[TowerTalk] Yaesu GA-3000 tower absorber

[Denis Coolican]

Jim, I would not think that the tower would be in question due to the
antenna torque. If it is a damper will not reduce the steady state
torque.  It may dampen out peaks but with a steady wind on an unbalanced
antenna the torque will be there.

You may be thinking about reducing the peaks on the rotator and as such
the damper should be between the rotator and the antenna.  The flex disk
shown by Michael Tope looks like a good start.

You can also fabricate your own using a piece of conveyor belting which
is available at belting stores.

:Large antennas or antenna arrays should not be turned at 1 rpm unless
you have a method of ramping them up and ramping then down.  Even 0.5
rpm is to fast for a large antenna if no ramp down is used.   0.25 rpm
is probably all you would want to turn a large antenna array without any
ramping controls.

You just have to be up there when the rotator stops turning  and watch
as the end of the boom keeps turning for another 3 to 5 secs depending
on the size of the array.  Then you will realize that you have to absorb
the energy someplace.

If the rotator has any sort of worm drive in it or brake that is applied
when it is stopped  it will stop dead and expect other components to
take up the energy absorption.  That is when it is nice to have an
absorber of sorts. It could be a rubber flex disk or a coil spring or a
longer mast of  twistable material.

Denis Ve6AQ  / Ve6FI


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