Which wires are the G1s

[TinCanAlley]

I'm doing the color purity, grayscale and convergence tomorrow and will be using a pattern generator. It comes with clips that pierce the wires for the color gun and allows you to short them out for setup/testing. This approach seems better than turning the G2 controls and messing up colors each time. The only issues is, I don't know which wires are the G1 (in another thread I was told they go on the G1s not the G2). I know the G2s are white w/red, green and blue stripes. That leaves two more sets on the socket. I'm attaching a pic and hope someone can point to the G1s. They're either the yellow w/r,g and b stripes, or the solid r,g and b.

Thanks, sure wouldn't want to damage something.

[Electronic M]

I always use a test pattern DVD with solid field patterns of each primary. That way I don't need to touch the screens or pierce the CRT socket leads. I've got test equipment which can pierce the leads for connection too, but have never used that part of it because I don't the potential arcing and shorting hazards that will be with the set after piercing the leads(I also don't like the idea of damaging the insulation of wires I plan to keep even if there is a purpose to it).

[TinCanAlley]

Originally Posted by Electronic M

I always use a test pattern DVD with solid field patterns of each primary. That way I don't need to touch the screens or pierce the CRT socket leads. I've got test equipment which can pierce the leads for connection too, but have never used that part of it because I don't the potential arcing and shorting hazards that will be with the set after piercing the leads(I also don't like the idea of damaging the insulation of wires I plan to keep even if there is a purpose to it).

Aren't you relying on the color decoder being accurate in order to use color patterns from a DVD? Wouldn't the red from the gun be more accurate than a signal decoded from a DVD hooked up through an RF modulator?

I know what you mean about not wanting the pierce the insulation. I really don't, but certain setup procedures required the cutting off of certain colors and that's after grayscale has been set. Using the screen controls would mess up the grayscale and would need to be done again. Seems like chasing my tail.

[Electronic M]

If the color decoder is not working there is not much point in doing a purity adjustment. I have used the pure primary test pattern method for purity for years and it has always worked fine. As long as you are getting a color on the screen that indicates your desired primary is much brighter than the others it will work for setting the purity. The tint does not need to be EXACT for this to work. As long as red is fairly red, green is fairly green, etc. it will work fine.

I have a 71' Zenith where you can unplug leads to kill individual guns. I've set it's purity with the primary color test pattern method then unplugged the guns to check my work, and it looked the same with the blue and green guns unplugged as it did with a red test pattern purity wise(there was a slight color shift in the red but not much).

[TinCanAlley]

Wish this set had a way to disable the guns other than the G2 controls. Without knowing which wires are the G1, I will have to go that route.

Thanks. I'll let you know how it goes.

[Don Lindsly]

The solid colors are the control grids.
The yellows are the cathodes.

[TinCanAlley]

Originally Posted by Don Lindsly

The solid colors are the control grids.
The yellows are the cathodes.

Thanks!

[old_tv_nut]

The color DVD will work fine - all you have to do is turn the color up high until only one gun is conducting.

[Username1]

Turning the color up high is not the way to do purity. Any noise will energize the other guns to want to fire, like color noise, bad idea.

You disable any signal, like setting the tuner between stations so the screen is white, no snow. turn color off. (The 2 drives set at mid-point if after doing gray scale once, you find the tube does not track well through brightness range using the untouched drive settings.) Then turn the screens down except for the one you are adjusting, adjust brightness control, turn contrast down all the way. Make your adjustment at a mid to lower brightness, then turn that one off, do the next color. When all purity is done, set the gray scale, then adjust the drives if needed as you check the gray scale as you change brightness.

This is the way I was taught in tv repair school, purity is done with no signal applied. Screen is white, no snow, tuner is between channels, brightness turned down to cutoff, and each gun turned down to cutoff, no retrace lines on any color should appear while making gray scale adjustments. The brightness range should have cutoff, but no retrace on full brightness.

[old_tv_nut]

Originally Posted by Username1

Turning the color up high is not the way to do purity. Any noise will energize the other guns to want to fire, like color noise, bad idea.

You disable any signal, like setting the tuner between stations so the screen is white, no snow. turn color off. (The 2 drives set at mid-point if after doing gray scale once, you find the tube does not track well through brightness range using the untouched drive settings.) Then turn the screens down except for the one you are adjusting, adjust brightness control, turn contrast down all the way. Make your adjustment at a mid to lower brightness, then turn that one off, do the next color. When all purity is done, set the gray scale, then adjust the drives if needed as you check the gray scale as you change brightness.

This is the way I was taught in tv repair school, purity is done with no signal applied. Screen is white, no snow, tuner is between channels, brightness turned down to cutoff, and each gun turned down to cutoff, no retrace lines on any color should appear while making gray scale adjustments. The brightness range should have cutoff, but no retrace on full brightness.

We were talking about using pure color field from a DVD - no snow.
Secondly, if you are viewing a pure color field signal, turning up the color causes two guns to go into cutoff, so even if there were some snow, it would only be visible in one gun. The other two would still be cutoff, and therefore the purity adjustment would work just fine.

The technique you describe is a method to use when you don't have a test signal.

[Username1]

The idea is that you don't use the tv circuits to generate a color, because if the source and circuits are not perfect, other colors are produced.

Besides, if the tv can be made to do this without a test signal, and its one of the few setups you can do without one, why would you want to it any other way.

Electronic M pointed out also if the color circuits are not working right using a test dvd will lead to incorrect colors, he is right too.

You guys can do it any way you want, as a tv tech years ago, no one used a test equipment signal to do purity, mostly because the next step is always setting up gray scale, and brightness range. You will be turning screen controls here anyway...

At any rate, good luck with your adjustments, you can do it any way you like and get comfortable with.....

[TinCanAlley]

I managed to set it by first disconnecting the IF lead, turning all controls down, setting the taps to HI and then starting with the red control. I turned it up 'til light raster and back it down 'til it just turned off. I did the same with the other two colors. When I was done I reconnected the IF lead and put on a b&w program. The grayscale was good (to my eye anyway) and all I did was move the taps to MED and all was good.

Seems there are different ways to get the end results. I know the SM approach was BS as I couldn't get it right by a think horizontal line on the screen.

[Username1]

The single line service switch is very stupid. There was a company that put one in with 3 positions on it. One position was a white full screen, that was helpful, but of course never caught on. Might have been GE, I don't remember.

Pulling the rca plug from the tuner to if strip is ok, I was not sure if you were aware of it. But you have to cut the color knob to zero also, just to be sure no color noise is getting through.

Well, setting the gray scale, is actually making sure the different shades of gray are actually gray. If as the darker gray colors may look a little more green, or red, whatever, those are adjustments made with 2 controls called "drive" but you set basic white screen by turning "screen" controls, there will be 3 of them. Rarely will you have to go back and turn the screens after doing the drives.

[Electronic M]

Originally Posted by Username1

The idea is that you don't use the tv circuits to generate a color, because if the source and circuits are not perfect, other colors are produced.

Besides, if the tv can be made to do this without a test signal, and its one of the few setups you can do without one, why would you want to it any other way.

Electronic M pointed out also if the color circuits are not working right using a test dvd will lead to incorrect colors, he is right too.

You guys can do it any way you want, as a tv tech years ago, no one used a test equipment signal to do purity, mostly because the next step is always setting up gray scale, and brightness range. You will be turning screen controls here anyway...

At any rate, good luck with your adjustments, you can do it any way you like and get comfortable with.....

Actually what I was trying to say is that the primary test pattern method is only useful on a set where all the video circuits and CRT bias controls are properly functioning and properly adjusted, but the purity is off. I tend to get kind of OCD when I set up CRT bias and tint, and some of my sets (especially ones without built in degauss) occasionally develop purity issues, so instead of disturb the CRT biases and spend a lot of time dialing them back in after the no pattern method I find I can nail the purity fast without making additional work by simply using a primary pattern and only adjusting the yoke and purity rings. I only use the no pattern method when the CRT biases clearly need adjustment as since in that case I need to adjust them anyway there is no advantage in leaving them set as they are.