Help identifying transformers

[machprod]

I have a couple of transformers that look like the "4276" from this picture https://groupdiy.com/attachments/img_1367-jpg.42929/

I am pretty sure I got them from a AMS Neve. I thought they were line IN and OUT but...

IIRC resistance at 1KHz
Red-Blue 50 Ohm, Green-Yellow 200 Ohm - mic?
Red-Orange 600Ohm, White-Yellow 600Ohm - line in?

Question: Any idea what the model/part might be? I cant find a picture of them in circuit to be sure I know what I am talking about.

 

[emrr]

"ohmed out" resistance would suggest 10x Z values. Please clarify.

 

[machprod]

Sorry, I mean the resistance determined by the voltage drop, when a 1KHz tone passes over it.
I assume that is the correct way to measure? Does that make more sense.

 

[abbey road d enfer]

Sorry, I mean the resistance determined by the voltage drop, when a 1KHz tone passes over it.

Define "passes over".

I assume that is the correct way to measure? D

No.

oes that make more sense.

No.

 

[machprod]

Well, I am pretty embarrassed now, I dont mean to waste your time. I'm really sorry about that. It has been a long time since I dealt with electronics so this is all rather vague.

For the record 1) I dont recall how I got those numbers. 2) I realize now that a transformer is not a simple coil, so what I was *trying to say* probably wouldn't work.

But, fwiw. this diylc sketch is what I was trying to say, whether or not it was wrong.

 

[abbey road d enfer]

But, fwiw. this diylc sketch is what I was trying to say, whether or not it was wrong.

This method identifies the impedance at 1kHz, which is of no interest in most cases.
Usually the nominal impedance is about 1/10th to 1/5th the impedance at the lowest fequency of interest.
Example: if you measure 1kohm at 1kHz, the inductance is 0.159H (L=Z/2.pi.F)
Assuming a LF limit of 20Hz, the impedance is 20 ohms, which suggests a nominal impedance of 100 to 200 ohms.
Most transformer mfgrs specify their products for a LF limit of 20 to 40Hz, so you can see that for a given inductance, the nominal impedance can vary in a ratio of 1:4.
Actually, as emrr mentioned, you often have a much better evaluation by measuring the DC resistance with a DMM and multiplying it by 5 to 10.
THis is because the DCR is a source of losses and a good designer would want to minimize those losses.
Actually, the impedance of a transformer is a non-entity because the impedance that can be measured varies with frequency (in about 1:1000 ratio for 20Hz-20kHz audio).
The designer of the xfmr choses a target in the context of a specific circuit and operation.
For example he choses a source Z of 200 ohms for a mic input and a load Z of 10kohm in accordance with the active circuitry, which results in a set of values for the primary and secondary inductances; when he achieves the specific goal that he has set, he then says "my xfmr is a 200:10k xfmr".

 

[CJ]

Those are mic input transformers, you can tell by the package, small core, mu can for shielding,

Do you have a signal generator?
Do a ratio test.

Solid state circuit suggests 1:2 as a typical ratio,

4276 sounds like a Sowter number

 

[Cqwet Dbdfte]

They are probably bad, send them over to me for disposal.