On Sun, Sep 22, 2019 at 11:57 PM, Kurt Poulsen wrote:
Incorrect, that is not a measurement of the CH1 input impedance. The cable
between Ch0 and Ch1 create impedance transformation.
Actually, you're right my previous screenshot was taken with no calibration for cable end plane. :) Previously I already performed this measurement with calibration for cable end and without and didn't found significant difference for VSWR measurement. So I simply repeated measurement with no full calibration for my previous screenshot.
But how did you found that this is not cable end calibration? :)
Here is measurement with full calibration at the end of cable, you can check it on TDR screenshot. As you can see VSWR is almost the same. I'm using good quality 10 cm RG405 cable, so it doesn't affect VSWR measurement much even with no calibration on cable end.
I also tested CH1 with another type VNA and it shows the same result.
