CTC-4 Director 21

[SwizzyMan]

I replaced the CRT with a 21FB that is a bit stronger. It displays a beautiful picture with all colors strong except for red which is weak. This has do to a problem with the circuitry driving the red cathode. I have been tracing back through the circuit and have been finding resistors that have gone off. I think I will tackle this problem before I continue on the color sync issue.

[SwizzyMan]

Im starting to really think the replacement crystal may be bad since it does have a big dent in the side of it (Must have occurred during shipping) and I cant seem to get the color to lock no matter what I do. With the last crystal I could get the color to lock I believe. I will swap the crystal once I can find one. Work has been slow this whole year and I admit I have been lazy with the restoration of this set and have not worked on it as much as I should have. Summer is coming up soon so I hope to have the set finished by August. Slowly but surely this set is shaping up!

[Phil Nelson]

Sounds like you're nearing the finish line!

If you have a signal generator and scope, you can do a bench test of the crystal. In my CTC-4 article, scroll to the section titled, "Bench Testing the 3.58-MHz Crystals":

http://antiqueradio.org/RCACTC-4ColorTelevision.htm

Thanks to dtvmcdonald for that tip.

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

[SwizzyMan]

From what I am gathering, I think the crystal may be bad. I have it setup to be bench tested. I'm not seeing a real big change in amplitude when I get around 3.58. First picture is at 3.58 and second is way down around 1mhz. This is what I believe the change should look like https://antiqueradio.org/art/RCACTC-...lAnimation.gif

[SwizzyMan]

Any thoughts? I believe the crystal is bad, but I'd like some advice before I go out and buy one.