[TowerTalk] 2-el 15/20 meter duobander

[john at kk9a.com]

I do not remember the 3el minimum in YO that is too bad. YO certainly was
no user defined control of the impedance making an OWA design impossible. 
I did design a 2el OWA 40m Yagi in AO which worked well but it required
multiple optimization attempts to obtain the direct feed match. In my
opinion, the actual impedance of both YO and AO was higher than
calculated. I believe EZNEC is more accurate. Still, it was fantastic DOS
software which greatly improved Yagi design.

John KK9A



from Jim Thomson
To:	<towertalk at contesting.com>
Subject:	[TowerTalk] 2-el 15/20 meter duobander
From:	"Jim Thomson" <jim.thom at telus.net>
Date:	Wed, 29 Nov 2017 06:42:53 -0800

YO would also not allow you to design any OWA yagi either.  YO software 
would not allow any 2 els to get closer than  .09 wavelengths, so that
killed any notions of any OWA  design right there.  YO had a limit on how
long..or short each ele could be..in any monobander.  Trying to tweak a
gamma or oemga match on a DE that was way out on the boom was a trick in
itself. Ditto with any version of a HB hairpin.


Later... Jim   VE7RF