On Sep 26, 2007, at 6:34 pm, Bexley Hall wrote: > Hmmm... that doesn't sound right. Usually you end up > with *unbearable* hum if one side of the telco line > is grounded. <shrug> Ever heard of radio? :-) You only have one waggly bit of signal to pick up -- the other is ground. Depends how you modulate it, how you filter it. R.