This is some interesting reading. It seems to be the first E1 burst that can kill small electronics even if they are not plugged in to the grid. The E2 and E3 are dangerous for things plugged in but not otherwise. The E1 does not extend so far, I think, its the E3 that covers large areas, or what do you guys?
https://techprotectbag.com/
These two links will bring you to an Electrical Engineer who is also prepper minded. Unlike many EE's he has worked a lot hands on. The first is general EMP info regarding how to prep for it, the second is more vehicle centric.
Electromagnetic Pulse Protection - EMP - Futurescience.com
EMP Effects on Vehicles - Futurescience.com
Excerpt:
If you have a shortwave radio, it is likely to be knocked out by the EMP unless it is adequately shielded. To be adequately shielded, it needs to be kept inside of a complete metallic shielded enclosure, commonly known as a faraday cage, and preferably inside
nested faraday cages. A faraday cage is an
total enclosure made out of a good electrical conductor such as copper or aluminum. (Steel also works well, but it is often more difficult to make a total enclosure with steel.) Large faraday cages can get extremely complicated. For small portable electronics, though, completely covering the electronic equipment in heavy-duty aluminum foil makes a good faraday cage around the equipment. The foil covering needs to be complete, without any gaps. Wrap the device in plastic or put it in an insulated box before wrapping the covered device in foil. (Otherwise, the foil may simply conduct the EMP energy into the device more effectively.) A single layer of foil may not be adequate. In order to enclose the equipment in a
nested faraday cage, place the foil-covered device in a plastic bag, such as a freezer bag, and wrap that bag completely in aluminum foil. If you really want to protect the equipment against a large EMP, add another layer of plastic and foil. The layer of plastic needs to be the thickest plastic bags that you can easily find. (They don't need to be terribly thick, but do try to find some heavy-duty bags.)
If you have done an absolutely perfect job with the first layer of aluminum foil, the "nested faraday shield" is not needed. As a practical matter, though, the "nesting" procedure helps greatly in protecting against both inadvertent gaps and possible later accidental punctures through the aluminum foil that may severely compromise the shield.
Just adding many layers of foil directly on top of foil won't do as much good, due to what is called "skin effect." I won't bother to explain skin effect here, but you can look it up if you're curious.
