[Alex KL-1]

If you change the mind and want to implement the inputs:

For video: you can isolate the pin 5 and feed all subsequent circuits. You feed using a 47µF capacitor from the Video line (the video line terminated with a 75 resistor at RCA teminals). The positive of capacitor will connect to TV circuits; the negative, you connect to central RCA pin (the cable signal). But, the sync separator will be without DC bias, and the video followe (if TV have one). SOlution: you connect a 10k resistor from the positive of this capacitor (the TV internal video circuit) to ground, AND another 10k resistor from this same signal point to the IC +B (pin 20). Then the video operation will be fully correct.

Not forget to ground the video cable ground (to TV signal grond). You can use anything connected to the tuner case (for simplicity).

For audio, you isolate the pin 11, and inject the audio for the following circuits. No bias needed, and no caps etc. Just direct.