Hi Stan

Thank you for your summary of the common sense of an experienced, it is convincing, in fact I have just done the comparative tests of the same dipole antenna with the same coaxial cable Zc = 77.7 Ohm RG59 with and without compensation of calculation of DiSlord of its function Z--> 77.7 Ohm with the same NanoVNA H4 firmware Dislord 1.2.40, the results are as follows:
without Zc compensation: SWR = 1.22 Fr = 14.385 Mhz
With Zc compensation: SWR = 1.16 FR = 14.112 Mhz
there is 0.06 sheeft for SWR and 272 Khz sheeft for Dip frequency

But with DiSlord conversion function it's much better to use and it's a simple and beautiful function .
Thanks
73's Nizar