axolotl wrote:

Winston wrote:

I figure a 200 W microwave amplifier should result in ca 100 KW ERP at
the feed horn of a 30" diameter parabolic dish.


You may be confusing ERP and presumably ERIP (power relative to that
radiated by a dipole or an isotropic radiator respectively) with raw
power. ERP is the amount of power you would have to feed to a dipole to
get the same energy that the directional antenna delivers to a given
area.

Yes, if you couple 200 W into a ~30 dbi parabolic antenna, it will
radiate as much power (into a spot) as would a dipole driven by ~100 KW
(into the same area, though the dipole is radiating isotropically).

(Power != field strength, always.)

A high gain antenna does not generate power; it puts a given
amount of power into a smaller area.

Yes. Just the ticket for inducing eddy current and the resulting power
dissipation in conductors within a limited, steerable aperture.

If you need 200 Watts of power
coupled into something for some purpose, you will need to feed the
antenna with a lot more than 200 Watts.

Yes. But the necessary power into the load (sans resonance) could be as
little as say 2 W given Don's range of 0.67 W to 1.63 W. My question
is: if we provide a 30" diameter field that has a power density of 2 W
at 24" and we are radiating at the resonant frequency of the initiator,
would that reliably disarm or failing that, trigger the device?

--Winston