[TowerTalk] rotor digital readout /reply de K0FF

[K0FF]

I did it on an HDR 300, used an old HAM-M box as the basis. The resistor in
the motor unit is a little different, but basically it's just a balanced
bridge. Use the "digital panel meter" also called "Voltmeter/Ammeter
Module"available at Radio Shack. In my small town it was a special order but
the # is 910-4915. This is the one with larger LCD digits and a backlight.
About 25.00. When project complete, it reads 0-360 degrees. Only uses 2 of
the resistor wires from the rotor. One from slider the other from one arm.
Also, I used two more in a homemade AZ-EL positioner for the portable EME
array.
You have to gut the meter power supply in the control box and rewire it. Go
ahead and filter it and regulate it while in there. Add one more cal pot.
Set one pot for "0" the other for "360"  Most any motor resistor can be
calibrated that way, even 10 turn types that are geared down. Only bad thing
is that you can't power the display module from the same voltage source that
runs the bridge circuit, so an additional 9-12V PSU or wall wart is needed.
No big deal.

Happy Building, Geo>K0FF


>
>Anybody seen any plans/schematic for using a digital readout instead of the
>meter on a Ham V or Tailtwister type control box.
>
>


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