Unknown transformers

[rafafredd]

Luckly someone will have a datasheet or maybe just some notes about this transformer type.

I would also be interested in knowing some more about this company and what they produced. Hifi? Professional audio? Recorders? I´ll try a google search...

By the way the transformers I have are octal plugin type and repeat coils. Looks like low level, and low inductance (500mH?), but my inductance measuring method is not that great. I would like to try CJs method posted here: http://www.groupdiy.com/index.php?topic=3209&start=0&postdays=0&postorder=asc&highlight=, but I can´t understand the jig perfectly. If someone could make a drawing it would be nice. I really would like to be able to test inductance on my many unknown transformers...

It also looks like M6 core, but could be mumetal. So, if those are really just 500mH M6 transformers, I don´t see any nice use for it. Unless, I want a transformer based low cut :? . But the good part is that it was almost free, and I have four nice housings for T4 now, in case those are really useless.

But if those are mumetal core, the H readings are probably on the lower side, and they could be used as a 1:1 mic input transformer. The housing also looks like mumetal. Any methods to test a material with chemicals to know what´s mumetal and what´s not?

 

[gyraf]

500mH might do fine, if you drive them from very-low output impedance, like an opamp with a transistor buffer stage..?

What is the inductance of the API-type output transformers?

Jakob E.

 

[rafafredd]

The problem is that it looks small for a discreet opamp output transformers. Big case, small tranny inside. But, the API output transformers reads as 180mH per winding with my inductance-DMM whyle these ones measures 500mH with the same DMM.

Maybe this small cores would give nice saturation/distortin, but probably not enought low end, not because of inductance, but because of core size.
I would have to try it out... But I was hoping those are mumetal core, mumetal cased, for mic input. I like 1:1 mic inputs, just for balancing the inputs, then to a very low noise stage, parallel fets, or LM394 or good opamp, or whatever...

Instead, those doesn´t look like high quality mumetal transformers at all. Probably just a consumer grade tranny. Most probably ****. In this case, nice T4 cases.

any info on testing the core and cases for nickel presense? I have a wide range of chemicals available at home.