Russell,

You may be overlooking the fact that the stated antenna pattern is only
valid when far away from the antenna. For example, if you have an antenna
that has a 0.01 radian beamwidth, and a 100 meter diameter, you would
calculate that the beam should only be about 1 meter wide at 100 meters
away. However, it will be more like 100 meters wide. A rough approximation
(to the actual diffraction effects going on) is that the beam is as wide as
the dish and not divergent, right up to the point where the beamwidth times
distance equals the dish diameter, and it is divergent with the stated
beamwidth beyond that.

Also, it would have to be a mighty fast SCR to respond to GHz range
signals, wouldn't it?

Sean

At 11:50 AM 5/30/2002 +1200, you wrote:
> > I'm compelled to state that I *seriously* doubt personnel
> > were allowed anywhere near where a 'personnel hazard'
> > could possibly exist and I also doubt that the 'sidelobes'
> > at distance from such an antenna would contain enough energy
> > to damage electronics as well ...
>
>
>You may be right.
>But there is an awful lot (technical term) of power involved.
>Antenna gain is 40 million (75 dB) and transmit power is 400 kW so that's 16
>Terrawatts (16,000,000,000,000) EIRP.
>
>Wouldn't need to much of a sidelobe to do quite some damage. All the camera
>needs is for some highish impedance point to rise to a voltage somewhat in
>excess of local supply voltage and the energy from the camera supply could
>do the rest - SCR latchup or something similar by a normally never biased on
>pathway.
>
>
>
>         RM
>
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