GE Clock Radio Model 660

[MadMan]

Originally Posted by old_coot88

I can't pull up the schematic on my (Linux) rig, but am curious as heck about that series/parallel filament wiring. Presumably it's running from B+ thru a dropper. If so, then if one string goes open, then the other string will have twice the voltage on it. A zener would be great for protection, but there were no zeners when the radio was made. Just bein' curious.

HERE

The PSU wiring was actually extremely confusing for me. They could've just had the double transformer, two selenium rectifier bridges, and maybe a capacitor or two, but instead they came up with this crazy contraption. Before I got the diagram, I actually drew my own just to see if I could make sense of it! The really weird thing is... they have a proper rectifier bridge for the filament power, and then they just use a tiny single diode for the (what I would consider much more important) 67.5v B+. I just... don't even. And actually, despite what the diagram says, the power coming 'out' of the transformer for B+ is actually 110v. It really looks like they put one diode in there to roughly halve the power, and cleaned up the oscillations with a capacitor and called it good. Come to think of it, maybe that's the reason that capacitor went bad in the first place.

Originally Posted by jsowers

They were very much like mini-blind rods, clear plastic with ridges all around the edge, but solid on the front and they had a slightly raised pointer ridge, but you could just paint a line on the knob. What would be hard is to get the hole in the back right with the divider in it. Those shafts are split and the knob would just spin without the divider. The clock even has a sleep timer for the radio, which was a high-end thing in the 1950s. It didn't have a snooze control, though.

Actually I was thinking about it. I could cut sections of a miniblind rod, polish them, drill the holes, and for the divider thingy, I could make a tool - a copy of the shafts on the clock - and cut a toothed pattern in a tiny strip of sheet metal, then use the tool to press the sheet metal into each knob, thus creating the divider.

Speaking of which, one of the shafts is damaged (and poorly repaired), so I'll have to make a replacement at some point.

Originally Posted by jsowers

The tips of the hands glow in the dark, or mine did.

That's great that you got your tubes in the right place and it works! I'm glad that's all it was.

Mine do... but they're very very faint even in a pitch black room. The halflife of the radioactive crap must be up. Unlike my vintage refrigerator, which has a neat inside door handle that still glows brightly in the dark. Ahh, delicious radioactive material all over my food.

And actually, I'm positive the giant waxy capacitor in the PSU was also bad before I replaced it.