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## Re: [TowerTalk] Plumbing a Tower

 To: Re: [TowerTalk] Plumbing a Tower "Dale Martin" Sun, 3 Dec 2006 01:05:23 -0600
 ``` ________________________________ From: K7LXC@aol.com [mailto:K7LXC@aol.com] Sent: Saturday, December 02, 2006 3:03 PM To: towertalk@contesting.com; kg5u@hal-pc.org Subject: Re: [TowerTalk] Plumbing a Tower In a message dated 11/28/2006 8:56:24 A.M. Pacific Standard Time, towertalk-request@contesting.com writes: > > I played around on the other day doing some mainteance. I made up a little jig out of string to suspend between the three legs of my Rohn 25G. I looped and loosely tied one string to one leg. I tied the other end of the string to the horizontal brace directly across from that leg and halfway between the two other legs. I did the same for the other two legs and strings. The point at which the strings all crossed each other is supposed to be the center of the tower...right? > Umm, I'm not sure if I'm following all that but all you have to do is to stand back aways and hold your plumb line in front of you and look along each leg and you'll see how vertical it is. You're allowed to be out three inches in 100 feet so it doesn't have to be exact. Hi, Steve Basically the three lines intersect in the middle of the tower....at least, that's how it worked in Geometry class. I was standing out at the backyard guy post this afternoon thinking about just what you described. Except, I was going to plant 2x4's each with a little arm to hang the plumb lines out from each of the guy points. Then I could make adjustments, walk back to them and bring everything into plumb that way. I just wasn't sure how accurate it would be looking through the upper portion of the string at the tower top 90 feet way. But, if you say it a workable solution, them I'm on it. > > I may have done this all wrong. I read N4KG/K7LXC's comments about plumbing a tower. I just used a deep 1/2" socket as my weight and nylon twine as the line. Way too light compared to N4KG's #20 wire and 5 lb. window sash weight. I haven't yet found a day since hanging the line where the wind is light enough to even let the string hang anywhere near the center even 20' down from where it's hung. > Drop the end of the plumb line into a bucket of water and the wind won't blow it around. It wasn't a matter of the weight blowing around; at a point about 20 feet below where it was hung, the line was arcing over nicely into the side of the tower by the breeze. It seems like no matter how light the breeze, the string is way over to one side. I can grab the weight, move it to the center and pull down and the line straightens out, but let go and the air moves it to the side. :-) I just need a heavier, much heavier weight...like th 5 lb. weight N4KG used. > > I also think maybe I should do the plumb thing in stages -- in my case, my tower is 70' and I have two sets of guys. Should I plumb from the lower set of guys to get that portion of the tower plumb, then plumb from the upper set of guys to the lower set? The plumb line would be shorter and maybe less influenced by any wind. > > Has anyone tried a laser? Seems like it would be easy to make up a laser target jig to place through the tower, then, on the ground, use a laser in the center of the tower and aligned to the vertical. Anyone done that? > I think you're making a bigger deal out of this than necessary. What I do is to climb up to the first set of guys with a little bubble level and put it on each leg. You can have someone on the ground tighten or loosen each turnbuckle until you've got it where you want it. Again, it doesn't have to be exactly vertical. Yeah...I do that...too much time on my hands... > Then all you have to do is stand on the ground next to a tower face and just look up. You can tell easily how much it's out of plumb and which way because it'll be pretty obvious. I'll get it sorted out this week. It's supposed to get up into the mid sixties by Wednesday. 73, Dale, kg5u _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
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