Towertalk
[Top] [All Lists]

[TowerTalk] computer rfi

To: <towertalk@contesting.com>
Subject: [TowerTalk] computer rfi
From: twoway@scoden.ma.ultranet.com (Scott Bullock)
Date: Mon, 14 Jul 1997 22:24:02 -0400 (EDT)
Hi esteeemed towertalkians, This is a follow-up to a previous posting
today..... Well, I got itchy tonite after picking up some emi/rfi paint
($19.00 per can), I took my monitor apart-it was already coated with some
emi paint-even measured the resistance-right up to spec-7 ohms per inch, I
recoated it completely anyways, as the can I got said multiple coats were
more effective.

For anyone that is contemplating doing this, make sure you take it OUTSIDE
before you paint it!  This stuff has Methyl Ethyl Ketone in it-serious
stuff-also good buzz for those of you that like to sniff the stuff-IT'S STRONG !

At the same time, I took the monitor video extension cable off, I found that
the interference would come and go when it was unplugged from the pc, even
if the monitor wasn't connected! I cut the extension in two pieces, slid on
a full length of rg-8 shield and two MAMBO beads, resoldered it together,
heatshrinked, etc, and plugged it all back in-grounded the new shield to the
pc case, and also connected other end of the extension with short solid wire
to the metal monitor video connector. Voila!!!!!!!!!!!!!!! No more interference!

One of the worst frequencies for receiving the crap was believe it or not
14.195.0   It is now completely quiet!  Also powered up the SB200 and ran
full key down on each antenna-no herringbone/squigglies at all! Maybe this
monitor won't go kablooie like the last one did from rf!

For those of you that have this problem, give this a shot, it only took me
about 1.5 hours even playing with different grounds before I hacked up the
cable to install the shield. Definitely worth the time, maybe now I will be
able to hear the next DXpedition better on that frequency.

Also fyi, the monitor is 1.5 feet above the ts-930, and the cable runs down
through the bench directly behind the amplifier output, and the computer is
below the radio by abt 1 foot. I would think this is a worst case scenario
for any monitor/computer!

73 to all, hope this was a help to those that needed it, email me direct if
you have any questions.

Scott
KA1CLX

P.S. the smell of the emi paint is enough to scare the birds and the moles
away for good!  :)


--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search

<Prev in Thread] Current Thread [Next in Thread>