AGC stability requirements for the decoder interface

In order to insure the RF AGC system is stable for any cable decoder connected to any receiver, the gain and time constants for both must be specified. These requirements and their development are given. The analysis results in a gain-bandwidth specification for the receiver's RF AGC line, a minimum phase response for both the receiver and decoder IF AGC loops, a maximum capacitance for the decoder AGC line and a minimum resistance for the receiver's AGC port. Further, the phase response for the IF AGC loops is separated into more easily measured gain and bandwidth requirements.