[TowerTalk] Stacking Antennas

[K4SAV]

YO is not likely to work well for stacking dissimilar antennas.  You 
might be able to do it with NEC if you are very careful and model the 
entire system.  If the antennas happen to have dissimilar matching 
networks, the phase delay thru the matching networks can be very large.  
For example a transformer match might have near zero phase delay while a 
hairpin match might have 25 or 30 degrees of delay.

Jerry, K4SAV

Brian Machesney wrote:
> Mention was made of simulating with NEC to see what one would get from a
> particular stack. Assuming the results are not what one wants right out of
> the gate, how can one optimize the antennas to get the "best" or "desired"
> results? I can't find a replacement for Yagi Optimizer which, I understand,
> was used by WA3FET to optimize his OWA designs for stacking.
>
> How did YO work? Did one simply parameterize the antenna design and then let
> YO plot patterns for many different combinations of parameters? If so, I can
> do that with MultiNEC (also, sadly, no longer available). 4nec2 says it
> includes,"AO-style gradient/hill-climbing optimizer" and "Genetic Algorithms
> based optimizer." Does anyone have experience with this aspect of 4nec2?
>
> Thanks,
>
> Brian K1LI
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