[XorNot]

A metal box.

EMP isn't magic: it's an induced electric field in any long conductor from the a broadband intense burst of electromagnetism - basically any conductor turns into an antenna.

This sucks for transistor electronics because they're tiny, and the induced current can easily damage and blowout MOSFETs.

But any sealed metal container is a Faraday cage: the net electric field across it is zero. Same story for anything buried underground - the ground is conductive and zeros out the induced field almost immediately.

So pretty much a metal box is high likelihood, a buried metal box guaranteed.

[mauvehaus]

Ok, this covers my end. What about the broadcast end? It's not like they can collapse down the antenna and bury the transmitter in an ammo can when the antenna is a couple hundred feet tall and permanently attached to the transmitter.

Is there some kind of national contingency plan for this or something whereby there's a a way to get critical radio infrastructure back up after a nuclear exchange?