My CTC-16XL Project.

[Yamamaya42]

I may be overthinking this, but to me , this sawtooth wave here (at C1a) just does not seem right, but the SAMS does not have a reference for a wave at that exact point, I have replaced C1a with an much larger cap and am still seeing it, its mostly filtered out by L45, but I don't think it should be there at all, its still present at the end of the 400v source ( very faint )

I'm running the set with HV disabled ( yolk disconnected ) when this wave was captured.
I have not replaced the LV rects yet ( they are hard to get to ) but I plan to, as I suspect them to be a problem. ( unless someone thinks that sawtooth I'm seeing is normal ) as mentioned, I chose 1N4005G for that as they looked rather close to what was in there..

https://imgur.com/a/U5mvTBT
https://imgur.com/a/6vEuABP

[maxhifi]

Originally Posted by Yamamaya42

I may be overthinking this, but to me , this sawtooth wave here (at C1a) just does not seem right, but the SAMS does not have a reference for a wave at that exact point, I have replaced C1a with an much larger cap and am still seeing it, its mostly filtered out by L45, but I don't think it should be there at all, its still present at the end of the 400v source ( very faint )

I'm running the set with HV disabled ( yolk disconnected ) when this wave was captured.
I have not replaced the LV rects yet ( they are hard to get to ) but I plan to, as I suspect them to be a problem. ( unless someone thinks that sawtooth I'm seeing is normal ) as mentioned, I chose 1N4005G for that as they looked rather close to what was in there..

https://imgur.com/a/U5mvTBT
https://imgur.com/a/6vEuABP

If you're getting a sawtooth waveform at first filter capacitor, don't be too surprised. These sets use a voltage doubler power supply, and it's going to have lots of ripple at the first filter. In other words, I'd kind of expect a sawtooth there.

Where did you get C1A from? What cap is it on the RCA schematic? Is that a sams or an RCA part number?

https://www.boxcarcabin.com/rcaschematics.html has most of the early rca schematics.

I sold my CTC16 some time ago, but it was a cool TV. Make sure to check for bad soldering of power resistors, and also I'd go over the chassis ground points. The spots where the boards are soldered to the chassis can cause intermittent issues if the solder isn't good, it would be a good idea to re-flow them. Clean all the tube sockets too.

[Yamamaya42]

Originally Posted by maxhifi

If you're getting a sawtooth waveform at first filter capacitor, don't be too surprised. These sets use a voltage doubler power supply, and it's going to have lots of ripple at the first filter. In other words, I'd kind of expect a sawtooth there.

Where did you get C1A from? What cap is it on the RCA schematic? Is that a sams or an RCA part number?

https://www.boxcarcabin.com/rcaschematics.html has most of the early rca schematics.

I sold my CTC16 some time ago, but it was a cool TV. Make sure to check for bad soldering of power resistors, and also I'd go over the chassis ground points. The spots where the boards are soldered to the chassis can cause intermittent issues if the solder isn't good, it would be a good idea to re-flow them. Clean all the tube sockets too.

I'm going from the sams , that matches my CTC-16XL (set 812 folder 2 )
there is slight difference in the CTC-16 vs CTC-16X, so much that they have different releases . but both have full bridge rectifiers, and look nothing like voltage doubler in the link you shown (odd) , the bridge and C1 a is in a link i pasted above, Was 80uf, (400v) now is 100uf (500v)

I took a peek at all RCA color types leading up to the ctc-16, I'm not sure what rev that was in your link, but it's not a 16, for the following, when they came out with the 16, the voltage doubler was removed when they added the degaussing coil circuit, also, some of the tube types dont match up with what is in the set as shown.

[Electronic M]

Originally Posted by Yamamaya42

I'm going from the sams , that matches my CTC-16XL (set 812 folder 2 )
there is slight difference in the CTC-16 vs CTC-16X, so much that they have different releases . but both have full bridge rectifiers, and look nothing like voltage doubler in the link you shown (odd) , the bridge and C1 a is in a link i pasted above, Was 80uf, (400v) now is 100uf (500v)

I took a peek at all RCA color types leading up to the ctc-16, I'm not sure what rev that was in your link, but it's not a 16, for the following, when they came out with the 16, the voltage doubler was removed when they added the degaussing coil circuit, also, some of the tube types dont match up with what is in the set as shown.

There were about 6 schematics in the boxcarcabin link.... easy to miss unless you zoom out and scroll... The CTC16 a in 2 variants is there near the bottom.