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Re: [TowerTalk] Help With First Tower

Subject: Re: [TowerTalk] Help With First Tower
Date: Mon, 7 May 2012 13:06:38 -0400 (EDT)
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> Here is the dilemma the designer has presented to me.   (The following are
not real examples, but are just used to illustrate the  point.)  I could use
Rohn 25 with 18 total guys or I could use Rohn 65  with 9 guys.  In the
first case, the tower sections would cost less than  in the second case, but
there would be more labor in installing 19 guys (and  the guys would cost
more) than 9 guys. Also, the amount of concrete in the  base and the guy
anchors would be different.

>  There must  be a way to determine the most cost-effective selection of 
of tower and  number of guys.

Okay. You're proposing an  aggressive tower and antenna system in one of 
the highest windspeed areas in the  US. First of all, Rohn 25G will never meet 
your criteria so that's out. Many  hams who want HD installations go with 
55G. But if that won't accomplish your  goal, then you should consider 65G. 
    Second, basing your decision on the cost of  the guys is not realistic. 
Guy wires are a fraction of the total cost of the  installation, especially 
considering the tower cost; e.g. 55G is around  $370 per 10-foot section 
while 65G is $1050 for a 10-foot section. 
    You need to decide what your budget is and go from  there. You're after 
reliability, which is an area that you don't want to  economize in. If in 
doubt, err on the size of over-engineering. 
    A guy up here in the PNW had a rotating Bertha  designed to survive 140 
MPH or so winds. The idea was to have the antennas shear  off but leave the 
tower intact. 
    Your decision should be based on reliability. The  big test is the 
first time a big storm blows thru and you're laying awake  in bed hoping you 
everything right. 
Steve     K7LXC
Professional tower services for hams
Cell: 206-890-4188

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