[RFI] intermittent noise

[Tom Berry]

I have an intermittent noise that has about a 30 second cycle. It starts and
stops like a switch being thrown.
It always goes away about sun set and it goes away if it rains.
I can hear it from 80 meters through 10 meters.

I know it is in a NE direction from my house.   There are a few houses in
that direction as well as a power line.

Anybody have any suggestions as to what I should be looking for?

Thanks
Tom AA4VV