[TowerTalk] 2nd thrust bearing inside tower - you opinions??

[ersmar at comcast.net]

John:

     On my tower I have a top bearing plate (with an industrial bearing on it), a second bearing plate about three feet below that one with NO bearing, just a set of back-to-back muffler clamps; and a rotator plate with the rotator five feet below the middle plate.  The muffler clamps are not sitting on the middle plate, but an inch or two above it on the mast.  I would use this clamp to provide support for the mast/antennas when I remove the rotator for whatever.  

     I agree that lining up the rotator and top bearing plates will be tricky enough without the additional hassle of a middle plate and bearing. 

BOTTOM LINE:  Install that middle plate but NOT the middle bearing.

73 de
Gene Smar  AD3F


 -------------- Original message ----------------------
From: <john at kk9a.com>
> Tower top plates and rotator plates are not manufactured very precisely and 
> trying to line up two bearings plus your rotator bearing could be difficult. 
> If it's not lined up exactly it will cause some binding and add more stress 
> to your rotator and I don't see any benefit to having a lower bearing if you 
> are using an adequate rotator.   I think just using a top bearing and a 
> heavy duty rotator about 6' below would be a better choice.   I'm not sure 
> what a good rotator would be for this system, perhaps a Yaesu G-2800DXA or 
> an even larger Prosistel.
> 
> 73,
> John KK9A (P40A in the ARRL DX Phone Contest March 3 & 4)
> 
> 
> 
> 
> To: <towertalk at contesting.com>
> Subject: [TowerTalk] 2nd thrust bearing inside tower - you opinions??
> From: "K5XA John" <k5xa at godfather-ridge.com>
> Reply-to: k5xa at godfather-ridge.com
> Date: Wed, 21 Feb 2007 08:37:59 -0600
> List-post: <mailto:towertalk at contesting.com>
> 
> Howdy,
> 
> Need a little advice.
> 
> Planning about 130 feet of Rohn 45 - 20 to 22 feet of mast - Force 12 Magnum
> 240N over a Force 12 C31-XR at the top - side mounting another C31-XR.
> 
> Considering a 2nd thrust bearing inside the tower.
> 
> Any suggestions/ideas/experiences you might share?
> 
> Tnx!
> 
> 73 ............... K5XA
> 
> John Guida
> k5xa at godfather-ridge.com 
> 
> _______________________________________________
> 
> 
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk