Roy, this brings up a question , and am curious about-- Just what are the
differences between EZNEC and EZNEC -4 ? Have had copies of Elnec, thru
EZNEC, and you keep doing great job improveing each one, but keep hearing
about NEC-4 (as opposed to NEC, and NEC-2), and am curious (no puns
intended), as to what are the major advantages of NEC-4 over NEC, and NEC-2
(what ever happened to NEC-3?) Is it worth upgradeing to, or, of interest
only to someone doing complex arrays ? I'm sure others would also be
interested, as am not in a position to get engineering tomes (am retired),
but am curious. Kinda like a teacher that was at Oregon Institute of
Technology (last name of "Barber"), who ran a company that built antennas
for military planes - turned out a curtain, so if part of hull was shot, the
rest of the hull would radiate! Wished I had more oppurtunity when still in
K.Falls to pump him, but they cut his teaching position. Guess you the
expert to ask, now-- Jim NN7K




"Roy Lewallen" wrote in message
...
I passed along this info to Dean Straw, N6BV, the ARRL Antenna Book
editor. He replied that since the 19th Edition, he's used EZNEC/4 (an
NEC-4 based program) for generating rhombic and vee beam data. I'd hope
that it would agree closely with the 1980 NEC analysis.

Roy Lewallen, W7EL

Crazy George wrote:
Scott:

The curves for V Beams in the ARRL Antenna Handbook, and apparently also
in
the engineering texts were derived from a few experimentally determined
data
points assuming a sinusoidal current on the arms. In the July 1980 IEEE
Transactions on Antennas and Propagation, Gary Thiele and Ernie Ekelman
published a rigorous NEC analysis of the configuration, including a
couple
of useful curves. Both the optimum included angle vs. arm length and
directivity vs. arm length differ significantly from the previously
published curves. So, dig up a copy of IEEE-A&P Trans., Vol. AP-28, No.
4,
and look on pp. 588-590 for the full story.

--
Crazy George
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