[TowerTalk] Re: TowerTalk Digest, Vol 18, Issue 43

[Pete Smith]

At 08:52 AM 6/15/2004, mahlonhaunschild at cox.net wrote:
>Mike,
>
>Please explain how you arrived at your 14.4 sq ft figure for this tower 
>configuration.  Based on the information at:
>
>http://www.rohnnet.net/rohnnet2001/catalog/pdfs/25G/25G-7.pdf
>
>the answer is 8.7 sq ft, assuming round antenna members.  The 45G guy 
>tables have additional sq ft taken into consideration for antenna 
>supports, beacons, etc. as referenced in the "Notes" section of the guy 
>drawings:
>
>http://www.rohnnet.net/rohnnet2001/catalog/pdfs/45G/45G-9.pdf
>
>but no such assumptions appear in the 25G drawings.
>
>Brad:  My recommendation to you is to replace your 25G tower with 45G and 
>stick to the drawings' limitations.


Note also that some antenna manufacturers publish their antennas' wind area 
in terms that are NOT directly translatable to Rohn's round antenna member 
numbers.  Be sure you have apples and apples.  I have 97 feet of Rohn 25 
and have done this calculation, and the wind load is almost maxed out with 
2 small tribanders (C-3E's) and a shortened 40m yagi.

73, Pete N4ZR
The World HF Contest Station Database
was updated on June 5, 2004
2728 contest stations at
www.pvrc.org/WCSD/WCSDsearch.htm