[TowerTalk] Tower guy wires / EHS size

Dale Martin kg5u at hal-pc.org
Tue Apr 24 14:04:03 EDT 2007


 

I'm curious, Steve, where 1/4" EHS is used in place of recommended and
spec'd 3/16" EHS, does one tension the 1/4" EHS to 400 lbs. as one would do
with 3/16" or to whatever tension 1/4" is rated for?

Looking from another aspect, is the 400 lbs. tension specified when using
3/16" EHS on a Rohn 25g based on the tower type/heighth where 3/16" EHS
conveniently has a stength of 4000 lbs and the 400 lbs tension is just right
for the tower?  Or should the tension be 10% of whatever guy wire size
strength is being used...e.g., 670 lbs. based on 1/4" EHS strength of 6700
lbs.?   

73
Dale, kg5u

   
>  
> In a message dated 4/23/2007 9:03:02 A.M. Pacific Daylight 
> Time, towertalk-request at contesting.com writes:
> 
> >  I am in the process of erecting a few towers at the new 
> QTH  and have 
> > a guy
> wire size question.   Two of the towers will be  Rohn 45 @ 
> 100' and the third
> will be Rohn 25 @ 100'.  They will all  have multiple yagis 
> at various heights on them, so not just a top mounted  
> antenna.  The Rohn book indicates that each tower should be 
> guyed at  three elevations and the bottom two guys should be 
> 3/16"  EHS.
> 
> >  QUESTION:  I have LOTS of 1/4" EHS and guy  grips.  Is the 3/16" 
> > mandatory
> to
> meet the specs (as in the 1/4" is  too heavy) or - is the 
> 3/16" simply suggested (as in the 1/4" is not  necessary but 
> acceptable)?
>  
>     While the LXC Prime Directive to "DO what the  
> manufacturer says" still applies, what you're proposing is a 
> little bit of  over-engineering (which is not discouraged, BTW). 
>  
>     The capacity of any tower is a function of its  leg 
> strength. By using bigger guys you'll be putting more 
> compression on the  legs but at the heights you mentioned, 
> it's not a big deal. 45G will go to  300' and 25G will go to 
> 200' so you're not overstressing anything. 
>  
> Cheers & GL!
> Steve     K7LXC
> TOWER TECH -
> Professional tower services for hams
> Cell; 206-890-4188
> 
> 
>
> 




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