FAQ's (4)

Q: Why my control unit displays a different antenna position than my ARS interface?

A: Some rotors as Yaesu or Kenpro, include a complex mechanish for displaying at the Control Unit the antenna position. Basically those units have inside the CU a small DC motor and another POT connected into this motor axis. Also at this axis, a GAUGE is connected, and it's used as antenna appointing or indicator. Example: G600, G800, G1000, G2000, G2800, ...

Some Op's IC's are working as a comparator between the Voltage feedback that comes from the external POT (V1) and Voltage from the internal POT (V2). If V2 is greater than V1, it means the user has moved the antenna into the left, so the comparator IC's will activate the internal POT towards left (CCW) till both V's are again equal.

You can suppose that those extra elements can add some errors. The errors are due to:

• The internal POT quality use to be not very good (bad linearity response)
• The comparator has a margin actuation, it means some small votage differences at the inputs, don't activate the internal motor

Control Units as HAMIV, or as Yaesu/Kenpro 5500, 5600 works as a voltmeter. The Voltage feedback is displayed directly into the meter without any extra electronic component.

As the ARS works as a voltmeter (this feature is done by means of the ADC's) it should display the REAL position, of course, if it's calibrated correctly. I have checked many ham stations when they were running the ARS and those Yaesu/Kenpro Control Units. I could appreciate till more than 15º between the ARS and the Control Unit. I can assure that in ALL cases, the error was due to the control unit.

In any way, the ARS includes an extra feature: The Offset Correction, that allows to make the ARS equal than the user control unit (Yes, when we use this feature, we are adding a error into the ARS....Hi)

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