[CQ-Contest] Contesting Computer

[Gerry Treas, K8GT]

Tom, et al,

Open up the power supply in that beast and see if the power line filter
components are in place.  I bought a case and power supply in 1996 from
a local computer packager to house a used 486DX100 I got from a friend.
I had it upstairs on the kitchen table above the shack and turned on,
and went down to the shack and had S7 to S9 noise across all bands.  I
then remembered posts here on the Contest Reflector, mentioning the lack
of power line filter components in some imported power supplies, just
jumpers where the toroids should go and no bypass caps in place.
Apparently they can get by importing those because it's not a complete
package and since they go to resellers, it qualifies as Class A
(Commercial/Industrial area) instead of being the more stringent Class B
(Residential) rating.  I had a Corcom 3 Amp line fiter with an IEC
Chassis connector on it.  I removed the original IEC connector by
drilling out the rivets, and the Corcom filter just fit.  After that the
noise level dropped to zero.  The trash couldn't get to the power line
to use as an antenna.  Every computer or power supply I get now, whether
new or used, I always check the power supply.

Just my $3 (for the filter at a local swap), and YMMV

73  Gerry  K8GT



Tom Osborne wrote:

>Hans said:
>
>  
>
>>My old 1900's model WIN98 Compaq 345MHz/128Meg ram >is getting a
>>    
>>
>little short of horsepower for many applications, >and it's probably
>time to upgrade.
>
>Hi Hans et al
>
>One thing for sure, take a little portable AM receiver or better yet,
>a shortwave receiver and listen for birdies.  I have one computer here
>that I though was a great deal, but it is nothing but a wide band
>noise generator.  I can pull up in the driveway and hear it screaming
>in my AM radio in the car half a block away.  It don't matter how good
>of a deal you get if it's useless.  I use my old 125mhz pentium for
>all my ham software.  It's super quiet.  I even run some dos software
>on my old '386 DX40.  Seems like the manufactureres aren't paying much
>attention to "FCC specifications" any more.  New computers are a lot
>noiser than the older ones.  73
>Tom W7WHY
>
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