New Project RCA 16t152 Trying to learn to troubleshoot better

[bandersen]

Part of the vertical circuit is usually powered by a boost voltage that comes from the horizontal circuit.
There is also often a lower B+ voltage derived from the audio output amp.
I can be difficult to just work on one specific circuit and get it to work perfectly,

[Penthode]

I would have to question why anyone would want to do a dim bulb investigation on an unknown set of 1950 vintage? As the set has been retired for decades, firing it up could do a lot of damage.

Ah yes you may say that it will give the electrolytics a chance to reform. This is the point I have tried to make repeatedly that if you refrain from powering it up and carefully analyse separately and in a controlled manner reform the electrolytic dielectric, there is a good chance they will survive. I have saved at least 80% of the original electrolytics in that way as well as transformers, resistors and tubes destroyed by leaky paper capacitors.

Maybe the dim bulb business could be used on post 1965 sets since by that time paper dielectric capacitors were essentially obsolete. On the otherhand what is the point of powering it up before you have completed at least a good visual evealuation of the set with the chassis pulled?

I welcome other opinions for and against.

[Kevin Kuehn]

This TV is one of RCA's early and unusual Direct Drive horizontal output designs. Basically an auto transformer directly driving the horizontal yoke winding. They work quite well when restored. And more energy efficient than the traditional flyback of the time. But the air core design only existed for a year. I believe in the second year models they added a small ferrite core, but the horz yoke winding remained in series with the high voltage winding.

[edit] Looking at the schematic this does appear to be the second version with the small metal core. But take a look at the unusual horizontal output configuration.

Here's the early and later variety. The one on the right is an air core, the left has some very small core, but I'm not exactly sure what it's made of. I'd be curious to hear what Penthode knows about these RCA Direct Drive models.