The voltage will depend on the item being measured. For the final stage grid chokes, 50v RMS is more than my signal generator can do. There is no standard set of conditions. This makes comparisons impossible, unless you are out to duplicate them, instead of shopping.

It is also why I planned on setting out the test conditions prior to doing a measurement, that way the method could be evaluated. Seems an interesting sport to criticize the project, but that's not unexpected. Lead, follow, or get the Hell out ov my way.

I think three voltages at each frequency point would allow the shape of the curve to be accounted for and any small variance in signal voltage to be factored in.

From the impedance, we'll have the ability to post-process for the components like Cw and L. I am more interested in what these behave like at HF. There are a few non-audio projects I've been playing with which make me question how something so imperfect as an Iron cored transformer can possibly sound good.
cheers,
Douglas