If an anteena has a specific range dominated by its power input and a
distance thru air would not a ntenna with more gain allow it to0 travel a
longer distance until the plane came to a distance to allow a relay to drop out.

If you were able to place both the transmitter, and the plane in free
space, and there weren't other signal sources in the area, this
approach might work out.

In practice, though, I think you're going to find multipath and
reflections to be a real problem. Irregularities in the ground, the
presence of buildings and trees, etc. are going to generate enough
reflections to cause some serious, and unpredictable changes in the
signal strength as seen by the receiver in the plane.

De-sensing of the receiver by transmitters on nearby frequencies,
noise pickup, directional variations in the plane receiver's antenna,
etc. are also going to be problems. I think you'll need a fairly
narrow-band receiver, with a well-controlled and fixed gain and a wide
dynamic range, and some form of averaging circuitry to get you past
the multipath / picket-fence problems.

I'm sure that something like this _can_ be done, and can probably be
done well enough to result in meaningful measurements. To do so, I
think you're going to have to invest a good deal of time, energy,
thought, and perhaps money in the design. A poorly-designed approach
would introduce so many sources of possible error that any results you
got from it would not be particularly meaningful or significant.

I was looking for a meaningfull indication of gain that would not be
assaulted gurus negatives with respect to isentropic gain and disbelief of
calculations made.

I'd suggest studying how this sort of measurement is performed in a
professional context - e.g. on antenna ranges located out in the
country well away from strong RF sources, and in shielded RF-anechoic
chambers (for near-field measurements and for higher frequency
measurements, where the chamber is a reasonable number of wavelengths
across).

What better way for the man in the street to understand antenna gain rather
than messing with dbi, dbd e.t.c., which an amateur uses to fulfill his need
for conflict?

Please don't confuse "conflict" with "criticism". The former is
unnecessary (although unfortunately it's rather common). The latter
is utterly necessary in any form of scientific endeavor!

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
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