Re: Signal vs. Idle debate (was: Here's a new idea)
Jack,
You wrote,
> I don't see it that way. Any scheme of idle pairs mid band insertion runs into
> exactly the same problems as phantom power. Both schemes have to address the
> compensation required to maintain Cat5 performance through the additional connectors
> necessary to insert power.
I see an idle pair scheme as having fewer problems than a signal pair
(phantom) scheme. The important difference in the mid-span insertion
configuration is that by using spare pairs one does not have to interject a
new signal (power) into the signal leads. This injection most certainly
will require ADDED high quality magnetics. This introduces added cost and
potentially affects signal quality. Whether signal quality is affected is
subject to evaluation. But as I recall Geoff Thompson stating at the last
meeting, there is no degradation allocation or budget to consume. Therefore
judging the acceptability of any degradation will be difficult. Power
inserted on the spare pairs has additional coupling loss to the signal
leads and its insertion should be less expensive. Both approaches run into
the same issues regarding connectors.
Regards,
Don Stewart