As of 2023 there are many badly performing clones on the market. V2/3GHz NanoVNA uses parts like ADF4350 and AD8342 which are costly and clones have been cutting costs by using salvaged or reject parts.
See official store and look for V2 Plus4/V2 Plus4 Pro versions only to avoid getting a bad clone. We have stopped selling V2.2 versions since October 2020, so all V2 hardware that are not Plus or Plus4 are not made by us and we can not guarantee performance.
Hi, the SOL calibration code example can be found here:
https://gist.github.com/nanovna/af6d7c93221a5673451e6f6e64f210e7#file-read_points-py-L212
You may apply a normalization for thru for SOLT calibration.
Thanks
Hi,
Thank you both for the information! I indeed came across this code.
Regarding the thru (S21) measurement I'm a bit confused: Indeed for some frequencies, the normalized S21 parameter is >0dB, indicating the need for calibration.
Why can I just normalize the curve to a maximum of 0dB? Are there no frequency-dependent calibration effects at all? (or are they negligible?)
Best!
Typically the calibration would make the S21, with just the cables, be 0 dB, flat. The raw measurement won't necessarily be flat (the detector gain varies, the source level varies, the loss in the cables varies).
Thank you very much for the help! I now have a properly working Matlab code for the NanoVNA V2 Plus4. After some field testing I think I'll upload it to the Matlab Exchange.
Best,
Shlomi
Hi,
>
> Are there no frequency-dependent calibration effects at all? (or are they
> negligible?)
The thru normalization is to be done per frequency, so each frequency point is separately normalized, which takes care of frequency dependent effects.
Thanks
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