It’s a matter of the mating surfaces that are acceptable for the big grips,
the Philly end, insulators & shackles. You don’t want a big grip tone bent
over the small diameter of the shackle or shackle pin. You want the broader
surface of an insulator to mate to the big grip.
On Thu, Jul 30, 2020 at 11:41 PM M Gerber <wh7w.us@gmail.com> 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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