[amsat-bb] Re: Pendulum type elevation measurement
ko6th.greg at gmail.com
Sun Feb 24 10:18:05 PST 2013
I made an El rotor years ago, and used the weighted pendulum method for feedback. Besides the weather pushing the weight around, the other problem was hysteresus. Small changes in reverse position didn't cause any change in indication. If you are looking for improved position accuracy (vs what?), you should figure out a way to anchor the pendulum. That should solve both problems.
Joe <nss at mwt.net> wrote:
>I see no problems at all. I have done it with that method in the past.
>The only thing I noticed that was a problem was if the pendulum is
>exposed to the elements. As in weather not antenna elements. Gusty
>would move the pendulum and cause a not steady reading..
>but not that much of a problem did not happen all that often.
>The Original Rolling Ball Clock
>On 2/24/2013 5:45 AM, Richard Ferryman wrote:
>> For some time I have wanted a more accurate antenna elevation
>measurement system. Shaft encoders are beyond my budget. It seems
>sensible to use a pendulum operated system. Digging through my 'junk'
>box I find I have a new Spectrol precision potentiometer still sealed
>in it's package. This pot is 21mm diameter, has a servo type mount,,
>ball race bearing, 340 degree track (continuous rotation possible) and
>specification is 0.5% linearity.and is very low torque. Does anyone
>know if there are any drawbacks to using this method of position
>> 73 de Dick G4BBH
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Sent from my Android phone with K-9 Mail. Please excuse my brevity.
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