Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!cbatt!neoucom!wtm
From: wtm@neoucom.UUCP
Newsgroups: comp.sys.att
Subject: Re: AT&T 6300 Color Monitors
Message-ID: <540@neoucom.UUCP>
Date: Mon, 6-Apr-87 21:29:47 EST
Article-I.D.: neoucom.540
Posted: Mon Apr  6 21:29:47 1987
Date-Received: Wed, 8-Apr-87 06:01:17 EST
References: <614@ttidca.UUCP> <539@neoucom.UUCP>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 26
Summary: RF sensitivity


I intended to mention in my previous article, Re: the Taxan model
640, that the 640 is relatively sensitive to RF.  Running on the
AT&T 6300, I occasionally have trouble in the graphics modes with
the monitor apparently loosing horizonal hold in a few isolated
portions of the screen.  Placing my hand near the monitor or
repositioning the monitor signal cord will usually make the problem
go away.

I determined that the the vendor-supplied cable for the AT&T
computer's db-25 (as opposed to the more normal db-9) connector
does not carry the frame shield through from the computer to the
monitor.  This allows the monitor chassis to pick up RF.  To put an
end to the problem, I added a ground strap from one of the screws
on the 6300's case to a screw on the Taxan's case.

I talked to Hitton Patel, the video Engineer at Taxan, and he
claimed that the vendor-supplied cable was the culprit.  He sent me
a replacement cable; alas it has a db-9 on the end -- but it does
carry the shield through.  It's curious that the noise problem is
peculiar to the 6300's graphics screen.

I'm not sure who makes the Taxan 640; the newer models' guts are
made by JVC for Taxan.

  --Bill Mayhew  (wtm@neoucom.UUCP)