CTC5 Pickup!

[old_tv_nut]

I'd describe it as follows:

The CTC-5 does not have diodes to clamp the dynamic waveforms at the center like later sets, so in the CTC-5, points halfway between the center and edge stay motionless while the center moves the opposite of the edges. The trick is to rough in the DC in the center, then adjust the dynamics to get parallel R, G, and B lines, then fine tune the DC for best overall (and then maybe retweak the dynamic a tiny bit).

Hope your DC control pots are in good condition and not burned just at the proper setting point like mine were (both originals and replacements from a parts donor).

100 ohm carbon pot with tap at 25 ohms IIRC. Really pushing the limit on low total resistance for a carbon pot. I made up a substitution with 6 wirewound pots and three switches to pick a tap just above or just below or at the nominal tap point. If I was doing it again, I'd be tempted to try subbing a later cloverleaf with permanent magnet DC adjustments, but I don't know if the coils would be right for the dynamics.

[Davala]

Been a bit since I posted. The set worked great for one good 10-hour watch session. Then on the next power up I had no color. I assume the surgery I had to do on the 2nd band-pass transformer didn't hold up. You can see a few posts back the repair I did. I'll try another poke with my soldering iron at it....

As for replacements there are some bandpass transformers that look similar on ebay. How critical is it that this needs that exact RCA 102259? Seems like that is unobtanium. I asked Moyers already.

Does anyone have a scrapped chassis for the CTC-5 deluxe that they could pull a replacement from?

Thanks!
Matt Davala

[Electronic M]

ISTR David Goodling mentioning having a CTC-5 parts chassis. Might be worth talking to him.

Another thing to consider is the CTC-5 had a deluxe and a super chassis and one of them had an extra tube in the color circuit and thus a different color circuit....So that coil may or may not be different between the two different CTC-5 chassis sold.

[Davala]

I sent David Goodling a private message and got no response. Does anyone have his email address?

It seems I'm at a dead end with a burned bandpass amp transformer.

Thanks,
Matt Davala