This has been discussed on Rparts forum a couple of times. The power unit
of the BD series of compressors is a variable frequency inverter and is
notorious for creating RF noise. Danfoss makes an aluminum shielded model
but they are hard to find and don't help with conducted noise. The digital
thermostat is not normally a source.

Some things that will help are ferrite chokes on all wires going to the
power unit to reduce conducted noise. You may have to experiment with the
size to cut the frequencies that you need. Also lining the compressor
locker with metal screening tied to ground reduces radiated noise.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"krj" wrote in message
...
I just finished installing an SSB on my boat. When I turn on my freezer I
get noise on the radio that sounds like morse code. The freezer has a
Danfoss BD50 compressor with a digital thermostat. Has anyone else had this
problem. I think I remember Gordon West writing about this problem in one
of the sailing mags. but can't remember which one or when.
krj