oh... you may have been hearing the mother of all woodpeckers!

"Pete Holden" wrote in message
news:G%bXb.30491$uV3.52579@attbi_s51...
Well, thank you all for your ideas. I did check my dimmers and electric
blankets but found no RFI from them. It didn't seem to be anything from
the
thermostat either. I do have a battery charger which maintains a lead
acid
battery for my sump pump. I don't know about that yet. Of course, since
yesterday all has been quiet.

And, by way of full disclosure, I live within spitting distance of a
massive
array of radar antennas associated with our Distant Early Warning system
that supplies input to NORAD in Cheyenne Mt. and who knows what sort of
RF
they might be putting out occasionally?

Thanks again, Pete