[Al Skierkiewicz]

Phil,
The noise you are looking at is likely the same. In the upper photos, you were at 5ms/div in the most recent you are at 20ns/div. The distortion in the line voltage is unusual. How were you attaching the scope to the line? There is a possibility that someone attached to the same transformer as your house has something unusual connected to the power line. The distortion you see can occur when the power transformer is trying to supply more than it was designed for. In my area, residential power line transformers are typically feeding no more than eight individual homes. Design varies for different parts of the country.

The hum in all the radios is indicative of the problem. You need to walk or drive around the neighborhood with your battery op radio and try to loacte the problem. Broadband over power lines (BPL) has been a hot subject in ham radio circles for a couple of years now. I have no personal experience with the issues but the system produces wideband noise sufficient to wipe out communications for ham radio operators. There is a system (Motorola) that uses radio frequecy filters at ham, TV and radio frequencies to prevent interference.

Let me know if you find anything. Whenever I have had local hum, a quick drive around the neighborhood with the car radio on AM will usually locate the insulator. There is no doubt when you drive under the offending pole. If you live near high voltage lines, this will be much harder to find. High voltage lines have insulators that break down all the time. In your case the noise will get worse on rainy days or those days just following a rain.