RadioBanter - View Single Post

December 27th 03, 09:23 PM

In article ,
(RHF) wrote:

PETE -or- Anyone,

Concerning this Two Conductor Un-Shielded Wire Pairs.

* Is it OK to leave this Wire Pair a straight flat pair ?

* Or, should these wires be "Twisted" (Twisted Pair) about One to Two
Turns-per-Inch to 'reduce' Noise Pick-Up ?

I have always been told that these Wire Pairs should be 'twisted' to
"Reduce" Noise Pick-Up and have always done so. But is this an
exercise in Stupidity-Dumbness based on an "Old-Tech's-Tale"

Whether twisting the wires or not does any good depends on your
engineering design goals. If the receiver at the one end is
differential then having a certain twist per foot of the connecting
cable will balance the noise field they are immersed in causing the
noise induced signal to be nearly the same on both wires. The
differential receiver can then by virtue of its common mode rejection
improve the signal to noise at its output. Single ended input
amplifiers will not benefit as much from the wire twisting.

--
Telamon
Ventura, California