On Tue, 19 Oct 2004 19:10:01 -0300, "Bob MacBeth"
wrote:

Someone going by 'Bob':
Someone has to produce an example.

"Richard Clark"
...I've done that here through modeling
too using exactly your point. The results
were trivial, but for some, extremely
hard to swallow. [**] ;-)

Can you clarify your findings (please and thank you)? Were you able to find
an antenna system (pair) that displayed direction-dependant pathloss?

I've use EZNEC to demonstrate any number of "impossibilities" all
without violating or compromising the modeler's constraints. The
effects were trivial to say the least, but demonstrated that Axioms of
antenna theory had limitations that were unexpressed (until you got to
the graduate level of the same sophomore course work).

Since
you can't prove a negative and I know that you know it, I assume that you
did. If so, perhaps you could post the example on your website.

Well, it has been a great while in this particular instance of path
reciprocity. I did use the scale of range you suggested (and perhaps
further). It was not so much about loss however, but the failure of
reciprocity (a common topic in photography - which, here, is an
aside).

I frequently use two or three antennas in one model, with the
second/third being receive models with termination resistors. They
would be called sniffers in field work or bench work. This work that
I engaged in had no particular demonstration of your curved field
issue (which, through simple abstraction suggests any differences you
would observe would be out several decimal places and beyond the
ability of any instrumentation to resolve with accuracy). Then again,
maybe it did (it may have involved an inclined sniffer which
demonstrated the curvature in one direction, with a corresponding
difference in the other). I would suggest you simply follow this last
speculation and see where it takes you.

I suppose you could search the archives for my name and the key words
of "reciprocity failure" and confine the search to the mid to late
90s.

73's
Richard Clark, KB7QHC