[TowerTalk] 2 vs 3 ele 40m yagi - opinions?

[JayTerleski]

   From: 
        "Dan Levin" <djl@andlev.com>
     To: 
        "tower talk" <towertalk@contesting.com>

A bunch of stuff snipped out:

"2) I have to choose whether to use full size 40 meter elements, or to
load
them somehow (probably capacity hats at the ends of the elements.  4 2'
spokes shortens the elements to about 56' - 8' of hat spokes saves 5.5'
of
tip length (per side).  Maybe F12 style linear loading line the new N
elements.).  It seems clear that electrically, the full size elements
are
better.  Mechanically, it isn't clear to me which way to go.  Any
thoughts
on why the shortened elements might be better?  Less torque on the
mast/rotor?"




I have a thought. The Cal-Av type dual driven elements will give you
great F/B 20+ dB and steady gain over most of the 40m band.  Also the
gain is higher than a 2 ele parasitic beam as well as very close to a 3
ele beam.

http://www.arraysolutions.com/Products/2d-40patterns.htm  Will
demonstrate the patterns you can achieve with two full sized elements.

The gain with shortened elements will be less but the F/B should be the
same.


-- 
Jay Terleski
WX0B - Array Solutions
Phased Arrays - Horizontal and Vertical
RF Switches, Antennas, Towers
www.arraysolutions.com

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