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March 31st 04, 05:06 PM

On Tue, 30 Mar 2004 22:19:50 -0600 (CST),
(Richard Harrison) wrote:
Some of the dish`s beam may bounce back from the glass into the room,
but it loses 22dB in the first wavelength (about 5 inches?) back from
the reflection, and then 6dB more every time the distance doubles after
that. I wouldn`t worry or if I did, I would simply interdict the energy
with suitable screening.

Hi Richard,

This characteristic is incorrectly applied. The 22dB is not "lost,"
it is simply unavailable to a dipole that could accept the power. The
concern is with tissue absorption, not tuned, directional antenna
elements. Further, it is not "lost" given that if it is a nuisance
through reflection, there are as many re-reflection opportunities
available within the region into which it has been reflected
(provided, of course, that room is not an anechoic chamber). This,
then, renders the room into a gross dimensioned, lossy microwave oven.

Some of the reflected power will be absorbed by the walls, the
furnishings, be "lost" out the same window it reflected from; and yes,
absorbed by the turkey.

Chuck,

Our best advice has been given, carry an NE-2 neon lamp, observe it
glowing to tell when you are "done."

Let's put some real perspective to this. We are talking about all of
500mW? Let's boost that 15 fold to 7.5W, concentrate it into a patch
of 1 square inch. Now, imagine the sensation of holding a lit
christmas tree bulb (the traditional big ones). Do those prospects
bring terror? Pain? Annoyance? A mild warmth? Now turn down the
burners to that original half watt.

The common experience of a christmas past should quite capably guide
you at this point.

73's
Richard Clark, KB7QHC

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