Re: Getting started with the nanoVNA guide
Jerry Gaffke
I don't feel I know something until I touch bottom with physical reality,
assuming such a thing exists. In the case of the S parameters, that means describing them as a vector ratios of two vector voltages, using complex number arithmetic: https://en.wikipedia.org/wiki/Complex_number https://en.wikipedia.org/wiki/Electrical_impedance https://en.wikipedia.org/wiki/Reflection_coefficient https://en.wikipedia.org/wiki/Scattering_parameters Bottom paragraph of post https://groups.io/g/nanovnausers/message/1318 shows that I got hung up on that for awhile. Many sources did not explicitly state S11 (for example) was a voltage ratio. I assumed it dealt with power, like SWR. (Historically, some "S parameter" models did deal with power ratios.) Baier's paper on correction factors has some great stuff, but does not touch bottom: http://sdrkits.net/DG8SAQ/VNWA/12_term_dg8saq.pdf He never bothers to mention that all his variables are vector quantities. Never describes what physical properties they measure. Figure 1 shows a two terminal load ZL connected between the lines representing the incident and reflected voltages (wrong!). The TXOscillator port of Figure 1 is ignored in the math. Maybe I should let HexAndFlex write that guide to the nanoVNA, and I'll write a guide to help nonRF people like me navigate Baier's paper. Jerry, KE7ER

