The Design of if Amplifiers for Color Television Receivers

The designer of IF amplifiers for color television receivers is confronted with the problems inherent in black-and-white amplifiers, plus new problems introduced by the addition of the chrominance subcarrier and its sidebands. This paper evaluates these problems as they affect the design of the IF amplifier. The principal problem is that of providing adequate rejection at 41.25 mc without introducing excessive delay in the color sideband region which is separated from the sound carrier by less than 1 per cent of the signal frequency. Novel non-minimum phase shift trap circuits are described which provide the required attenuation with low delay distortion.