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Old July 13th 06, 03:16 AM posted to rec.radio.amateur.antenna
Tom Ring Tom Ring is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 230
Default Antenna optimization

Richard Clark wrote:

As for automated optimization, NASA spent huge bucks on this stuff to
design twisted paper clips to replace Walt's work of 30 years ago. I
can well bet that license runs pages. If the testimonials to Beezley
are any indicator, the utility of the software is in inverse
proportion to the length of its license.

73's
Richard Clark, KB7QHC


However some of it does work very well. YO, when used correctly can
just barely beat K1FO's designs, which were done on a PDP11, using a
special version of BASIC, as I remember from conversations with him long
ago.

He got the designs as right as possible, using an EME'rs version of
right. He hit max gain for boomlength within less than 1dB, pattern is
wonderful, SWR BW is astonishing, and pattern and gain are all fairly
constant across the usable SWR BW. Input impedance is not too low, at
about 20-25 ohms, and efficient match can be had with a T-match. And it
handles ice and rain detuning perfectly. Build sensitivity is nice; you
can skew the design by induced errors of +-2mm element length and +-5mm
vertical off the boom and +-2mm element position on the boom with no
significant change. Gain not off by .1dB, pattern not off by 2dB,
normally less. I ran a lot of tests. And I could be misremembering a
bit, but probably by too high rather than too low.

And YO could beat K1FO by only hudredths of a dB. If he'd had more CPU
power to do more runs per day...

tom
K0TAR