In an earlier contribution to this discussion,
Simon wrote:

Hello -

I'm writng some software to run on a PocketPC with a built-in GPRS
phone, and I need to test the software when the GPRS signal is weak,
intermittent or non-existent. The cheapest way to do this seems to be
to build a Faraday cage with adjustable leakiness. It needs to have
some holes in it so that I can see the screen and tap it with a
stylus. Unfortunately I'm working at a location that has excellent
GPRS coverage.

I've already confirmed that a metal tin that previously contained
Marks and Spencers chocolate biscuits is 100% effective, but I can't
see through it or operate the PocketPC. I've also tried making a cage
out of a single sheet of galvanized chicken wire with 12mm square
holes, held together with plastic cable ties, with overlapped joints.
This only caused a small amount of attenuation, the PocketPC hardly
noticed. I'm guessing that it failed because the diagonals of the
holes are larger than 10% of the wavelength that GPRS uses (1800MHz
?) or because the plastic cable ties don't provide good conductivity
at the joints.

Before I go out and buy some expensive perforated copper sheet, can
anyone offer advice on improvements?

Thanks

I've got an excellent Faraday Cage. It's better known as a caravan!
--
Cheers,
Roger
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