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Re: [TowerTalk] engineering help? Antenna weight for US Tower TX472

To: "'Richard \(Rick\) Karlquist'" <richard@karlquist.com>, <kr2q@optimum.net>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] engineering help? Antenna weight for US Tower TX472
From: "Gary Schafer" <garyschafer@largeriver.net>
Date: Thu, 11 Jun 2015 14:15:53 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
What about having the boom on the same side of the mast as the raising cable
is connected to the tower? That might help balance it a little?

Another thing to do is keep a rope tied to the top of the top section that
you can pull on a little to help with the binding as you are raising.
I do that on a small crank up that I have so that if there is a strong wind
when I need to get it down I can pull the tower top a little into the wind
so that it does not bind.

73
Gary  K4FMX

> -----Original Message-----
> From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
> Richard (Rick) Karlquist
> Sent: Thursday, June 11, 2015 12:36 PM
> To: kr2q@optimum.net; towertalk@contesting.com
> Subject: Re: [TowerTalk] engineering help? Antenna weight for US Tower
> TX472
> 
> 
> 
> On 6/11/2015 10:07 AM, kr2q@optimum.net wrote:
> > Hi all,
> >
> 
> > 2.  What point is the weak link for the 200 pounds?
> >
> 
> Here is the surprising thing I ran into with my HDX-5106,
> a MUCH bigger tower.  It has a MonstIR on top, figure
> 250 lbs.  Also a short mast and a prop pitch, figure
> another 50 lbs.  Figure another 100 lbs for cables,
> so lets call that 300 lbs.  Should be fine.
> 
> What happens is that when I get within about 5 feet
> of full extension, I start to get noise and vibrations.
> The working theory is that this is due to IMBALANCE of
> weight, rather than just the weight itself.  The sections
> start to bind a little when the overlap gets small.
> 
> I removed the antenna to change the cables in the tower,
> and ran it up and down a few times, and the problem
> went away under those conditions. The MonstIR has a
> very flexible boom that exascerbates the imbalance
> problem.  Once it starts to lean a little, the boom
> flexes in the direction that makes it worse.
> 
> What I am doing as a workaround is manually stopping
> the raising winch just before the problem begins.
> I know from experience where this point is.
> 
> Rick N6RK
> _______________________________________________
> 
> 
> 
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