Steve, my uncle was one of the first ham radio operators in the US. Fantastic guy, rivoting stories from his long life before he passed away around 1985... His first ham call sign was 7GI - ya, no W or K in front back in the early 40's or late 30's. But I digress.... He used a spark gap and morse code key to transmit. Made a spark at low freq....
Anyway, it turns out that an ARC of a loose connection on a power line, even though only 60hz, will happen at both the plus and minus voltage peak, so actually is 120hz most of the time. But it is the energy of the arc itself that makes the RF noise. Yep, it goes from dc all the way up to at least 1ghz! Right up there near our RC and FPV freqs!
Remembering that the energy in the fields goes down by the cube of the distance, this noise is not likely to bother us 20-50m away too bad, assuming it is a nice smallish, low energy arc....
The other thing to remember is both the RC and VPF RECEIVERS have a spec called front end selectivity. This is a spec showing how the radio receiver will respond, or not respond, to off frequency signals. Now comes those arc energy pulses ever 4msec (120 times per sec).... if strong enough, they WILL get into the receiver and block the real signal we want to hear. Is this a big issue? Prob not real big because there are seldom reports on the forums of phantom folks loosing it near power lines. Again, the cube distance reduction is really our friend...
some notes if anyone really interested in reading more about this fascinating topic:
http://www.arrl.org/power-line-noise
http://www.downloads.siemens.com/do...aspx?pos=download&fct=getasset&id1=BTLV_40672