RCA CTC4 color alignment needed

[rcafan]

Can someone scan the ctc4 color alignment portion of the RCA
Service data. SAMs folders have miminal info.
thanks

[Electronic M]

I'd like a copy too as I may have to do some adjustments on my CTC4's color circuits once I get a couple of other bugs fixed.

[miniman82]

The procedure doesn't make sense to me, it tells you to read the CRT grids while observing rejection of signals from the other colors. Adjust for minimum blue in the red and green kine grids, ect. As I said before, it's best to just use color bars and tweak the CW trans for best picture with the tint centered.

[rcafan]

Nick
Easy to say, hard to do after the crystal has been changed. One can
get a rough adjustment, There are too many many coils to properly
adjust after cap and crystal change.-----This is what I found.

[miniman82]

What's hard about it? First make sure you are tuned in, if in doubt inject composite into the video amp tube to eliminate the tuner/IF as a fault. Then zero beat the 3.58 osc: short the reactance tube grid to ground, then adjust the osc slug till the bars slowly float by. Remove the short and tweak the CW trans (top and bottom) till the bars look correct. Helps having a reference monitor to look at while doing this, so you don't get confused. It doesn't get any simpler than that, or at least I haven't found a better way.

[Penthode]

I think we are confusing adjustments here. The adjustment for demodulator quadrature phasing is done by first shorting the green and blue control grids to ground through 100K resistors. You must use a gated rainbow generator to make the adjustment. Adjust L125 until the sixth bar in the gated rainbow to matches the background. Then after removing the blue grid resistor and then grounding the red control grid through it, adjust T115 until the third and ninth bars blend with the background. I have done these adjustments and it works: it is to ensure the quadrature demodulator is accurately aligned.

The AFC adjustment does indeed suggest grounding the reactance tube grid and adjusting for zero beat. This is only to set the 3.58 MHz oscillator to precisely lock.

However, that leaves the chroma bandpass amp: that is to be sweep aligned. Is that what you require?

[miniman82]

Originally Posted by Penthode

You must use a gated rainbow generator to make the adjustment.

That's why it's a lot easier to just tweak both sections of the CW transformer at the same time till the bars look right, not everyone will have the correct equipment to do it like Sams asks you to.

[rcafan]

Penthode, That is the info I am looking for.
appreciated, Thank you