Back to the VT-71H

[bandersen]

Yeah, that's some next level engineering.

[timmy]

There are I believe capacitors wired to one side of the heaters in the IF strip they are missing and 240pf micas are in place I have no clue if they are right or not or the value that should be there because the schematic don’t show these caps

[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]

There are four 250 pF caps on the IF tube heaters. They are shown on the schematic in the filament string section. The values are not critical to the TVs operation. They just filter RF noise off the heater supply.

[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.

Originally Posted by bandersen

There are four 250 pF caps on the IF tube heaters. They are shown on the schematic in the filament string section. The values are critical to the TVs operation. They just filter RF noise off the heater supply.

There is 240pf mica caps in place should these be ok?

[bandersen]

Yes, sorry I meant NOT critical. Mica is overkill for that matter. Any cheapo ceramic disc cap would be fine.

[timmy]

Unless I’m just nuts but the schematic shows there is v10AB v11AB v18AB but where exactly is the clipper shows v10 but both 18 and 11 is being used for audio and oscillator and afc and osc.

[timmy]

I’m just rambling this simple set suddenly is alittle above simple LMAO.

[Chris K]

Originally Posted by timmy

I’m just rambling this simple set suddenly is alittle above simple LMAO.

No wonder this clumsy novice had no luck with it. Most of the vintage sets I’ve restored needed parts replaced rather than intense analysis. When I did need help I found it here and I was often successful but with this Motorola I obviously was in way over my head!

[bandersen]

Yes, V10 sections A & B are the clipper. Not sure where the confusion is? There really shouldn't be any need for intense analysis.

[timmy]

I think I’m getting screwed up here because I have a voltage chart that I don’t think is the right one for this ts-4h does anyone have the correct voltages for v10 clipper. I only have the schematic no tube location and most numbers are blurry and can’t make out what is what.

[Yamamaya42]

The voltages shown in the SAMS should be rather close in all versions, not sure why so much focus is being drawn to this clip circuit, it's most likely OK, the circuits tied to it (v11) , transformers ETC, almost look like a horizontal blocking oscillator setup, and if there is raster, it must be running.

[Yamamaya42]

OK, so I guess the better name for this “clipper” would be sync separator.
But as seen in Bob's YT videos before, the GIGO principal has major impact here, if the received video is not up to par, too high/low or distorted in some way, the sync sep won't have clean info to pass through to the sweep circuits, thus you get unstable video lock.

[timmy]

Vertical is affected and looks like horizontal lines as well it looks like it’s trying to tear but can see a nice clear picture in between the tearing I thought maybe it was overloading at the video level but not sure as yet I have something else I’m going for.

[timmy]

If the video signal is overloading to much for the sync to work then ok possible but from what I understand the slug on the detector was turned maybe this would cause this not sure.