• 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.

Can you identify this transformer? 70V line matching?

I wonder if someone can help me identify what type transformer this is. I have two of them- one is ink stamped 12X6Z and the other 24Y6Z. Google hasn't helped. They seem/measure almost identical.

Using the DMM, I can tell that the black is the CT for the brown leads (.3 ohms between brown leads). Because the other leads are not color coded in pairs, I'm wondering if these are 70V line matching transformers, but not sure how to confirm.

Just guessing, I use the green as common and get these measurements. The voltage is the result of inputting 1VAC @ 400Hz into those leads and measuring at the brown leads:

green-to-white: 15.6 ohms, .14VAC, turns ratio= 7.14
green-to-blue: 17.5 ohms, .125VAC, turns ratio= 8
green-to-yellow: 44.8 ohms, .074VAC, turns ratio= 13.5
green-to-red: 50.4 ohms, .068VAC, turns ratio= 14.7

Those ratios don't ring a bell, so maybe I'm using the wrong common? Using the red as common gives slightly different figures, but nothing recognizable (to me).

Here's a photo:


Weighs about 2.5pounds, core measures approx 2.5"w x 1.25" deep x 2.2" tall. 5 watts?

Is there a standard color code for these type transformers?