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Old May 16th 05, 01:07 PM
Al Dykes
 
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In article .com,
Tim Shoppa wrote:
xpyttl wrote:

[Good hints about where to look for shielded cases,
esp. related to FCC standards]
[...]
the case isn't nearly the problem the wires are


This is very true. A typical SVGA copper cable puts out all sorts of
hash (as well as the monitor!). And lotsa junk is radiated and
conducted out by the power supply cable, even for the "best of the
best" PC clone supplies.

I've discovered and/or engineered some workarounds, consisting of going
to optical fiber instead of metal whenever possible. But my converters
are usually outside the PC case so this doesn't completely eliminate
the radiation from copper cabling.

I'm starting to think I should just sit inside the Faraday cage with my
computer, and put all the radios outside!

Tim.



They "lumps" found on many power and data cables are ferrite cores
that attenuate the RF hash that leakes out on the conductors.
Building an RF-proof case is trivial if you don't need any
peripherals. RF comes out on the wires.

Look at a copy of the Ham Radio _The ARRL Handbook for Radio
Communications_, in any decent library or bookstore. They cover RFI
solutions.

Do you have an EMI problem ?







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