Dove right in! Help with RCA 21-D-8628

Y'all. I don't beleive it. One new tube, and this happened.

[Kevin Kuehn]

Looks like the CRT has some life left in it. Is it possible you have the yoke rotated 90 degrees?

[Electronic M]

Good progress.

If it will pass a signal and you can feed it a test pattern then you can accurately assess what it still needs.

Originally Posted by Electronic M

Good progress.

If it will pass a signal and you can feed it a test pattern then you can accurately assess what it still needs.

How does one find a test pattern? I have an analog VHS player, so if there was a tape with a black and white pattern that would be great.

[Notimetolooz]

I don't want to be over critical but I don't thing your cap installation shown in post #72 will be reliable. You should have just left the old cap where it was for appearance and added the new caps under the chassis. The way it is now only a slight slip of the new capacitors will result in a short to the chassis. New electrolytic capacitors don't have to be located exactly where the old ones are.

Originally Posted by Notimetolooz

I don't want to be over critical but I don't thing your cap installation shown in post #72 will be reliable. You should have just left the old cap where it was for appearance and added the new caps under the chassis. The way it is now only a slight slip of the new capacitors will result in a short to the chassis. New electrolytic capacitors don't have to be located exactly where the old ones are.

I can relocate it, and I share your concern. I need to find some longer wiring, and relocate several resistors and a some of the video caps. It isn't really going to be easy to do this.

[old_tv_nut]

Originally Posted by BandDirector

How does one find a test pattern? I have an analog VHS player, so if there was a tape with a black and white pattern that would be great.

You don't need a test pattern to start, any video will help to note gross problems.

[Electronic M]

Originally Posted by BandDirector

How does one find a test pattern? I have an analog VHS player, so if there was a tape with a black and white pattern that would be great.

There are a number of ways to get a test pattern. If all you have is a VHS deck end credits often give evenly spaced horizontal lines that work for vertical adjustment and yoke rotation....a close up of a clock can be used for centering, linearity and setting proportional size of H and V sweeps to get a nice round circle.
If you also have a DVD player (especially one that can play a picture file off a USB stick) your horizons really open up. You can download test pattern DVD ISOs from the internet and burn them to disc. You can download jpeg images of patterns to a USB and play them (if your player supports that) or use a program to make a DVD out of them. Most DVD players lack RF output but do have composite video (yellow RCA or green if you set output to 480i and don't need color video) and audio output...plug that into the video and audio input of your VCR and tune the VCR to that input and the RF modulator in the VCR should pass the signal to your TV.

You could also use one of the many hardware based test pattern generators out there if you don't mind having another box in your life.

Sound is okay, fine tuning is at an extreme to get an image. Vertical sync/horiz sync is wonky.

See image

Also the bright line across the center won't go away

[Kevin Kuehn]

Scan lines are compressed on bottom and wide on top. The vertical linearity and size should adjust that, they interact to some degree. I'm pretty sure you have a sync and agc control on the back side of your chassis? I'd try adjusting the sync first and see if that allows your vert and horz to lock in better. If not, possibly the agc control needs to be advanced.

Still flickering

Need to adjust framing (or up/down split image)

[Kevin Kuehn]

Vertical linearity is still way off. So is the picture continuously rolling bottom to top? Appears locked in horizontally, but it's hard to tell from a still picture.

Originally Posted by Kevin Kuehn

Vertical linearity is still way off. So is the picture continuously rolling bottom to top? Appears locked in horizontally, but it's hard to tell from a still picture.

Here is a clip from just now

https://youtu.be/SLgqi98x-hk

See attached pics for controls

[Kevin Kuehn]

If that is still a VHS player you're using for a signal source it could very well be your problem. It almost appears like a video tape not tracking. And the sync pulses are dependent on the head speed. Does the vertical hold control on top the TV have any influence on moving that black bar near the center screen up or down? I would suggest trying a DVD player though an rf modulator. You could probably even run the DVD player into an auxiliary input on the VHF player and still use it's rf output.

This is a combo device, playing a DVD