This is my first attempt at restoring a battery eliminator. They were commonly used in 1920's radios once a household became electrified. Most ofte they only supply B voltage, but this one also supplies A voltage for 2 volt tubes. This came with a shattered type 80 rectifier which will be replaced. At first glance I see 4 tranformers, what appears to be a humungous selenium rectifier and some equally huge capacitors. I also see a couple of newer capacitors, so this has been worked on before. There is also what appears to be a pad of asbestos lying on a couple of the capacitors. I'll need to deal with that as well.

I've put in an 80. No A voltage and all of the B voltages are present but elevated by 30-40%. I see the long candohm that I suspect is used as a voltage divider. Having no schematic, I don't know what the values are supposed to be, but I should be able to figure that out.

But first I want to replace the remaining e-cap which is a dual 8uf. Those being changed, now the voltages are about twice what they should be. Time to take things apart.

I'm going to experiment and put a 3000 ohm resistor inline with the candohm. I think that will drop the voltage by 60 volts. Of course I have to order one. In the meantime, I'm trying to sketch out a schematic to visualize how this is put together.

The 3K resistor did not have the expected result. I see now that there is 1 power transformer and 3 apparent chokes. Still working on the schematic.

Decided to make my own candohm. I had to adjust the circuit slightly, but I'm getting voltages within a couple of volts of where they're supposed to be. Good enough.

New Candohm

Installed after removing the old one

Now to work on the A supply

 I do have voltage which changes with the control, but the needle bounces. I'm guessing a problem with the selenium rectifier. I'm going to replace that. I measured current going through at 40ma. I will need to add a dropping resistor. there is 11v coming in. I'd like to drop it 8 volts to get it down to around 3 volts. E-IR. 8/.04=200 ohms approximately. I'll start with that.

After some experimenting, I replaced the selenium rectifier witha 10amp silicon rectifier and a 22 ohm dropping resistor. The meter reads well now.

Finished 6/23/26