RCA CTC-36 Woes

[Kamakiri]

So....back on the CTC-36.....the good one

Did some work on it, and replaced 4 caps in the vertical. One, much to my surprise, had a loose solder joint.

The set looks great, but I'm having one problem that I just can't shake. I just can't get the red horizontal convergence correct....it's off to the right on the crosshatch. I won't say that it's off linearly, but close. Vertical is right on. No matter what I do, I can't bring the red back to the left about 1/2". What the heck could be causing this?

[DaveWM]

can you post a pic of the convergence problem? with the cross hatch.

[Kamakiri]

Wasn't able to get a good one last night, but I did this morning. Also, as you can tell, it needs degaussing, but all I manage to do with my degaussing coil is make it worse.....

Picture is pretty watchable, but as you know, the crosshatch brings the issues to the forefront.

[DaveWM]

thats mostly a center converge problem. double check the posistion of the convergence cluster, should be able to correct with the RG magnets that are attached to small rotating knobs on that set. the RG are the ones on the sides of the cluster approx 4 and 8 o'clock. once you get the center convergence done the rest will be a LOT easier.

[DaveWM]

do you have the setup procedure for that set?

always start with the degauss then purity, then static, then dynamic with static touch up after each dynamic.

[Kamakiri]

Originally Posted by DaveWM

thats mostly a center converge problem. double check the posistion of the convergence cluster, should be able to correct with the RG magnets that are attached to small rotating knobs on that set. the RG are the ones on the sides of the cluster approx 4 and 8 o'clock. once you get the center convergence done the rest will be a LOT easier.

That's kind of what I was aiming for.

Unfortunately, I don't have a center dot setup, I only have crosshatch, white screen, gray scale, and color bars (using a test pattern DVD transmitting via agile modulator). One thing I should note, the purity rings on the tube have a light coat of rust on them, and to be frank, I'm not exactly sure *how* they work to begin with.

I tried rotating them on the crosshatch screen to try to affect something, but if I'm understanding this correctly, I need to do that on a white screen first.

[DavGoodlin]

Tim, This is a great lesson here. I'm anxious to see how well this turns out, and it will too.

You get this right and you can converge any round-tube color set even better!

[andy]

...

[Kamakiri]

I took a minute, and did a purity setup on a white screen. Took me about 10 minutes, it's as close to perfect as I can get it, which I'm satisfied with.

The convergence assembly does have a pivot on it, and a stationary point. I'm not sure how it would affect anything, but I tried to move it, and I was right....it doesn't affect anything

[DaveWM]

so if you turn all the screen drives down and turn only the red up, you get a uniform red screen? if so then purity is good to go, next is the static magnets, the 3 around the convergence board at 8/12/4 o clock.. use those and see if you can get the center of the screen cross hatch good. Note the blue lateral will have to be used as well to move the blue from side to side the top blue magnet is up and down, the 4 and 8 move the R and G diagonally. Do the RG 1st then move the blue to match them.

[Kamakiri]

I'll be back on this set in a couple days. Just knocked out a '52 Admiral resto, and want to give it some playing time before I button it up.

[Kamakiri]

Now have a new tool at my disposal! Gonna resume this week, and hopefully, get it right

[Electronic M]

Couple of years back I found one of those for 2$ at a thrift that had been WELL used. It has been my go to crosshatch generator since. Tip:If it is not working or goes funky pull and reseat each socketed IC....This goes for most heath gear of this era.

Also before doing convergence play with the channel tuning of the generator and brightness/contrast controls of the set for thinnest least blury cross hatch lines. Also the three clip leads for CRT grids/cathodes to allow those switches to turn off guns are a waste of time in most sets IMO.

[sampson159]

i have 2 of these units

[Dave A]

I've been looking at my RCA 19" portable CTC-36 and found this old thread. I'm adding on to this one to keep all the past notes in one place. And great notes they are. My dad bought the set in 1969 as an extra set for his early Super Bowl parties (Madmen in Rockford, IL). I have powered it every few years or so and it still powers with a full raster and a working but tired picture (with color), but not a tired CRT. The 19HNP22 tests like new on my REM tester. The Beltron did not like it but I think the Beltron has issues. The first problem is the service switch. It has rotted out in pieces thus no pix of the set operating for now. I do have a NOS but I think it is for another model with slightly different pin bending on the bottom. It should fit. A sample testing of tubes was an exercise in just order a whole new tube lineup. My plan is to retube first and see where I am as I have everything else needed for a picture. Now I need to figure out how to get the chassis out unless I decide to jumper the service switch so as to not disturb the rest. Any thoughts on that path?. Does anyone have a CTC36 .pdf they can spare? It's a summer project so don't expect overnight news on this one. This one is for dad.