My Brand New CTC-7!

[Phil Nelson]

Wiring two caps in parallel adds their values. Wiring them in series decreases the capacitance value. Combinations also affect the voltage rating. The details are explained in the following article:

http://antiqueradio.org/recap.htm

Scroll down to "Substituting for Unavailable Values."

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[Tim]

Caps in parallel add and have a voltage rating of the lowest voltage rated cap.

Caps in series cuts the value in half if the two caps are the same value. The voltage doubles if the caps are rated for the same voltage. Just to finish the thought, some recommend putting equalizing resistors across the series connected caps. This is not applicable to your current situation.

[SwizzyMan]

OK got the board recapped... I am extremely nervous to whether I broke any traces or made good solder joints. The damn wax everywhere made it very difficult to do things.

[SwizzyMan]

Got it back in... Horizontal is only a bit better and vertical isn't any different. And the picture signal still isn't great there is a lot of snow mixed in with the show being broadcasted and it is pretty hard to make out what is being shown in the show. Sound is crystal clear though.

[Phil Nelson]

Originally Posted by SwizzyMan

there is a lot of snow

Are you broadcasting a signal with your B-T modulator, or connecting your video source directly to the TV? You might want to connect directly, to simplify the equation while trying to obtain normal picture quality.

Did you ever clean the tube pins and sockets in the RF and IF sections? Have you tested those tubes recently? It's not unheard of for a tube to fail, even though it initially tested good.

Have you cleaned the tuner? (By cleaning, I don't mean spraying a gallon of WD-40 inside and working the channels a couple of times, which can soak phenolic parts and do more harm than good. I mean opening the tuner and cleaning the contacts with a Q-tip and DeOxit.)


Phil Nelson

[SwizzyMan]

Did Clean the tube sockets and tubes but not the tuner itself. Hooked the input directly to the RF out on the BT modulator and the picture is crystal clear.

[SwizzyMan]

OK I think I am ready to start the picture quality adjustments... What should I do first?

[tvcollector]

Sounds like there is problems with the BT Modulator.. It's very common to find them defective on eBay.. The very first one I bought had issues like that.. Even when connected directly I could not get a picture without slight noise.. I could not fix it, even after recapping and replacing the transistors in the power supply.. I would suggest not using the BT modulator all together unless you know it's working properly... Coax output of a Cable Box, DTV converter box, or DVD player is going to show you the real results...

[SwizzyMan]

Went ahead and tried some preliminary convergence I think I did OK the lines in the middle look pretty good.

[Phil Nelson]

Originally Posted by SwizzyMan

Hooked the input directly to the RF out on the BT modulator and the picture is crystal clear.

That answers your question about snowy picture. Quit using the modulator to broadcast and stick with a direct connection until your TV works normally.

As to which picture quality adjustment to do first . . . don't waste time on any of the color adjustments until you have a flawless black and white picture. No horizontal or vertical jitters or bending, no problems with vertical and horizontal linearity, and so on. Going back to mess with those things after you have spent hours on color adjustments may force you to do the color adjustments all over again.

The multi-step procedure for color adjustments is described in pages 28-38 of the RCA factory service manual:

http://antiqueradio.org/art/RCACTC-7...toryManual.pdf

You begin with purity. After that, you set the grayscale using the screen and background controls (the manual calls this "kinescope color temperature adjustment"), and so on. Do these procedures in the order laid out in the manual, and if you can't get the right result at any point, stop and find out why.

BEFORE doing all of that, you might want to look very carefully at your picture to judge whether those procedures are needed. It's quite difficult to get perfect convergence around the far edges (top, bottom, sides) of a roundie color picture. If yours already looks good, you might want to let sleeping dogs lie. Look for color fringing in the edge zones -- that's a sign of less than perfect convergence. If your TV looks nice and watchable already, maybe it doesn't need twiddling.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[SwizzyMan]

I would probably be satisfied with it now but I can't be sure since the color oscillator is running at the wrong frequency so I cant get any color.

[SwizzyMan]

OK got the grayscale adjusted to the best I could do. Now how do I get my color?

[SwizzyMan]

OK read up on the color issue. I guess I have to adjust a coil? How can I do that without the proper tools?

[miniman82]

Follow what the manual says, usually it goes something like this:

Ground the reactance tube grid with a color image on screen, and adjust the local oscillator coil till a rainbow pattern just floats by. Remove the ground from the grid, and color should snap right in. Of course this assumes there aren't other problems with the set, such as the tuner being off frequency which will throw off the chroma response so far that the set doesn't even see it (even though a normal B&W image appears, this is no indicator that the tuner/alignment is anywhere close to correct).

[SwizzyMan]

What kind of tool should I use adjust the coil? A type of screwdriver?