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-   -   CTC-9 Winslow (http://www.videokarma.org/showthread.php?t=276970)

Zsuttle 11-18-2024 04:00 PM

Hopefully this should work better
https://flic.kr/ps/45md7a

old_tv_nut 11-18-2024 05:54 PM

That's messed up allright!
Do you get a good black and white image with the color turned down?
Have you checked the demodulator and color amp tubes?

old_tv_nut 11-18-2024 05:56 PM

If you swap the two 6CG7's or 12AZ7's, do you get a different result?

Zsuttle 11-19-2024 10:17 AM

Black and white is getting through, all tubes were tested when I started working on it. I swapped the two 6CG7s, no difference. There's only one 12AZ7 in the set, and I don't have a spare

Here's some photos of what I'm seeing:
BW Colorbars https://flic.kr/p/2qv4NNR
"Perfect(tly lazy)" Convergence https://flic.kr/p/2qv4NPs

old_tv_nut 11-19-2024 11:30 AM

Quote:

Originally Posted by Zsuttle (Post 3261067)
...There's only one 12AZ7 in the set, and I don't have a spare...

oops sorry - misread the schematic

old_tv_nut 11-19-2024 11:36 AM

Have to think more about the problem with the colors.

The multiple edges on the bars and multiple vertical lines on the convergence pattern look like some sort of delay line problem. Not necessarily the line itself but maybe an open component on the output termination. L16 maybe? Short it temporarily to see if it improves.

Edit: I'm looking at the SAMS, so, L16 in the SAMS.

old_tv_nut 11-19-2024 11:51 AM

I guess I would poke around the network that sets the phase difference between the X and Z demods.
SAMS L29, C118, C 119, R168, C5

Zsuttle 11-19-2024 12:09 PM

I may need to realign parts of the chroma section. On a hunch I decided to peak the phase detector transformer by sight and was able to get the colors correct. I didn't do the whole AFC alignment originally, just the first part. Definitely will be doing the whole thing. May as well align the whole set while I'm at it. Had to readjust the tuner as the fine tuning control was maxing out. It really is starting to feel like someone has been in here messing with things.

Of interest, the RCA manual has a lot simpler ways for doing adjustments. The SAMS requires a lot more equipment to do some of the same adjustments. EG, with the demodulator adjustments, RCA has you do it by sight on the picture tube, SAMS has it done on an oscilloscope. Not sure if there's much of a difference.

Shorted L16, no luck. 1800ohm is reading 780ohm, I'll pull it and take a look at the actual resistance. In theory, the center areas of the convergence should be converged right? Just the edges are adjusted through the convergence board?

old_tv_nut 11-19-2024 04:50 PM

It appears DC-wise that the 1800 ohm is in parallel with a 1500 ohm resistor on the delay line input, so the 750 ohm in circuit reading may be normal, but it won't hurt to check. But also ckeck that the coil in series with the delay line input (9 ohms) isn't open.

In theory, the convergence controls should affect only the edges, correct. I think the three diodes in the convergence circuit are meant to provide the stable center. So it may be worth checking them. But note that the instructions say that center touch up may be necessary after adjusting the edges.

Just for comparison, the CTC-5 did not have diodes, and adjusting the dynamic convergence moved the edges one way and the center in the opposite direction. The null points were somewhere between the center and the edges - so adjusting the dynamics always required readjusting the DC (center).

old_tv_nut 11-19-2024 04:56 PM

Glad you got the colors correct. I tried to figure out what the phase offset was from the colors, but it seemed that there had to be a different offset in each demod. Glad it was a simple overall offset after all.

Yamamaya42 11-19-2024 07:05 PM

ehh? that weird Convergence pattern is being caused:scratch2: by the color section?

Yamamaya42 11-19-2024 07:48 PM

That convergence picture just does not make much sense, it's like the static convergence is way WAY off or the convergence yoke is off center mark, or there is a horizontal signal missing to the static convergence sections REF pins 6,7,8 on the convergence yoke plug, which can be checked with an o-scope ( SAMS ) , if wrong or missing, could cause really weird stuff,

Zsuttle 11-19-2024 07:51 PM

I'm wondering if that convergence pattern may be some sort of artifact off of my generator. My BK 1249 doesn't do that, but the tek pattern generator seems to have multiple of the vertical lines. Either way, I'm adjusting with the BK from now on, and everything looks normal.

Either way, convergence is better, I still need to finish up everything and figure out why I can't seem to get it to converge correctly. I'll have to check the diodes, the center is definately moving. I'm hoping I just suck at convergence. It wasn't bad to do the convergence on my CTC-16, hoping it may be something simple. I will admit, the Delta gun setup makes me miss doing convergence on arcade monitors. (Something I never thought I would say)

A few other things, how warm should the flyback get? I was clocking like 150F with my thermal camera. I know these aren't prone to eat flybacks, but I'm super paranoid after my CTC-16 decided to munch on one( even while religiously monitoring my HOT current.) I'm debating on putting a fan to circulate air. I'm running on a variac at 115v.

My cathode current is currently sitting at 192mA after adjusting the horizontal linearity coil to the limit. HV maxes out at 24KV, I'm running it close to 21KV. Not sure if I should bump it up. The sine wave coil didn't appear to adjust the amplitude of the waveforms at all, it definitely changed the frequency, but waveform wise the peaks stayed relatively the same

Here's a video of it playing Charlie Brown. At least the colors are 95% of the way there
https://flic.kr/p/2qveVZZ

Zsuttle 11-19-2024 11:36 PM

A few other things, I pulled the selenium rectifier to check it, all three diodes checked out. I replaced them with 4007s instead of putting the selenium back. Vertical convergence isn't bad, but for some reason the horizontal bars are WAY too thick. It's gotta be a generator thing. (I'm still seeing evidence of a ghost red image 1/8" to the right of all red images) The vertical bars are thinner than a pencil body, but the horizontal bars are as thick as a sharpie. I've had to redo the center convergence like 3 or 4 times as I do the rest of the convergence. The horizontal will not converge because the thickness of the lines is different. Red is the thickest, blue green are about equal

I've noticed a focus issue, where it's running out of range before it focuses completely. I popped open the HV cage and the 66Meg resistor stack was measuring 98Meg. I put in one of the bumblebee 66Meg resistors to hopefully solve that issue.

Still debating on a fan or not. Definately some fresh wax after running it for an hour

Electronic M 11-20-2024 03:28 AM

Flyback temperature shouldn't be that hot. Warm to the touch is what you want. Why are you running the HV that low? Most roundys usually specify 25KV. The lower you set the HV the more HV current, loading and heating the HV regulator causes in the flyback.

An additional thing you can do once you have all horizontal adjustments optimizedand bad components identified and replaced is swap the HV rectifier and or focus rectifier tubes for solid state substitutes...The SS parts don't have heaters and reduce the flyback loading a few watts which can be helpful in cases like this.


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