[TowerTalk] Tower Update

[K7LXC at aol.com]

In a message dated 12/30/2007 7:32:04 A.M. Pacific Standard Time,  
towertalk-request at contesting.com writes:

>  I guess another question would be, since I was thinking of  leveling it 
with a bubble level, but I dont have one that is over around
a  6" long. Will a plumb bob through the center of the first section be 
accurate  enough to make the tower straight as I go up in
height to say 80 feet or  so?


    A bubble level is fine. I use one of the 8" or so  variety - it's close 
enough. Industry standards let you be out 3 inches in 100  feet and still be in 
spec. 
 
    If the bottom section is in concrete, then that's  place to start. If 
it's plumb, then the rest of the tower is easy. Stack the  sections and then use 
your level at the first set of guys. For subsequent  sections, just look up 
each face. It'll be pretty obvious when it's in plumb  and when it's not. Feel 
free to use your level at each guy level as you direct  your ground crew which 
guys to tighten. 

>  I was rethinking  the vertical leveling and thought I might just tie a 
string at the center of  the top of the section (ten foot
bottom section) I am going to cement in -  

>  tie a rock or something to it 
eyeball it to be in the  center of the section
at the end of the string at ground level
then  cement it in

>  But then remembered the higher I go 
the  more off center it will get if I am off at all at the bottom.


I use this all the time for self-supporting  towers since the only thing 
plumb is the side of the leg. You don't cement it  in. Just let it dangle with a 
weight on the bottom of the string and  sight thru the face to the opposite 
leg. 
 
    BTW the concrete base requirements for a guyed  tower aren't as critical 
(e.g. undisturbed earth) as for self-supporting  towers. The only thing the 
guyed tower base does is prevent the tower from  sinking. There is no 
overturning moment on the base like there is on a  self-supporter. 
 
Cheers,
Steve     K7LXC
TOWER TECH -
Professional tower services for hams
Cell:  206-890-4188








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