[RFI] Quiet Shack PC Systems?

[Jim Brown]

On Thu, 18 Mar 2004 21:40:58 +0000, Ian White, G3SEK wrote:

>Then feed each side separately through its own 
>*three-wire* mains filter that includes a ground choke. 

Hmmm. Are you putting a choke on the ground lead? Doesn't that prevent
the protection it SHOULD provide for HF transients like lightning and
power line misbehavior?  I can't imagine that being blessed by an EE
that can read and write. All codes I know of require a low impedance
bond between grounded objects. That choke has a high impedance at some
frequency. 

Or do I misunderstand what you are suggesting? 

But your post does remind one that all that noise current being shoved
into a long ground lead by bypass capacitors can radiate and get picked
up by your antenna. While a choke would minimize the ground current, it
doesn't pull the current to ground. Unfortunately, a choke on the
ground conductor is a cure that is worse than the disease. 

Jim Brown
Audio Systems Group, Inc.
Chicago
http://www.audiosystemsgroup.com