[BARC-List] Re hypothetical, emp, scenario

[Bill Ricker N1VUX]

Omnibus reply ... 

 Dave --
> Is there a reason why equipment that is built to withstand natural EMP
> attacks (learby lightning) would not withstand a man-made one?

Lighting has two issues -- the current grounding the cloud, and the induced
voltage in any conductors near the large current. EMP from curious devices is
only interested in the latter kind. Most ham stations are built to withstand
only the first kind (and only then mostly not the right way, but that's a
separate discussion.)  You've got to avoid induced surge coming in on any of
the other connections, in addition to avoiding it jumping the airgaps.  

 Steve & Mike & Eric -- 

My mistake about the HW8, I thought it was an bone fide antique ;-)

 Steve -- 
> 1/R (assume this relates to further away you are; but what is R)
 -- normally we speak of 1/R**2, Radius-Squared or distance squared for the
power drop, but for both EMP danger and receiver sensitivity is more
one-over-R, inverse distance.

> OTH (over the hill, referring to old equipment, maybe?)
  Over the Horizon, Beyond Line of Sight

> LOS (loss of service?)
  Line of Sight, the nominal VHF limit (but not really, talk to me about Tropo
sometime)

 Mark - 
> maximize the EMP burst (a variant on the neutron bomb concept,

Actually, you don't need a dirtier bomb or a special bobm to enhance the EMP,
you just have to "fuse" it explode it well *above* the atmosphere -- then you
let the Xrays or Gamma rays (I forget which) shine down on the atmosphere. The
interaction triggers a wide-area EMP. This provided a use for old lame bombs
and missiles that couldn't be aimed at anything smaller than a large city and
couldn't break anything harder than glass office buildings.

There are other devices designed to produce EMP without nukes, but they use a
LOT of electricity ... or a really really weird combination of exposives and
electromagnets that I don't care to go into here.

Yes, the Pentagon did a lot of work with EMP. Some co-workers of mine worked
at the site deep in the desert where they built their big test generator.

73

Bill