Towertalk
[Top] [All Lists]

[TowerTalk] Rohn 25G or 45G?

To: <towertalk@contesting.com>
Subject: [TowerTalk] Rohn 25G or 45G?
From: w7ni@teleport.com (Stan Griffiths)
Date: 13 Jul 1998 08:17:50 -0000
>
>On subject of 45G being more than 25G.
>
>ROHN BOOK:
>80 FOOT TALL
>25G   70MPH-15.7 SQ.FT.
>45G   70MPH-15.3 SQ.FT.  
>OR
>100 FOOT TALL
>25G   70MPH-15.0 SQ.FT.
>45G   70MPH-14.2 SQ.FT.
>
>Interesting that at 70MPH ratings the 25G has higher SQ.FT. ratings.  Go to
>90MPH & 45G is better as we expect.  But there's no question the 45G wider
>leg spacing adds stability when you climb'um.  
>
>73  Robert W5AJ
>
>PS:  if you don't have your ROHN book, call Steve & get one!

Hi Robert,

There are a few important details you did not mention regarding you 25 vs 45
comparison above.  Both 25G towers have 3 sets of guys while both 45G towers
have only 2 sets.  Both 25G towers have the top set of guys attached only 5
feet below the top of the tower while both 45G towers have the tops set 15
feet below the top of the tower.  If you just used the same guying on the
45G towers that is shown on the 25G towers, it would make a huge difference.
So it was not a simple case of 25 vs 45 but also a comparison of 2 sets of
guys vs 3 sets.

You have to realize that the configurations shown in the Rohn book are only
a few of the hundreds of possible configurations you might use.  As soon as
you deviate from the Rohn examples, though, it is time to get a PE involved
to make sure the changes you propose are safe.

Stan  w7ni@teleport.com


--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm


<Prev in Thread] Current Thread [Next in Thread>