One of my clubs moved to a field adjacent to power lines. This was a couple years ago, and part of the process involved getting our AMA AVP or frequency guru to visit with a spectrum analyzer.

Several visits showed power line generated signals of interference level on channel 56 only. One of our members was using #56, and he switched to a different channel.

Only one member has filtered his aircraft through the power lines...

Best wishes,
Dave Olson