Hi Stan
Thank you very much for clarification info about Nano-VNA App PC program, impedance conversion DiSlord function can be very usefull especially when using 75 Ohm coax's, indeed even my RG58 50 Ohm coax have around 57 Ohm measured impedance, so measurement of SWR with a 50 Ohm calibrated NanoVna will not be accurate enought to adjust antenna resonance, but coax impedance conversion function do the job and make it as easy as for perfect 50 Ohm coax cable.. SWR function measurement is altered if our coax does not have an accurate 50 Ohm impedance without using the DiSlord conversion function .

So My question : is there any other pc program that can include coax impedance conversion function to ensure an accurate SWR measurement and antenna resonance ??
73s Nizar