Reliable rotator is an important part of amateur radio. The use OM0A rotator AR-300XL, despite the small size of the handle to rotate the major KV direction. It is mainly thanks to high-quality metal transfer. Drawback is, that after a few rotation difference occurs between the real and the indicated direction on the imaging.
Therefore, it is advantageous to supplement the rotator attached Viewer. Very good construction described Vlado OK1VPZ to http://www.ok2kkw.com/rotator/rotator.htm . Uses 36 LED diodes (indication of 10 °) exciters with LM3914. Sample Viewer function is on video. The sensor is a potentiometer mechanically interlock with the necessary rotator.