> 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
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
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