An Integrated TV Video Modulation System

New developments in T. V. add-on areas such as V. D. R., games, and data display, have produced a common need for composite video encoding and R. F. modulation circuits to interface with the T. V. receiver. This paper reviews the basic reqiurements for this area and then presents a new T. V. video modulation system using only one integrated circuit.* The new system includes the sound subcarrier oscillator and chroma subcarrier encoding circuits, in addition to R. F. oscillators and modulators for two low-V.H.F. channels. Channel switching is achieved with a d,c.-operated switch.