[TowerTalk] Tribander Spacing

[Bill via TowerTalk]

Of the general rule of thumb is, shorter booms can have smaller  spacing, 
to a point.  Larger longer booms require more spacing than short  booms.  28 
foot spacing works quite well for 6/7 elements.  At least  it does for me.
 
K4XS
 
 
In a message dated 2/21/2015 6:42:06 P.M. Coordinated Universal Time,  
john at kk9a.com writes:

I have  never modeled tribanders but most of my monobanders have around  1
wavelength spacing.  28 foot spacing on 10m is not too wide in my  opinion.

John KK9A




To:     towertalk at contesting.com
Subject:    Re: [TowerTalk] Tribander  Spacing
From:    Pete Smith N4ZR  <n4zr at contesting.com>
Date:    Fri, 20 Feb 2015 15:56:32  -0500

Assuming you meant a second C-3, I did extensive modeling of  pairs of C-3s
back in the late 90's when I put my stack up. There was an  NCJ article, but
if you like I can try to dig up the manuscript  here.

I wound up with C-3Es at 97 and 69 feet. It's too wide for the  best 10m
pattern and not wide enough for optimum on 20, but it worked out  to be the
best overall compromise. I would have put up a third antenna at  around 35
feet, but the tower would have been marginal.

Your case  will depend on local terrain, and on take-off angle data for your
part of  the country. HFTA modeling will give you figures of merit for
various paths  that you can use to reach the best compromise, given your
location and,  perhaps, the prospects for 10M in the next cycle.

73, Pete  N4ZR
Check out the Reverse Beacon Network  at
http://reversebeacon.net,
blog at reversebeacon.blogspot.com.
For  spots, please go to your favorite
ARC V6 or VE7CC DX cluster  node.

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