Need help with a CTC-15 vertical problem!

[reeferman]

I know you said you checked the caps, but if it's pulling up from the bottom sub the 50 mike on pin 3 of the output.
It fixed a lot of them 50+ years ago.
But then again that was 50+ years ago.

[zeno]

If the pix has good lin & caps are fresh its usually one of the
high ohm resistors feeding the height control. You have to
lift one end to properly measure them.

73 Zeno
LFOD !

[Yamamaya42]

Originally Posted by reeferman

I know you said you checked the caps, but if it's pulling up from the bottom sub the 50 mike on pin 3 of the output.
It fixed a lot of them 50+ years ago.
But then again that was 50+ years ago.

And is part of the feedback loop mentioned above, the 50uf cap & 5.6k resistor on the cathode is tied to pin 2 of the socket of the convergence assembly, found out the hard way that weird stuff happens when not plugged in and loaded correctly!

[old_coot88]

Most common cause is the electrolytic coming off the cathode of the vert output. Plate load resistor of the vert oscillator often goes 'waay off spec (high) due to being hammered by high level spike.

[Turle]

Originally Posted by Yamamaya42

And is part of the feedback loop mentioned above, the 50uf cap & 5.6k resistor on the cathode is tied to pin 2 of the socket of the convergence assembly, found out the hard way that weird stuff happens when not plugged in and loaded correctly!

3FDB6951-A264-4CC1-9BC1-67A2A281A48D.jpeg

This is not a widescreen program. The linearity looks fine. There is just not enough deflection

[Yamamaya42]

Originally Posted by Turle

Attachment 206077

This is not a widescreen program. The linearity looks fine. There is just not enough deflection

read through this thread, and what he had to do to get full screen back :O
http://videokarma.org/showthread.php?t=271514&page=5

on MINE, a CTC-16xl i had to replace what is R105 & R106 on your CTC-15, the resistors on each side of the height pot, they were way off on mine.

[old_coot88]

You indicate all resistors check good. But double-check R104. It's a 2.2 meg half-watt, going to pin 8 of the 6GF7. It's the plate load resistor of the vert osc. https://www.earlytelevision.org/pdf/...ams_0673-2.pdf

[Turle]

Originally Posted by old_coot88

You indicate all resistors check good. But double-check R104. It's a 2.2 meg half-watt, going to pin 8 of the 6GF7. It's the plate load resistor of the vert osc. https://www.earlytelevision.org/pdf/...ams_0673-2.pdf

It’s measuring about 2.5, I figured it was close enough to being within tolerance that it wasn’t causing the issue

[old_coot88]

Originally Posted by Turle

It’s measuring about 2.5, I figured it was close enough to being within tolerance that it wasn’t causing the issue

Yep. Scratch that one off. A good thing to bookmark though. It's a frequent failure point in designs that run the vert osc from B Boost (not just RCA)