Nanovan2+4 DUT Firmware Nanovna saver VNA-QT
V.05.4





Hello, I have owned a Nanovna2plus4 for 1 year, the measurements work. The firmware is V.1.1. The device is not a clone , was bought in an official shop. The Nanovna saver V0.5.4. software was installed to upgrade the device. Calibration was done, then came the measurement of a current balun ( 20 turns on 140-43 ferit core). The curve looks very different in one area than on the Nanovna2plus4. There is a range between 14 MHz and 17 MHz that is clearly different from that of the VNA. I can't explain it. At first I thought it was bad ferrite material. Then a measurement was made with a VNWA3, which was similar to the one on the NANOvna2plus4 LCD.
Why is a different curve shown in the software? Are there any known problems with the data transfer? Who has experienced similar phenomena, or is it an operating error on my part at some point? The VNA-QT program also shows a different curve than on the NANOvna2plus4 display. Can you help me?

Regards Norbert


Gesendet von Mail für Windows

Hi Norbert,
maybe calibration?
When you use the software, the calibration should be in slot 0 of the memory.

See here:
https://github.com/NanoVNA-Saver/nanovna-saver
"A calibration of both ports across the entire frequency span, saved to save slot 0, is sufficient. If the NanoVNA is completely uncalibrated, its readings may be outside the range accepted by the application."

I use the calibration assistant in NanoVNA Saver and save the respective calibrations on the HDD. Works just fine.

Best regards
Dieter DL5RDO

Short line to DUT short line to DUT DUT with DUT with USB2 with long line to DUT Long line to DUT standalone nanovan2+4
USB2 with Ferrite USB3 with Ferrite short line Long lines common shoke USB2 with Ferrite UBS2 without Ferrite
saver software saver software saver software saver softwar


Hello all, I have solved my problem of different display in S21 measurements, once with the standalone NanoVNA2+4 and the other with the installed nano vna saver software. Through a small comment on a post in HexAndFlex by Neal Braeman:
„It‘s worth mentioning that the performance of the USB cable/port needs to be reasonably good. I started using the software befire I was very familiar with the standalone unit. The results on the software were very random and confusing but I noticed that they were a lot different the those on the device itself. Moving from a USB2 to USB3 port immediately fixed it.“

Previously, I also suspected an antenna effect of a cable that leads to the NanoVNA. I could exclude the calibration, but repeated it again on the VNA and also in the software. After I provided the USB2 line with ferrite ring in the kind of a current Baluns, the faulty representation disappeared.
I have tried with different long leads to the DUT (Balun). Of course the representation with short supply line is to be preferred. Furthermore I notice a difference between USB2 and USB3 connection to the PC. The USB3 is better for clean relatively equal display of waveform standalone and nano saver program.
My conclusion, for my particular situation
- USB3 connection to PC
- Choking USB cable with current balun or verry well shielded cable
- and of course with such a DUT setup with single wires short lines

This was my situation, another may well have a different experience.

Many thanks for the received hints and ideas.
Greetings from Norbert






Gesendet von Mail für Windows

Von: Dieter Horst
Gesendet: Samstag, 25. März 2023 16:51
An: NanoVNAV2@groups.io
Betreff: Re: [nanovnav2] nano vna saver program with nano van2plus4 connect

Hi Norbert,
maybe calibration?
When you use the software, the calibration should be in slot 0 of the memory.

See here:
https://github.com/NanoVNA-Saver/nanovna-saver
"A calibration of both ports across the entire frequency span, saved to save slot 0, is sufficient. If the NanoVNA is completely uncalibrated, its readings may be outside the range accepted by the application."

I use the calibration assistant in NanoVNA Saver and save the respective calibrations on the HDD. Works just fine.

Best regards
Dieter DL5RDO