Yes, the weather did get cold last night & today, but I never had the
problem last winter.

No water leakage, no recent rain. Don't know about the bad ground
possibilty. No settings have been tinkered with. All transmitters work when
in close proximity, so the codes must be right.

I guess I can open the unit up & check the connection of the antenna, but I
wouldn't know how to recognize a bad solder joint.

Verizon is in the neighborhood, beginning digging about 300 feet away for
new optical phone line installation along the street at the top of my
driveway. Workers have been in the area marking utility locations the last
couple days, maybe they used some kind of radio wave sensors to locate the
buried wires??

Perplexed,
David