On 08/08/02 16:27.19, Theaterworks said...
Twisted pairs are inherently shielded as a result
of the twist if they are run in balanced, i.e.
push-pull fashion. If a hum occurrs near a balanced
cable, half the hum is picked up as "push", half
as "pull", and they cancel each other out.
Well, yes and no. The noise-rejection only works if the input fed by the twisted-pair is a differential amp, which rejects common-mode signals (signals equal in strength
and polarity in both conductors).
Larry
www.fineelectricco.com
