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

[K7LXC at aol.com]

In a message dated 2/22/2007 10:03:15 A.M. US Mountain Standard Time,  
towertalk-request at contesting.com writes:

>  John you need a 2nd thrust bearing and the correct mast,be  it 4130 chrome 
molly or what ever.I run 45G with the 1st bearing on the top  section.The 
second bearing is midway down the top section. Then the rotor  close to the 
bottom of the top section.
 
    Actually I don't recommend a middle bearing.  It's just another chance to 
introduce more bind in this imprecise system.  

An intermediate something would be useful  when you have a long mast and a 
stack of some sort of yagis. That way the  top-heavy mast is captured in case 
you need to do a rotor swap. A rotator  shelf with a hole in the middle would 
suffice for the intermediate capturing  device. An intermediate thrust bearing 
is redundant and a waste of money since  the top bearing typically holds the 
vertical weight, leaving nothing for the  middle one to do. 
 
>  The antenna is a Force 12 C3S/HH turned by a Yaesu  G-1000DXA.Yaesu has 
the specs on how much weight can set directly on the  rotor.I believe they call 
it the K factor.
 
    Actually the K Factor is used to rate the  rotator for antenna load; it's 
weight times turning radius. 
 
    For a relatively small single yagi  installation like the aforementioned 
C3SS, a second TB might make  you feel better but is even less necessary.
 
Cheers,
Steve        K7LXC
TOWER TECH 



 
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