I have acquired a small Stolle aerial rotator without the controller. I found a diagram for a controller which shows that it requires a 120 uF capacitor to feed one motor winding depending on the direction of rotation.
I have built the controller using 3 Maplin non polar 100 volt capacitors in parallel and it works, but the capacitors are quite physically small and as I suspected, they get warm quite quickly.
What sort of capacitor would be suitable? Mains voltage motor run caps are physically much larger than the cap in the other rotator controller I have and the motor is only 20V.
My rotator doesn't have the position pot so I have not attempted to reproduce the positioning circuitry, direction lamps etc. which is partly electromechanical anyway.