A Comparison of Solid State Sub-Carrier Oscillators for Color TV Receivers

Increasing use of semiconductors in color TV circuitry has permitted the evolution of many different methods for color sub-carrier regeneration. This chassis function is a major contributor to color picture quality since phase errors introduced in the regeneration process can result in tint errors easily discernible by the most unskilled viewer. The solid state circuits commonly used or recommended for use in this area may be classified by operating principles as follows: 1) Automatic phase control (APC) loops 2) Injection locked oscillators 3) Crystal ringing circuits.