Letter Re: Effective Range of EMP?

I’m looking for info on the range (radius) of direct electromagnetic pulse (EMP) effects from a nuclear detonation. If you could point me in the right direction, I’d be most appreciative.

Sincerely, – Todd H.

JWR Replies: I have discussed this before in SurvivalBlog, such as in my reply to this letter posted in 2009.