Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!nosc!humu!uhccux!munnari.oz.au!wcc!tom
From: tom@wcc.oz (Tom Evans)
Newsgroups: comp.dcom.lans,aus.mac,aus.computers
Subject: How to Break your Cheapernet - bad Tee pieces
Keywords: BNC Tee Ethernet Cheapernet EtherTalk
Message-ID: <335@wcc.oz>
Date: 12 Jul 89 05:32:26 GMT
Organization: Webster Computer, Melbourne, Australia
Lines: 31

Sorry about the wide posting, but this affects Unix, PC and Mac Lans.

Your Cheapernet consists of cables and "Tee" pieces. If any cable or
Tee piece goes bad, your net comes down (or gets sick).

I bought four "Brand A" Tee pieces from an electronics store.
The centre pin diameters varied. They consistently had one "tight"
and one "loose" socket. At least pins and pin-sockets were gold-plated.

After complaining, I got six "Brand B" ones. These have tin-plated
everything. The pins are loose, and break contact when you move
them. The outer-shield mechanics are so bad as to give intermittent
SHIELD continuity. The pin and surround diameters are all wrong - they
connect to each other badly, and to real BNC connectors terribly.

I have to call them "Brand A" and "Brand B". They are both NONAME -
not a single identifying mark anywhere.

Acceptance test.
Join all your Tee pieces together in a line. Put a terminator (or a
short) on one end and a multimeter on the other. Wobble the lot.
If the resistance changes, you've got a problem that could cost you
hours in real-life. Try your cables as well.

			    ---------
Tom Evans  tom@wcc.oz		| If "the Network is
Webster Computer Corp P/L	| the Connector" and
1270 Ferntree Gully Rd		| the connector is
Scoresby VIC 3179    Australia	| broken...
Australia			|
61-3-764-1100  FAX ...764-1179	|