[TowerTalk] Glen Martain

[Rex Lint]

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)
N833R World's oldest Debonair
www.rogerhalstead.com

> KA7RRA
>
>
>
> _______________________________________________
>
> 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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_______________________________________________

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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