Vertical troubles
 

OK guys and gals, I ned some help! this little GE I'm working on has a vertical roll problem.

It will roll both ways but just won't quite lock in for more than a second at best.

I measure 10 volts at pin 2 of the (new) 6AU8 where there is supposed to be 45. (is the "Clipper" the same as the sync separator tube?)

Would I be correct in guessing that integrated component shown in the dotted line might be the problem? (It has the 135 volts going in to pin one of that component)

I know those network type components cause a lot of problems in Predictas so maybe in GE's too?

Schematic here: http://www.vintagetvsets.com/ebay/geschem.jpg

Thanks:D

Eric

Eric,

It looks like your integrated component (RC-201) is probably the culprit. You can build a new one out of discrete components easier than trying to find the original (if you can find it at all). Just get some perf board at Radio Shack, and use the leads of the discrete components to interconnect them. :cool:

And yes, the sync separator and sync clipper are one and the same.

Hi Bill, that was the problem!

I noticed that the 135 volts only goes through one 47k resistor inside the component so I bypassed it with an external resistor and the voltage popped up to around 50 volts.

Slapped the CRT back in and :D a rock solid picture!
It must have been affecting the horizontal also because it would occasionally roll sideways before but it's perfect now!

Funny thing is I measured across pins 1-2 on the component and it measured right around 47k? I guess it's defective in some way that it craps out under load :dunno:

I think I will just leave the external resistor in place rather than building a whole new network and hope nothing else goes bad inside.

Thanks for the help :D