[Towertalk] Mixing EHS and Phillystran + specs

K7LXC@aol.com K7LXC@aol.com
Tue, 16 Apr 2002 12:08:02 EDT


In a message dated 4/16/02 8:00:42 AM Pacific Daylight Time, 
jskatz@sk.sympatico.ca writes:

> I need to insulate the top section of my upper guys from my tower to
>  eliminate some tower-antenna interaction I think I am getting with my 
C31XR.
>  Is it okay to use a few feet of Phillystran for the top section and EHS for
>  the rest? 

    Sure. Using Phillystran at the top and EHS to the anchor is the 
recommended installation method anyway. That keeps the Phillystran out of 
reach of possible vandals or fire. 

    You'll probably need more than "a few feet" to get any benefit from the 
Phillystran. 

    Is the C31 on top of the tower and the above the guys? What does the swr 
do when you key the xmtr and rotate the antenna? If it changes, then the 
culprit is typically the guys.  

    I guess the more basic question is what kind of interaction are you 
seeing? 

>  If it is then what is best method to use to couple the EHS and the
>  Phillystran? 

    Since you'll have a termination loop at the end of each segment, one way 
is to couple them loop-to-loop (getting the two thimbles inter-connected is 
usually the hard part since you may have to open one of them up). The other 
way is to use an intermediate shackle (also known as a clevis) to connect the 
loops. Just use a shackle twice the size of the guy wire. 

>  Or is there a simpler inexpensive solution to isolating the EHS from the 
tower?

    Not really. You could use johnnyball insulators but then you need them 
and more Preforms so there's really no price advantage. 

    Someone asked a couple of days ago asked about the relative size specs 
for Phillystran. Rather than bother Ken at Phillystran (who's really an ace 
guy), here is the info:

Nomenclature    Jacket OD   Breaking #  EHS equivalent
HPTG1200            0.17"       1200#       3/32"
HPTG2100            0.22"       2100#       1/8"
HPTG4000            0.30"       4000#       3/16"
HPTG6700            0.37"       6700#       1/4"

Cheers,
Steve     K7LXC
TOWER TECH -
Professional tower services for industry and amateurs