radio shielding

A really good screen room is hard to make, but solid material isn't necessary. Better conductors make better shields, but a dollar's worth of iron is a better shield than a dollar's worth of copper. Openings -- including slits -- larger than about a tenth of a wavelength -- make the shields ineffective. Doors are hard to seal at frequencies that interest you.

Jerry

You don't need to ground the building. You don't need to join the metal panels together ( though that's best ) but you do at least need to overlap flat panels by a reasonable amount so they are in effect shorted together capacitavely at HF. Mesh of sufficiently small aperture ( lot less than the target wavelength ) will attenuate HF a lot, or use wave-guide beyond-cutoff pipe arrays to let in air and a little light.

Basically you want a Faraday cage, which is an equipotential surface (i.e. a conductor ) with no gaps.

The really tricky stuff is LF.

Andy.

Hello Jerry,

Not really. At frequencies that Gary needs (>500MHz) a nice big overlap should do. For lower frequencies they have finger stock but I always avoid touching it. If it's copper beryllium it may not be such a good idea to touch it and then eat a sandwich as the oxide of it is pretty toxic.

Regards, Joerg

It's hard to make an overlap without a lateral gap. A narrow gap can act like a waveguide beyond cutoff, but it can also become a slot antenna. Choke joints can be very effective over a narrow frequency range.

Beryllium is toxic, especially when compounds are inhaled. Once alloyed, the result is about as inert as any metal can be. Like the mercury in amalgam fillings, it is so tightly bound as to be innocuous.

Jerry