CTC-7: Convergence, Convergence, Convergence

[reeferman]

Chad,

I agree very much with what you say! All I'm saying to Jeff is not to expect the set to perform like it did 40 yrs ago

Phil

[jbeary]

Hello again All,

I do think some of you guys are right and I shouldn’t beat myself up over a few little shadow marks. Like my dad said when he first saw the TV working; "when you've been looking at black and white your entire life, color looks pretty good" (I’m not giving up my B&W though). Just about everyone that sees the TV working comments on the color (rich and vibrant) and no one has mentioned seeing a few weird artifacts on the screen.

In 1958 I guess that most people were just happy to see a color broadcast. I know that most if not all of the issues that plagued the earlier color sets had been worked out by the time my TV was designed and that there were probably only a handful of color sets bought in 1958 that were installed correctly and that people most likely settled with a mediocre set-up. However, it does not make sense to me that I can't get perfect convergence across the entire screen. The way I'm thinking is that my set should work at least as good if not better than it did when it was new. I mean, I've replaced about a 1/3 of it alone with swapping out all of the capacitors. And rarely have I done a complete overhaul of any TV and not had to adjust something and this one is the same. Everything from the power supply to the tuner works GREAT except for the convergence being off.

Now, like I said before, I may be being nit-picky but every time I go through the convergence process, I get differing results. I start with the purity adjustment and go from there since I'm pretty confident that all of my screen controls are balanced. It looks very in focus to me, but I'm definitely going to fiddle with the contrast as well as the brightness and focus controls. I wish someone would tell me how and where to inject the video signal from the generator and how to use the horizontal trigger. I've read documentation, but the last thing I want is to blow up something in the video chain or my dot generator. So if someone has hooked up a generator this way before on a CTC-7, please let me know how you did it. I've always read that I need to put it on the second IF amp and use some RCA WG-306A adapter. I'm in the dark because I lack the knowledge and the confidence.

I'm also worried about the placement of the yoke, convergence yoke, purity rings, and lateral magnet. The plastic that held the lateral magnet disintegrated from me fooling with it too much, so I made one from some heat shrink tubing which seems to work okay. The point is; I've messed with these things so much I'm afraid that without seeing where exactly they should be on another set that works perfectly, I may as well just abandon the idea of having perfect convergence. I know that they're in about the right positions, but I've noted that as soon as you bump a purity ring, the shape of the dot changes. So very often I would start with good purity and then bump the magnet ring mistakenly and change vertical or horizontal convergence without being aware of it. Then I'll go onto doing all the rest of the convergence steps only to be dissatisfied with the results. The big question is where do I put the convergence yoke? The center convergence magnets should be directly over the poles, but I have no idea where the pole pieces are because the inside of my CRT is shadowed and the outside pole pieces cannot be viewed from the glass envelope. If anyone can let me know how far forward from the pin side of the socket I'll need to go with the convergence yoke that would be great!

I printed out the 50 page "Service Clinic" for the 800 series that someone sent me a link to and it is packed with useful information that I've yet to see compiled in one place. So THANK YOU for that. If you guys have anything else that you can send, please forward it to [email protected]. I’m also available to answer questions about basic TV restoration if anyone out there needs help with something. I wish I had more time to devote to a website, but I’m unfortunately over-burdened!

THANK YOU ALL AGAIN!
Jeff