Were you in the habit of leaving the radio on for extended periods of time with the antenna collapsed?

This is a no no...and I believe it ended up costing me a plane..and a radio system. I used to discharge the battery by just leaving the radio on, antenna down, in the basement, and ended up learning the hard way.

EDIT: Any way you cut it, there's nothing out there that's bulletproof...so unless the field you're at has interference on some of the FM channels..I wouldn't discount it right away.