[TowerTalk] Antenna modeling/ testing

[Donald E. Stiles]

Aloha,

I have enjoyed the recent communications about antenna modeling and testing.
It's great, and I'll
bet there are many others reading along too.

To put any antenna into use, it has to be tuned to a resonant frequency.  That
is difficult due to
the changing conditions of the ground properties, atmosphere and other
variables.

I have found that to tune a yagi it is best to mount the antenna in a
verticalposition with the
reflector down and the directors up.  At that inclination, an antenna is not
subject to ground
conditions and other var's.  All my yagis are tuned in this manner for the most
power out, then
SWR becomes a minor problem.  After this is done, then I'd like to see the
results from the
models and actual tests on the range.

BTW, the ARRL will not allow any antenna mfg. to advertise any information
regarding "gain" in
their journal.  The differences between isotropic and ddipole conditions is
significant, and some
manufacturers compare their gain to an ISOTROPIC condition.  Most beams will
respond to
tuning near to, or less than the claimed dB gain.

Your models are trying to produce an isotropic antenna's gain and other
factors.  Keep up the
good work, it sounds interesting, and many of us are reading intently on the
subject as it goes
.
Aloha,

n8csp

tnx es 73 de n8csp
http://www.wwcpm.org




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