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You got it! Yes.

Dave - W?LEV

On Mon, Apr 28, 2025 at 10:24?PM Andreas Ott K6OTT via groups.io <andreas=
[email protected]> wrote:

Hello,

On Tue, Apr 22, 2025 at 8:40?AM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

You will only have valid measurements within the frequency range you
calibrated.

Am I reading this right as: I should always configure the stimulus range
first, and then calibrate. For example, if I want to get an overall (not
finely granular) sweep of a multiband antenna from 3...30MHz, I would first
select this as stimulus range and then calibrate? If I then want to show a
single band, like just 40m or 20m, I would again set those respective
ranges and recalibrate?

Thanks, andreas K6OTT

--

*Dave - W?LEV*


--
Dave - W?LEV

Hello,

On Tue, Apr 22, 2025 at 8:40?AM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

You will only have valid measurements within the frequency range you
calibrated.

Am I reading this right as: I should always configure the stimulus range
first, and then calibrate. For example, if I want to get an overall (not
finely granular) sweep of a multiband antenna from 3...30MHz, I would first
select this as stimulus range and then calibrate? If I then want to show a
single band, like just 40m or 20m, I would again set those respective
ranges and recalibrate?

Thanks, andreas K6OTT

I'm real time on my H4, so hope this maps to yours.

QUOTE (Dean, W8ZF): This just confuses me again. "Remove the calibration
and save that to the default slot (0 slot) when using NanoVNA Saver."

Remove *which* calibration? And save *what* to slot 0? Are you talking
about the H4 device? Do you mean from the calibrate menu, choose "Reset"
and then "Save" to memory 0?
What values does this put into memory 0? And since nanovna-saver depends
on the calibration of the H4 device, what is that calibration now (after
reset and store 0)?

"When you calibrate the Nano (on device calibration) in the range as the
documentation suggests 0-900MHz with 401 points..."

Where is there an option on the H4 device to select the number of points
used for calibration? I haven't seen that as a menu option.

Calibrating on the native NANOVNA, there is no choice for number of
points. I believe it will default to the maximum number of points which is
401 (??).

Always remember to "RESET" before a new calibration.
***

If the calibration of nanovna-saver gives different results, depending on
the state of the H4's calibration, I don't know what to believe.

It depends on how different the results are. Remember, the FW interpolates
between measured and stored cal values. Saver can be configured with 1001
points so the cal. sampling is much finer than a cal. on the native NANOVNA
(without SAVER).
***

Forgive me, I still don't understand how this works together. I don't see
why nanovna-saver can't just read raw results from the H4, and then use
those for a calibration (which would make it independent of the H4's
calibration). There have been some mentions about different numbers of
points, about reporting invalid values, etc.

Again, using SAVER, there is the option to use considerably more points for
calibratioin: Native is 401 points, SAVER allows up to 1001 points. So
extrapolation between measured points using the two calibrations will be
coarser with the native VNA cal than with the SAVER cal.

If you simply were able to upload the native cal (H4 alone) to SAVER, you
would not take advantage of a number of additional measurements and
presentations. SAVER is considerably more powerful than the FW within the
native NANOVNA.
*


Does anyone KNOW, not guess, what the proper procedure to calibrate this
system using nanovna-saver is? Nanovna-saver is what it is, I'm not
bashing it or trying to change it -- I'm just trying to understand the
limitations and requirements to get good results out of the software. The
ability to store calibrations, write s-parameter files, and plot using
different formats is invaluable to me. I *really* want to use it for these
features, but not if I can't be sure of the measurement.

Once you have "woke up" your NANOVNA by a native calibration, connect and
run SAVER. Treat SAVER as a totally independent set of FW/SW from that
within the NANOVNA. SAVER has all the options to connect, reset, do a
complete cal potentially with more points than the native NANOVNA can
support. Again, SAVER offers much more capability the the FW embedded
within the native NANOVNA.
***

General Comment: Remember we are not expecting metrology lab comparisons
between the native NANOVNA and the SAVER results/measurements. Differences
with carefully and faithfully duplicated setups, disagreements in the first
significant figure, or maybe in the second, should be of little concern.

For example, if you measure a single 50-ohm resistos with three different
DMMs, you will get three different results. Here you go using a stock
50-Ω, 3%, 1-watt resistor:
[image: image.png]


INSTRUMENT MEASURED VALUE (Ω)

HP 3478A 49.994

Cen-Tek P37772 50.1xx

Sperry DM-6400 49.8xx

HP 4261A LCR Mtr 50.8xx

Well, which one would you pick? Is it a 50-Ω resistor? None of the
measurements indicate it's 50-Ω. Is it within the 3% specification of ±1.5
% or ± 0.75 ohms? Yes, by three of the four measured values made on four
different instruments.

Dave - W?LEV

On Mon, Apr 28, 2025 at 8:25?PM Dean W8ZF via groups.io <dwfred=
[email protected]> wrote:

Dragan,
This just confuses me again.

"Remove the calibration and save that to the default slot (0 slot) when
using NanoVNA Saver."

Remove *which* calibration? And save *what* to slot 0? Are you talking
about the H4 device? Do you mean from the calibrate menu, choose "Reset"
and then "Save" to memory 0?
What values does this put into memory 0? And since nanovna-saver depends
on the calibration of the H4 device, what is that calibration now (after
reset and store 0)?

"When you calibrate the Nano (on device calibration) in the range as the
documentation suggests 0-900MHz with 401 points..."

Where is there an option on the H4 device to select the number of points
used for calibration? I haven't seen that as a menu option.

If the calibration of nanovna-saver gives different results, depending on
the state of the H4's calibration, I don't know what to believe.
Forgive me, I still don't understand how this works together. I don't see
why nanovna-saver can't just read raw results from the H4, and then use
those for a calibration (which would make it independent of the H4's
calibration). There have been some mentions about different numbers of
points, about reporting invalid values, etc.

Does anyone KNOW, not guess, what the proper procedure to calibrate this
system using nanovna-saver is? Nanovna-saver is what it is, I'm not
bashing it or trying to change it -- I'm just trying to understand the
limitations and requirements to get good results out of the software. The
ability to store calibrations, write s-parameter files, and plot using
different formats is invaluable to me. I *really* want to use it for these
features, but not if I can't be sure of the measurement.

73,
Dean W8ZF

--

*Dave - W?LEV*


--
Dave - W?LEV

Can anyone direct me to the latest SAFE version of nanovna-app? I went to GitHub and found a branch under DiSlord. There is a Win32 release of NanoVNA-App.exe from 2 months ago. When I try to run it, it fails the MS Defender malware scan. That is common for many apps that don't pay MS for the "safe" tag, so it may be fine. I just wanted to verify before I bypassed the warning and ran it.
Thanks,
Dean W8ZF

Dragan,
This just confuses me again.

"Remove the calibration and save that to the default slot (0 slot) when
using NanoVNA Saver."

Remove *which* calibration? And save *what* to slot 0? Are you talking about the H4 device? Do you mean from the calibrate menu, choose "Reset" and then "Save" to memory 0?
What values does this put into memory 0? And since nanovna-saver depends on the calibration of the H4 device, what is that calibration now (after reset and store 0)?

"When you calibrate the Nano (on device calibration) in the range as the
documentation suggests 0-900MHz with 401 points..."

Where is there an option on the H4 device to select the number of points used for calibration? I haven't seen that as a menu option.

If the calibration of nanovna-saver gives different results, depending on the state of the H4's calibration, I don't know what to believe.
Forgive me, I still don't understand how this works together. I don't see why nanovna-saver can't just read raw results from the H4, and then use those for a calibration (which would make it independent of the H4's calibration). There have been some mentions about different numbers of points, about reporting invalid values, etc.

Does anyone KNOW, not guess, what the proper procedure to calibrate this system using nanovna-saver is? Nanovna-saver is what it is, I'm not bashing it or trying to change it -- I'm just trying to understand the limitations and requirements to get good results out of the software. The ability to store calibrations, write s-parameter files, and plot using different formats is invaluable to me. I *really* want to use it for these features, but not if I can't be sure of the measurement.

73,
Dean W8ZF

AppCAD. Brian, I mentioned this way back when you started this plotter project.

It is now available as....

And is the old HP semiconductor group, formed AVAGO semi off shoot and now under BROADCOM.

It does more than S parameter 2 port circuit analysis and is quite worthwhile to bring into a classroom environment.
Program permits up to 6 s data files to be compared and I have used it to illustrate stability analysis on amplifiers as
I can add feedback and compare an unstable s data file with one that is stabilized.

Many features at an attractive price,,,

Alan

No relay to switch the source to the second port.
(and no bridge on the second port, either)
The NanoVNA doesn't use a directional coupler - it's a straight up bridge on Ch0 and a pad on Ch1.

Now that you mention it, that would have been a fairly easy thing (but hard to fit in the original 2x3" size)

You can, in fact, use two NanoVNAs with SMA T connectors to do a full 4 parameter measurement without having to move cables. You can "almost" do it simultaneously, even. If NanoVNA B sees the sweep from NanoVNA A, (or vice versa) you get a momentary spike in the displayed data.
I tried it using NanoVNA-Saver (running two separate instances) and it calibrates nicely, etc.

Brian,

Ahh yes, the old HP AppCAD program. I loved that thing back in the day. Not perfect, but a pretty decent tool, and you can't beat the price. For those looking for more information on this program, and I recomend it highly for those wanting a useful tool, try starting at the following website for older versions, as well as related help files and information:



Good call, Brian, I hadn't used that in a while, because I'm currently teaching space engineering courses, but a useful program for anyone working with microwave circuits, filters, baluns etc.

Randy

Randy J. Jost, PhD
r.jost@...
435-770-9855 (c)

On Mon, Apr 28, 2025 at 08:22 AM, RANDY JOST wrote:

Really looking forward to your updated program to show students in my EM
courses how it should be done.

Randy, if the program proves helpful for your students, that would be just great.

I didn't set out to write an s-parameter plotter. I wrote a little utility to renormalize the s-parameter reference impedance. This lets you use a VNA to measure a filter whose termination impedances differ from 50 ohms without building a matching network. When it came time to test the program, I looked around for an s-parameter plotter. The only ones I could find either did not handle all s-parameters, had bugs, or were very awkward to use. So I wrote my own. While I was at it, I built renormalization into it.

If you need an s-parameter plotter oriented toward amplifiers for your students, try AppCAD:



It hasn't been updated since 2012, but it has many features for amplifiers I found nowhere else. I think this is the program that took me 45 minute to see a plot! This also may be the one with points slightly off in a group delay plot. Nevertheless, I think students might find it helpful.

Brian

Computer Results: Remember maybe four or five decades ago (man, its been
that long!) when all the computer "Yagi Design" applications hit hams with
stars in the eyes? Some were good, some were mediocre, some yielded
unreasonable results, and some were just off the wall. The "math" or
models behind them was fixed and allowed little, if any, real input from
the user other than frequency and number of elements. The general belief
was almost universal: "I designed it on my computer so it must be right and
better than any other option!" Wrong....... But hams almost "worshipped"
the results totally believing the computer could and did offer far better
results than any other method under the sun and blue sky.

At present, I would venture an hypothesis that we're in a similar situation
with the tried-and-true Smith Charts vs. the computer generated reams and
columns of computer generated numerals. Take your pick. I'm an old
fuddy-duddy fossil, and I'll stick with what is so clear and designed for
impedance space: The Smith Chart.

Yes, I use SimSmith extensively, but it's still the tool that was designed
specifically for impedance space, the venerable and highly useful Smith
Chart.

Would you say the computer, PC is better at the following?

Time Domain: The oscilloscope ... not a PC
Frequency Domain: The spectrum analyzer ... not a PC
Impedance Domain: The Smith Chart ... That's what this thread is all
about
Temperature Domain: The thermometer ... not a PC
Color Domain: The optical spectrometer (similar to the spectrum
analyzer) ... not a PC
Voltage Domain: The volt meter or DMM ... not a PC
Current Domain: The ammeter ... not a PC
Power Domain: The proper power meter ... not a PC
....
.....
......
.......

Fill in your favorite "space".

Dave - W?LEV

On Mon, Apr 28, 2025 at 3:07?AM William Heller via groups.io <wheller34052=
[email protected]> wrote:

While in colledge I took a computational physics class and was assigned a
matrix with fractions such 1/3, 1/7 to evaluate three ways by long hand
pencil and paper, with a handheld calculator, and writing a fortran
program. The calculator gave fairly consistent results among the students
while the computer results varied between plus and minus infinity. What a
clear leason that was.

On Sun, Apr 27, 2025, 7:14 PM Maynard Wright, P. E., W6PAP via groups.io
<ma.wright@...> wrote:

The Smith chart, of course, can be replaced by any of many software
packages that yield just numerical results, but not the feel for what's
going on. One may be really happy with incorrect numbers that fall out
of a computer or calculator where the Smith chart might make one think
"That ain't right!"

I still use slide rules for pretty much the same reasons. Although I am
thankful that I don't have to work my way manually through hyperbolic
functions of complex argument as I did early in my career when no
calculators or computers were readily available.

73,

Maynard
W6PAP

On 4/27/25 14:45, W0LEV via groups.io wrote:

From the original publication in the early 1950s, the Smith Chart

addressed

impedance space, not just line lengths.

I once had in my hands while working for a living (now retired) the
original publication which introduced the world to the Smith Chart. I
offered the engineer who owned it $200 on the spot. He refused. I

upped

my offer to $300 on the spot. He again refused. He also refused my

$400

offer. I gave up. At least I got to actually handle and leaf through

it!

Now I have the time in retirement, but no $$ for "frivolous" things

like

that.....

As an EMC/RFI/RF design engineer and spending a good amount of my
professional life as well as on the hobbies designing, building, and
matching antennas and any number of RF/?W circuits, the Smith Chart

will

go

to my grave with my decaying body......

Dave - W?LEV

On Sun, Apr 27, 2025 at 9:30?PM Team-SIM SIM-Mode via groups.io

<sim31_team=

[email protected]> wrote:

Hi
The Smith chart is simply a specific graphical method for illustrating
impedances—originally as a function of line length, and now, with the
NanoVNA, as a function of frequency. Its advantage lay in simplifying

the

plotting process on paper using just a compass to draw the impedance

circle

based on the electrical length of the line, resulting in a neat circle
centered on the chart's origin. With the NanoVNA, this also produces a
clean circle around the center, but by varying the stimulus

frequency.?

This method has allowed me to measure the characteristic impedance of
coaxial cables precisely and reliably at a given frequency by

centering

the

impedance circle on the chart's origin. This is achieved by adjusting

the

normalization impedance using the feature provided in DiSlord firmware
version 1.2.40.

No other graphical method offers such performance and ease for

measuring

characteristic impedance (Zc) with this level of elegance and

precision. It

truly is the 'magic circle' of the Smith chart.?

73s Nizar

















ChatGPT peut faire des erreurs. Envisagez de vérifier les informations
importantes

--

*Dave - W?LEV*


--
Dave - W?LEV

Hi, Brian,

This looks really good to me. Very crisp and sharp lines. Using Gwenview under Kubuntu here in case it matters.

73,

Maynard
W6PAP

Hi,

home made antenna is with ONE sma connector (no balun added) while factory made has a wilkinson splitter and two cablesz

have I ever mentioned that to be a difference ? yes, one has SMA, the other has solder joints. Both have had the same balun (obviously)

factory antenna has a triangle "groundplane" (while homemade has not) ... so yes you may see high difference cause they are not as identical as you think

what triangles and what "groundplane" would those be ?

sidenote: it looks way roo small for 300mhz ... are you sure its not for 3 ghz?!? ;-)

pretty sure ;-)

Thanks

Wow, I love spirograph art, so cool! :-) Really looking forward to your updated program to show students in my EM courses how it should be done. Using a Smith Chart program along with the equations really helps to remove the black box / black magic aspect of so many aspects of antenna, transmission line and microwave engineering. At least for we old timers, I guess.

Randy J. Jost, PhD
r.jost@...
435-770-9855 (c)

Thanks, Dean. The S22 Smith plot is available. I've attached one that looks like abstract art. I was just curious whether I was gilding the lily.

The program includes a utility to merge two .s2p files containing S11 and S21 to produce a file with all four s-parameters. This is for NanoVNA users willing to take the trouble to measure both forward and reverse response. Both reference impedance renormalization and the Y21 method work best with all four parameters.

The 800 x 600 test plot looks fine. I think the forum rescaled the 1024 x 768 and then scaled it back to its original size.

I'm going to leave admittance for another day (probably tomorrow). I keep finding small bugs so I'm going to concentrate on digging them out before posting the program later today.

Brian

Brian,
S22 is also useful and a Smith chart presentation would be desirable. But this would have less priority because the nanovna does not have the capability to measure it. Plus, you can always measure s22 by reversing your ports and measuring S11.
I dont know if the nanovna lacks the second directional coupler or the chipset has this limitation, but you can work around, for $70!

73,
Dean W8ZF

This is just a test plot. I noticed that the 1024 x 768 plots I posted earlier were not exactly reproduced. They are slightly fuzzy and colors are a bit off. Let's see how well this this 800 x 600 plot does.

Brian

Well, I'm getting there. So many pesky details.

I find Smith plots fascinating. It's hard to resist the urge to post dozens of really strange and interesting curves. I hope I don't become an insufferable Smith plot zealot!

I think the value of Smith plots for me will be much more in the realm of instant pattern recognition than analytical.

I've provided for S22 Smith plots as well as S11. Does anyone use them for S22?

Brian

home made antenna is with ONE sma connector (no balun added) while factory made has a wilkinson splitter and two cablesz

factory antenna has a triangle "groundplane" (while homemade has not) ... so yes you may see high difference cause they are not as identical as you think

dg9bfc sigi

sidenote: it looks way roo small for 300mhz ... are you sure its not for 3 ghz?!? ;-)

Am 28.04.2025 um 10:58 schrieb kellogs via groups.io:

Hello,

Homemade BLUE bowtie antenna vs factory made BLACK whole board with the same bowtie antenna.

Over 300 - 330 MHz range I am seeing some ~20 change in reactance with the home made antenna and ~50 ohm with the factory made. Also the resistance is 7-8 times greater for the factory made antenna, also varying much more.

Sames:
- placement of the antenna
- calibration place, cables and others related (*)

Diffs:
- calibration range: 300-330 for home made vs. 235-395 for factory made
- (*) connection to home made antenna through SMA connectors vs. direct soldering for the factory made antenna;
- calibrated with standards for home made vs. with wire / nothing / two 100 ohm resistors measured at 50.5 ohms with DMM

Is it normal to see such large measurement differences ?

Thank you

Is the Nanovna connected?
Nanovna-app doesn't sweep until you press the start sweep button, did you do that?