RCA ctc36 short issue?

[Findm-Keepm]

Originally Posted by zeno

Controls are a problem. You may have to mouse that.
Someone used to make a kit to build them with shafts,
elements & housings. Maybe someone here has one.
One from a scrap chassis probably no better & NOS
probably all gone but worth a try.

73 Zeno

Ah, the CTS Striptrol kit - I have a small kit, with a few housings and elements. Sams shows two multisection pots - the horiz hold is in the 126346 part number one. Talonix shows two in stock: http://www.talonix.com/shop/item.aspx?itemid=15929

[pendulum]

Originally Posted by Findm-Keepm

Ah, the CTS Striptrol kit - I have a small kit, with a few housings and elements. Sams shows two multisection pots - the horiz hold is in the 126346 part number one. Talonix shows two in stock: http://www.talonix.com/shop/item.aspx?itemid=15929

I had actually just ordered one of the pots from talonix today! I have put new 5gh8 tubes in, checked most of the resistors in the afc circuit, and put in a new dual diode to see if that helped. Image was the same, so I am feeling pretty confident that the issue is in the crummy pot. Part should arrive monday, so i'll post an update probably monday night.

[pendulum]

part actually arrived earlier than expected. Was able to replace the horizontal hold today. Unfortunately this did not solve the problem. I will do some voltage measurements next.

[pendulum]

ok, I measured the voltages of the horizontal afc/osc tube and there are some issues there. Here are the voltages I got compared to what the sams says they should be.
pin # sams what I measured
1 225v 224v
2 -.2v 3.5v
3 80v 38v
4 and 5 are filiment
6 140v 19v
7. 2.5v 4.3v
8 .1v .16v
9 60v -50v

So clearly something is wrong in the horizontal hold circuit. I linked the relevant part of the schematic earlier in the thread to those interested, I qill start double checking components and making sure I didn't put a wrong value component in.

[pendulum]

Anyone have ideas here. I'm pretty sure the issue is with the 5gh8 horiz afc/osc tube. The voltages come of the 260v line and seem fine, but when looking at the schematic, I measure the other side of the 3.3 meg resistor the voltage is pulled down to -50v. I checked the two coils in the area and they measured fine. I have replaced the resistors and caps so I am not sure what would cause the voltage to be so low. Any ideas? I posted the relevant part of the schematic, but more of it is uploaded elsewhere in this thread.

Here are the voltages again
pin # sams what I measured
1 225v 224v
2 -.2v 3.5v
3 80v 38v
4 and 5 are filiment
6 140v 19v
7. 2.5v 4.3v
8 .1v .16v
9 60v -50v

[tom.j.fla]

I see one thing wrong is that + 60 volts on pin 9 grid. It should be -50 volts or so more negitive. Plus 60 volts on the grid would red plate the triode and most likely crack the glass. Sams blows it yet again with dumb errors. You should try to find the factory service manual or pdf for any set that you want to restore or just repair.All the best,Tom

[tom.j.fla]

One other thing that jumps out is the +3.5 volts on pin 2 control grid of the pentode,it is turned on hard. Ckeck for leaky C83,carbon track between pin 2,3 on board or in the socket or solder brige in same place. All the best,Tom