Wow...sounds like somehow, moisture was released inside the building. If it's 20ºF outside the building, and 22ºF inside the building, it's hard to imagine how frost could form on the equipment, since the relative humidity indors would have to be lower, unless...there was water forced up through a crack in the floor, etc.
73, Paul, AE4KR ----- Original Message ----- From: N1BUG To: Repeater-Builder@yahoogroups.com Sent: Tuesday, August 31, 2010 4:52 PM Subject: Re: [Repeater-Builder] Moisture/condensation (was: Duplexers) Condensation and moisture can be a strange thing... I have 2 meter and 440 repeaters in my own unheated building on a local hill. Several years ago in the middle of a cold Maine winter, both repeaters started having assorted audio problems and controller glitches. Upon arriving at the site I was horrified to find a thick layer of white frost completely covering every surface inside the building. Floor, walls, ceiling, every bit of equipment, cables, everything pure white and "hairy" with frost. I scraped away some frost and removed the cover from the repeater controller cabinet... and was even more horrified to find the controller PCB completely covered in frost! Couldn't even recognize the larger individual components on the board... What to do? I VERY slowly brought up the building temperature with a temporary heater over a period of a few days. The frost slowly vanished, not so much by melting and forming water but by dissipating into the air. Everything returned to functioning normally. The funny thing is, it never happened before or since. Just that one time. I never did figure out exactly what conditions caused it. Paul N1BUG