Hi Jhon
In fact I redo the measurement of the characteristic impedance of the first balun with more care of bad contactes, i measure Zc=60 Ohm see screenshoot below , wich gives SWR = 1.2 with 50 Ohm coax and 1.3 with 78.5 Ohm Coax wich explaine the more losses with 78.5 Ohm renormalized coax , I think the renormalized impedance function on Dislord firmware + H4 is accuracy enought here to give a correct results , we assume here that coax has 78.5 Ohm and antenna has also 78.5 Ohm S11 = S21 , No problem right now about firmware modeling , butit will be appreciated if we can renormalise also the port2 impedance independly of port1 one on the future firmwares: it will be really wonderfull .
One important conclusion : if we want to fully optimize out ferrit balun we should measure it's characteristic impedance with a resistor trimmer terminaison and adjust it to much as near as possible the coax characteristic impedance to have less losses , NanoVNA H4 + DiSlord firmware should help a lot .
73's Nizar
