Last post about my convergence - Videokarma.org TV - Video

andy · #1 08-25-2013, 06:01 PM

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TinCanAlley · #2 08-26-2013, 12:11 AM

Quote:

Originally Posted by andy

The plug is so that you can easily remove the chassis.

Just in case you don't know, you can remove the convergence panel, and mount it flipped up so that the controls are facing the front of the set for easier access.

Yep, I learned that from my brother. I said to him I thought it was an odd way to mount the controls and he said to flip it up so I can easily adjust while in front of the set. I was so busy wondering why it was mounted there I never thought about it being functional with a little movement.

I get it. You can take the chassis out and work on the bench. I've been flipping her over and it works for me. If I had a business going, I'd sure go the removal route.

TinCanAlley · #3 08-26-2013, 10:56 AM

If I jumper the terminals of a convergence pot while it's turned all the way down, there shouldn't be any movement of the lines, right? I would like to do a little testing of the pots on the board and figured I'd jumper the terminals of each pot and see how it responds. Then I'm going to run them through their full range (un-jumpered) and see what kind of range they have on the screen. I'll finish it off by giving the pots another deoxit and fader lube session. Once that's complete I'll try the convergence procedure over again, starting with the center convergence.

Can a pot be accurately measured while still connected? If I connect to the terminals and turn the pot, can I expect a close to accurate readout? If so, should I be looking for a full range (0 to stated ohm value), or do they not zero out fully CCW?

I figure if something is wrong with one of the pots, this should help me determine.

TinCanAlley · #4 08-26-2013, 03:55 PM

Okay, did another cleaning with deoxit on all the pots and followed up with Fader Lube to keep them lubricated. I then tested each pot and found one that makes a clicking sound at full CCW and you can also feel it. I checked the resistance across the tabs and it was much lower than the other two pots of the same resistance (120ohm). Two showed that value, but this one only showed about 23ohm. When I connected to the wiper, the other two pots showed 1.2 to 123. This one started at 1.8, when to 27.9 and then started to drop back down to 2.8 and never go anywhere near it's value of 120.

I tracked down an NOS pot and will be purchasing it long with the R/G vertical lines right coil. It is seized in the position left from last adjustment.

I'm attaching pics of the current convergence I've achieved. I think with the pot replaced and the new coil, I should be able to tweak it to make it better. I know perfect is not possible, but I'm pretty close to a convergence I can live with.

Thanks to many here, I'm almost there!

sampson159 · #5 08-26-2013, 08:42 PM

this is as good as your going to get.all my zeniths look about like this too.turned out very nice.you will never,ever achieve absolute perfect convergence.from about 5-10 feet away,it will look perfect.nice job and now sit back,relax and enjoy this masterpiece!

TinCanAlley · #6 08-26-2013, 09:01 PM

Quote:

Originally Posted by sampson159

this is as good as your going to get.all my zeniths look about like this too.turned out very nice.you will never,ever achieve absolute perfect convergence.from about 5-10 feet away,it will look perfect.nice job and now sit back,relax and enjoy this masterpiece!

Still have to replace the one pot and coil. Both are responsible for the right lower section that is still quite a bit off. Watching a B&W image is painful as it's not just a little blue or red on an edge in the image. It's a large blue, magenta and yellow edge on almost everything in the lower right. It immediately pulls your eye to it and is quite distracting.

While I know perfect isn't possible, those lines should be closer together. I should have the replacements here and installed by next Monday (hopefully).