TT:
I installed an industrial bearing atop my tower. I use it to steady
the mast at the top as well as to provide some support for the vertical
antenna load. I accomplish the vertical support NOT by relying on the puny
set screw, although I did tighten it so that the collar would rotate with
the mast (otherwise why install a bearing?) I support the weight of the HF
antenna with back-to-back (or facing-each-other) muffler clamp saddles.
After I had installed the V/UHF vertical and 40M rotatable dipole on
the mast, raised it into position and installed the rotator, I installed the
muffler clamps so that they sit against the bearing collar. Then I
installed the Bencher Skyhawk tribander. In this way the mast weight and
that of the higher antennas is supported by the rotator, and the HF Yagi
gets additional support from the mast clamp setting against the top bearing
collar. (Thanks to K7NV for this hint.) And if I ever got enough nerve to
climb my mast for antenna work, I'd install a second auxiliary clamp on the
mast against the middle rotator/bearing plate for additional support.
BOTTOM LINE: If you want your top bearing to provide vertical support for
the weight of your mast/antennas, use an auxiliary clamp of some kind, not
just the set screw for centering the mast inside the bearing's collar.
73 de
Gene Smar AD3F
----- Original Message -----
From: "Noel" <yaesurig@msn.com>
To: <towertalk@contesting.com>
Sent: Thursday, July 22, 2004 1:49 PM
Subject: RE: [TowerTalk] Re: Thrust bearing
> Agreed with everthing except the statement. "...Then make sure the
> collar can rotate around the mast without binding".. Seems to defeat the
> point of having a thrust bearing? Why not have just a collar then? I
> think the bolts in the thrust bearing should be tightly holding the mast
> or at least very snug. Not bearing weight but enough to support any
> lateral movement. Your method would cause the bolts to eventually scar
> the mast even though you say the clearance is minimal, unless one used
> shims.
>
> I'm curious haw many people who utilize thrust bearings, allow the
> bearing to "rotate around the mast" or make sure the mast and bearing
> are tight and rotate together?
>
>
> Noel
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
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> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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