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Re: A Question on Mu?

 

Hi Larry,
You can found some details on the document linked to this message.
David.

-----Message d'origine-----
De : [email protected] [mailto:[email protected]] De la part de Larry Naumann
Envoy¨¦ : jeudi 14 novembre 2019 23:07
? : [email protected]
Objet : [nanovna-users] A Question on Mu?

Okay, I have been reading a bunch of stuff on ferrite cores.
My main interest right now is xfmrs for EFHW antennas.
I see charts with u' and u" (mu' and mu").
I can't seem to find an explanation of what u" is.
Can someone enlighten me?
Thanks
Larry
n0sa


Re: A Question on Mu?

Larry Naumann
 

As usual, I found the answer right after I asked the question.
One is lossless permeability the the is lossy permeability.
Found the answer in a Fair-Rite printout.
Larry
n0sa


A Question on Mu?

Larry Naumann
 

Okay, I have been reading a bunch of stuff on ferrite cores.
My main interest right now is xfmrs for EFHW antennas.
I see charts with u' and u" (mu' and mu").
I can't seem to find an explanation of what u" is.
Can someone enlighten me?
Thanks
Larry
n0sa


Re: NanoVNA-Saver 0.2.0

 

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 (¦Ì'r and ¦Ì''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
Envoy¨¦ : 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/¦Ø and X/¦Ø, 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...
:-)




Re: Parameter Explanation Please

Larry Naumann
 

Thanks for all the good links, looks like I have a lot of reading to do.
I am trying to learn all this stuff and it takes me awhile to get my head wrapped around all of it.
Larry
n0sa


Re: Parameter Explanation Please

 

On 11/14/19 9:54 AM, Bob Albert via Groups.Io wrote:
Larry, this is basic electric circuit theory.? Any linear bilateral complex impedance can be expressed as an equivalent circuit of two components, a resistance and a reactance.? You can express them either as a series combination or as a parallel combination.? So all the parameters you mention are the results of that calculation.
A series combination is usually expressed as R + jX, and the R is called series R, or Rs.

???? And given the impedance in series format, it is possible to convert to an equivalent parallel circuit - and vice versa.? The equivalency will only be valid over a limited frequency range.

???? There are a lot of places on the web that can help you with this stuff.? For example, microwaves101.com.? Some specific pages, in no particular order:



















???? Wikipedia also has some good stuff:




???? A good source of information on all things RF (Radio Frequency) is the ARRL Handbook for Radio Communications.


Re: NanoVNA AURSINC v H, Q-0.4.3, images

 

You have connected the 50 ohm load to CH0 and you are looking at noise on CH1
More noise implies better isolation and that is what you want
(I think....)


--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK


Replacement Power switch

M Garza
 

Hello all,
I broke the power switch on my nano. Does anyone have a part number to it?
I did some searching but could not find it.

Thank you

Marco


NanoVNA AURSINC v H, Q-0.4.3, images

 

I have 2 NanoVNA, one bought from AURSINC on Amazon, which I originally thought was not a knockoff, and one bought from a link provided by Hugen, that I learned of only after getting the AURSINC and finding this forum.
I set up both units (AURSINC on left) with the same traces and freq range.
Both are running Q-0.4.3.
I calibrated both units with ~3.5m RG316 connected to each port, and 2 50 O terminators.
Immediately after each calibration, I put on a 50 O cal terminator, and took the picture.
Exclude image quality...I took the images w my mobile, and they are notoriously easy to lose focus at close distances.
--
73 de Rich NE1EE
On the banks of the Piscataqua


Re: Batteries

 

Oh - and as for the size of a larger battery - several forum members including myself have used larger cellphone batteries up to 1500mAH.
You can just solder the wires directly to the + & - pins of the battery.? The IP5303 essentially charges the battery according to its instantaneous voltage instead of just pushing constant current into it, just like it would be charged in a cellphone - just don't use a really old cell for this.
Any 18650 cell will be way more than enough for the nano's needs.

On Thursday, November 14, 2019, 1:10:11 p.m. GMT-5, Larry Rothman <nlroth@...> wrote:

All lithium -cells- need to come with overcharge, overcurrent (ie:shorting its terminals), undervoltage and overtemp protection (and balancing sometimes is also built-in).
And that is just that small board on the cell itself !??

The IP5303's charging circuit knows nothing about the physical condition of the Li cell.If the IP5303 fails catastrophically, you want the battery to protect itself.
I have several two-way radio batteries that have disabled themselves due to a fault somewhere but when I opened them up, the individual cells were fine.

I also have 3.6V cells where the protection module shut off the output voltage. I use those cells in other projects.

Better safe than fire......

? ? On Thursday, November 14, 2019, 12:45:10 p.m. GMT-5, Nick <g3vnc@...> wrote:

I am currently repackaging my nvna and would like to include a (much) bigger battery.

What is the biggest battery capacity (Amp-Hours) I could use with the IP5303 charging circuit?? Looks to me like there is no limit since the IP5303 will limit the charging current so the initial constant current phase of charging will simply take longer.

Why does the? 450mAh battery supplied with the device include a built in circuit for over drain protection etc?? The IP5303 already has "Input over-voltage, over-current, battery over-charge, over-drain, over-current protection" built in.

I'm thinking a fat cell phone Lithium Ion battery should be fine as reported by Larry Rothman here...
/g/nanovna-users/photo/0/40?p=Created,,,20,1,40,0

(I was at a flea market a couple of months ago and there was a seller who had a lot of new cylindrical LiIon cells about 3Ah as I recall.? They were very cheap, but I did not have a nvna then.? I wish now that I had bought a few.)


Re: Batteries

 

All lithium -cells- need to come with overcharge, overcurrent (ie:shorting its terminals), undervoltage and overtemp protection (and balancing sometimes is also built-in).
And that is just that small board on the cell itself !??

The IP5303's charging circuit knows nothing about the physical condition of the Li cell.If the IP5303 fails catastrophically, you want the battery to protect itself.
I have several two-way radio batteries that have disabled themselves due to a fault somewhere but when I opened them up, the individual cells were fine.

I also have 3.6V cells where the protection module shut off the output voltage. I use those cells in other projects.

Better safe than fire......

On Thursday, November 14, 2019, 12:45:10 p.m. GMT-5, Nick <g3vnc@...> wrote:

I am currently repackaging my nvna and would like to include a (much) bigger battery.

What is the biggest battery capacity (Amp-Hours) I could use with the IP5303 charging circuit?? Looks to me like there is no limit since the IP5303 will limit the charging current so the initial constant current phase of charging will simply take longer.

Why does the? 450mAh battery supplied with the device include a built in circuit for over drain protection etc?? The IP5303 already has "Input over-voltage, over-current, battery over-charge, over-drain, over-current protection" built in.

I'm thinking a fat cell phone Lithium Ion battery should be fine as reported by Larry Rothman here...
/g/nanovna-users/photo/0/40?p=Created,,,20,1,40,0

(I was at a flea market a couple of months ago and there was a seller who had a lot of new cylindrical LiIon cells about 3Ah as I recall.? They were very cheap, but I did not have a nvna then.? I wish now that I had bought a few.)


Re: Parameter Explanation Please

Bob Albert
 

Larry, this is basic electric circuit theory.? Any linear bilateral complex impedance can be expressed as an equivalent circuit of two components, a resistance and a reactance.? You can express them either as a series combination or as a parallel combination.? So all the parameters you mention are the results of that calculation.
A series combination is usually expressed as R + jX, and the R is called series R, or Rs.? And so on.? Read a basic ac circuits textbook to get full explanations.
Bob

On Thursday, November 14, 2019, 06:45:41 AM PST, Larry Naumann <n0sa@...> wrote:

Okay, I have a NanoVNA ordered and I have a VNWA.
I know the differences between X, R and Z.
What I do not understand is Xr, Xp, Rr, Rp, Zr, Zp, |Z| etc.
I know the r and p mean series and parallel but I do not understand how it
functions with single and two port connections.
What are the differences, what does it mean as far as connections and readings goes?
I need a Dummies Guide to these parameters, explaining differences and connection
examples, etc.
A reference to a book or webpage would be nice.
Thanks
Larry
n0sa


Re: Batteries

 

18650 cells (especially cheap ones ) rarely have the current capacity they are marked with. I bought 20 cheap 3ah cells from amazon and all of them were closer to 1.5.

Cheap batteries can be a false economy.

Alan

On Nov 14, 2019, at 12:45 PM, Nick <g3vnc@...> wrote:

?I am currently repackaging my nvna and would like to include a (much) bigger battery.

What is the biggest battery capacity (Amp-Hours) I could use with the IP5303 charging circuit? Looks to me like there is no limit since the IP5303 will limit the charging current so the initial constant current phase of charging will simply take longer.

Why does the 450mAh battery supplied with the device include a built in circuit for over drain protection etc? The IP5303 already has "Input over-voltage, over-current, battery over-charge, over-drain, over-current protection" built in.

I'm thinking a fat cell phone Lithium Ion battery should be fine as reported by Larry Rothman here...
/g/nanovna-users/photo/0/40?p=Created,,,20,1,40,0

(I was at a flea market a couple of months ago and there was a seller who had a lot of new cylindrical LiIon cells about 3Ah as I recall. They were very cheap, but I did not have a nvna then. I wish now that I had bought a few.)



Batteries

 

I am currently repackaging my nvna and would like to include a (much) bigger battery.

What is the biggest battery capacity (Amp-Hours) I could use with the IP5303 charging circuit? Looks to me like there is no limit since the IP5303 will limit the charging current so the initial constant current phase of charging will simply take longer.

Why does the 450mAh battery supplied with the device include a built in circuit for over drain protection etc? The IP5303 already has "Input over-voltage, over-current, battery over-charge, over-drain, over-current protection" built in.

I'm thinking a fat cell phone Lithium Ion battery should be fine as reported by Larry Rothman here...
/g/nanovna-users/photo/0/40?p=Created,,,20,1,40,0

(I was at a flea market a couple of months ago and there was a seller who had a lot of new cylindrical LiIon cells about 3Ah as I recall. They were very cheap, but I did not have a nvna then. I wish now that I had bought a few.)


Re: NanoVNA Firmware and Software Versions and updates

 

FW/funktion SreenCopy maxFreq 4/2traces CW-SWR NanoVNASaver, Vbat_state NanoVNA-Web-client, TAPR, NanoVNASharp comment
-Q Y 1.5G 4 Y Y Y Y Y Y Ok on Android smartphone OTG

--
*73, Lucio I0LYL Rome, Italy


Re: NanoVNA-Saver 0.2.0

 

Rune,
Just a note for any Fedora users out there. The right click to save an
image does not work under Wayland. I had to switch back to standard
gnome.

I also had an issue with the fonts in the marker area not using what
the rest of the screen was set to. I went back to 1.5 for now.

The software is great and I really appreciate all you efforts.

On Thu, 2019-11-14 at 14:49 +0100, Rune Broberg via Groups.Io wrote:
Hello Karsten,
The software takes readings from the NanoVNA, and displays them and
does
calculations on them. The readings taken are the S-parameters, S11
and S21,
so any settings for traces on the device are ignored. NanoVNA-Saver
does
its own calculations of derived values, including TDR. It allows
reading
more than 101 points by stitching together multiple "segments" of the
total
span of interest.

Calibration is available on the PC-side in NanoVNA-Saver, which
allows you
to get a calibration with more points than on the device itself, as
well as
the ability to use custom calibration standard sets.

The application does not (currently) support taking screenshots of
the
NanoVNA - there are excellent scripts that do this out there - but
you can
save images of any of the graphs via the right click menu.

Frequency generation is still fundamentally part of the firmware -
NanoVNA-Saver tells the firmware the start and stop frequency of the
"segment" it is currently reading, and gets back a list of the actual
frequencies read, and the values at those frequencies. To get a step
size
lower than 100Hz, you would need a firmware that supports steps of
that
size.

The software does not need a specific firmware, but newer firmwares
have
bugfixes, and I recommend using a new firmware to get the best
experience
with your device in general.

I hope I've answered your questions, otherwise, don't hesitate to ask
here
on the list :-)


Re: NanoVNA-Saver 0.2.0

 

Herb,
I will certainly consider adding a screenshot feature :-) No promises when
it will be in ;-)

--
Rune / 5Q5R

On Thu, 14 Nov 2019 at 15:16, hwalker <herbwalker2476@...> wrote:

Rune,
Seems at least a few members are requesting the capability of taking and
saving a screenshot be added to NanoVNA-Saver. The python code is included
in edy555's nanovna.py script. From my experience, the primary "got you"
is the NanoVNA needs to be reset when taking screenshots of the version
screen or a screen including the on-screen keyboard.

You might pow-pow with QRP regarding the latter two problems as he seems
to have figured it out in NanoVNA Sharp V3. Not sure if he solved it by
firmware modification or in code.

- Herb




Re: NanoVNA-Saver 0.2.0

 

Thank you for these words Herb,
I have not to much improved SNASharp in last months because I was very busy.

But I will get back to it :)

David..

-----Message d'origine-----
De : [email protected] [mailto:[email protected]] De la part de hwalker
Envoy¨¦ : jeudi 14 novembre 2019 15:58
? : [email protected]
Objet : Re: [nanovna-users] NanoVNA-Saver 0.2.0


On Thu, Nov 14, 2019 at 05:42 AM, David F4HTQ wrote:

" ¡­ The limitation of 100Hz comes from the firmware, and maybe even
hardware ¡­."
----------------------------------------------------------------------
-------
David,
I forgot to acknowledge the fine work you have done on the SNASharp application. I couldn't resist the D6 board at its price point and it probably would have joined a host of other boards in my desk drawer were it not for SNASharp. I plan on making your impedance matching suggestions in the future.

The introduction of smt components took a lot of fun out of DIY for the radio amateur. Low cost tech like the NanoVNA and D6 help to restore the balance.

- Herb


Re: Parameter Explanation Please

 

A reference to a book or webpage would be nice
Here is a start


Re: NanoVNA-Saver 0.2.0

 

On Thu, Nov 14, 2019 at 05:42 AM, David F4HTQ wrote:

" ¡­ The limitation of 100Hz comes from the firmware, and maybe even
hardware ¡­."
-----------------------------------------------------------------------------
David,
I forgot to acknowledge the fine work you have done on the SNASharp application. I couldn't resist the D6 board at its price point and it probably would have joined a host of other boards in my desk drawer were it not for SNASharp. I plan on making your impedance matching suggestions in the future.

The introduction of smt components took a lot of fun out of DIY for the radio amateur. Low cost tech like the NanoVNA and D6 help to restore the balance.

- Herb