Date: Sat, 25 May 91 12:19 PDT
From: John Higdon <john@zygot.ati.com>
Organization: Green Hills and Cows
Subject: Re: Why a Twist in Modular Cables?

rees@pisa.citi.umich.edu (Jim Rees) writes:

> Every ready-made RJ-11 cable I've ever seen has the plugs attached on
> the same side of the cable at each end.

> So is there a reason for it, or is it just manufacturing convenience?

Yes and yes. Bulk cable (for putting the ends on yourself) has a ridge
on one side. By standardizing which way the ridge goes into the
crimper, it is easy to accurately and speedily put modular plugs on
the cable without worrying about whether you have "end A" or "end B"
in your hands.

Modular receptacals come in two flavors: receptacal and instrument.
There is an assumption of pair rotation between the two, hence the tip
(green) and ring (red) will match at their respective ends, regardless
of the actual color of the conductor in the cable, which can vary
depending on which way it is "facing".


        John Higdon         |   P. O. Box 7648   |   +1 408 723 1395
    john@zygot.ati.com      | San Jose, CA 95150 |       M o o !