[TowerTalk] Foldover at roof level?

[David Hachadorian]

----- Original Message ----- 
From: "ChetMoore" <ChetMoore at cox.net>
To: <towertalk at contesting.com>; "Justin Wilson" 
<j2sw at mtin.net>
Sent: Monday, February 20, 2006 7:50 PM
Subject: Re: [TowerTalk] Foldover at roof level?


> You probably know that the rohn 25g foldover came as a 
> standard 40
> foot tower? By inserting one straight section below the 
> hinge and one above
> the hinge you could tilt over 60 feet.

Actually, the basic tower was 48' with options for 58 and 
68.



>
> 25G tower (when built to rohn specs) uses a 4 wire guy 
> system below the
> hinge & 3 guys at the top.

Actually, Rohn drawings show four below the hinge & four at 
the top, using the same anchors.



>There is quite a lot of  weight/moment
> consideration when the  the antenna is cranked about 2/3 
> of the way up.  You
> may have to  do some reinforcing to the building where you 
> bracket the legs
> to the building.

When the tower is folded over, keep in mind that it will be 
pressing against the building, not pulling on it.


>   Initially that tower performed well.  Once totally
> vertical, the counterweight/boom is pinned and extra bolts 
> go into the tilt
> over section .  That means  you still have to climb to 40 
> feet to take the
> bolts out to crank it down up and then go back up and put 
> the bolts back in
> when done but at least no antenna work had to be done on 
> the tower.


Those bolts are for shipping only. You don't reinstall them 
once the tower is erected, so you don't have to climb up 
there.

I think the basic idea of mounting the hinge right at the 
roofline sounds like a good idea. You would still need guys 
at the top for any sizable antenna. Three-way guying at the 
top would work fine. Remember that the safe load at the apex 
is only 130 pounds. The whole tower, including winch, cable, 
and cantilever boom are designed around this limit. From 
various reports, there is not much margin of safety.

Dave Hachadorian, K6LL
Yuma, AZ











































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