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-----Message d'origine-----
De : [email protected] [mailto:[email protected]] De la part de Bob Albert via Groups.Io
Envoyé : jeudi 14 novembre 2019 23:33
? : [email protected]
Objet : Re: [nanovna-users] NanoVNA-Saver 0.2.0

David, can you explain exactly how you got the curves? I would like to do it also.
Bob
On Thursday, November 14, 2019, 02:06:06 PM PST, David F4HTQ <f4htq@...> wrote:

Hi All,
I add some explanations.
I asked Rune if he could add this graphic because it is very useful.
It display curves that have exactly the same shape as the complex permitivity curves (μ'r and μ''r) of the ferrite datasheets.

The values do not match those of the constructor curve ( to have the right value the software might know the exact geometry of the inductor) , but the shape is absolutely identical.

This allow to easy identify unknown ferrite core, and to better understand how to use it in a RF device.

For example, here is the true curve of material 43 of Fair rite.



And here's the one I got with NanoVNASaver


It works really well.
David, F4HTQ.


-----Message d'origine-----
De : [email protected] [mailto:[email protected]] De la part de Rune Broberg Envoyé : mercredi 13 novembre 2019 08:23 ? : [email protected] Objet : Re: [nanovna-users] NanoVNA-Saver 0.2.0

Hi John,
my experiments in this field have been very limited - the feature was added with the encouragement of David F4HTQ. He submitted to me an S2P file of a measurement of a toroid, and a curve shape:




He believed this could be approximated as R/ω and X/ω, so I implemented it, and managed to create the following graph:

[image: image.png]

Which seemed to fit quite well, even though the units aren't exactly the same.

So, for now, all I know how to do is: Given a permeability chart from a manufacturer, replicate the same curve shape vs frequency using the NanoVNA.

I hope it's useful ;-)

--
Rune / 5Q5R

On Wed, 13 Nov 2019 at 01:22, John AE5X <ae5x@...> wrote:

Now that the capability is there in the software, how would one use
the NanoVNA to check a toroid's permeability? New territory for me...
:-)