James Knott <bit_bucket@rogers.com> wrote:
>Steve Wolfe wrote:
>
>>> Plus don't you have to earth them [STP] at one end?
>>
>> And only one end. Grounding (Earthing) at both ends creates a path for
>> current to flow to ground OTHER than the mains wiring, and if there are a
>> few amps (or more) going to ground, you do not want it going through your
>> shielding ("Hey! Why did the network just die?"). You also don't
>> necessarily need the hum from having the ground loop, either.
>
>Actually, that should be at only one point. You can ground the shield
>anywhere along it's length, so long as there is only one grounding point.
>However, with most cables, it's easiest to ground at the ends.

Virtually *all* outside plant telecom cables are grounded at
each splice box. That is, *both* ends of the cable are
grounded.

It reduces noise induction into the pairs. Likewise, if it is a
large cable, grounding both ends of all spare pairs will also
reduce noise.

--
FloydL. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com