• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Now THIS is an output transformer

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I bet George could find some uses!

Let's see. I've got a 240 volt 200 amp breaker panel right next to my work bench, and about 1000 12AU7's........That thing is about 200 miles away.....road trip.

Seriously, I have 2 pairs of Plitron OPT's that are designed for high quality, high power audio and rated for "400 watts at 20 Hz" that will probably be as far as I will go. First I need to finish building my new basement lab, then it will be time for the rise of Franken Amp.

Some shaker tables get to that power I think.

We had a big old shaker table at work. The power amps (at least 4 of them in a tall rack) were solid state and made by Crown I think. There was a separate voice coil for each axis. The Y axis coil was at least 8 inches in diameter. There were the usual settings with various waveforms, and some pre-recorded settings that were originally made with force and velocity sensors in the target environment.

I spent a lot of time there working on a certain "ConvertaCom" console product. It was an underdash mounted box that swallowed a police officers walkie talkie converting it into a mobile radio. It seems that these things could be made to spit out the radio when mounted in certain cars and driven over certain roads, or bridge spans. The engineers but sensors in the car and drove it in the exact places that invoked the radio puking.

My favorite setting was "military Jeep." Bolt a 30 pound trunk mount mobile radio to the table using the prescribed mounting hardware, run the "military Jeep" - "off road, rocky" profile, turn the levels up to about 3/4 and watch it fly apart. We could videotape the action and then play it back frame by frame.

Note, the radio in question was NOT rated for "military Jeep."
I am confused !

4 secondaries of equal turns would give impedance ratios of 1², 2², 3² & 4², i.e 1ohm, 4ohms, 9ohms & 16ohms
Why does the label show 1, 6, 8, 12?

Look atb the other pictures :
the red connector plate shows winding ID numbers, not impedance.

the blue label shows proper winding connections to get 16 / 64 / 256 ohms output impedance which follows the correct 4:1 sequence.

It's probably
* all windings parallel
* wired series parallel
* all in series

*if* it's an AM transmitter modulation transformer , core must be gapped to stand huge RF amplifier DC supply current, that might account for the poor 100Hz low frequency limit to save weight/cost; the 50kHz upper limit might imply Sonar applications as mentioned above ; although in truth publication says nothing about that.
It is a marine setup, for sonars.

Probably not shipboard equipment. The matching power transformer is available from the same seller. The primary is 3 phase 280/230/240 volts 60Hz. A ship big enough to need 5000 watts of sonar would have 400Hz power.

Anatoliy, what would be the actuators for that?

Most sonar that I have seen (admittedly low power, 100 Meters range) has used ceramic transducers, rather high impedance stuff. The output voltages were in the same ranges though (100 to 300 volts) so it could be from a large industrial sonic welder, or boiler.

*if* it's an AM transmitter modulation transformer , core must be gapped to stand huge RF amplifier DC supply current

The output impedances look far to low to be a modulation transformer.

The shaker table would have needed far lower output frequencies as well. I think ours went down to 5 Hz, maybe.

although in truth publication says nothing about that.

Exactly. There is not enough information to get farther that a few wild guesses as to the original application.
I think Tubelab has it right as a plastic welding xfmr.

One could re-rate the xfmr, with the 16 Ohm secondary reduced to 8 Ohm, the frequency response would extend down to 50 Hz. So 5400/2 = 2700 Ohm primary Z (plate to plate) and 2500 Watts.

Or could re-rate to 6 Ohm output, with frequency response down to 37.5 Hz with 2025 Ohm primary Z (Plate to plate) and 1875 Watts. Disco/Rave Amp?

Pretty much a boat anchor. Maybe $75 worth of copper scrap.
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The seller says

"Used 5000 Watt Audio output transformer from a 5000Watt tube amp. The primary is 5400 Ohm center tapped; it operated at 7kV plate voltage at 1 amp DC bias current with a pair of 4CX3000A power tetrodes in push-pull. It has four secondaries with 18.4:1 turns ratios to the primary. They can be used independently or connected in series / parallel to obtain various output impedances as shown in the photo. Buyer may arrange for local pickup or shipping with a freight company of your choice. Shipping weight is 200 lbs."
Well, someone bought it.
Wonder if we will be hearing about a new Mega Amp project.


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