[TowerTalk] Phillystran As Strong As They Claim?

[K8RI]

On 11/19/2011 7:31 PM, Steve Maki wrote:
> The strength of Philly is in the (very) small Kevlar core, not the outer
> jacket which is there to provide abrasion and UV protection for the
> core. Kevlar (and other similar and even stronger synthetic materials)
> is stronger than steel on a cross sectional area basis.
Regular wire and wire rope loses a great deal of strength when those 
clamps are used (up to 50%) while Phillystran loses little if any as 
it's the jacket that gets compressed. Also the jacket protects the 
Kevlar from moisture as moisture can cause a great deal of deterioration 
of the Kevlar core.

73

Roger (K8RI)
> -Steve K8LX
>
> On 11/19/2011 11:42 AM, Wayne Willenberg wrote:
>> 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?
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