I can't I can justify the cost for this but I was trying to figure out just how I can turn my entire house into a faraday cage. I can line the walls with copper mesh, drive a whole bunch of ground rods, convert cable & telco over to fiber outside the house, but there is one piece I can't figure out, power.
My question is this, can you isloate utility power from an EMP?
I thought about a natural gas genset, fed with plastic pipe of course, inside the 'cage'. Would a simple isloation transformer provide true isolation?
There's an unclassified army manual for EMP-proof facilities design, EP 1110-3-2. All your answers are in there The amplitudes are completely different between EMP and TEMPEST and frequencies vary a little, but the level of attentuation and design for protection for both is practically identical.
To get 90dB attentuation, you can't just use tin foil, you have to use a significant thickness of steel or copper or another conductor, otherwise a significant portion of the EMP burst will transmit straighit through it and still come out the backside at reduced but dangerous levels. The thickness depends on the frequencies and desired level of protection, and of course the material being used- welded 1/4" carbon steel will provide this protection.
You can buy filters for power and communication lines that provide > 90dB protection.
Build your own with 4 foot thick reinforced concrete walls and ceiling, bonded to about 2 dozen ground rods. Power would be supplied by an on site generator, or a nearby set of batteries with inverter, which could be kept charged by the utility power.