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