On Thursday, December 31, 2015 at 3:23:05 AM UTC-6, Don Y wrote:
On 12/31/2015 2:11 AM, gregz wrote:

A good cage will reject RF. I've used cell phones in elevators. I can ring
my cell phone in my microwave. A microwave is only optimized at the
magnetron frequency.

Correct. You just have to control size of openings wrt the frequency
you're trying to block. As I have control over *my* (desired) RF,
I can tune the shield to fit *it's* needs, not try to block *all* RF.

However, as I can't just pick *any* frequencies ("intentional radiator"),
I can't be sure my shielding won't also block some things that I might
otherwise *want* to permeate the shield -- now or at some future date
(when who knows what the frequency allocations might be!). So, I
have to be prepared to live without "other needs"; and, be prepared
to undo what I've done when/if the house is sold (I suspect a future
homeowner would not consider the shielding to be an ASSET!)

Are you familiar with the passive repeater antenna systems for tunnels and mines? They systems use a "leaky" coax pulled through the tunnel but a pair of connected antennas could also be cut to length and and use bandpass filters between them to allow only what you want in your shielded room. Hum, you could connect your shielded room to the outside world using only a fiber optic connection. Gee, that could be a really interesting project. ヽ(ヅ)ノ

[8~{} Uncle Shielded Monster