Actually the Orion OR-2800 does exactly what you describe, Yuri. It is
a self locking worm gear design (no brake), with a programmable ramp-up
and ramp down feature. Rotation speed can also be programmed from
something like 1/4 RPM to 2 RPM. The fastest speed is a bit much for a
large array however. When I stop the 4 element 40 meter beam/KT34XA
stack at W6UE (both with heavy duty boom options) from the highest
speed setting on the Orion, the overshoot/recoil oscillations of the
antenna/mast assembly are pretty violent [I don't make a habit of doing
73 de Mike, W4EF................................
----- Original Message -----
Sent: Wednesday, September 11, 2002 7:05 PM
Subject: Re: [Towertalk] Mast Coupler
> In a message dated 9/11/02 2:36:20 PM Eastern Daylight Time,
> firstname.lastname@example.org writes:
> > Has anyone built the shock absorbing mast coupler described in Leeson's
> > "Physical Design of Yagi Antennas"?
> The better way for large antennas is to use rotator that ramps up its
> gradually and then coasts to stop. No need for shock absorbers.
> The best rotators are the ones using self locking worm gear drive, (no
> for brakes) and with speed control. Good old Telrex comes to mind.
> Yuri, K3BU
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