ADC Military Transformers - Help Understanding Winding.

[beezer4]

Hey all,
Looking for some help/perspective on these ADC transformers I recently snagged on eBay. I’ve seemed to suss out the primary and secondary windings (drawn in pic below with measured impedance in ohms w/multimeter). Seems like a mic step-up input or step-down output with center tap on each side. There is an additional set of connections (7,8) that also pass signal when signal is applied to either the primary or secondary. Could this be a feedback winding or ground? The impedance measurement between 7 and 8 is about .5 ohms. Pin 7 and 8 do not have continuity to the case.

They test flat 20-20k both ways as step up or step down.

One aside question… is there a good way to test if a transformer can handle DC ie for push-pull or single ended output?

Thanks!

 

[emrr]

Looks like plate to line, sounds like a possible feedback winding but it could be a speaker tap winding. Anything PP will take DC up to some point. This looks like small signal size, so.....

 

[beezer4]

Looks like plate to line, sounds like a possible feedback winding but it could be a speaker tap winding. Anything PP will take DC up to some point. This looks like small signal size, so.....

Thanks, that’s a good call. They are just a tad smaller in physical size than the UTC A-series transformers.

I’ll try one out in a test circuit and see how it rolls.