How to read a transformer data sheet?

Question

I have been trying to understand this datasheet but I think I am missing some core knowledge. I just want to know what the inductance of the primary is when the secondary is unloaded (I am using the transformer primary as an inductor for an audio resonant filter), but in the process, I'd like to understand how I should read the sheet.

How should I interpret the impedance values given for primary and secondary? Do they provide the impedance at some fixed frequency? If so, what frequency? Or is there something more to it?

Answer 1

There's not that much to get really. The info is not that complete, they don't actually say at what frequency the impedance is measured, but given that the device seems designed for telephone BW (300-3.4kHz) and they talk about impedance variation at 1kHz, it's probably at 1kHz.

Answer 2

All datasheets are to be read like devil reading the bible.

In your particular case, you can derive the inductance from the impedance, postulating it is the impedance at 1kHz.

As you are trying to build a resonant whatever, you may as well think about +/- 10% variance of the impedance, as well as the pretty much unknown non-linearities.