Baldwin organ transformers

[no gas]

I scored a bunch of Baldwin organ iron on ebay for peanuts but some of the stuff eludes me. I have no idea what model they came out of so I can't find a schematic. The tubes used were 6L6 in PP and a few 12au7 and 12ax7s with 5U4 rectification. There is a nice big choke with a DCR of around 200, no idea of the inductance. There is a core with THREE wires coming out of it, what could it be? Two wires on one side and one on the other about a pound in weight? Any ideas? There is also a mini transformer with two wires in and two wires out and about an inch cubed, what might it be? A one watt single ended? Anyone know where to find Baldwin schematics?
At there very least I've got some monsterous power transformers but I'd like to use as much as I can.

[mashaffer]

I do not know the inductance of the PS choke but I used one from a Baldwin 61P in replacing a fried field coil speaker in my radio with a PM type and it worked fine. It would be useful in a PS filter network for a reasonable sized SE amp. The one I had was not used in the plate supply for the 6L6s but it did filter the screen supply and the supply for a bout 60 preamp tubes so I figure its current capability is pretty decent. In my application I was running about 110mA through it and it didn't even get warm.

The three lead coil is probably for an oscillator tank. I have not figured out a use for mine.

The little tranny is probably a part of the tuned circuits in the tone generator. Probably not useful as an output transformer. I doubt whether it is wound carefully enough to be used as an interstage or input transformer but you could try it and see how it measures.

[no gas]

Originally Posted by mashaffer

I do not know the inductance of the PS choke but I used one from a Baldwin 61P in replacing a fried field coil speaker in my radio with a PM type and it worked fine. It would be useful in a PS filter network for a reasonable sized SE amp. The one I had was not used in the plate supply for the 6L6s but it did filter the screen supply and the supply for a bout 60 preamp tubes so I figure its current capability is pretty decent. In my application I was running about 110mA through it and it didn't even get warm.

The three lead coil is probably for an oscillator tank. I have not figured out a use for mine.

The little tranny is probably a part of the tuned circuits in the tone generator. Probably not useful as an output transformer. I doubt whether it is wound carefully enough to be used as an interstage or input transformer but you could try it and see how it measures.

Good to know about the choke, I was hoping I could use it in a RH-84 power supply. It looks beefy but the resistance is about 200 ohms so it must be high inductance with lower current. If you got away with 110ma it will be perfect for a stereo RH-84.

[mashaffer]

Yep, I would say give it a try and if it gets too hot you can always save it for a preamp project or something. Do you know what model organ yours came from?

[no gas]

Originally Posted by mashaffer

Yep, I would say give it a try and if it gets too hot you can always save it for a preamp project or something. Do you know what model organ yours came from?

It was a 51P from what the seller posted. Any ideas on a schematic for a 51P?

[mashaffer]

justradios.com apparently has it but not free.

[ChrisA]

Originally Posted by no gas

I scored a bunch of Baldwin organ iron on ebay for peanuts but some of the stuff eludes me. I have no idea what model they came out of so I can't find a schematic. The tubes used were 6L6 in PP and a few 12au7 and 12ax7s with 5U4 rectification. There is a nice big choke with a DCR of around 200, no idea of the inductance. There is a core with THREE wires coming out of it, what could it be? Two wires on one side and one on the other about a pound in weight? Any ideas? There is also a mini transformer with two wires in and two wires out and about an inch cubed, what might it be? A one watt single ended? Anyone know where to find Baldwin schematics?
At there very least I've got some monsterous power transformers but I'd like to use as much as I can.

It is best to measure yourself. First figure out with an ohm meter which leads are primary and secondary and tap from either of these. this is not hard.

Next get a 12V AC (not DC) low amp "wall wort" type power supply or a very small filiment transformer. Connect 12VAC across one side and measure the volts on each side. turns ratios equals volts ration and impedence ratio is the square root of each. Next you guess and figure transformer with an about 1000:1 impedance ration was an output transformer and if the speaker was 8ohm the other side is 8K ohm.

For chokes you have to dummy up a bread board power supply and load and measure reactance (or really deduce reactance from AC voltage drop) and work backwards to inductance. But be sure and measure at full DC current.

Current? uild a dummy load and let it run for 30 minutes, check the temperature of the transformers and then reduce the resistance of the load and keep going until you think the transformer is two hot.

I have a ton of old Hammond transformers and, there is no good shortcut. Even if you find a schematic all it will say is a part number, not helpful. You just have to measure them

But no need for high voltage. most of the tests can be done with a safe 12VAC source protected by a 1/4A fuse