First steps
Buy NanoVNA, plug in the USB cable and turn it on. If you’re using Windows 10, the device should be recognized as USB CDC (Communications Device Class) on a virtual serial port (e. g. COM6). Next steps will be a little bit annoying: create an account on the National Instruments (NI) homepage, download and install the NI LabVIEW Runtime Engine (Version 2011 SP1 32-bit, size ca. 215 MB) and NI VISA. I have installed VISA v17.0 which is a 750 MB chonker. It contains drivers for USB/Serial communications any many others (also some important drivers for my obsolete GPIB test equipment which aren’t supported in the newer versions anymore). Install VISA and the Runtime Engine and spend your precious life with many reboots. I highly recommend to read Joe Smith’s User Manual, otherwise you may run into problems.
There is a possibility to enlarge the screen size to fit on the monitor?
FYI: a discussion about VNA calibration error models goes here:
https://groups.io/g/nanovna-users/topic/34237712
This paper seems directly related to the Unknown Through Calibration error model, as I understand:
https://www.researchgate.net/publication/358164808_Measurement_Uncertainty_in_Network_Analyzers_Differential_Error_Analysis_of_Error_Models_Part_4_Non-Zero_Length_Through_in_Full_Two-Port_SLOT_Calibration
Thanks. I had read that email chain and was talking with a friend about it the other day. The translation makes it difficult for me to follow. It will require I spend a lot of time to try and make sense of it. I did not download the tools and source code to try and replicate their tests. I also didn't read their final report. There were some other nuggets I found in that mail chain but again, it takes time to research. Did you read it and attempt to follow? Were you able to rebuild their code as well?
I've read up to where they had started to post their BASIC programs. I attempted to run some of what they have shown but I have not tried to feed in my own data. So far, everything is a one port but I skipped to the end and see they also discuss a 2-port system. While they mention the NanoVNA throughout the thread, I have not seen where they added their algorithms to the open source software.
It appears to be more a theoretical work, as far as they had published several scientific papers on the topic. I doubt it may have any practical implementation in low-cost VNA FW code.
Their last paper about 2-port systems analysis might trigger some discussion on the topic, but the subject seems too complicated to dive deep into details
I use this as base for calibrations.
Also add calibration standard suport, for this part i use various sources.
I had to deduce some formulas myself and optimize the calculations. Since initially they were very cumbersome for calculations (a large number of calculations in complex numbers is quite resource-intensive for the microcontroller, especially since hardware support for floating point numbers is disabled in V2/V2Plus/V2Plus4, since not all GD32F303 processors have this module. The processor in Lite is faster and there support is always on).
For thru calibtaiton most good result show ISOLN/THRU calibration as on H/H4. It allow good remove leakage from measured data.
When running CW, why isn't the data rate faster than with swept mode? Is it throttled for a reason?