[TowerTalk] Phillystran to EHS tail connection and shackle questions

Tim Duffy k3lr at k3lr.com
Fri Jul 31 09:57:08 EDT 2020


Hi Keith:

>From DX Engineering
https://www.dxengineering.com/parts/dxe-504

73
Tim K3LR

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Keith
Dutson
Sent: Friday, July 31, 2020 9:28 AM
To: Tower Talk
Subject: Re: [TowerTalk] Phillystran to EHS tail connection and shackle
questions

Thanks for the info about insulators on the tower.  I have some maintenance
to perform and will add the insulators.  Where do you get your insulators?

73, Keith NM5G

-----Original Message-----
From: TowerTalk <towertalk-bounces at contesting.com> On Behalf Of Tim Duffy
Sent: Thursday, July 30, 2020 10:59 PM
To: 'M Gerber' <wh7w.us at gmail.com>; towertalk at contesting.com
Subject: Re: [TowerTalk] Phillystran to EHS tail connection and shackle
questions

You can do that - but know that the Phillystran preform is 3 feet long and
if close to  Yagi it will cause distortion of the Yagi pattern if you do not
have insulators at the tower connection point. Insulating the Phillystran at
the tower at K3LR was very important to insure proper (modeled) directive
performance of the Yagi.

I do not understand your lightning concerns - please explain in a private
email.

All of the K3LR towers are guyed with Phillystran and are doing very well
with the insulators as described.

73
Tim K3LR

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of M
Gerber
Sent: Thursday, July 30, 2020 11:41 PM
To: towertalk at contesting.com
Subject: [TowerTalk] Phillystran to EHS tail connection and shackle
questions

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
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk



More information about the TowerTalk mailing list