[Top] [All Lists]

Re: [TowerTalk] unguyed heights for Rohn 65 etc.?

To: 'towertalk' <>
Subject: Re: [TowerTalk] unguyed heights for Rohn 65 etc.?
From: Jan Erik Holm <>
Date: Fri, 14 Jan 2005 06:54:41 +0100
List-post: <>
Dont you guys ever do calculations on things like this?
A little bit of mathematics will figure all this out,
also I´m pritty sure there would be computer software
that can do stress calculations on towers depending
on how much load you put on them etc etc.
Used to do this when I was in the university, however
it was 30 years ago and darn it if I can remember how
to any more, should be able to study up on it I guess.
However these days I guess you do it in computers and
not by hand and brain.

73 Jim SM2EKM

Okay, it looks, then, as if Rohn 65 would do the job at 50' but wouldn't be enough at 60' -- unguyed. I would guess that Rohn 80 would have a little more capability, being huskier.

Even putting one guy set on the tower should greatly increase its capability -- I'll have to think about the aesthetic and footprint tradeoffs versus the other options.

73 - Rich, Ke3Q

----- Original Message ----- From: "Joe Subich, K4IK" <>
To: "'RICHARD BOYD'" <>; <>
Sent: Thursday, January 13, 2005 10:59 PM
Subject: RE: [TowerTalk] unguyed heights for Rohn 65 etc.?

Anyone have an idea (or facts) how high I could go unguyed
with Rohn 65, assuming a single 48' boom monobander for 20,
or 15, or 10 (plus appropriate rotator, and I'll have the
yagi right above the tower, shortest mast possible within

The Rohn Commercial Catalog (11993) gives the following allowable antenna areas for Rohn 65 at 80 MPH (Prince Georges Co. is 75 MPH zone):

Ht. no ice 1/2" ice

50'       19.7       19.1
60'        9.4        4.1

Note 3:  Designs assume two 7/8" lines on each tower face.
        (nb: 7/8" line is .0875 sq. ft. per lineal foot)

Okay, let me toss out another possibility:  Rohn 80 (I know
it comes in various sub-models, some 40" face, some 44" face
and there may be other differences, but assume the basic or
the typical one).

No chart in my book for Rohn 80 free standing. "Each tower is individually engineered to handle a particular job."

Rohn 80 is 41" center-to-center on the legs however the legs
vary from 2" to 3" in standard (schedule 40?) and X-STR
(schedule 80?).  Rohn 80 has both standard (zig-zag) and
cross braced sections.


... Joe, K4IK


See: for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

TowerTalk mailing list

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