开云体育

I have some S21 data (see attachment) that I want import into Excel as either tab or comma delimited frequency data pair. Neither nanovna-saver or nanoVNASharp support exporting to a CSV file. Has anyone written a python script that will get the NanoVNA S21 data and save it in CSV format? I suppose I could use nanovna-saver or nanoVNASharp to save to a s2p file and then parse that file to CSV, but I don't have the programming skills or understanding of the s2p format to do so. Any help would be appreciated.

Regards,

-Herb

I just have not found them in the menus

This should help find things in menus:


.. or this, for newer firmwares:


You could first turn of all traces, then enable one,
then, under DISPLAY, keep trying options until you like one.
Then, back to TRACE, enable another, and repeat.

Sorry, Just got my second NanoVNA. The first one was DOA, back screen light, but no display. Second one seems to work fine at my limited time getting to know it.

A few questions, I am used to working in rectangular coordinates with R and j displayed. I don't use the smith chart, it is a distraction for me.So.
1. what gets you to the rectangular display with R and j?
2. How to get rid of the Smith chart in the background.

I know these are simple things, but I just have not found them in the menus, sorry.
--
Mel, K6KBE

On Sun, Oct 13, 2019 at 11:03 AM, W5DXP wrote:

If we replace the balun with a 50 ohm dummy load, disconnect the antenna, and
measure the impedance looking back down the feedline, what do we measure?
TLDetails says very close to 189+j1000 ohms, actually considering losses,
195+j994 ohms, i.e. a near-conjugate match.

I agree. This is true of any lossless (or essentially lossless) matching network (be it a tuned feedline or a lumped-element matching network) that has been tuned to match an impedance attached to the network's output to, say, 50 ohms, If you then disconnect the load and attach 50 ohms to the input of the network, and then measure the impedance presented by the tuner at its output (using your NanoVNA, for example), the measured impedance should be the complex conjugate of the impedance that had been attached at the network's output. See attached drawing.

I've used this technique to determine the "match-space" of various antenna tuners (that is, the range of impedances a tuner can match to an SWR of 1:1). If I attach 50 ohms to a tuner's INPUT and then measure the impedance at its output terminals as I vary its tuning controls, I am measuring the complex-conjugates of the load impedances that this tuner can match to 50 ohms. For an example, see:

Of course, if a network is lossy, the measured impedance presented by the tuner at its output (when its input is terminated with 50 ohms) will diverge from the actual complex-conjugate of the load impedance.

- Jeff, k6jca

Oristo, I just googled this term "USB TypeC CC resistor" and read docs from ST & Cypress that appeared:
(page 8)

You may do the same...

Is that resistor missing on current nanoVNA?

Definitely - starting from schematic diagram, where bot CC pins are NC.
There should be 5k1 resistors connected to device GND installed!

I do not understand; nanoVNA ties together DN and DP from either side of USB-C.
If both CC pins were terminated in nanoVNA,
then would that not inform USB hosts that both sides are available independently?

DJ7BA,
Thanks for your input. I have already ordered another, and plan to use the old one
just as you described.

73,

Andy - W4KIL

From: QRP RX:

On Sun, Oct 13, 2019 at 04:29 PM, W5DXP wrote: For maximum power transfer, the impedance looking back down the transmission line from the EDZ feedpoint needs to be 175+j1000 ohms, the conjugate of the feedpoint impedance.

That's not true.

I was just quoting the following from:
Maximum Power Transfer Theorem for AC Circuits: It can be stated as in an active network, the maximum power is transferred to the load when the load impedance is equal to the complex conjugate of an equivalent impedance of a given network as viewed from the load terminals. ("equivalent impedance" means the impedance transformed by the transmission line's SWR not being equal to 1:1.)

Here's a simple example based on TLDetails:

100w XMTR---50 ohm coax---1:1 balun==========59.5 deg 600 ohm feedline======== EDZ Zfp=189 - j1000 ohms

There is an SWR of ~12:1 on the 600 ohm feedline. The forward power is ~350w and the reflected power is ~250w. The SWR on the coax is 1:1, i.e. zero reflected energy is reaching the source. The power delivered to the antenna is 97.9 watts, i.e. 97.9% efficiency in power transfer. Where did the 250 watts of reflected power go? When it encountered a 50 ohm Z0-match at the balun, all the reflected power was redistributed back toward the antenna load through the processes of re-reflection and total destructive interference toward the XMTR. There's only 2.1 total watts lost in the 600 ohm feedline, i.e. 0.094 dB, mostly I^2*R losses.

If we replace the balun with a 50 ohm dummy load, disconnect the antenna, and measure the impedance looking back down the feedline, what do we measure? TLDetails says very close to 189+j1000 ohms, actually considering losses, 195+j994 ohms, i.e. a near-conjugate match.

The conservation of energy principle tells us that if zero reflected energy is reaching the source (XMTR) in a low loss system, that most of the reflected power is being redistributed back toward the load (antenna). That's what Z0-matches do.

More info at:

Maggie is very responsive and I was very happy to buy from hugen

#44 : Answers

@Gary O'Neil - Sun, Oct 6, 2019 at 05:28 AM:
/g/nanovna-users/message/4169

- also any other interested reader and/or contributor -

Dear Gary,

Once again : We are terribly sorry for this delayed
reply. However, our excuses remain constantly the
same : hard work. Please, accept our apologies.

Anyway, as we promised, here are our answers to your
specific questions:

1
The [ANALYSE] Tool (Documentation : PDF 2/15) is an
application software that we developed in order to control
through HP-IB and synchronize the overall operation of
the following five 5 different instruments:

(1) An HP8505A VNA

(2) An HP8660C Synthesized Signal Generator for PLL

(3) An HP5340A Frequency Counter in order to achieve
100 Hz frequency accuracy

(4) A step-motor, extracted from a big printer, as well as
a motor controller, which we built to be used for antenna
radiation/pattern measurements, and

(5) the computer we used to collect the indications of both
magnitude/amplitude/modulo or what other name and the
phase/argument can be used for all of them.

Thus, it was indeed a software tool designed and developed
for our automatic VNA measurement system and it is of course
independent of the rest of our work for our definition of DERs
and DEIs, as well as their determination.

Nowadays we see that VNAs use different ways to communicate
with the user and to give their data. For example we took the
[NanoVNA] data with the [Putty] via the USB interface.

This is all the reasons of why we do not describe in details this tool.

2
The 4 files [SH.SC], [OP,OC], [LD.LD], and [ME.ME] are the four
4 needed measurements in 101 frequencies, from 600 to 1000 MHz,
with a 4 MHZ step, for a ground plane antenna, as we have already
mentioned. The first three 3 are for the calibration with the "known"
SLO "standards" and the last one is the measured indications of the
antenna. All these text files have the same simple format:

frequency [MHz] - magnitude [dB] - argument [degrees]

The number of digits used are what we have from our measurement
system. And since these files are text files we can easily change their
format.

And we indeed changed recently the frequency format, since the
frequency counter we have now available can not give us -at least for
the moment- the 100 Hz accuracy we had 10 years ago - only 10 KHz.

Note: All the measurements in all of our presentations in ANAMET
- Automatic Network Analzer Metrology Club of NPL - or in our papers
were taken in CW mode, while we haven't used yet our [NanoVNA]
in CW mode.

3
The so-called system "errors" (D,M,R) or (Ed, Es, Er)
or (D,S,R) or whatever else other name, are just intermediate
complex variables and that is why we do not included an
output file for them. But we could add one easily, of course,
if there is such a need.

4
The well-known full one-port "error" model was adopted,
and the well-known relation of the bilinear transformation
was used * w i t h o u t * any simplification or term
elimination. All the involved quantities are in the complex
plane.

5
The method of determining an uncertainty estimation
in the reflection coefficient of the full one-port DUT, or of
any other quantity or "quantity" that is dependent on the
reflection coefficient such as e.g. the input impedance,
is based on the usual total differential laws as we applied
them in this specific case of complex functions of many
complex variables.

6
As we already mentioned elsewhere in our messages to
the group:

In order to keep the relations general the capital letters
A,B,C was used for the three "standard" loads for the
calibration and the three small letters a,b,c for their
corresponding measurement indications. Thus for a SLO
calibration we have - once again:

A = S = -1 (magnitude 1, argument 180 degrees),

B = L = 0 (magnitude 0, argument undetermined), and

C = O = 1 (magnitude 1, argument 0 degrees).

For their uncertainty we have - once again :

S : -0.01 for magnitude, +/-2 degrees for argument,

O : -0.01 for magnitude, +/-2 degrees for argument, and

L : 0.029 for magnitude, none for the undetermined argument

For the measurement inaccuracies, we used for all the four
4 measurements s, l, o, m:

+/-1 digit of the LSD for both magnitude and argument
readings or indications.

Thus, the uncertainties of the "standard" loads and the
inaccuracies of the measurements are all in the complex plane.

7
The final estimated uncertainty for reflection coefficient
of the DUT is the Differential Error Region DER in the
complex plane for each frequency with the corresponding
Differential Error Intervals DEIs for real and imaginary parts
in the Cartesian form, as well as and the DEIs for the
magnitude and argument in the Polar form.

Maxima was used basically for that presentation in ANAMET
and especially for the DERs, since for the DEIs any program
that plot points and lines can be used. But the plotting of a
DER needs a special treatment in order to correctly combine
rather many straight lines and circular arcs and thus it is
more tedious to be drawn.

Details for the DERs and DEIs are given in our papers and
thhree ANAMET presentations.

Please, stay tuned !

Best regards,

73

nikolitsa oe3zgn|sv7dmc & petros oe3zzp|sv7bax @ arg iaoi nfi

44#

Yes. It's a blob of noise with some wild lines around it at 25 + j0 ohm
As it is difficult to observe frequency in a Smith chart I assumed showing both R and jX would be simpler.

Using guidance from various kind people on issues with the power supply I was able to modify nanoVNA to enable the first real measurements at 2GHz.

Measurements are done WITHOUT averaging, only some more points so it is easier to see the noise levels. You will get the same results on a standalone nanoVNA

The first picture is a scan of S21 from 1.9GHz till 2.1GHz of a 20MHz BW 2GHz cavity filter
There is still a level problem as the loss of the filter is for sure less then shown. Dynamic range is a bit more than 20dB. Did not try yet if an amplifier after the filter will help

The second picture is a scan of a 25 ohm resistor that clearly shows what to expect in the future.
From 1.6GHz till a bit above 1.7Ghz the bridge stops working. Above 1.7GHz the SNR is bad but with some averaging possibly will be workable.
Now I need a 2GHz antenna for further testing.

Hope this will inspire people to explore and expand the performance boundaries of this wonderful little device.

The Alibaba store shows the following price scheme for the NanoVNA-H:

1-9 Sets 10-49 Sets >=50 Sets
$60.00 $39.00 $35.00

There is a larger than expected price disparity between single quantity and 10-49 sets, than between 10-49 Sets and >=50 Sets. I expect the NanoVNA-H will be bought in quantity by sellers and sold on eBay and other places for around $50. The current NanoVNA's without cases will probably drop to $40 or less.

- Herb

So before i downgraded to 0.1.1 firmware, i did a full calibration including clicking reset and saving to slot 0. I made sure the correction was selected as well. The correction was taking effective at least from what could tell from the output of Nano-saver cli. But the correction above 300 mhz still was not correcting what ever issue is there.


After i downgraded to 0.1.1 the smith chart was correct with a 50 ohm load. So between 0.1.1 and 0.2.x something change with the harmonic mode that caused the issue with my device. Im not seeing any more reports of this issue, but i have not modified (minus adding a plastic case) the nanovna in any way.

On Sun, Oct 13, 2019 at 05:53 PM, Oristo wrote:

Is that resistor missing on current nanoVNA?

Definitely - starting from schematic diagram, where bot CC pins are NC.
There should be 5k1 resistors connected to device GND installed!

My sister bought a bunch of unpainted Altoids size steel tins and gave me a few. I was organizing stuff yesterday and when I was putting them up I realized they were about the size of the nanoVNA. So I thought I'd investigate.

I need to redo the switches to get it in, but it looks as if it will fit with push buttons and a power switch moved to the RHS of the front panel and the SMA connectors coming through the side. It might need the PCB corners radiused a bit to clear the lip on the tin. Then the lid can be closed to protect the screen. Add a couple of SMA dust caps and it should be quite safe from harm carried in a pocket.

Reg

Yes the firmware did take. the version show 0.2.3-11 + <hash> i didnt get a change to write it down before i reflashed it with 0.1.1.



Once i reflashed back to 0.1.1, and re calibrated the smith chart looks correct under a 50 ohm load. I tried ever release 0.2.x released version as well, and those all cause the issue. So its confirmed its a firmware issue at least my device.

USB TypeC CC resistor is also installed

Is that resistor missing on current nanoVNA?

Hi Andy,

It certainly looks like the firmware update caused it. But mechanical handling
might perhaps be another possibility:

My first NanoVNA (white Gecko) fell 60 cm from the table to a soft carpet
because of touching the USB cable with my knee when charging the battery.
From then on the display didn't work anymore.

I opened and found that the very thin and fragile flat cable connecting the display
was partially cut after the fall due to the display's glass weight. No chance to fix.
I ordered another NanoVNA (now black with shield), as that was an affordable 'fix'.


So I had to learn the hard way:

Please take much care, so it will never fall even a short distance, especially when
charging from a PC under the table. Treat it more carefully than a raw egg.

And in case your display first worked, but now no longer, check for broken display flat cable.

Imho, such break easily can happen already by normal shipping, that a raw egg would survive.

In case, your display never worked, suspect an all too easy shipping damage.

I thought: A total loss, but affordable. Interestingly, the white gecko still works flawlessly
with Rune's Nanovna save software. So if used with PC or Notebook, it is still much better
than nothing. Maybe it becomes a nice present to a poor student. For now I can use it for
FW update experiments, limiting the risk value when doing that.

Any construction improvement hints? Hard to tell. But some form filling stuff comparable to
chewing gum on all four sides of the glass might reduce the vulnerability.

Any improvement ideas are most welcome.

73, Hans
DJ7BA

-----Ursprüngliche Nachricht-----
Von: [email protected] <[email protected]> Im Auftrag von Andy Yates
Gesendet: Sonntag, 13. Oktober 2019 02:36
An: [email protected]
Betreff: Re: [nanovna-users] Firmware upgrade - Touchscreen not worki

Thanks.

Removed the cover plate. No trash.
Still not working. It's got to be bad.

Andy - W4KIL




--
Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft.

Good point Rune. I prefer to support folks doing the work to move things forward. So, if there was a “Credits” page in Github or other central place that listed (like you have done in this thread) the major contributors that would help me and maybe others focus our Paypal payments. I know alot of the major contributors are actually not doing it for money, rather love of the topic, and for them being credited may simply warm their hearts or direct good karma.