Return loss at equipment port can vary by how the cans are tuned and interacting with cable lengths. You could see 3 dips in the return loss response. Those dips are relating to the pass tuning. ?20dB is good.?
you don¡¯t need to use pads when using good VNAs which are 50 ohms. ?Pads were used in the past when old signal generators and tracking analyzers were used. ?A lot of the old tuning instructions were based on old equipment and not today¡¯s VNAs.?
BTW, I have worked at Sinclair in the past as the application systems engineer and have tuned up hundreds of systems in other lives.?
