Dear Tim Which model do you have , if it is for TV then it has to turn 360 I have found that the small takeup gear on the base control unit turns out like biscuit and powders over years of operation. A lot of my friends are facing the same problem here. Mine worked for good for about 10 years. Asked Channel master if they could provide spare gears and the answer was a blank one. The base unit has a motor to turn in synch to the rotor on the mast , just a parallel motor. So you can add a switch to the motor and indicator for position A search on google " Adding a potentiometer to TV rotator " and many other ideas. Good luck Best 73 Pop VU2POP
Do any of them offer full 360 degree rotation. I picked up a channel master, it only travels 180.. 73 de Tim, K4SHF