RCA CTC-36 Woes

[Kamakiri]

Originally Posted by bgadow

I'd forgotten about that trait-I have a pile of CTC-53's but only one inside and cleaned up. It holds my record, by a quite a bit, for longest warmup. I think I timed it at over 60 seconds to get a raster. I do find the picture they make to a have a pleasant quality. Biggest problem with my "good one" is something heat sensitive in the vert circuit that causes a lot of drift until it's good and warmed up. I've replaced the tubes and caps, not sure if I started replacing resistors or not. That set hasn't been turned on in probably 3 years

Happen to have any parts sets? I could use a brightness pot for mine....someone at some point installed a pot with a different shaft, probably replacing one that was defective.

[Kamakiri]

Originally Posted by DaveWM

Dont forget to check that diode. I dont know what make it is but to be safe you should heat sink it before removal (you maybe able to check in circuit, did not look too close to know for sure).

I will, definitely. I think to go further, I'll need a SAMS on the set. Going to have to order one online.

[dieseljeep]

Originally Posted by bgadow

I'd forgotten about that trait-I have a pile of CTC-53's but only one inside and cleaned up. It holds my record, by a quite a bit, for longest warmup. I think I timed it at over 60 seconds to get a raster. I do find the picture they make to a have a pleasant quality. Biggest problem with my "good one" is something heat sensitive in the vert circuit that causes a lot of drift until it's good and warmed up. I've replaced the tubes and caps, not sure if I started replacing resistors or not. That set hasn't been turned on in probably 3 years

I found resistors on the vertical board that changed value really bad.
My CTC51K wouldn't stop rolling and the size and linearity wouldn't adjust properly. Even when I replaced the 13GF7 and the 50MFD 'lytic.
My set is a real cheapie. It never came equipped with a degaussing coil.

[Kamakiri]

As long as we're discussing this chassis, what the heck is this lever thing? Is this how horizontal centering is accomplished, or is it something else? I haven't touched it, but it seems like it would rotate in the opposite direction if it was....

[DaveWM]

prob loosen the yoke

[dieseljeep]

Originally Posted by DaveWM

prob loosen the yoke

It's a long screw for the yoke clamp. Actually for the whole yoke and convergence assembly.

[Kamakiri]

Makes sense, thanks. I was hoping deep down that it *was* some type of horizontal centering adjustment, as I can't get the set to fill out about an inch on the right side of the screen.

Linearity was a little out of whack, but it pulled in fine with a little tweaking.....sounds like I may be looking at new resistors there as well, but damned if I can figure out how to adjust the horizontal centering.

[lnx64]

Yea my TV has the same yoke clamp.

http://img.photobucket.com/albums/v3...n/tvboard3.jpg

[dieseljeep]

Originally Posted by Kamakiri

Makes sense, thanks. I was hoping deep down that it *was* some type of horizontal centering adjustment, as I can't get the set to fill out about an inch on the right side of the screen.

Linearity was a little out of whack, but it pulled in fine with a little tweaking.....sounds like I may be looking at new resistors there as well, but damned if I can figure out how to adjust the horizontal centering.

It's been ages, since I did TV repair on a regular basis. Trying to remember if there is a horizontal centering option on that chassis.
Are you sure the damper tube and horizontal output tube is perfect? When you see an image on the screen, such as text, does it seem centered?
If so, your problem is insuffient sweep. Is your B+ Around 255 volts?
BTW, is that the CTC53 or the CTC36, as you seem to be working on two sets.

[andy]

...

[DaveWM]

I seem to recall reading somewhere that defects in the dual diodes in the horz AFC circuit can sometimes cause odd shifts in the horz centering.

[bgadow]

You need Sams 1342-2. I'm sure somebody on here could set you up with a copy (I have one but not a spare, and I'm trying to keep one full set). The part number for that brightness pot is 126307. It has to come from the CTC53XM chassis; I'll have to check what I have.

[lnx64]

I think my local library has some SAMS there. I could perhaps see if I can photo copy the book if it's not too many pages.

[Kamakiri]

Originally Posted by dieseljeep

It's been ages, since I did TV repair on a regular basis. Trying to remember if there is a horizontal centering option on that chassis.
Are you sure the damper tube and horizontal output tube is perfect? When you see an image on the screen, such as text, does it seem centered?
If so, your problem is insuffient sweep. Is your B+ Around 255 volts?
BTW, is that the CTC53 or the CTC36, as you seem to be working on two sets.

This is the CTC53. I'm sorry, I really should have broken this into two threads. The sets seemed so close in appearance I had no idea until I got the back off that these were two significantly different animals.

Everything seems centered, but it's so damned close to the edge right now I can't tell if it's a sweep issue or a centering issue. I didn't check B+, because I figured there *had* to be a simple adjustment for this. Ain't seeming like it . And my tester won't do these particular tubes....again, figuring it was an adjustment.

Pretty sure that something somewhere has drifted in value, because after a couple hours of play, it seems to have just about centered itself somehow. I'm not going to ask HOW, but now there's maybe 5/16" of blank real estate on the right side, and that I can live with for now.

I decided that I'm going to go ahead and replace the resistors on the board of the CTC36, I just have to determine the rating of them. Since I don't have the sams for it, I may wait until I get one, I'll probably order over the weekend. I would assume that 1 watt would do, but I don't want to get any surprises down the road.

[old_coot88]

Originally Posted by DaveWM

I seem to recall reading somewhere that defects in the dual diodes in the horz AFC circuit can sometimes cause odd shifts in the horz centering.

It can also cause very weak H sync.