SOLVED: RL02 faults when RX02 is on - test-drb@ccmp.vtda.org

5 Apr 2007

I had a similar problem when I put together my first PC-XT clone. It had an open-frame
Panasonic 9" monitor on top of the main box, which was made of 1/4" plywood
(cherry stained). Putting a sheet of aluminum under the plywood top solved the problem.

Bob

...
 Message: 20
Date: Thu, 05 Apr 2007 00:20:47 -0700
From: "Chuck Guzis" <cclist at sydex.com>
Subject: Re: SOLVED: RL02 faults when RX02 is on
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Message-ID: <461440DF.25843.2CADF4F8 at cclist.sydex.com>
Content-Type: text/plain; charset=US-ASCII 
<snip>
...
 I wonder if it's more EMI than RFI, because it
reminds me of a nasty 
problem we had when developing the Durango F85.   
...
 If you look at the machine, there's a 9-inch CRT
placed above the 
dual floppy drive.   
<snip>

...
 The diskette drives refused to work on the production
model.   
<snip>

...
 The engineers were baffled--until someone took the
monitor off of the 
top of the diskette drive area to attach a scope probe--and the 
problem went away.  It turns out that the FBT was kicking up noise 
something fierce in the read channels of the diskette drives.  An 
shield made of sheet aluminum didn't get rid of the problem, but one 
made of steel worked just fine. 
<snip>

...
 Cheers,
Chuck 