Guys are specified in the Rohn catalog as 8' down from the top (to allow for
large dish mount, I presume) vice at the top plate where most of us put
them. That likely makes a pretty big difference, too. I don't worry about my
45G coming apart. I do worry about my rotor getting trashed by long boom
antennas. Also, I note you said 20.3 sq ft at the TOP of the tower. Put that
much footage up 10 or 15 feet (or even 5 feet) above the top of the tower
and suddenly all bets are off, unless you are using the mother of all masts.
:-)
73, Jerry W5KP
----- Original Message -----
From: "Jeffrey Okamitsu" <x703jko@starpower.net>
To: <force12talk@qth.com>; <towertalk@contesting.com>
Sent: Tuesday, October 23, 2001 8:13 PM
Subject: [Force 12 Talk] Maximum Wind Load on Rohn 45G Towers
> Thanks for reading this email.
>
> I am in the process of putting up two 130 foot Rohn 45G towers as per
> Rohn's 90 mph specifications. Maximum allowable projected area at the
> top of the tower, as specified by Rohn, is 12.3 square feet for round
> antenna members.
>
> The question I have is this: if you read the notes in the engineering
> drawing for the 90 mph specs, it states (note 4) "Tower designs include
> three side arms, symmetrically placed, having a total effective
> projected area equal to 8.0 square feet."
>
> Does anyone agree with my conclusions that this implies that if the side
> arms are NOT used, the maximum allowable project area at the top of the
> tower is actually 20.3 square feet?
>
> Let me know what you think.
>
> 73...Jeff, KN2R
>
>
>
>
>
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