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[TowerTalk] Re: Plumbing a Tower (or tapered pole)

To: <>
Subject: [TowerTalk] Re: Plumbing a Tower (or tapered pole)
From: (
Date: Sun, 21 Jun 1998 16:08:28 EDT
In a message dated 98-06-21 14:45:35 EDT, writes:

> I use two plumb bob's, at right angles, to sight the tower and believe
>  I can get within an inch or two with this method.  I use stranded
>  insulated
>  #22 wire and a 5 lb. window weight.  Once it is stable it makes an
>  excellent
>  straight vertical line to sight.  
>  On Thu, 14 May 1998 10:48:19 -1000 Jonathan Starr <>
>  writes:
>  >A Builders Transit is the only tool that can properly plumb a vertical
>  >structure. Any wind or slight convection will make a plumb bob 
>  >useless.

      I have used many different methods to establish tower plumb. The easiest
and fastest is to use a string/cord with a plumb bob on the end. I use a
wrench, big nut, etc. for the weight. When the wind is blowing, get a bucket
of water and drop the weight into the water. It'll dampen it just fine. 

     For new tower construction, I use a bubble level at the first set of guys
and then just sight up the tower for additional sections/guy levels. Anything
that's out of plumb looks pretty obvious. 

     Once you have something plumb, use it as a reference. I've used a nearby
cellular monopole, building edge or known tower to line up another tower. 

    BTW, tower specs allow 3 inches out of plumb per 100 feet.
>  >
>  >My 100' Rohn 80 tower on sloping ground was plumbed as best possible
>  >using a plumb bob, 8' level (while climbing up and down), the horizon,
>  >and eyes, and we thought it was pretty good. The only clue that
>  >something wasn't right was that the guys on one side sounded 
>  >different,
>  >duller, when tapped sharply with a wrench. This turned out to be the
>  >down side.
>  >
>  >When I brought a Transit home from the pawn shop, I was shocked to 
>  >find
>  >the tower over 2' out from vertical, necessitating two new big grips.
>  >Luckily we had left the guy wire ends trimmed long to loop through the
>  >turnbuckles.

       Another reason not to use a pier pin base. Congratulations for
listening to the guy wire sounds and getting an instrument to verify

     KH6X - BTW, your tower and antennas look pretty impressive on the cover
of the latest Force 12 catalog. 

Cheers,  Steve   K7LXC    --->>>  Check it out!

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