开云体育

Hi Peter,
just a quick note: On the NanoVNA, you calibrate the device itself, and
what it outputs on its screen, and via the USB cable. In NanoVNA-Saver,
you calibrate exclusively within the software - it relies on the
calibration on the NanoVNA itself remaining constant. This also allows
calibrating with more data points than the NanoVNA itself allows. Using the
"segments" setting, you can get many more points than the 101 of the device
itself. There is no way to save calibration to the device. Neither the
firmware, nor NanoVNA-Saver, supports this.

Since we are on the subject of calibration: NanoVNA-Saver has a calibration
assistant, and 5 manual buttons for calibration. Use the assistant. The
manual buttons take whatever is currently stored (and being displayed) by
the application, and uses that as the calibration data. It does *not* make
a separate sweep for the new standard - it assumes the user knows to do
this themselves. The latest version has a warning popup if a user tries to
use the manual buttons.

I hope you enjoy using the application :-)

--
Rune / 5Q5R

Hi Gyula,
Many thanks for the answer.Will see what I can do wiy saved calibrations on
the Hard disk.
Best Regards !

Hugen released new firmware today for NanoVNA-H and NanoVNA-H4. Version number is 0.4.5-4.

The final post here

indicates that pip 19.3.1 fixed the problem on Debian Buster,
whereas it didn't for you.

Built nvna-a 0.2.2 with python 3.7.6 on Win7 x64 (mingw64) first with pip
19.2.3 then pip 19.3.1. Everything including PyQt5==5.14.1 was installed
without a hitch!

Do not know what to make of all this. Will do more tests.

Yes, Windows does not match the linux/POSIX paradigm for directory ownership;
this cache ownership bug cannot occur on Windows.

One workaround for linux user den is:
`chown den /home/den/.cache`

if /home/den/.cache does not exist, then
`mkdir /home/den/.cache`

If /home/den/.cache is already owned by someone else, then:
`sudo chown den /home/den/.cache`

Then repeat for /home/den/.cache/pip

The "fix" for pip was to disable caching, which seems dumb (to me):

Hi Peter,

You can't save to your device with the nanoVNA saver.
The backup is done to your computer.
It is advisable to write detailed information in the note.

Gyula HA3HZ

Hello All,
When calibrate the device (nanoVNA-H) all is 100% OK.
When I do calibrate with nanoVNA saver (several versions incl.0.2.2-1), all is
also OK 100%, exept lhe last step - saving the calibrtion in nanoVNA-H. No way to
save this calibration in nanoVNA-H.I can save it to the Disk only.
Seems somewhere I make mistake,,,, Where ?
The connection between the Saver and device is established and active.
The VNA-H is not prepared to get data ?
I have not found the procedure for recording in the device via NanoVNA Saver anywhere. Many things are described how to calibrate, but this is not exactly what it is.
Any Help will be appreciated.Thanks in advance,
Peter

Hi Herb,

Thanks for the information. There is also a contact link from where you can download it

73, Gyula

On Sat, Jan 18, 2020 at 08:10 AM, Gyula Molnar wrote:

Updated firmwares.
the dates in the file names represent the latest release.
=================================
Gyula,
The updates are much appreciated. I just received my NanoVNA-H v3.4 unit and a version no. appears to have been snuck in by hugen (see attachment).

NanoVNA-saver identifies it as follows:

0.4.4-1- Dec 18 2019 NanoVNA-H version compiled on December 18, 2019
1. New scan command
2. Screenshots

Again, please note that currently this firmware version is only distributed with the NanoVNA-H v3.4.
- Herb

measuring cable and insertion loss ala

Added to "External Links" wiki page
/g/nanovna-users/wiki/External-links#related-28RF29-links

Updated firmwares.
the dates in the file names represent the latest release.

73, Gyula HA3HZ

Thanks for the tips everyone. After sending I realize what I'm particularly interested in is measuring cable and insertion loss ala .

Given that I'm looking at seven days straight of rain (the joy of Seattle in the winter) disconnecting parts of the transmission line and testing them independently is not a near-term project :-).

I had previously seen the collective wisdom part of the wiki, some great gems in there.

Thanks,
Chris

Hi Ben -

what was going on here

Please check out the Wiki
/g/nanovna-users/wiki

Good morning all,

Just signed up for the list and thought I'd introduce myself. Name is Ben Hall, ham call KD5BYB. Was introduced to the NanoVNA buy an article on the RTL-SDR blog talking about an e-book on Amazon for the NanoVNA. The article also mentioned an upcoming NanoVNA 2.0 with additional frequency range. I was floored when I saw the specs of the original NanoVNA on Amazon and had to know more! So I joined up to the list to see what was going on here. :)

Thanks much and 73,
Ben, KD5BYB

NanoVNA can do the TDR measurement without external software

FWIW, the Wiki main page /g/nanovna-users/wiki/home#Documentation
now clarifies that measurement techniques and tips are collected here:
/g/nanovna-users/wiki/Application-Notes

On Fri, Jan 17, 2020 at 11:03 PM, Bob Larkin wrote:

Nick, might your issue with PyQt5 be the installation of that package, not a
Python3.6 (source language) issue?

Bob

Yes it is an issue with installing PyQt5==5.14.1 on LM19.3 (and other distros from what is reported here).

I have not used Python3.6 for any of my tests, only Python3.7.

73
Nick

On Fri, Jan 17, 2020 at 07:28 PM, Denis Collins wrote:

Thanks again for the hack

Thank you for your results Denis.

The final post here



indicates that pip 19.3.1 fixed the problem on Debian Buster, whereas it didn't for you.

Built nvna-a 0.2.2 with python 3.7.6 on Win7 x64 (mingw64) first with pip 19.2.3 then pip 19.3.1. Everything including PyQt5==5.14.1 was installed without a hitch!

Do not know what to make of all this. Will do more tests.

73
Nick

IF you need a little more flexible test board, take a look on SDR-Kits :

Not all software functions of the DG8SAQ software can be used, but the supplied experiments can also be done with a NANO-VNA. The Training slides needs some basic RF knowledge to follow: it is not fully "entry level". So I would recommend a look into the slides and the assembly instruction before ordering.

There is no need to go to high frequencies (>100MHz) to understand the functionality of an VNA. The standard measurement functions and limitations get already visible on the lower frequencies.

vy73 de Karsten, DD1KT

Hello Chris,

the NanoVNA can do the TDR measurement without external software (Firmware updated last year November) :

- CH0 Real (Display-> Format -> more-> Real), Smith
- Display -> Transform -> Low Pass
- Transform on
- Velocity factor to be defined in % e.g. 0.6 = 60% (is needed to determine the right distance)

In the attachment a twisted pair cable with 50Ohms Termination was measured.
The 103 Ohms is compared to the ~150 Ohms determined by L (shorted) and C (open) a bit low and the 50Ohm return not perfect, but it can be used as indicator for line impedance changes.

One comment to your mesurement:
"8) Comet duplexer and antenna"

The VNA TDR measurement consists of calculating results of a frequency sweep. For this the cable should have the same impedance for the hole frequency range used in the measurement. This is not the case with having an antenna at the End of the cable. Best would be to replace the Antenna with 50 Ohms Termination to measure the cable!

This is the difference to TDR measurements with the reflection method, where steep short pulses are used for the measurement.

vy73 de Karsten, DD1KT

On Fri, Jan 17, 2020 at 07:43 PM, Chris Prosser wrote:

" My return loss measurement is just fine, -35dB at 2m, -55dB at 70cm. So...do I care? "
====================================================================

If you your concern is the impedance measurements; then no, I wouldn't. care. The NanoVNA-saver impedance plot tends to stack impedances and both Rune and Sali (the originator of the impedance algorithm) are working towards future solutions. So far the only program that accurately returns NanoVNA TDR impedance measurements is written in MATLAB, but the functions used are not available in the language (Python) that NanoVNA-saver is written in.

- Herb

Hi Chris,

Somehow it looks like your 30ft length(5) is not lmr-400. On both ends the jump in impedance as well as the reflection do not match.
Could you try to measure just the 30ft peace?

The return loss might be good depending on the position. Just 1/4 wavelength more and it might be very poor.

Eric