If i had to guess;
the EMP has 3 pulses. 2 of them are line of sight only. if you are over the horizon, you'll probably get missed by the first two pulses but the third pulse is coupled to your power lines. anything plugged in, that has a microchip, will probably not work after a ground detonation.
so, battery or crank power should work. this effect can travel long distances (on the order of 100+ miles in the right conditions).
if its a high altitude EMP then your battery or hand crank radio may not work, unless you have protected it in some way.
- LOS is based on horizon distance. at sea level its about 3 miles. for an 2000 ft altitude air burst its about 55 miles. A high altitude EMP could be detonated 200 miles up with a horizon distance of 2400 miles in diameter.
