[spam][crazy] How a Hobbyist Might Start Building Shielded Rooms

step 1: be able to measure shielding effectiveness This takes two radios: an emitter and receiver . It also takes a variety of antenna to handle various frequencies and modes. There are a number of formal guides (commercial and military specs) for how to do this, which are a good starting point but leave some things out. Basically, you measure signals under identical conditions both with and without the shielding. This gives a metric of attenuation for the exact signals and locations measured.