[BC] Amatuer radio spectrum

[RichardBJohnson at comcast.net]

I think you are referring to EMP generated by a nuclear event.
Unfortunately there are many kinds of EMP. The EMP generators
used for weapons generate both an E field and its corresponding
H field that has terawatt frequency components up to about
30 GHz. There are three basic ways of making such a device.

One uses a super-cooled magnet in which a few thousand mega-
amperes are circulating. Once near the target, it gets "quenched,"
read blown apart. This magnetic field suddenly exists with nothing
to confine it, and no magnetic domains except perhaps the oxygen
molecule, to slow its rate-of-rise. The result is at t(0) a field
approaching infinity. Of course as the EMP propagates, its field
is diminished as it gives up its energy destroying anything
that has an electrical resistance.

The second method uses a multi-layer capacitor, which is charged
en-route to a high potential. Once near the target it gets blown
apart. The result being that the charge from a voltage once charging
a 1/2 farad capacitor of perhaps 5 kV, now gets transferred to a
few picofarads of flying debris. The voltage from the stored
charge of (C*V*V)/2 with little or no remaining C tends towards
infinity. The result being that it gets attenuated as it destroys
anything with an electrical resistance as well.

The third method uses a nuclear bomb. They are not efficient EMP
generators although the explosion of a "space bomb" over some
Pacific islands in the last ‘50s was reported to have killed
some early transistor radios.

So don't underrate EMP. It's currently our first line of defense
against enemy radar sites and they do work.

Cheers,
Richard B. Johnson
Book: http://www.AbominableFirebug.com/

----- Original Message -----
From: "Ronald J. Dot'o Sr." <ron.doto at comcast.net>

There are a lot of misconceptions about EMP and a lot of ways to 
survive it.

Most of the pulse is in the lower frequency spectrum and is gathered 
by long runs of wire (power, phone, cable TV, long conduit runs etc.) 
that act as an antenna and bring the pulse indoors and fries 
everything.