1936 RCA RR-359B Restoration

[bandersen]

LOL, yes that would be handy. I've already order up a heavy duty lazy Suzan turntable to put it on.

Now let's take a closer look at the upper chassis. Here's where things get really ugly.

Here it sits just after I got it home.


As mentioned earlier, the tuner is gone. It was originally a continuous tuner covering around 40-90 MHz.
Some sort of later tuner was hacked in where all we see all those blue labelled wires. Some run down through an empty tube socket. That's the mixer tube which I assume wasn't needed.

Also, notice there is an empty tube socket on the left side. That's for the 1-V damper tube.


I popped a new one in and didn't think much of it until I noticed a more modern octal tube socket had been added at the bottom of the chassis.



I found a 117Z6 full wave rectifier tube in it with the filament connected directly to the AC line. Sure enough, it was wired to replace the 1-V damper.


While we're down here. Notice the mess? There are two candohm resistors down there with many taps.
Likely some sections have gone bad and were bypassed with external power resistors.
There wiring is also a mess and some caps have been added. How do I know? More on that in a bit.


Now, for the last major bit of ugliness.
This was the vertical oscillator consisting of a 6A6 dual triode and blocking oscillator transformer.
Instead, we have this mess. The original subassembly is completely gone and replaced with an 884 thyratron.
More commonly seen as the timebase oscillator in early oscilloscopes.
I suspect the original transformer went open and this substituted for it.


By the way notice the 001073 stamped on the chassis? Remember that.


I intend to restore the original circuit.
Nice thing is the horizontal oscillator is nearly identical, and I can use it as a model.


The last bit of ugliness (so far) is all the tacked in caps. None of these are original or should be in these locations. Instead, there should be a box containing two this is missing.
The rest should be in a box on the other side. The box is still there but bypassed. I'll be restuff / fabricating as needed and restoring the original wiring configuration.