In a message dated 11/19/2011 12:01:01 P.M. Pacific Standard Time,
towertalk-request@contesting.com writes:
> I used 1200I Philliystran for a small dipole pole support. The end of
the
Philliystran was terminated, per their directions, using one of their
termination kits (4 cable clamps and a thimble). When I was done, the
termination looked just like one of their pictures.
> I recently took the dipole down and unscrewed the Philliystran clamps.
I
was surprised to find at each point where the a clamp was placed, the two
pieces of Philliystran were each permanently indented in a ?U? shape, and
at the thinnest part of the ?U? it measured only about 0.092 inches thick
(I used my micrometer).
> Can the Philliystran really have a break strength of 1,200 pounds
(as they advertise) with the type of deformation I have described? Or, did
I do something wrong?
Well, you could always do a destruct test to find out.
When the current generation of Phillystran was introduced, the
only way to terminate them was with cable clamps. The problem was that the
aramid fibers cold flowed with potential fatal problems. Later they developed
the Preformed grips for Phillystran and that problem was solved.
There aren't any grips available for the 1200 so you still have to
use clamps. Is the strength compromised? Maybe. But if you're using 1200,
it's probably for a non-mission critical application such as your dipole
support. If your 1200 Phillystran breaks in your application, there would be
a lot more to worry about than your dipole.
Cheers,
Steve K7LXC
TOWER TECH
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