NanoVNASaver Software Walkthrough + NanoVNA Firmware Updates Bring 1.5 GHz Max Range

The NanoVNA is an open source VNA project by @edy555 and ttrftech that has recently become extremely affordable at less than US$50 for a fully assembled unit thanks to Chinese manufacturing (or a little more if you order it via Amazon).

Ohan Smit had recently been playing with the NanoVNA and came across a software package from Rune B. Broberg (5Q5R) called NanoVNASaver. NanoVNASaver is an open source program that can be used to read and plot data from the NanoVNA. It has some nice features like the ability to display multiple charts, increase the resolution up to 10k points, measure cable length via TDR calculations, save Touchstone files and more.

Over on his blog, Ohan has put up a walkthrough guide about using NanoVNASaver. He shows how to setup the application, calibrate the NanoVNA, and then demonstrates how to use NanoVNASaver to measure the response of some filters.

Testing our RTL-SDR.COM BCFM Bandstop filter with a NanoVNA and the NanoVNASaver Software.
Testing our RTL-SDR.COM BCFM Bandstop filter with a NanoVNA and the NanoVNASaver Software.

Later in the same post Ohan also includes an update about his experiments with some new experimental NanoVNA firmware that extends the maximum frequency range from the previous maximum of 900 MHz up to 1500 MHz. Results show that while it can work up to 1500 MHz, accuracy rapidly degrades above 900 MHz.


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I have spent hours and hours trying to download NanoVNAsaver. What an absolutely awful load of rigmarole to go through. I have registered with Github, in an attempt to get some kind of sense out of this. I have even put Python 64bit (to no avail) on my widows 11 laptop.Why do they make things so difficult?

Gary Barth

I just downloaded and ran NanoVNASaver for the first time last night, and it seemed fairly intuitive, until I realized that the NanoVNA display had nothing to do with what the NanoVNASaver was doing. The instructions say to fully calibrate the Nano before connecting it to the software, but when I did connect, the Saver said the Nano was uncalibrated. The freq range on Saver was the Save 0 span – okay – but if I changed the settings on Saver, it had no effect on the Nano. And I had to re-calibrate using Saver.

Then I started realizing that whatever you set, and run, on the Saver has no effect on what you are seeing on the Nano screen. So am I to understand that when you are running Saver, it is using the Nano outside the Nano display? And if I change anything in Saver, do I also have to re-calibrate in Saver?

I kind of expected Saver to just be a larger duplicate of the Nano screen. But it seems to operate totally separate from the Nano visual screen. Is that how it works? If I’m running Saver, I have no reason to any operations on the Nano itself?


Looking for more information on the NanoVNA

John Battle N4OE

I want to communicate with my nanovna directly with an ascii terminal on my MacBook but I don’t understand how to accomplish that. I tried installing an ascii terminal on the Mac but I can’t seem to get anything to connect. I assume that the nanovna needs to be running but I don’t know exactly what serial port to use and how to make the nanovna establish a connection.

John N4OE

John Battle N4OE

Everything works fine on my linux box but when I tried to install nanovna-saver on my Mac I get this runtime message. Anyone have any ideas? I want to use my nanovna to collect data at the feed point of an antenna and my linux bos it too big to move out to the antenna.

John N4OE


Is there a document describing the NanoVNA-Saver SOFTWARE concept ?
I did not find much about HOW it interfaces with NanoVNA in github.
Flow chart / block diagram would be nice.
In pseudo code

setup serial – word length, baud rate etc…
send data via USB (serial?)
verify NanoVNA “signature”


I had installed all of them before I tried to run nano….

Peter Kirk

Paul, I had problem on win7 64bit because the virtual usb driver was unsigned and windows would not allow it to run. The driver in question can be located: “C:\Windows\System32\drivers\usbser.sys”

I downloaded the utility “dseo13b.exe” free on the internet to create a signature for the usberser.sys driver: try:

good luck


Peter, Thanks for your response. When I try to run nanovna-saver-v0.2.2-1.exe in cmd window I am getting the following message:
Traceback (most recent call last):
File “”, line 17, in
File “c:\user\ieuser\appdata\local\programs\python\python37-32\lib\site- packages\PyInstaller\loader\”, line 627, in exec_module
File “NanoVNASaver\”, line 21, in
ImportError: Dll load failed: The specified module could not be found.
[376] Failed to execute script nanova-saver
Have you had the same error message or something else?

Peter Kirk

Paul, probably the driver signature issue causing the python script to fail.

1) Connect your nanoVNA to the usb port and make sure the nanoVNA is turned on.
2) Windows should generate a sound if it detects the presence of your device (you may see a driver msg in lower right of screen)
3) Open your system device manager and check for a driver error in the PORTS (COM & LPT)
4) If you see the following driver error: STMicroelectronics Virtual COM PORT, then you probably need to sign the usbser.sys driver as per my previous post. (make a back up a copy of the original usbser.sys for piece of mind)


Device manager shows the PORTS (COM & LPT) and STMicroelectronics Virtual COM PORT with No error message (“This device is working properly”).
The error message I quoted in my previous message appears regardless I have Nano-VNA connected or not to PC…
I asked a friend of mine who does not have Nano-VNA meter but has win 7 (64bit) installed on his PC to downloaded and run nanovna-saver-v0.2.2-1.exe. And he was successful. So maybe there is something wrong with Win 7 config on my PC?

Peter Kirk

For Windows 7, it does require Service Pack 1 and Microsoft VC++ Redistributable you should download both 32 and 64 versions.


I had installed all of them before I tried to run nano…


I have problem with running nanoVNASaver on win7 (64 bit) – cannot start. Where can I get any support?

Tory G

I don’t suppose this software is available for Mac OS?


Click on the github link and READ, and follow the instructions for “Mac OS: Homebrew” ?

Tory G

Ok, thanks very much.