1956 RCA CTC-5 is ALIVE!

[DavGoodlin]

6CB5's cathode current AND high voltage varies with brightness. Checking cathode current on 6BK4 (850 microamps) is part of the procedure. If you adjust the HV for 24 kV(?) and the current at 6BK4 falls below that value, the eff coil needs readjusted. Lots of interaction.I'll check my library of RCA stuff to see the exact procedure and email it.

Hopefully the eff slug was not adjusted with a metal allen key, which splits it, requiring very careful removal by hand, using a drill bit.

[bigaudioal]

Originally Posted by DavGoodlin

6CB5's cathode current AND high voltage varies with brightness. Checking cathode current on 6BK4 (850 microamps) is part of the procedure. If you adjust the HV for 24 kV(?) and the current at 6BK4 falls below that value, the eff coil needs readjusted. Lots of interaction.I'll check my library of RCA stuff to see the exact procedure and email it.

Hopefully the eff slug was not adjusted with a metal allen key, which splits it, requiring very careful removal by hand, using a drill bit.

Pretty sure that normal operation of the CTC-5 chassis was more like 19-22kV with the optimal reading being 20kV. This chassis is the one everyone complains about having lower HV.

[bigaudioal]

CTC-5 update. Well I think I got all the kinks ironed out. The beefier variac seems to be able to handle running the set indefinitely at 115V. No issues there. I adjusted the horizontal sweep coil, which is now running steady at 194 mA (instead of 230 mA).

I had a wonky horizontal for a bit and think it was due to rusty and dirty ground contacts on the horizontal board. Popped it out, cleaned them up and horizontal came back and has been rock solid ever since. I mounted the blue gun vertical amp/tilt control pots with some epoxy to the chassis. Seems to have worked well. I watched several hours of football on Saturday and Sunday without any issues. I placed a small muffin fan inside the cabinet aimed at the power transformer and two rectifier tubes. Boy, that really helps keep them WAY cooler while the set is operating.

Loving it!!! Below is a video link and some photos for your enjoyment. The photos seem to white-wash the picture a bit. Looks better in person.

I feel extremely lucky to have my first vintage color restore come out this well, especially on a CTC-5. Think the like-new, rebuilt in 1968, 21AXP22 has a lot to do with it. Supposedly it was never used after it was rebuilt.

https://www.youtube.com/watch?v=a4ZNEQDVRNM

[DavGoodlin]

Great job Al! I like how that tuner just pulls WJLA-TV right out of the air - Its tuned to ch 7, right?

I have to tune my RCA's to 3 and hook up some silly box

[bigaudioal]

Originally Posted by DavGoodlin

Great job Al! I like how that tuner just pulls WJLA-TV right out of the air - Its tuned to ch 7, right?

I have to tune my RCA's to 3 and hook up some silly box

Ha!! I wish it was that easy Dave. I have DirecTV hooked up to my agile modulator (which broadcasts out analog channel 7). I built a dipole antenna for channel 7 frequency for the modulator to transmit with.

[DavGoodlin]

Originally Posted by bigaudioal

Ha!! I wish it was that easy Dave. I have DirecTV hooked up to my agile modulator (which broadcasts out analog channel 7). I built a dipole antenna for channel 7 frequency for the modulator to transmit with.

I remember now, its in the same room ten feet away

I have mods for channel 5 and 7, not set up yet until I find a UHF BT-AM60 or such. About half my 52-64 sets have UHF.

And that "new" Color set of yours has it too!

[Stlouisian]

I also have a CTC-5 Arliss and was wondering the controls behind the pencil box have knobs on them besides the horizontal hold?

[Steve D.]

Originally Posted by Stlouisian

I also have a CTC-5 Arliss and was wondering the controls behind the pencil box have knobs on them besides the horizontal hold?

There are no knobs located behind the CTC-5 pencil box. However, no shortage of pots many dual function some within the customer controls.

-Steve D.