Re: [amsat-bb] TV aerial rotator question - reply

[Norm McMillan <njmcmillan@xxxxxxxxxxx>]

At 07:22 08/01/2002 +1000, you wrote:
>First, thank you for the huge number of replies. I wondered how the
>controller's pointer moved and I never thought of a second motor. Anyway, my
>worst fears have been confirmed, so it's back to the drawing board.
Snipped....

Phil,
what order of pointing accuracy do you want? I ask this because I have used 
my stock set up for more years than I care to remember with excelent 
results for LEOs and terrestrial VHF/UHF weak signal work. The odd 
Stop-to-stop and cal against the moon (much easier than the sun!!!) is all 
that seems to be required.

On the other hand, if you want auto control, how about 1 turn from a multi 
(5?) turn pot. Or maybe a Gray Code position sensor, or count shaft 
rotations of the motor with a Hall-effect or optical-interupt sensor?

An engineer mate of mine said you could do it with unequal length arms, 
which he described as "linear gears." What about belts/pullys, say from a 
discarded tape deck.

let me know how u go. I've battled this same problem and finished up doing 
nothing!




Norm, VK2XCI
Voice of The Edge of The Outback
njmcmillan@bigpond.com

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