Rotor-EZ Turning Range Fix

Rotor-EZ Turning Range Issue

We have noticed a few rare problems in which the rotator is unable to travel throughout its complete range (we are not talking about the Electronic End Point Protection option, which prevents the rotator from coming within 5° of the end points when the option is selected).

We have had a few cases where it is impossible to get the rotator to turn as far south at either end of the scale as it should using the “point and shoot” capability of the rotator, even with the end point protection over-ridden.  Everything else is fully operational as described in the manual.

Should you have this problem, this “fix” may well cure it.  Solder a 100 kΩ 0.25 W resistor across resistor R14, in parallel with R14.  Then recalibrate the system as instructed.

The rotator should now cover the full range.

Needle Wiggles When Near Either End Point.

We have run into two isolated cases where the potentiometer inside the rotator used for directional readings was 1 kΩ instead of the normal 500 Ω.

In both cases the rotator had been rebuilt.  The replacement potentiometer was originally designed for a different product, but the 1 kΩ potentiometer works OK in rotators not modified for Rotor-EZ.

However, Rotor-EZ as it comes from the factory will not work properly with such rotators.  The symptoms show themselves when the display indicator approaches either end limit.  When it is within 10° or 15° of either limit, the indicator needle continuously shakes.

If you suspect this is a problem, first, measure the resistance across the potentiometer.  This is the resistance between pins 3 and 7 of the rotor cable.  To measure at the control box, disconnect either the wire to pin 3 or to pin 7, then measure the resistance across the two wires.  If the resistance is approximately 1 kΩ, then you have discovered the cause of your problem.

If such is the case, you can gain proper operation by removing resistors R1 and R4 from the Rotor-EZ board.

Then, calibrate the unit according to the instructions and all should be well.