Tom,

I gotta disagree with you.  If what you said were true every PC manufacturer
would ship their product in a plastic case without any shielding.  Take your
average home PC and remove it's case and it will fail FCC Class B (required
for domestic use) by at least 20dB.  This is not just a problem at the main
clock frequency either, consider all the data buses with sub 10nS rise and
fall times and what you end up with a really nice broadband noise generator.
Most PCs do not meet FCC requirements with the case on.  (Over the last ten
years I have tested enough of them to know.) 

The amount of interference will depend on how close you are to the radio/TV
station you are trying to monitor and their broadcast strength.  It may not
bother you in the same room trying to listen to KQRS, but your neighbor down
the street trying to pick up shortwave transmissions will probably go nuts.
If you start interfering with air traffic or police/fire frequencies the FCC
can and sometimes will show up and make you shutdown your "transmitter".  

A wood/plastic case will not solve the ESD/safety problems either, the steel
in a typical computer case also serves as an earth ground for safety
reasons, a shield from ESD, and most importantly if something fails and gets
really hot steel does not easily burn.

I'd find a small steel case and build something that looks nice around it.

Blah, blah, blah........



-----Original Message-----
From: Thomas T. Veldhouse [mailto:veldy at veldy.net]
Sent: Monday, January 14, 2002 10:11 AM
To: tclug-list at mn-linux.org
Subject: Re: [TCLUG] Static electricity (and an offer to buy)


You are spending too much time in Physics class.  In theory this is correct,
but the output is extremely low and should not interfere much with anything,
as per FCC regulations.  It would be easier to bring in your FM to your
receiver using Coax (by nature a RF sealed system, again in theory -- or you
wouldn't need shielded cable) than it would to wrap your PC in a Faraday
cage.  Not to mention, there is software out there to allow you to trasmit
AM broadcasts using your monitor -- so you need to wrap it as well.

:)

Tom Veldhouse
veldy at veldy.net

----- Original Message -----
From: "Jared Burns" <jared-linux at mn.rr.com>
To: <tclug-list at mn-linux.org>
Sent: Monday, January 14, 2002 8:05 AM
Subject: Re: [TCLUG] Static electricity (and an offer to buy)


> You machine will emit RF (radio frequency) radiation at the frequency of
your
> machine's clock frequency (100kHz, 133kHz, etc.).
>
> Make sure you have the components inclosed in a Faraday cage or you and
your
> neighbors will have a hard time picking up radio signals (at least around
the
> frequency of your clock) while your machine is running. :)
>
> - Jared
>
> On Sunday 13 January 2002 02:53 pm, you wrote:
> > I'm looking at building my own PC, but in a literal sense,
> > including making a case (why not? to answer your obvious
> > question.  Actually so that I don't have to have an obvious
> > computer case if I want it in the living room.)  One option
> > is to house it in a plastic storage tub, but it suddenly
> > occured to me that ths may be a static electricity problem
> > waiting to happen.  Any thoughts from the engineering types?
> >
> > As part of building the box, if anyone has a Socket A chip
> > of any speed they want to get rid of (i.e. if you're
> > upgrading) I'm in the market.
> >
> > Cheers, Paul
> >
> >
> > _______________________________________________
> > Twin Cities Linux Users Group Mailing List - Minneapolis/St. Paul,
> > Minnesota http://www.mn-linux.org
> > tclug-list at mn-linux.org
> > https://mailman.mn-linux.org/mailman/listinfo/tclug-list
> _______________________________________________
> Twin Cities Linux Users Group Mailing List - Minneapolis/St. Paul,
Minnesota
> http://www.mn-linux.org
> tclug-list at mn-linux.org
> https://mailman.mn-linux.org/mailman/listinfo/tclug-list
>

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