[RFI] computer RFI

Cortland Richmond ka5s@earthlink.net
Fri, 1 Mar 2002 10:47:31 -0800

This is interesting. Here's why:

I used to do EMI work at a (now defunct) computer company in southern
California. Its founder (the one left) was said to occasionally chastise
directors for spending too much on things like power supplies and cabinets.
He'd bring in something he'd bought at Fry's, and ask why we were paying
more from the manufacturers than Fry's was selling the items for at retail.
So then we'd have to do test them. The EMI would be high, the chassis would
rust, the power supply would burn out at rated load, or fail the safety
testing (or never have a safety cert at all), and he'd acquiesce. For a

There is no substitute for quality. You DO get what you pay for. There are
three categories of equipment: Cheap, good, and easy. But in any one piece
of equipment, you can can only GET two of those at once.


> [Original Message]
> From: Berry Griffin <serazin@pacbell.net>
> To: <rfi@contesting.com>
 > Date: 2/28/2002 8:12:23 PM
> 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!
> W6EZ
> _______________________________________________