[thinktreasure]

Hello. Thye power switch/on-off is also the tone control.
Don't know what you mean by power portion your looking to revive is non operational.
There is a 1 page schematic on the Nostalgia Air web site.
If you don't have a speaker for it, there is a way to test with a perm. magnet speaker. You might try searching for how to do that. I have not tried myself. Be carefull where those speaker wires come through the chassis. They have very high voltages on them. Good luck.

On the power switch it clicks into 4 positions.
The power line goes to the 2 terminals on the back.
That switch is NG. Wiith the On OFF in any position that switch does not make contact.
I'm not familiar with this vintage radio, could it be some sort of standby mode? or as you say different tone positions.
The point being it's not a VR.

That is why I was asking. I mean at some point I'll investigate it myself and pull it apart but I'd like to know what I'm getting into before I get there. I'm sure this issue has come up before.

I was surprised that the schematic I saw do NOT include voltages, like the Sams schematics that came later.

There are 4 wires for the speaker, 2 from what I see would go to the matching transformer, 2 to provide power to the speaker electromagnetic.

I wondering where the best place is to get at ground to take readings and connect a signal tracer.

I assume the variable control is the volume, which I should be able to connect a signal tracer to without the speaker for now.