Needs to be improved
For NanoVNA V2 Plus4
Compared with the first version, nanoVNA did not like:
1. Incorrectly measures capacitance and inductance.
2. For each new frequency range, you need to do your calibration. In the first nanoVNA, I did a calibration once, and switch the frequencies as you want - the calibration will work fine.
3. The battery charge indication is made by a line of four LEDs, and not by a symbol on the LCD.
I think that all this can be improved by fixing the firmware.
25.06.2020:
Capacitors 6.19nF + -0.5% and 38.3nF + -0.5%
nanoVNA ver.06.2019: 6.2-6.21nF 38.4nF
nanoVNA ver.11.2019: 6.19-6.2nF 38.5-38.6nF
nanoVNA2: 5.97-6.05nF 42.0-42.1nF (immediately after switching on)
nanoVNA2: 6.15-6.24 nF 42.0-42.1nF (10 minutes after switching on)
nanoVNA2: 6.19-6.30nF 41.9-42.0nF (25 minutes after switching on)
The measurements were carried out at a frequency of 50 kHz. The capacitance of the capacitors, measured by an attorney with an error of 0.3%, was 6.2 nF and 38.3 nF.
When measuring an inductance of 5 μH + -10% at a frequency of 50 kHz, nanoVNA2 shows 2.41-4.77 μH (readings randomly jump) and only at frequencies of 1-2 MHz the readings are normal - 5.4 μH. Your nanoVNA2 is very hot compared to the first version. When I try to determine the heat source by touching the board with my finger, the device failed - on the Smith diagram it shows 5 Ohms with the input open. I touched the details above the lower right screen (CH1). Tell me, what kind of chip could fail?
Response from HCXQS group | June 24, 2020
Can you give an example of incorrect capacitance/inductance measurements? Other users have done accuracy comparisons: http://www.dd1us.de/Downloads/Brief%20comparison%20of%20NanoVNA%20V2%20with%20a%20professional%20VNA%20HP-8753E.pdf