Yes, you are right...The U bolt failure caused the slippage.
It is an small TV antenna rotator. Yes the antenna is balanced. The antennas
is big spiderbeam...a big cross 46 ft by 46 ft.
Pin the mast to the rotator is a good idea but I am worry about the U bolt
that join the Center hub with the mast...if that U bolt fail then will get
problem with the coax again.
I will try installing a telescopic tube in the tower leg...with a pulley can
move up or down the tube if I want rotate the antenna...that tube is a
protection if the U bolts fail...If the U bolts fail, the tube will stop the
rotation of the center hub.
73,
Doug, CO8DM
-----Mensaje original-----
De: TowerTalk [mailto:towertalk-bounces@contesting.com] En nombre de Earl
Morse
Enviado el: lunes, 04 de abril de 2016 16:18
Para: towertalk@contesting.com
Asunto: Re: [TowerTalk] Need install a BRAKE to protect antenna and rotator
Thought maybe you had a rotator with no brake installed but then saw that it
was a U-Bolt failure that caused the slippage.
You can pin the mast to the rotator if slippage is a problem but you should
have a rotator with a brake so that the rotator doesn't slip.
What kind of rotator? Is the antenna balanced about the mast?
Earl
N8SS
------------------------------
Message: 2
Date: Sat, 2 Apr 2016 20:49:33 -0700
From: "John V" <vjohnv@cox.net>
To: <towertalk@contesting.com>
Subject: [TowerTalk] Fwd: Need install a BRAKE to protect antenna and
rotator...
Message-ID: <009501d18d5b$d5ceb850$816c28f0$@net>
Content-Type: text/plain; charset="iso-8859-1"
"Hi,
I installed a modify spiderbeam few days ago. Spreaders are 7m long because
I added 2 elem (shortened) on 40m.
Few days ago, during a windy day, both U bolts with saddle clamps in the
rotator fail...the antenna mast (aluminum tube) rotate inside the saddle and
broke both coax cables.
I quickly tie a pipe between the center hub and one leg of to tower until I
find a solution.
Maybe I need a Brake mechanism to protect the rotator. Some kind of
mechanism to operate with a rope from the bottom of tower.
It is very interesting...the center hub is connected with an U bolt with
saddle clamp to the alum mast...I think strong winds will turn the center
hub, so, I need protect the center hub too.
Any idea ?
Thanks,
Doug, CO8DM"
Doug,"
Doug, great that you are getting up some good antennas!
One option would be to use some brake parts from a smaller car. You would
need to find a brake drum setup and attach the backing plate to the tower
and the drum to the mast. The brake pads could be actuated with a master
cylinder near the ground. If you used a rear brake drum there is a chance
that it could have an emergency brake cable that you could extend to the
ground and not need any hydraulics.
Una opci?n ser?a utilizar algunas partes de freno de un coche m?s peque?o.
Necesita encontrar una configuraci?n de tambor de freno y coloque la placa
de soporte a la torre y el tambor en el m?stil. Las pastillas del freno
podr?a accionarse con un cilindro maestro cerca de la tierra. Si usted
utiliza un tambor de freno trasero hay una posibilidad de que podr?a tener
un cable de freno de emergencia que podr?a extender en el suelo y no es
necesario ning?n sistema hidr?ulico.
Regards, John NA6L
------------------------------
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