[TowerTalk] Re: 25G Foldover

[Mark Shaum]

Hi, Leslie.  First of all, the Rohn foldovers (#25 and #45) use a
special hinged section that places the pivot point from about 22 to
32 ft. above ground, with either two or three 10 ft. regular
sections below the hinge section.   One or two  more regular
sections and a topper are used above the hinge section, which is
about 8 ft. long.  A large "back boom" mounts to the upper half of
the hinge section, extending down the "backside" of the tower. 
This provides some counterbalancing and general leverage for the
winch located near the base. So the hinge supports the rear boom,
upper 30 ft or so of tower, and top load of antennas, rotor and
mast.  With #25, the maximum weight Rohn recommends for the topside
antenna load ranges from 100 to 150 lbs, depending on how many
tower sections are located above the hinge.  When the tower is
erect, it's as strong or stronger than any regular #25.  Rohn looks
to limit the forces on the hinge pins as the tower is folded over
with a topside load.

For a base, I used the short #25 base (3 ft. 6 in), although using
a regular 10 ft. section with 3 to 4 feet in concrete would work
just as well.  

Rohn sells kits to convert an existing #25 or #45 tower to the
foldover models, but they aren't cheap.  My tower was converted
from a 60 ft. regular to a 68 ft foldover by the previous owner
about 8 years or so back, and I believe the cost of the #25
foldover kit (hinge section, boom, winch, cable, misc. parts) was
in the $1100 range, including shipping.  

> 
> Hi, Mark- new to the reflector here. Could you please advise: I
have
> several perfectly good, straight sections of 25G, and no base.
Are you
> satisfied w/ the foldover? Doesn't the weight of everything rest
on the
> fulcrum pin/bolt? (Or am I worrying unnecessarily?) Am trying to
decide
> on purchase of a base, and foldover might be appealing, then
again, not
> even sure if I actually have enough space in my small yard to use
the
> feature. I imagine adding sections from roof of house, and using
the
> house wall-attachment bracket I also have. However, that
procedure might
> be unwieldy. Any thoughts would be appreciated.
> 	73, Leslie


----------------------------------------
Mark Shaum  K9TR
mashaum@fcg.net
Central Illinois Grid EN50
---------------------------------------

--
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