[drh4683]

only thing to say about the 1077B is that it will probably work, but the vertical linearity will be way off. No big deal as you are looking for a good signal. Turn the channel dial to IF, then connect the RF output into the IF input of the TV. Turn up the RF gain control and tune the IF dial to around 4.5 mhz. A picture should show up, adjust the RF gain as needed so you dont overload it. I assume you have some kind of immage or test pattern in the CRT slot inside the unit.

Problem isn't in the chroma circuits. Like when your fine tuning is off on a normal working set, you lose color because the color subcarrier is not tuned to the proper IF freq and you lose gain to the point where the color is gone. Really sounds like tuner trouble to me based on how you describe it.