[TV MAN]

Progress:

I got the 1077 running and made some tests (starting to really like this instrument!).

First, AGC. I think I tracked down the loss of video. I could inject a reduced RF signal and get video to come through, sound weak. My voltage at the grid of the RF amp tube in the tuner was -1.2, and the video IF was a -few tenths. I concluded that my AGC wasnt working right and the pic overloads when I bring the signal up. I set a bias voltage into that circuit and found I could get a decent picture when I had the voltage about -5.75 volts or around. So, that confirmed I had AGC trouble. After some tests I found an open winding on the flyback transformer. It must have been near the bottom side since I could get a signal off the top, but had little to nothing on the bottom. This is in reference to the schematic. This set is more like the RC201 in most of the sections, so in comparing, I tried pulling the AGC signal (keyed) off the top of the winding, and after some experimenting, found that a 33k resistor was about right to make things work. 

Next, I went after the sync. I found I could lock in the horizontal sync with a grid drive signal injected into the H osc, but not before it. That told me the H section was working, and the problem had to be between the sync separator H take off and osc. I found I lost the signal right before the osc grid. It was tracked to a 1600 ohm resistor to ground when it should have been a 4.7 meg. I tacked in a 3.3 meg and got my H sync lock back. I don't know if that resistor was bad or if I stuck the wrong resistor (likely) in there when I did the recap. I'll look at some pics and tell later. 

With that done, I began refining some details, but found some problems with the H sync wandering. I could always sync it back in with the hold control, but was not right. Cleaned the control which helped some, but decided that something was drifting, got the freeze spray out and tracked it to a weird stack of resistors on the H osc (2 resistors soldered in parallel). Measured 4k when it should have been 2.2k. I changed that and so far, seems the sync has stabilized. I checked the resistors out of the circuit and it was goofy, think it was a bad solder connection. They were "piggybacked".

I decided to neat up the IF where I replaced an open plate supply resistor (just tacked a 3.3k resistor in place to make it work) and found that resistor tested all over the place when removed, I mean from inf. to 100k. I noted it was different from the average resistors, so I checked the Sams, it was just a 1/2 (although it looked like a 2w) 5%. There were 2 more that looked like the same type so I tested them. They were both way off spec, so I changed them too. The other resistors checked fairly close, although there are some cathode resistors that are off too. May change those as well. I am a little reluctant to change much in the IF due to the chance I may have to align. 

   

Now, a really weird thing - in making some checks in the IF section, I found if I touched the Fluke probe to the 3rd IF plate that I get a lot better sound and even improved picture. I can get about the same effect by clipping a test lead on and connecting it to nothing. I also get improved sound when I touch the G1 of the 3rd IF stage (even better), or G1 of the 4th IF,  but it degrades the pic. I'm not sure what to think of that. I also replaced the IF tubes with NOS with some improvement. Remember, my sound takeoff is right off the tuner, before the IF strip, so I am a little stumped why touching the video IF would affect the sound. 

Anyway, I think I am finally winning, and while not quite there yet, hopefully down to working out details and fine tuning.