Hmm. CBs *do* tend to interfere with stuff - it doesn't take a lot to induce audible noise on amp feeds. Not sure what to suggest - cambscar might have an idea.

Hugo
(reminds me of a friend keying up his 25w SSB transceiver in a garage forecourt - very illegal and dangerous, btw as it's a suitably dangerous amount of power in terms of sparks - and it broke into the garage PA amplifier, so everyone within a couple of hundred meters could hear him through their speaker system).