Sorry, I meant to send this follow-up to the entire reflector.
The newer version Philly-strand is excellent - it has become the standard
for guying insulated AM broadcast towers, and is also used on some FM & TV
broadcast towers when guy lines have to pass thru the aperture of side-mount
VHF and UHF antennas.
73
Lloyd - N9LB
-----Original Message-----
From: Lloyd Berg - N9LB [mailto:lloydberg@charter.net]
Sent: Monday, January 13, 2014 5:15 PM
To: Grant Saviers; topband@contesting.com
Subject: RE: Topband: Ends for older Phillystran
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@contesting.com]On Behalf Of Grant
Saviers
Sent: Monday, January 13, 2014 1:15 PM
To: topband@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
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