I do not use insulators in place of thimbles with Phillystran. I am
not sure how heating of non-conductive Phillystran during a lightning
strike would occur, the path to ground is so poor. My towers have had
multiple direct lightning strikes and so far the guy wires have not
melted.
John KK9A
M Gerber wh7w wrote:
]
Can you mate the Phillystran dead end and EHS dead end directly with a
shackle instead of a 504 insulator?
Is there a reason insulators are commonly used to connect Philly and EHS
tails? It is obvious why you need insulators to break up EHS guy segments,
but Philly is nonconductive. I get it that 504 insulators are cheaper than
a high quality 1/2" Crosby shackle. Also, with an insulator, you can save
a few dollars on the dead end thimbles. On the other hand, I have heard of
502 and 504 insulators cracking. I doubt that a U.S. forged 1/2" shackle in
this configuration will ever be the point of failure.
Is there some concern that if a tower sustained a lightning strike, the
dead-end could heat up and melt the Philly? If that is the case, then the
attachment points of all Phillystran dead ends should be connected through
an insulator, which I have not seen done or recommended by other amateurs.
In other words, if you use Phillystran, not only should you use an
insulator at the EHS tail to turnbuckle/anchor, but also at your tower/guy
ring, you need a short EHS tail with an insulator as well. While I do see
DX Engineering makes a new product that K3LR mentioned here previously, the
Bent Pin Shackle Kit with 504 insulator, it is marketed as reducing RF
noise from the dead end rubbing against the metal tower guy
ring/attachment-----not for lightning protection of your Philly guys. The
bent pin shackle/insulator would isolate the Philly and its dead end from a
lightning strike. I guess the ultimate question is has anyone ever heard of
Phillystran failing at a dead end as a result of a lightning strike?
I have a related question regarding shackles. It seems like the bolt type
shackles with a nut and cotter pin are an easier solution for guy wires as
opposed to the screw pin shackle though at twice the price for the
same size shackle. That said, those of you using screw pin shackles, do you
routinely put Loctite on the threads and use a stainless or Monel seizing
wire to prevent the pin from backing out? These little details seem to be
left out of the amateur radio tower books and other online resources.
73
Mark WH7W
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