View Full Version : RCA CTC-5 Westcott help


Radiotronman
08-08-2017, 02:33 PM
A month ago I got this RCA CTC-5 Westcott and recapped it. I get great sound and video, but even after making convergeance adjustments, I cannot get very good overall color. Adjusting the color killer, color and hue controls does almost nothing. When I degauss it with a degaussing coil, I see all kinds of bright colors as I move it around the screen. What is going on here?

Radiotronman
08-08-2017, 02:35 PM
Here is the picture of the set!

SwizzyMan
08-08-2017, 02:52 PM
Looks like a problem with the flesh tones. Does it only really occur on people?

Electronic M
08-08-2017, 03:23 PM
What does it look like with SMPTE bars and the color control set to produce fairly mild (low saturation) colors?

zeno
08-08-2017, 04:52 PM
Center convergence is way off.
Do this to rough it in.
Dark room, color all the way DOWN. Brite & contrast about 2/3.
Dot pattern, Adjust the 3 conv magnets & 1 blue lateral ( not the rings)
to bring the dots together in the center ONLY.
The edges will fall into place much better then.
After you do this a few times & it "clicks" you wont need a generator,
you can do it by eye quicker.

The set probably needs a by the book set-up but this will get you
to the point to trouble shoot any other problems.

73 Zeno:smoke:
LFOD !

old_tv_nut
08-08-2017, 05:33 PM
As Zeno said, the convergence is way off in the pic you posted. But, you said you adjusted it, so do you have a pic after adjustment?

old_tv_nut
08-08-2017, 05:36 PM
Another note, something I found the hard way on my CTC-5. If you degauss it after adjusting the edge magnets, you will louse it up. You MUST follow the procedure from the beginning: retract the edge magnets fully, then degauss, then adjust yoke position and purity rings on the neck, then adjust edge magnets.

Radiotronman
08-09-2017, 09:25 AM
I read in the service manual about adjusting the edge magnets. I turn them and they just spin. How do you back them out like the manual says?

old_tv_nut
08-09-2017, 11:32 AM
The edge magnets are mounted on a screw thread, so if you keep turning counterclockwise, they will eventually retract fully and hit a stop.

jr_tech
08-09-2017, 12:18 PM
IIRC, the threads are seated against a spring... you can pull back the magnet by pulling out on the "knob". Likewise, you can push the magnets in to approximately the correct position and then turn the "knob" for fine adjustments.
At least that's the way it is on a CTC 4, I never had a 5.

jr

Radiotronman
08-09-2017, 12:19 PM
This is a picture of the crosshatch pattern coming from my BK1077.

Radiotronman
08-09-2017, 12:35 PM
This is also as good as I can get the color bars to come in.

Radiotronman
08-09-2017, 12:40 PM
If I turn the color control on and all the way up, I start to see more blues and greens, but still looks terrible.

oldtvman
08-09-2017, 12:57 PM
Color sets back then involved a two step process, first you set the parameters of a B & W picture and then you add color. Purity adjustment would be the first step to getting proper registration and then set the convergence. Your photo looks like ac running thru the picture which means you probably have leaking filter capacitors coming of the rectifiers.

old_tv_nut
08-09-2017, 01:13 PM
IIRC, the threads are seated against a spring... you can pull back the magnet by pulling out on the "knob". Likewise, you can push the magnets in to approximately the correct position and then turn the "knob" for fine adjustments.
At least that's the way it is on a CTC 4, I never had a 5.

jr

I don't think there are springs on the CTC-5, at least not that I noticed. Also, only a screwdriver slot - no knob to pull.

old_tv_nut
08-09-2017, 01:17 PM
If I turn the color control on and all the way up, I start to see more blues and greens, but still looks terrible.

This COULD be as simple as a fine tuning problem. I would do a quick check of what the picture looks like with a DVD or VCR, and if I could get it fine tuned right, go back to the color bar generator and make sure the channel frequency and fine tuning are right there.

jr_tech
08-09-2017, 01:25 PM
I don't think there are springs on the CTC-5, at least not that I noticed. Also, only a screwdriver slot - no knob to pull.

Too bad! must be tough getting to the ones at the bottom of the jug. :scratch2:

jr

Electronic M
08-09-2017, 01:54 PM
That is some poor convergence for having been adjusted. It also looks like your greyscale (balance of gun settings) is off, not to mention the purity.

With purity and convergence that far off color will not look good even if the circuits are working right.
Turn the color off, get purity perfect, try to improve convergence significantly (you may need to check the convergence circuits and convergence yoke position if that is the best it will do), set the greyscale so the blacks are black and the whites are white, get the brightness and contrast set for good monochrome pic then and only then turn up the color and try to get that right.

When the CRT setup is that poor turning on the color circuits is little more than a check of life in those circuits, since the CRT setup problems will bury the noticability most other issues....

old_tv_nut
08-09-2017, 03:34 PM
Too bad! must be tough getting to the ones at the bottom of the jug. :scratch2:

jr

You access them from the front after removing the trim frame, and all are equally accessible.

zeno
08-09-2017, 04:54 PM
As a few have said........
You need a good B&W picture before you can have a good color pix.
Turn the color level ALL the way down for now.

Your first mission is to make this as good a B&W set as possible !
I see retrace lines so start with a grey scale adj. When done you should
be able to turn down the brite & loose the pix. Also check the KINE bias
control. Remember this set never was bright & never will be. Its was
normal to watch them in a dimly lit room !

Next do purity. Try to make that perfect.

Now convergence. Follow the manual ! Remember this involves going back & forth center-edges as you go. It will NEVER be 100% perfect BTW.
The bottom is so far off that there may be a problem there. Some of the
adjustments are coils ( usually 3 ) be VERY gentile with them. They are old
& dried up ( like me:sigh: ! ).

After that put a picture on it & see how it looks. If its decent now you can
turn the color up & see how she looks.

good luck
73 Zeno:smoke:
LFOD !

Radiotronman
08-09-2017, 06:20 PM
Ok, thanks for the help. The color and hue controls seem to do absolutely nothing. Turning them off doesnt affect it much.

matt.caputo
08-09-2017, 06:25 PM
Just went through this with my Packard Bell that uses an RCA CTC-5 chassis. Send me a PM with an email address and I can forward you some photos. I just havent figured out how to attach them as a reply in this forum yet from my phone. These sets will show a fairly decent picture if set up properly.

old_tv_nut
08-09-2017, 07:15 PM
Another hint about the dynamic convergence on this chassis: it is AC coupled. This means that the center (DC) convergence moves when the dynamic is adjusted. One way to approach this (with a cross hatch pattern) is to first set the center DC, then adjust the dynamic controls to get parallel lines, then re-adjust the DC, which should superpose the parallel lines, at least approximately. Then you can do some fine dynamic touch up if you want, but don't get obsessive, because it will never be perfect everywhere. You can spend hours chasing slight misconvergence from one corner of the screen to another.

miniman82
08-09-2017, 09:46 PM
Only real solution to this problem, and it's a pretty bad problem, is for someone to sit down and figure out exactly how to add the diode pack the later chassis had. They keep things from moving around too much on dynamic convergence setups, vastly reducing the year out your hair factor.

oldtvman
08-31-2017, 05:39 PM
If you have an oscilloscope checking the dc power supply for any ac would be the first thing and then checked all the B+feeds from the power supply. Sometimes the problem is starring you right in the eye.