Rick:
In the case of conducted RFI a filter in the AC line is the correct
solution. A company by the name of CORCOM makes some really great filters
for this application.
73
Bob, K4TAX
----- Original Message -----
From: "Rick Williams" <ve7asr@telus.net>
To: "TenTec List" <TenTec@contesting.com>
Sent: Thursday, December 05, 2002 3:47 PM
Subject: Re: [TenTec] RFI Problem
> I use my computer at the rig for logging and playing. When I replaced the
> monitor with a Samsung LCD I lost almost 80 to 90% of the hash.
>
> However, now that the noise floor was significantly lowered I found I had
> another problem that I eventually tracked down to the computer's switching
> power supply. Unlike other birdies the power supply would slowly move up
or
> down the band -- especially on 80 metres.
>
> I fixed the supply with a brute force filter on the AC line constructed
> inside the power supply housing. The filter consisted of two windings of
> #18 wire on a 1 inch #43 toroid core. I wound about 12 turns (I think --
> it's been a while) and the choke measured about 180 uH. I spliced this
into
> the AC line and added bypass caps (0.05 mf) from the AC lines to ground.
>
> The components are not critical just make sure the caps are 500 volts or
> better.
>
> The results were dramatic. The computer power supply noise is gone and I
> can even listen to my 1930 Philco when the computer is running.
>
> 73,
> Rick
> VE7ASR
>
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