Pete: I use audio transformers to isolate my computer when I run psk31.
Build a cheap kit, it will probably solve your problem and you would have
another mode open to you. Check out http://www.packetradio.com/psk31.htm
for wiring diagrams, ideas and kits. Cheap kits, not fancy.
----- Original Message -----
From: "Pete Smith" <firstname.lastname@example.org>
Sent: Thursday, May 30, 2002 1:39 PM
Subject: [RFI] rfi to computer via sound card
> I'm setting up to record contests using an SB-16 sound card and Recall Pro
> software. At the moment I'm dealing with a severe RFI problem, which
> crashes the Recall software a few seconds into every transmission. I've
> determined that it is definitely coming in the [line in] cable from my
> radio's external AF output, because when I disconnect that line from the
> computer the program doesn't crash no matter how long I transmit. I've
> grounded the computer case and wound a number of turns of the [line in]
> cable around ferrite toroid cores, all without apparent benefit. Would it
> make sense to try .01 disc caps bypassing the conductors in the [line in]
> cable to the shield, in case this is differential mode interference rather
> than common mode, as I'd assumed?
> 73, Pete N4ZR
> Check out the World HF
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