[TowerTalk] Glen Martain

Mark - AA6DX aa6dx at pacbell.net
Wed Feb 2 19:04:28 EST 2005


Are the infamous impregnated wood thrust bearings still being offered for 
sale?
They worked swell for small tribanders, etc ......     Mark   AA6DX
----- Original Message ----- 
From: "Rex Lint" <rex at lint.mv.com>
To: <towertalk at contesting.com>
Sent: Wednesday, February 02, 2005 1:42 PM
Subject: RE: [TowerTalk] Glen Martain


>
> As long as you have a short mast (less than 10 feet) and only one beam
> (mounted close to the "tower", you can get by just using the sleeve as a
> bushing, and not use a bearing at all. Mount the rotator as low as you 
> can,
> so the mast has as much below the tower as above it...
>
> I've got a BIG tribander (KT34-XA and a 2 el 40M beam with a 20 foot
> hurricane fence pipe mast that's been up for 7 years without a thrust
> bearing and haven't had a problem (except with the driven element, but
> that's orthogonal to the discussion.)
>
> Rex
> K1HI
>
>>I just bought me a roof top tower from Glen Martain. They are out of 
>>thrust
>>bearings and wont have any for about 6-9 months can I use any thrust
>>bearing?  Iam going to use a Yaseu rotor for a  4 element crush craft  or 
>>a
>>3 element STEPPIR..
>
> Yaesu makes a nice, but light duty thrust bearing.  I'd assume it'd be
> adequate for what you describe.
>
>>
>> DO I use one to match the rotor or the tower?  Iam confused
>> Dave
>
> The rotor mounts down in the tower and the thrust bearing at the top.  It
> takes the side thrust and eliminates the leverage (tipping moment) at the
> rotor.  In some cases it helps to support the load, which you shouldn't be 
> a
> problem with a simple installation.  Some towers come with a pipe, or 
> sleeve
> at the top of the top section.  This serves as a good, simple, and 
> effective
> thrust bearing for most ham type installations.
>
> Roger Halstead (K8RI & ARRL Life Member)




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