I have in my homelan workshop 'trucload' of RF generators. Least one can be just plain Continuous Wave. For what all these need use this pulse mode for measurement. But there is more than just one zero span mode. 'SA' used here is based to better reference and it is least inside 0.1ppm. Yes it can also see that TCXO is far off but somehow acceptable stable in this class. Kind wish to development team, please look if it can make usable with just programming without any HW mod. Is in any 'to do' list so that may have some hope about small somehow working tiny RF generator because there is hardware already. In this use it is not so problem but same HW can use also for some kind of RF generator. Jitter, FM, residual FM, hopping, phansenoise or AM mod or what ever mess there is. Mode CW and then also selected sweep stop. Why there is CW mode if it is totally useless for anything but playing fun. Is it possible to repair just adjusting things in FW for generate more clean CW than this do now. There is quite ok TCXO reference and circuits what can generate much more clean signal than now - I believe.

It was quite big surprice to me that Nano works in this mode more like noise transmitter than anything else. It can asssume in this mode it generate normal CW signal as what ever RF generator or as example common SA's tracking generator in zero span mode. Even more there is selection for stop sweep. NanoVNA V2 have also 'zero span' mode as CW mode.

Nanovna saa2n