Consumer Electronics

SELECTAVISION (RCA)

The cheapest and the most basic of the three video disc formats, with the current models offering only mono sound and picture search, selectavision discs, based on the capacitance system, have a maximum running time of one hour per side.

The RCA stylus recovers information from the disc surface by direct electrical means. The selectavision disc is either formed from or coated with electrically conductive material and the stylus serves as a conductive electrode. Although the groove appears to be smooth, it does have tiny pits along the bottom which produce changes in electrical capacitance between the disc surface and the stylus electrode. These changes in capacitance are sensed by a tuned circuit to produce an output of video ...