In a message dated 4/22/2007 9:15:57 P.M. Pacific Daylight Time,
towertalk-request@contesting.com writes:
> I don't think the problem is a design flaw with the 2800, I believe it
not rated for very large 3 element 40 meter full sized Yagis (including
the SteppIR MonstIR) in strong winds.
> Orion 2800 rotators failed catastrophically in three different
installations in my local area when used with very large antennas
(full size 3 element 40M Yagis and SteppIR MonstIRs). In each case it
was a result of 40-50 MPH winds typical for this area. Each failure
occured soon after installation of the rotator.
Were the failures in the transmission or what? While I'm sure it
happens, I haven't personally been involved with an Orion failure. And yes,
they're
not a prop pitch but better than most other rotators available.
> "Square feet" is an inadequate rating for rotator capacity. Very large
antennas distribute wind loads over a large structure, and considerable
energy is stored in the flexing of very long elements in the wind. This
stored energy creates heavy torque loads that overload all but the strongest
rotators.
Quite true which is why Hy-Gain and Yaesu both went to Effective Moment
and K-Factor which are both the antenna weight times turning radius - a much
more realistic measurement.
Cheers,
Steve K7LXC
TOWER TECH
************************************** See what's free at http://www.aol.com.
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|