Simplified processing circuitry for a television receiver

The home entertainment television receiver contains "processing" circuitry that receives the demodulated video signal and produces from it proper signals for driving both the picture tube and the loudspeaker, as well as synchronizing signals for controlling the sweep circuits, and automatic gain control (age) for the receiver. As shown in the block diagram of Fig. 1, this circuitry consists of the video amplifier, audio demodulator, audio amplifier, age, and sync separator. Since the video signal passes through the video amplifier to other portions of the processing circuitry, careful design of this amplifier makes it possible to simplify the remaining circuits without sacrificing performance. The video amplifier described in this paper overcomes most of the objectionable features of more conventional d-c and a-c coupled amplifiers. In addition, it causes transistor capability to be more fully utilized and thus provides better performance and larger safety margins.