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Erecting Long Masts

To: <towertalk@contesting.com>
Subject: Erecting Long Masts
From: n4si@techinter.com (n4si)
Date: Wed, 18 Dec 1996 20:35:16 +0000
 
> I use Tri-Ex tower and they make movable intermediate mast plates for their
> towers.  Rohn does not make one apparently.  Since most of you guys out
> there seem to be using Rohn guyed tower, you should consider making your own
> plate. One way is to have a metal-fab shop  modify a Rohn rotator plate to
> act as an intermediate mast plate. The ideal intermediate plate has a
> slip-fit sleeve about 3 inches long welded on the underside of the plate,
> carefully centered, and another thrust bearing on the top of the plate, just
> like on the tower top.  This may be overkill but do it if you can afford it.
> 
> Gary, your oversize gin pole method is perfectly fine for insertion of the
> long mast.  I did it that way when I built the 9Y4H Rohn 55 tower, and we
> had to build our own long gin pole to make it all happen!
> 
> 73! Glenn K6NA
> rattmann@cts.com
> 

Good point Glenn. I modified a Rohn ASx5 rotor plate on my 
installation to carry a hardwood block for an intermediate plate. The 
key to homebrewing is your "carefully centered" phrase. I have a 
friend who broke the mast clamp on his HDR300 from having an 
out-of-alignment intermediate plate.

A little tidbit that many people don't realize who are first getting 
in to tower installations is that the AS25 accessory shelf for Rohn 
25 ONLY fits at the top of the tower section or at the bottom. It 
will not fit partway without modification. The AS45 plate will, as 
its design is entirely different.

73, Rod N4SI
    The DXer formerly known as N9AKE
         (c) 5 November, 1996

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