Topband: Ends for older Phillystran

[Steve London]

I have been hesitant to talk about this, for fear of incurring the wrath 
of the purists, but since Lloyd went first...

I obtained a quantity of new-old-stock of the old 15000 pound 
Phillystran a few years ago. I had the same issue - the ends. It dawned 
on me that in my application, the maximum force the Philly would ever be 
subjected to was 2000-3000 pounds. Thus, my ends only needed to handle 
that load, not the full 15000 pounds. I went with 3 Crosby clamps on 
each end. After 2 years, I don't see any sign of the inner strands being 
pulled inward.

Your mileage may vary.

73,
Steve, N2IC

On 01/13/2014 04:15 PM, Lloyd Berg - N9LB wrote:
> Hi Grant!
>
> I worked at WDAE Radio in Tampa, FL back in the 80's and 90's.  The engineer
> before me decided to try the new technology Philly-strand guy lines on the
> AM directional towers because they had constant problems with the original
> segmented steel guy wires/egg insulators constantly arcing over whenever
> there was a thunderstorm in the area.  To attach the Philly-strand, they
> used traditional metal saddle clamps on this early ( somewhat experimental )
> Philly-strand installation.  It was a real neat looking job with 3 clamps 3
> inches apart and all within 8 inches of the ends of the Philly Strand.  Just
> like you see on steel guy lines.
>
> It was written up in Broadcast Engineering Magazine with lots of pictures as
> the wave of the future for AM broadcast guyed towers.
>
> In reality, it didn't work well because we were constantly having to
> re-attach the lines because the inner strands pulled short inside the outer
> sheath, leaving just the outer sheath holding the tower up!  ( nude towers,
> no antennas on top ).    It didn't take long before we realized that we had
> to use a lot more foldback length and a lot more clamps!  We went with 36"
> foldbacks with six clamps evenly spaced to keep things from pulling apart!
> That worked and stayed together for the remaining 10 years I worked there.
> Yes, we had to insert 6 feet of steel line at the anchor points to make up
> for the lost length at each end of each guy lines.
>
> No guarantees, but that was my experience with the original Philly-strand.
> If you decide to keep it, be very careful and inspect it frequently!  They
> don't make that original Philly-strand for a good reason.
>
> 73
>
> Lloyd - N9LB
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com]On Behalf Of Grant
> Saviers
> Sent: Monday, January 13, 2014 1:15 PM
> To: topband at contesting.com
> Subject: Topband: Ends for older Phillystran
>
>
> Hoping for some help to be able to use some older Philly.  The factory
> tells me their grips won't work on "parallel strand" construction which
> is what I have, epoxy potted sockets are required.  However, they only
> pot at the factory (liability etc etc) which means tossing 6 x 300' of
> 5/8" 45klb ultimate strength.  Newer Philly (post 1991) is constructed
> of 7 twisted strands, something like 7x19 wire rope (not exactly the
> same, but similar) and the PVC sheath transfers the load effectively
> with the Philly guy grips.
>
> Any reports of success with field potting, materials, how to do it, and
> where ends can be obtained (or a drawing, I will machine them) would be
> appreciated.  I would have a load test done on each guy post potting.
>
> Grant KZ1W
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>