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Old August 15th 11, 10:58 PM posted to rec.radio.amateur.antenna
Jim Lux Jim Lux is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 801
Default 4nec2 hidden variables.

On 8/13/2011 3:59 PM, Helmut Wabnig wrote:
On Sat, 13 Aug 2011 14:15:22 -0700, Jeff
wrote:

..........


I am making progress, though.
Got the optimizer running and edited a few of the example files
to have the variables selection available.

Works.

Now I watch the optimizer quickly de-optimizing the antennas
until they radiate into the wrong direction or get stuck in a
circular radiation diagram. In one case the optimizer bent
and rotated the dipoles around, I bet no specialist can do what I can.

Real fun, that is :-)


Video of optimizer (25 min):
http://www.youtube.com/watch?v=kYy6Yur127A


Yeah, thats good. Sitting back and watch.
Thanks for the idea of watching the Youtube demos.
Better than endless trial-and-error.
My goal is to find out what makes a direction finding antenna
different from a gain optimized antenna.
F/B ratio is all that matters for ARDF, for example.
Gain is secondary and side-lobes should be absent.
I must get that NEC working by all means.


Then when you set up your optimization criteria in 4nec2, weight the F/B
or F/R with 100% and the others with zero (although sometimes, you may
want to weight forward gain at 10%, just to keep it from driving to zero
gain)