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.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.All the weight sits on the rotor the
thrust bearings alighn the mast thru the tower.The mast is pinned at the rotor
per Yaesu specs(rule #1 always do what the manufacturer says).It can be time
consuming to alighn all this,But the more work you do on the ground the less
you do in the air.Force 12 has a unique mounting system.that allows you to
install 1 plate on the mast,the second on the boom.when the antenna goes up you
just bolt the 2 plates together.Its designed so you can't do it wrong.I took
the top section on the ground,Installed all the parts and plates,aligned i
t and even tested the rotor on the ground and set the direction also.A rohn
thrust bearing has a different bolt pattern than the rotor.Custom Metal works
makes a bearing shelf just for this purpose.Cost is about the same as a second
rotor shelf and you won't have to modify it .Array solutions has the bearing
shelf.Do alot of planning ie square ft load , total weight.You did not mention
where your QTH is but ice and snow may need to be in the plans.The only other
thing I would recommend is use a crane if possible.You pick up 3 sections of
45G already assembled.You will be a lot happier doing it this way than with a
gin pole and a tram.The extra cost is well worth it.My antennna has been up
this way for 5 years now and with just a little maintainence it will be there
10 more. Just my op but it sure worked slickHope this helps.Oh by the way this
set up wen't thru 4 hurricanes the worst being Wilma and withstood 110 MPH
winds with out a problem.Florida is Paradise!
73 Joe K4XZ
>
> From: "K5XA John" <k5xa@godfather-ridge.com>
> Date: 2007/02/21 Wed AM 09:37:59 EST
> To: <towertalk@contesting.com>
> Subject: [TowerTalk] 2nd thrust bearing inside tower - you opinions??
>
> 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@godfather-ridge.com
>
>
>
>
> _______________________________________________
>
>
>
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>
JOE PATRICK
SENIOR PLUMBING/MECHANICAL
INSPECTOR CITY OF BOYNTON BEACH
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