I guess to complete the discussion, you can get the shielding spray.
I've done this on plastic cased scanners. It's pretty pricey at $20 a
can, though you could do a few scannners/radios with it.
http://www.mgchemicals.com/products/841.html
You can get it off the shelf at Fry's electronics.

I coated a Yupi MVT7100 then checked the RF leakage with a zap checker.
Quite a bit of RF leaked out of the speaker. When I get around to it,
I'm going to put a copper mesh fan filter over that opening.



Tom Holden wrote:
"John Steffes" wrote in message
...
Matthew&Wendy wrote:
I like to use my computer to translate CW and record shortwave. However,
the computer throws out a lot of RFI. If I build a Faraday cage around
it, will this help? Does the cage need to be grounded?

Matthew Plante
KC2KEI
Scars are the proof that man can survive his own stupidity.
Try some Mu-metal sheeting around the computer. It acts as an absorber of
radiated stuff. The benefit is that no grounding is necessary.

John
ARS KE0GG

I improved the electro-magnetic shielding of my DX-394 with the use of
galvanized steel sheet metal http://www.mods.dk/view.php?ArticleId=2493 . It
was cheap and readily available. Reduced the interference from the computer
and CRT that was coupling directly into its circuits so that the primary
signals getting to the receiver were those from the antenna, far away from
the PC, via shielded co-ax. The antenna was a G5RV with a choke for external
curents on the co-ax shield made by several coils of the co-ax at the
junction with the ladder line and again at the entrance to the house to
attenuate interference from inside the house being propagated up the outside
of the co-ax.

It's pretty hard to put the CRT into an electro-magnetic box and still be
able to see it!

Tom