开云体育

Erik,The Japanese Ham on twitter (I put photos in the files section) was running CH0 from an ext supply per the top photo. What would happen if you raised the supply voltage? It can take 8v max.?The spec sheet shows a VCC filter using a 5.5uH and a couple of caps.?
Also, that ip5303 is probably putting out a pile of radiated RF noise not only on the supply lines. Try running the device on 4 AA batteries for your next test. I don't know off hand what the max Vin for the 3v Reg is though.?
Larry



On Mon, 14 Oct 2019 at 3:04 AM, erik@...<erik@...> wrote: Changed the offset from 5kHz to 12kHz and running the nanoVNA? directly from a linear 5V power supply. Even with USB connected the latter makes a substantial difference in noise levels
Guess adding some inductors to the nanoVNA to block VHF/UHF supply noise is the next step

Those 2 resistors are only required if you are using a usbc to usbc cable on a usbc computer port as they tell the computer the type of device being connected. If you're using a usb3 to usbc cable on a normal usb3 or 2 port, they don't matter.

On Mon, 14 Oct 2019 at 1:33 AM, Starsekr via Groups.Io<Starsekr@...> wrote: Jacon, if the resistors are missing, what does that do to USB communication? Are they just for using the USB as a sink (load?) for charging a battery through the USB port? Without them does the upstream usb just see the Nano as a low power sink?

I had uploaded a zipped file in the Forum's file section that has info on the matching pad, if you would care to look at.?



On Mon, 14 Oct 2019 at 12:14 AM, Starsekr via Groups.Io<Starsekr@...> wrote: I started this topic because the original thread? got hi-jacked to antennas matching.? :-(
H Walker posted? in Msg #4702
/DMR,
/Thanks for your contribution.? A previous DFU file was uploaded for making 75 ohm system measurements
/ ("50-75 Ohm_Use transformer-10.10.2019.ra").
/The uploader made special note that in order for measurements to be accurate 50-75 ohm matching pads were required on CH0 and CH1.? Does your
/mod also require matching pads/transformers, or are you applying some type of mathematical correction factor?
/
/- Herb

** Herb,? I can't find that file.? Could you give us a message number?? Have you opened it?? ? Thanks? Jim

Dr. David Kirkby posted in msg. #4540
/1) Minimum loss pads can be used to allow calibration with 75 ohm
/calibration kits. There are 75 ohm versions of both N and BNC connectors,
/and calibration kits for both available

**David, I understand the 7 db loss pads..? Would wide band transformers work also?? Coilcraft makes several, one set is sold on Mr. Kurt Poulson's? SDR-Kit site and on eBay, or maybe we could roll our own , at least for 3-30 Mhz or 6, 4 or 2 meter bands.? One pad/transformer for each VNA port used?

* Anyone.? Assuming? I understand me using pads/transformers, and calibrating at the desired impedance (75 ohms) at the test fixture, then the NanoVNA Smith chart, while showing 50 ohms is actually 75 ohms reference, and the graphs will be ref. to 50 ohms, what math operation do I do to get a 75 ohm graph and (maybe using Excel) to get 75 ohm values?? URLs or pointers to web sites are welcome.

thanks,
Jim, KA6TPR

Hi Herb
The s1p and s2p files are plain txt files so you can open then directly from Excel, choosing a separator then you can save tocsv. However the first 4 lines are text telling what type of data are in the columns which you may removed.
I use also a plane txt editor like notepad+ to remove sections of the frequency range e.g. from 500MHz upwards and the like
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af hwalker
Sendt: 14. oktober 2019 04:06
Til: [email protected]
Emne: [nanovna-users] Save S21 data in CSV format

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

If you change just firmware for Z0=75 ohm it won't work for 75 ohm properly. It may show you proper resistance for zero reactance circuit (such as dummy loads and resistors). But if your circuit contains any inductor, capacitor or transmission line, you will get wrong measurement. Because it's Q-factor will be affected by 50 ohm hardware port, so you will get shifted resonance and different S11 and S21 reading.

On Sun, Oct 13, 2019 at 10:12 PM, John Gord wrote:

….. "To get dB, you compute 20*log(sqrt( real^2 + im^2)), or equivalently

10*log(real^2 + im^2).
10 * log (0.019876752^2 + 0.001359617^2) = -34.013, the insertion loss in dB.
You can also get the phase by taking the arctan (im/re). "
--John Gord

------------------------------------------------------------

John,
That's the key piece of info I needed. None of my web searches returned that conversion formula. I can now use Excel to convert the data to dB and then apply some additional correction factors. I would eventually like to use Python to read the data directly from the NanoVNA and post process, plot and save it to a factor file. That's something I never would have even considered before purchasing the NanoVNA. The device has expanded my learning horizon. Thanks to everyone who responded.

- Herb

Hi David,
the firmware is written in C.

I don't know that there are formal constraints, other than what the license
(GPLv3) puts on it. I personally, as an application developer, have a few
suggestions:
1) Don't change the way commands on the serial interface work - add new
commands instead,
2) If your firmware starts to deviate significantly from the stock version,
change the "board" information in the "info" command from NanoVNA to
something else,
3) Make sure your version numbers (version command) don't collide with what
the official releases use. If you base your mod on version 0.2.3, for
example, you could number it "0.2.3-kirkby-1".

--
Rune / 5Q5R

On Mon, 14 Oct 2019 at 10:49, Dr. David Kirkby from Kirkby Microwave Ltd <
drkirkby@...> wrote:

There are some features that I would like added to the firmware connected
with calibration. I don’t mind making them public, but are quite happy to
just add them for my own use.

Are there any guidelines around for what one should and should not do? Some
examples of adding menus? Constraints etc?

I believe that the firmware is written in Python. I have never written
anything other than the simplest program in Python, but I know C well, so
Python should not present me too many problems - I need to learn Fortran! I
would want to work in a Unix environment if possible. I actually use
Solaris as my main operating system here, but would be happy to use Linux
and I guess Windoze if absolutely necessary.?????

Dave.
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

There are some features that I would like added to the firmware connected
with calibration. I don’t mind making them public, but are quite happy to
just add them for my own use.

Are there any guidelines around for what one should and should not do? Some
examples of adding menus? Constraints etc?

I believe that the firmware is written in Python. I have never written
anything other than the simplest program in Python, but I know C well, so
Python should not present me too many problems - I need to learn Fortran! I
would want to work in a Unix environment if possible. I actually use
Solaris as my main operating system here, but would be happy to use Linux
and I guess Windoze if absolutely necessary.?????

Dave.
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

if the resistors are missing, what does that do to USB communication?

Indeed, that is the question, and I >>suspect<< is why some notice
more reliable nanoVNA connections via USB-2 hubs than to USB-3 hosts.

Are they just for using the USB as a sink (load?)

USB-C connectors are mechanically symmetric.
In order for half the 24 connections to NOT be redundant, electrical "keying" is wanted.

1) I >>guess<< that a single resistor from one CC to ground is wanted in nanoVNA for electrical keying
2) I >>suppose<< the original nanoVNA design, with DP1 tied to DP2 and DN1 tied to DN2,
was intended to suffice as symmetric don't-care.
3) I >>suspect<< that floating CCs provoke some USB hosts to misinterpret nanoVNA capabilities
and attempt sending signals via DP1 & DN1 that differ from those on DP2 & DN2
or even try to employ some lines not supported by USB-2 and not used by nanoVNA.

As with FAR too many other areas of commercialized innovation,
USB-C promoters evidently prefer acronyms to clear explanations,
with several documents "describing" functions to be accomplished by a USB-C cable,
called EMCA (really??), which make sense (to me) only if implemented by devices.

Hi ...

I would like to try You new nanoVNA v1.03 TD Rb4 (like TDR ...)

Thank You, Vlatko

Hi

Here is how to split "any somewhat formatted" text file using Excel 2003*. The procedure has been the same since the early 1990'ies:
- Open the file in Excel
- When the "Text Import Wizard" shows
(Step 1 of 3)
- select fixed width, in the case of a S2P file otherwise it could be delimited with e.g. "space", ";", ",", "tab" ...
- select the row to start the import
- select the file origin. Sometimes this may require some experimentation to match the OS locale
- click the Next button
(Step 2 of 3)
- click the Next button
(Step 3 of 3)
- click the Advanced button
- select the decimal separator (S2P file = .)
- select the thousands separator (S2P file = ,)
- click the OK button
- Click the Next button

*: I don't know how it is done in later versions or other spreadsheet programs.

Another way to convert the decimal separator is to open the file in a text editor and replace the decimal separator.

Bo

Changed the offset from 5kHz to 12kHz and running the nanoVNA directly from a linear 5V power supply. Even with USB connected the latter makes a substantial difference in noise levels
Guess adding some inductors to the nanoVNA to block VHF/UHF supply noise is the next step

On Mon, 14 Oct 2019 at 05:14, Starsekr via Groups.Io <Starsekr=
[email protected]> wrote:

I

Dr. David Kirkby posted in msg. #4540
/1) Minimum loss pads can be used to allow calibration with 75 ohm
/calibration kits. There are 75 ohm versions of both N and BNC connectors,
/and calibration kits for both available

Yes, and F connectors too.

**David, I understand the 7 db loss pads.. Would wide band transformers
work also? Coilcraft makes several, one set is sold on Mr. Kurt Poulson's
SDR-Kit site and on eBay, or maybe we could roll our own , at least for
3-30 Mhz or 6, 4 or 2 meter bands. One pad/transformer for each VNA port
used?

Yes, transformers will work, and given the fairy low dynamic range of the
NanoVNA, transformers would be better in *most* cases. However, by their
very nature they are not very wide-band and will present a short at DC.

Depending on what your requirements are, you may determine that not adding
any resistors or transformers is perfecly acceptable.

One thing to bear in mind is that the reflection coefficient at port 2
might not be low at 50 ohms. In fact from a previous note I see posted,
this would vary depending on the actual batch of chip used. I do actually
intend trying to improve the match at port 2 to 50 ohms by a series
resistor or shunt resistor. Before even considering adding a transformer on
port 2, you should determine what it’s impedance currently is.

Something else to consider is that given the cost of a NanoVNA, it might be
worthwhile to buy a second one and change the hardware to 75 ohms. I
suspect not only requires changing a few resistors, but I have not looked
at the circuit.

* Anyone. Assuming I understand me using pads/transformers, and
calibrating at the desired impedance (75 ohms) at the test fixture, then
the NanoVNA Smith chart, while showing 50 ohms is actually 75 ohms
reference, and the graphs will be ref. to 50 ohms, what math operation do I
do to get a 75 ohm graph and (maybe using Excel) to get 75 ohm values?
URLs or pointers to web sites are welcome.

If the VNA supposed 75 ohms properly, all that should be taken care of.

Whilst someone is going to the effort of supporting an impedance other than
50 ohms, it would make sense to me to make the impedance being able to set
to any value, but defaulting to 50 ohms.

thanks,
Jim, KA6TPR

Dave.

--

Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United
Kingdom

Jacon, if the resistors are missing, what does that do to USB communication? Are they just for using the USB as a sink (load?) for charging a battery through the USB port? Without them does the upstream usb just see the Nano as a low power sink?

Herb,
The S2P file can be in decibels and phase angle, or in real and imaginary part for each component.
In this case, I think "RI" indicates real and imaginary for each of the four S parameters (S11, S21, S22, S12) of a two port network.
The data is for only S11 and S21 here, so the last 4 entries in each line are zero.
To get dB, you compute 20*log(sqrt( real^2 + im^2)), or equivalently 10*log(real^2 + im^2).
10 * log (0.019876752^2 + 0.001359617^2) = -34.013, the insertion loss in dB.
You can also get the phase by taking the arctan (im/re).
--John Gord

On Sun, Oct 13, 2019 at 08:58 PM, hwalker wrote:

# Hz S RI R 50
50000 -0.009529378 0.000616876 0.019876752 0.001359617 0 0 0 0

Herb,

As you know S-Parameter files are actually text files.

The line with the "#" character is the format string for the file. This may or may not be the first line in a file.

In the case above, the frequency is in Hz, this is an S-parameter file, the data values are Real and Imaginary because the header has "RI" and the impedance system is Resistive and 50 Ohms.

1st column is frequency in Hz, indicated by Hz in the first line,
2nd column is S11 real part (-0.009529378 above)
3rd column is S11 imaginary part (0.000616876 above)
4th column is S21 real part (0.019876752 above)
5th column is S21 imaginary part (0.001359617 above)
6th column is S12 real part (0 above)
7th column is S12 imaginary part (0 above)
8th column is S22 real part (0 above)
9th column is S22 imaginary part (0 above)

nanoVNA-Saver does not save the data in dB format.

I hope this helps.

--
Bryan, WA5VAH

I started this topic because the original thread got hi-jacked to antennas matching. :-(
H Walker posted in Msg #4702
/DMR,
/Thanks for your contribution. A previous DFU file was uploaded for making 75 ohm system measurements
/ ("50-75 Ohm_Use transformer-10.10.2019.ra").
/The uploader made special note that in order for measurements to be accurate 50-75 ohm matching pads were required on CH0 and CH1. Does your
/mod also require matching pads/transformers, or are you applying some type of mathematical correction factor?
/
/- Herb

** Herb, I can't find that file. Could you give us a message number? Have you opened it? Thanks Jim

Dr. David Kirkby posted in msg. #4540
/1) Minimum loss pads can be used to allow calibration with 75 ohm
/calibration kits. There are 75 ohm versions of both N and BNC connectors,
/and calibration kits for both available

**David, I understand the 7 db loss pads.. Would wide band transformers work also? Coilcraft makes several, one set is sold on Mr. Kurt Poulson's SDR-Kit site and on eBay, or maybe we could roll our own , at least for 3-30 Mhz or 6, 4 or 2 meter bands. One pad/transformer for each VNA port used?

* Anyone. Assuming I understand me using pads/transformers, and calibrating at the desired impedance (75 ohms) at the test fixture, then the NanoVNA Smith chart, while showing 50 ohms is actually 75 ohms reference, and the graphs will be ref. to 50 ohms, what math operation do I do to get a 75 ohm graph and (maybe using Excel) to get 75 ohm values? URLs or pointers to web sites are welcome.

thanks,
Jim, KA6TPR

QRP,
I had looked at the S2P file using a text editor and could see the values were space delimited but the none of the columns were identifiable to me as the S21 log magnitude values displayed by the nanoVNA. For example at 50 kHz the insertion loss value was -34.013 dB but none of the values at 50000 in the S2P file below are that value.

# Hz S RI R 50
50000 -0.009529378 0.000616876 0.019876752 0.001359617 0 0 0 0



- Herb

On Sun, Oct 13, 2019 at 08:27 PM, <erik@...> wrote:

I was able to modify nanoVNA to enable the first real measurements at 2GHz.

What is your modification exactly?

S1P and S2P files are CSV compatible. You can just copy it's content into excel