[RFI] What would cause noise like this?

[Frank O'Donnell]

Thanks for the suggestions on locating noise sources with 
direction-finding gear -- I will check those out.

My main interest in posting was to ask if this pattern was an obvious 
smoking gun for a particular type of noise source -- or whether, say, 
the fact that it started an hour before sunrise would necessarily rule 
out solar panels. Dave's comments about the schedule of RFI appearance 
are helpful, and I'll keep an eye on that.

To answer Jim's question, this view covers about 180 to 440 kHz.

Thanks again and 73,

Frank K6FOD