[TowerTalk] DIR-DE-DIR on a 40m yagi ?

[David Gilbert]

If you want to make a 3 or 2 element array be bidirectional, tune the 
parasitic elements to the driven frequency.  Don't make it shorter or 
longer.  You can run that through EZNEC if you don't believe me.

73,
Dave   AB7E



On 11/14/2021 3:16 PM, jim.thom jim.thom at telus.net wrote:
> You folks   that have stepIR   3 el yagis..... I believe you can reverse
> the pattern
> 180 degs.... by turning the DIR into a REF...and vice-versa.
>
> Question is,  can you make  BOTH parasitic elements into  Directors ?
> IE:    DIR-DE-DIR.  On paper, it should become a  2 -element,
> bi-directional  yagi...with perhaps  4dbd  gain in both directions .   Does
> that concept work ?
>
> I'm  assuming equal spaced elements to begin with..and  DE mounted to the
> mast...above the boom a bit.
>
> Aside from the 180 deg reversal  feature,  for  SOME applications,  having
> gain in 2 x directions at once can be of benefit.
>
> Ok, here's a  dumb question.  What if both parasitic els are tuned as
> Reflectors ?   Does it implode on itself,  or is it  still bi-diectional
> with gain ?
>
> Jim  VE7RF
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