This is what I was getting at when I made my earlier post about about the old Gemini OR-360 TV rotators. The gear train is driven by a "540" sized DC motor. I can tell you from experience that one of these rotors will rotate a mini sized beam on HF. I do it everyday. So if we are driving a smaller array, we might be able to eliminate some or all of the gearing involved and go with one of the smaller motors. I can't recall the issue but it seems to me I saw an article in QST where someone was driving a small little beam on top of a tripod with a small little motor. I still think a position pot is a better option for pointing over a stepper motor though. Michael, W4HIJ On 2/27/2013 8:30 PM, Gus wrote:
Returning to this topic...
I'm thinking about a rotator that can handle a small system like the Arrow, or the Cushcraft A270-6s or even the A270-10s. NOT big boomers like the KLM 22/40 el CP yagis!
So we're looking at 1½ - 2 sq. ft of windloading, and maybe 10 lbs of weight. (Including some sort of crossboom, clamps, coax and counterweights. Rear mounted antennas like the Arrow will need a rear-mounted counterweight.)
Anybody qualified to say what that adds up to in terms of TORQUE required from the motors? With a little extra thrown in for a safety margin, maybe?
I think a simple, low-cost, easily reproducible design is probably doable, if we combine our ingenuity and expertise.
-- 73, de Gus 8P6SM Barbados, the easternmost isle. _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb