Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!wuarchive!uunet!jhereg!andrew
From: andrew@jhereg.osa.com (Andrew C. Esh)
Newsgroups: comp.dcom.lans
Subject: Re: Cable scanner recommendations?
Message-ID: <1991May10.140628.17601@jhereg.osa.com>
Date: 10 May 91 14:06:28 GMT
References: <15490@darkstar.ucsc.edu>
Organization: Open Systems Architects, Inc., Mpls, MN
Lines: 34

In article <15490@darkstar.ucsc.edu> brad@terra.ucsc.edu (Brad Smith) writes:
>We're on the market for a cable scanner.  This will be used primarily to test
>twisted-pair cable runs.  I have been evaluating the Pair Scanner from
>MicroTest.  I'm impressed by all the functions this scanner can accomplish,
>but it seems a little too "idiot proof."  It only reports the greatest
>reflection along a cable run.  Something that would report all reflections
>would be more useful.  Can anyone recommend any other scanners/TDR's that
>would be worth checking out?
>
>Thanks in advance,
>
>Brad Smith
>Computer Facilities Manager
>brad@cis.ucsc.edu

Microtest Pair Scanner? I'm not very familiar with that, and I don't feel
like digging through all my product literature to find it. I saw the
brochure and was not impressed enough to read it through.

ANYWAY: We use a Microtest Cable Scanner for Twisted Pair, and for coax. It
only finds the first major reflection, but it is useful. It gives voltage
and noise information also.

If you are looking for a scanner that gives multiple reflection readings,
you need a Time Domain Reflectometer. That will show the cable reflections
on a graph, with peaks and valleys where the reflections are along the
line. If you have the velocity of propagation set right, the readout is in
meters of cable, so you can find the break very quickly. The problem with
the TDR is that it costs about ten times as much as as Cable Scanner.
-- 
Andrew C. Esh			andrew@osa.com
Open Systems Architects, Inc.
Mpls, MN 55416-1528		Punch down, turn around, do a little crimpin'
(612) 525-0000			Punch down, turn around, plug it in and go ...