough frequencies. I located the source of a similar problem by raising
receive frequency until I could barely hear the noise, and each time the
noise became relatively strong, raising it again. I ended up at 440 MHz,
with a beam pointing right at the top of a power pole at a local airport.
Arcing on a cracked insulator was at that high frequency an efficient
radiator in its own right. Needless to say, THAT location got it fixed
--- Cortland Richmond
--- EarthLink: The #1 provider of the Real Internet.
> From: Bob Thacker <email@example.com>
> Have had a terrible time finding interference sources and been battling