The  following Youtube by Dr. Bradley is well worth watching if you are interested in the subject of EMP.  I don’t normally post information from other sites, but I think that this one is well worth sharing.
Howard
https://www.youtube.com/watch?v=y3S2KDuVxaU
Was wondering what your opinion is regarding the Earth grounding of a Faraday Cage? I have heard roundabout opinions on both sides and have not heard any definitive answer as of yet.
Thanks!
Mike
Mine are not grounded
Howard
Why not try wrapping aluminum foil around the lip, THEN tape the foil to both the top and bottom of the can. That way you get metal contact on top and bottom.
Fun-fact: Vacuum tubes are significantly more resistant to an EMP than solid state and integrated circuits. That’s why the Russian Federation still produces vacuum tubes, because they’re used in the electronic systems for a number of their nuclear missile launch sites (without any solid state parts whatsoever). And we musicians benefit because a lot of those vacuum tubes are also used in guitar pedals, amplifiers and other cool music gear.