I was able to get to the table and the 35 feet - 4.7 sq. feet numbers are
with 1/2" ice while the 35 feet - 8.7 sq.ft numbers are bare. Both are for
45G and 70 MPH winds.
----- Original Message -----
Sent: Wednesday, November 05, 2008 8:33 AM
Subject: Re: [TowerTalk] Rohn 45G Self Supporting and bracketed
> In a message dated 11/4/2008 1:08:00 P.M. Pacific Standard Time,
> firstname.lastname@example.org writes:
>> 10 Feet - 55 Sq Feet
>> 20 Feet - 25 Sq Feet
>> 30 Feet - 9 Sq Feet
>> 35 Feet - 4.7 sq Feet
>> This is based on the 70 MPH Winds.
>> To find this chart, go to
>> Click on On Line Catalog (Bottom Left of the Menu Bar)
>> GT Series (Top Right)
>> 25 G (Again, Top Right)
>> Then Allowable Antenna Areas
> I followed the above instructions and couldn't find the Allowable
> Antenna Areas anywhere. :-(
> OTOH I do have a Rohn brochure entitled "Manufacturer's Technical
> Information for Bracketed or Self Supporting Towers". I don't know the
> date of
> it so I don't know what rev of the TIA-222 it's based on. This is what it
> says for 70 MPH:
> 10 feet - 42.5 sq.ft.
> 20 feet - 22.0 sq.ft.
> 30 feet - 12.0 sq.ft.
> 35 feet - 8.7 sq.ft.
> 40 feet - 5.1 sq.ft.
> 45 feet - 2.3 sq.ft.
> I'm not sure how to reconcile the different specs but if you're
> going to err, err on the side of being conservative engineering-wise.
> For the record there is another base spec for a self-supporter
> is kind of hard to find too.
> For the guy who wanted to go 45 or so feet above a housebracket
> 45G @ 70 MPH, the same pamphlet says
> 14 feet above the housebracket is 31.0 sq.ft.
> 24 feet above the housebracket is 13.8 sq.ft.
> 34 feet above the housebracket is 5.5 sq.ft.
> Steve K7LXC
> TOWER TECH
> **************AOL Search: Your one stop for directions, recipes and all
> Holiday needs. Search Now.
> TowerTalk mailing list
TowerTalk mailing list