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#31
01-31-2011, 01:53 AM
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Was waiting for a tow truck to show up at my house, with family member's car on the hook. Ford's 4.6L plastic intake manifold had decided to crack, and leak coolant everywhere. Shop wanted $1600 to fix, so I said bring it here and I'll do it, etc. Boring sitting around the house, so we decided to watch some TV.
"what's wrong with your TV's colour?" "nothing, it's working fine, isn't it?" "the colour is all wrong... look that is supposed to be purple, and it's blue" "is it? looks fine to me.. uh oh" Looks like I did the best I could, and got used to it. OK found a station showing colour bars. Sat my Trinitron beside the Zenith, and no possible position of the RGB and tint controls makes them look the same on both sets. The (1979) Trinitron looks like a photo of a set of colour bars, but the Zenith will get either yellow or purple right, but not both at the same time! When purple looks good, yellow looks green, and when yellow looks good, purple looks red. Back to the bench it goes! 
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#32
01-31-2011, 10:38 AM
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1) is the monochrome tracking OK when you turn color all the way down?
2) could you post a pic of the Z and S side by side with color bars?
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#34
02-10-2011, 01:00 AM
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Finally found the charger for my digital camera.
Seems like today I was able to get the two to match a lot closer, but look how far off centre the Zenith's tint control has to be! Apologies for my extreme lack of skill in taking photos of TV sets displaying a picture.
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#35
02-10-2011, 07:56 AM
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Looks good! Do the color afc alignment procedure in the sams and it will get all the controls centered out. No special gear is needed except that color bar generator. Its usually on the same page as grey scale setup
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#36
02-10-2011, 08:24 AM
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A coupla comments:
1) The zenith looks like it has a little red purity problem (turning greenish) right down the center - I would try degaussing first. If that doesn't help, is the yoke glued on, or movable? Looks like it needs a nudge forward or back. 2) the Zenith has the typical color-correcting demod angles - makes the green bar a bit dim, the yellow a bit orange, and the magenta a bit redder - all designed so that a standard NTSC source will make the best flesh tones with the phosphors in that tube.
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#37
02-10-2011, 11:58 PM
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CTC17
I'm still trying to get my hands on a test pattern/color bar generator - if I can't get one locally I'll go the eBay or classified ad route. That said, the TV sure looks way better now than it has in ages! I want to pick up a decent VTVM too. The Sams procedure looks quite straight forward. old_tv_nut 1) The Yoke can be moved, and Sams has instructions for how to do this too.. I think it may be an artifact of the way I took the picture though, as in person red looks fairly even. I'm also afraid of messing up the convergence and not being able to get it back  2) Interesting... I've always liked the softer toned picture of this TV's chromacolor tube, but the dim green sometimes makes nature scenes look a bit less vibrant than they do on the Sony.
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#38
02-11-2011, 12:36 AM
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You don't need all that. Use the ntsc generator you show in the picture and just do the part where you adjust for the slowest moving bars and the adjutment to center out the tint control. Don't bother with all the voltage adjustments. Chances are if you get some old color bar generator it will have a drifted burst crystal and youwill align the set to that. Use your camera
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#39
02-11-2011, 12:58 AM
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The sams procedure says to hook up a color bar generator, and adjust a specific coil to maximize the amplitude of the 6th color bar, and then has a waveform where all the different color bars are labeled. The other adjustments are voltage based, and there's only three coils to adjust with all else being fixed. I am assuming the test is based on the old type of color bar pattern where the bars have space between them, and don't really know how to apply this with the signal I'm getting from my cable box. Actually tomorrow I will scan the instruction page from sams and post it here, so you can see what I mean. Perhaps buying or burning a test pattern DVD would be a better option?
Looking at the picture carefully again tonight, I think old_tv_nut has a point about purity.
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#42
02-11-2011, 08:07 PM
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The final step with setting bar #6 to max is equivalent to setting for correct hue with the hue control centered - you don't really need a scope or even that particular type of color bars - can do it by eye if you know what the colors should be.
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#43
02-11-2011, 10:30 PM
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Yep, exactly. First thing I would do is remove C135 and C136 and check them. 135 is going to be real critical as to the function of the tint control and it may just be a good idea to replace both of those. Good chance everything will fall in line.
Other option is to put the tint control it center and adjust A24 until the tint is right. You would be compensating for drifted components.
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#44
02-12-2011, 12:09 AM
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Fantastic... whittled a chopstick into a hex shape (need to order some alignment tools which fit!), A24 did the trick... tint control is in centre for same picture you see above. Thank you very much guys!
Next on the list is going to be getting the purity sorted out.
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#45
02-12-2011, 12:28 AM
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Make sure the degaussing is working. One easy way is to turn the green and blue screen down and the red up. Looks like you only need to move the two rings a tad to get red solid. Be careful because your going to trash the convergence. Dont go any further than moving the rings a tad without having a grid generator. MARK EVERYTHING!
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