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Hello everyone,

A newbie set of questions.

On the net, you have as many opinion, way of measuring etc. as you have
pages with the word ferrite in it.
Moreover, they are too few discussion to how to characterize a ferrite
with a VNA. Bunch of stuff for common mode chokes and the like, but not a
lot for baluns
Given we have now a wonderful set of tools, NanoVNA and nanoVNA Saver, I'd
like to understand how to make the right choice.

I'm only interested in receiving antennas, therefore no power will go
through, no heating concerns etc.
I'm, for now, interested in HF bands with, for now, a long wire.
I'm therefore aiming for a 9:1 balun.
I have a bunch of "no names" ferrites in my junk drawer, some from power
supply, therefore likely good for KHz ranges and others from various
sources.
As many of us, amateurs, I tend to use what I have handy, and not
building, from a web page, the, say, Fair-rite type 43 with 9 turns of 26
AWG, without "fully" understanding what I am doing.

My main question:
What will be the characteristics to look for when comparing ferrites - and
choosing the best one- for a 0-30Mhz 9:1 balun?

I have built an enclosure with dual sided PCB and SMB connectors (from
another junk drawer :-) ) with a 50R resistor at the input SMB.
Calibration is done with the enclosure. I'm using the same wire I will
likely use for the balun, between the input and either the ground or
another SMB connected to S2.

I have already zillions of NanoVNA saver screen shots with various
ferrites but I'm unable to find the right info to make a decision.
Will it be from the smith chart, SWR, Z, return loss, ??

Is there a way to find the right ferrite without winding a 9:1 balun each
time.

When testing a 9:1 balun:
Do I need to load the "output" of the balun with a 450R resistor?
Do I need to connect the output (loaded or not) to the S2 ?
If yes, what will be the right info to look for?

Any help or pointer to the right docs will be helpful.
Thanks in advance

Jean