[RFI] computer RFI

James C. Hall, MD nwtncc@iswt.com
Fri, 1 Mar 2002 09:16:58 -0600

Hello there:

This is a very common problem with cheap PC power supplies. I've tried to
modify and make better poor power supplies with limited success and very
little bang for the buck.  The best solution is to substitute a fully
shielded PC power supply (takes 5 minutes to do). There are lots of
sources - I used Poweron, Inc. Just do a Google search ;)


-----Original Message-----
From: rfi-admin@contesting.com [mailto:rfi-admin@contesting.com]On
Behalf Of Berry Griffin
Sent: Thursday, February 28, 2002 10:12 PM
To: rfi@contesting.com
Subject: [RFI] computer RFI

Have any of you had any problems with computer "birdies" showing up on
your HF rigs?

I just built a fairly fast system but it can not be on when I am on 75
meters.  There is a 20 over noise level.

I have already tried all the usual tests, i.e.: I got the computer up
and running and then unplugged EVERYTHING that was attached to it except

the Ac cord.

That made no difference what so ever.  I have and old and slow 200MMX
sitting less than 2 feet from the radio and other than hearing the fan
running I can't tell it is on, but this new system, egad!

I assume it is the switching power supply or RF leaking from the case.

Are there any ATX power supplies that are know to be birdie free, or at
least, very quiet?

How about cases? There must be some  laboratory or medical cases that
are built to keep the rf in.

Any suggestions? I do miss having my  hf rig  and  my computer on
at the same time.

73 all!

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