[TowerTalk] Tribander Spacing

[Jim Thomson]

Date: Fri, 20 Feb 2015 22:26:59 -0600
From: "Keith Dutson" <kdutson at sbcglobal.net>
To: "'Pete Smith N4ZR'" <n4zr at contesting.com>,
<towertalk at contesting.com>
Subject: Re: [TowerTalk] Tribander Spacing

Thanks Pete.  Your spacing is only 28 feet, less than a half wavelength on
20.  I also had a recommendation of 5/8 wavelength on 20.  That calculates
to 41 feet.  I was thinking 35 feet.  Guess I need to put it in HFTA to see.

73, Keith NM5G

##  For folks with crank up towers, like the UST-HDX 589 or 689 variety, there is another option.
With the top triband yagi  say 6-10 feet above the top of the tower.....and a  tic ring at the 55 ft level,  you
would have  40-44 feet  of separation.   This should work for 20m.    By lowering the tower a bit, the 
separation  can be better optimized on both 15m + 10m.   Since all the 4 x upper sections reduce by the same amount
at the same time,  you would not lose a lot of height on the lower yagi either.   IE:  top yagi at 75 feet, then the lower yagi
would be at 45 feet..with 30 ft separation....  assuming in that case, top yagi mounted 6 ft above the top of the tower.    

Jim   VE7RF