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Path: utzoo!mnetor!seismo!lll-lcc!ptsfa!well!rab
From: rab@well.UUCP (Bob Bickford)
Newsgroups: comp.periphs,comp.terminals,comp.dcom.lans
Subject: Re: Telco-style push down blocks and stranded cable
Message-ID: <2316@well.UUCP>
Date: Wed, 7-Jan-87 08:15:54 EST
Article-I.D.: well.2316
Posted: Wed Jan  7 08:15:54 1987
Date-Received: Wed, 7-Jan-87 21:49:36 EST
References: <2551@phri.UUCP>
Distribution: world
Organization: Whole Earth Lectronic Link, Sausalito, CA
Lines: 36
Summary: no stranded wire in telco blocks
Xref: mnetor comp.periphs:108 comp.terminals:116 comp.dcom.lans:118

In a previous article Roy Smith asks:
> 
> 	What I want to do is set up a panel with a termination for each
> port on one side and a termination for each external line on the other and
> patch between them as necessary.  Since patching won't be frequent, I don't
> need anything as fancy as plug-in patch panels; re-doing a punchdown jumper
> will be easy enough.  The problem is that we've got miles of Belden 8723
> (stranded shielded twisted pair) all through the building and I understand
> that punchdown blocks are made to only work with solid wire.  Has anybody
> tried using stranded wire in punch-down blocks?  Will it work?  The last
> thing I want is to have hundreds of connections start to work themselves
> loose in a year or two.
> 
  Nope, it won't work.  I've done this; it will come back and haunt you
(or your successor ) if you try it.  The whole mechanical design
of the silly things (telco punch-down blocks) is centered around a
single solid strand of the right size.  If you stick to that, they're
wonderful, though.

  On your wiring, the way you've set that up should give you wonderful
performance.  I was running between two and three hundred feet at 9600
baud on just plain old telco wire (doubled the signal ground) and it
worked fine....  In fact, I believe the entire building was wired that
way.
  Using the shield is both good and bad..... good if you have or
suspect EMI problems, bad on long runs because of the extra
capacitance.  Don't have my Belden catalog handy, but I seem to
recall that the stuff you mention is low-cap, so you should be ok.

-- 
Robert Bickford    {hplabs, ucbvax, lll-lcc, ptsfa, msudoc}!well!rab
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