What has been said so far doesn't give much help to Bob, AD5VJ,
in actually designing his antenna.
First, if anything I say is contradicted by GM3SEK, L. Cebik,
or many others, listen to them! :)
Second, don't worry about modeling antennas; lots of people have done
that for you -- use their designs!
Recent editions of the ARRL Handbook have lots of interesting antennas
that are more likely to be good designs than a 1959 Handbook. It doesn't
necessarily take huge changes to make an old mechanical design work well
(changing element lengths, spacing and driven element design).
Web sites with very good info are:
G3SEK's Amateur Radio Technical Notebook:
http://www.ifwtech.co.uk/g3sek/
(and many thanks to Ian for contributing to my re-education)
L. B. Cebik, W4RNL, has a huge treasure trove of info on antennas.
http://www.cebik.com/
There are quite a few people on towertalk that know more than I do;
put your ideas out and see what experience people have with them.
To quote Ian, G3SEK:
"If you are copying an existing Yagi design, you must copy:
* all the element lengths
* all the element diameters
* the element mounting method
That means: copy EXACTLY! If you change any of these important details, you are
building a new design!"
That wouldn't have been obvious to me.
--Walter K1CMF
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