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[timmy]

Originally Posted by Yamamaya42

equivalent part on the SAMS very clear, 680pf.

Thanks the schematic is blurry that I have.

[Chris K]

Originally Posted by timmy

Anyone have the schematic for the ts-4h to confirm c158 it’s very blurry looks like a 680

I agree...680pF on both sources...Sams and the one from the TS-4H schematic in the service manual

[Yamamaya42]

hmmm, SAMS has that cap and the 900pf near it listed as "fixed trimmer capacitor" whatever that is..

[timmy]

Originally Posted by Yamamaya42

hmmm, SAMS has that cap and the 900pf near it listed as "fixed trimmer capacitor" whatever that is..

It’s a mica

[Yamamaya42]

where you can get an exact replacement for the 680 if needed,
https://www.mouser.com/ProductDetail...dopvQ9sA%3D%3D

the same is not for the 900pf

https://www.mouser.com/ProductDetail...KcNnbMvA%3D%3D

best you can get is 910 :/

[Chris K]

Originally Posted by Yamamaya42

where you can get an exact replacement for the 680 if needed,
https://www.mouser.com/ProductDetail...dopvQ9sA%3D%3D

the same is not for the 900pf

https://www.mouser.com/ProductDetail...KcNnbMvA%3D%3D

best you can get is 910 :/

Tim, remember keep track of the time spent on this and the price of the parts. I'll compensate you for everything you have done.

[timmy]

Originally Posted by Yamamaya42

where you can get an exact replacement for the 680 if needed,
https://www.mouser.com/ProductDetail...dopvQ9sA%3D%3D

the same is not for the 900pf

https://www.mouser.com/ProductDetail...KcNnbMvA%3D%3D

best you can get is 910 :/

I replaced the 680 900 and 100 with micas in my sets things are much more stable

[timmy]

Does anyone have the other parts of the ts4-h schematic to see exactly what voltage b+ And b++ is supposed to be.

[Yamamaya42]

Bob stated that in a working set, B++ be around 230 volts, given the ballast and respective loads are correct.

[timmy]

But the b+ is very low and I disconnected b+ and it still has 111v on the wire and in taking that off the tearing of the picture remains the same so maybe the clipper is not running because of the low voltage to that tube. I don’t know at this point how to get that voltage up it’s 39v short if it’s 150v and my ballast with resistors made no difference at all I checked the cap responsible for the b+ it’s good. So if there’s something dragging the voltage down I would say it may be on the b++ that’s at around 276v if 230v is good then the 40v should go to the low b+. Getting lost a bit.

[bandersen]

I'm restoring a TS-4J right now and B+ is only 90 volts but the set works fine.
B+ is derived from 6 tubes acting as a voltage divider.

[timmy]

Originally Posted by bandersen

I'm restoring a TS-4J right now and B+ is only 90 volts but the set works fine.
B+ is derived from 6 tubes acting as a voltage divider.

Well I went over ever tube so whatever the reason is for the picture tearing from side to side maybe the problem this is where it’s starting to stump be from a simple TV set. There is a perfect picture that can be seen between the tearing.

[Yamamaya42]

Originally Posted by bandersen

I'm restoring a TS-4J right now and B+ is only 90 volts but the set works fine.
B+ is derived from 6 tubes acting as a voltage divider.

Ahh OK, I see!

Every tube that has it's cathode tied to B+ is working in tandem to charge up the bias cap and circuit for the B+ area. Sneaky!


EDIT-
I figured out how they did that trick in my Stromberg Carlson TV, where they sourced the secondary 90v from 2 seprate tubes from a larger voltage.

[timmy]

Originally Posted by bandersen

I'm restoring a TS-4J right now and B+ is only 90 volts but the set works fine.
B+ is derived from 6 tubes acting as a voltage divider.

Well if yours is good on 90v then 111v should be ok as well.

[bandersen]

Yeah, that's some next level engineering.