1950 RCA 16" 6T65 (KCS47 chassis) repairs and alignment

[Adam]

I picked this set up a few years ago. Did the usual recap. First sign that something was weird was the missing "doorknob" HV filter cap. The only replacement I could find was 30Kv and required I enlarge the hole it fits in, but that wasn't much of a problem. I try it out, but I get no HV and the 6W4 damper and 5U4 rectifier both light up like christmas trees inside. Next I start checking the yoke and flyback, and notice someone stuck both in here from another set that don't belong. This is when I also notice that the horiz hold control is open in most positions. And while I was poking around I also replaced a few more than 10% off resistors in the horiz sync circuit (but none were way off). Then, I get replacements for the horiz control, yoke, and fly and try it out again, but I still have the same problem. The trouble turns out to be in the power transformer itself, the damper filament winding shorting to one of the other secondaries. I briefly get the set to come up (with a blank raster only) using a separate filament transformer for the 6W4. But then something else in the transformer shorts for good.

Now I've replaced the power transformer, and switched the damper tube to a 6AX4GTB. Then I had a blank raster, no picture / no sound.

Then I adjusted the local oscillator going from ch 13 down, with the frequency counter, setting each for 21.5MC over the frequency of the channel. Then I had picture, and really bad sound (quiet with lots of buzzing).

I aligned the sound IF and detector transformer following a procedure in the sams with a signal generator set to 21MC into the control grid of the sound IF tube. This worked, but there was still some buzzing, and the picture didn't quite line up with the sound in the fine tuning. So I repeated the alignment with the tv receiving a signal on ch3 with the fine tuning set to best picture. Now the sound is good, with minimal buzzing.

But the sound still causes interference in the picture, horizontal bars across the screen increasing in intensity with that of the sound.

So now I want to try a complete re-alignment of the IF, both sound and video, partially because I think it will fix this, but partially just because I've always wanted to learn to do it.

So I have my sweep generator (RCA WR59B), television calibrator (RCA WR39C), and marker adder (RCA WR70A). They are all in very good and clean condition, and I have the manuals that came with all 3, and the cables and probes from the WR59B and WR39C, but not the WR70A. First I'm going to recap (paper and electrolytics) my equipment and make sure it is in working order. I'm ordering the caps I don't have now.