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Old March 4th 05, 08:56 PM
 
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Don't professionals use the term? Seems like it shows up in pro computor
programs.
Doesn't the Antenna handbook refer to TOA ? I do know they made a graph of
incoming
RF ray angles which amounts to the same thing. What is wrong with the common
perception
that it is the angle of maximum gain?
If you were designing a 'point to point' antenna would you not look for the
angle of maximum gain?
If so what would you call that angle ? If you are refering to an antenna
lobe pattern could you not invoke
the +/- 3 db points as used in many other places in antenna work?
Methinks that people are looking for problems to argue about
Art





"Roy Lewallen" wrote in message
...
Judging by newsgroup postings, I'd say the most common meaning of "takeoff
angle" is "that elevation angle at which an antenna radiates". For this to
have any meaning, it's necessary to assume that the antenna radiates at
only one angle and no others. Since this is a false assumption, the term
"takeoff angle" as used by most amateurs is meaningless. I've never seen
the term in any non-amateur publication --
it seems to be in the same category as "capture area" and "S unit",
creations which only amateurs seem to have a need for.

As you say, it has a precise definition as used in EZNEC. The first
versions of ELNEC, incidentally, didn't report "takeoff angle" because I
thought it to be unnecessary to point out what anyone can see from a
glance at the pattern, and felt that the term would be misunderstood and
misused. Turns out I was right -- it's misunderstood and misused, despite
my best effort at explicitly defining it. But you've gotta give the
customer what he wants, not what he needs.

Roy Lewallen, W7EL

Cecil Moore wrote:
wrote:

TOA is deemed to be the angle at which maximum gain occurs.
Seems like you are fishing for something, but you will not get
it from me.



The problem seems to be that the definition of TOA is
not standardized. Literally, TOA can be any angle but
has a special meaning when quoting EZNEC. Neither my
antenna books nor "The IEEE Dictionary" define TOA.
I did a search for "take off angle" and "TOA" on my
ARRL Antenna Book CD with zero results.
--
73, Cecil, W5DXP