3. Whilst the results are interesting (to me at least), nothing I have ever done in RF and microwaves has needed them.

Have you ever seen the impedance used for normalizing be anything other than a pure real? Have you ever calibrated your VNA with anything other than a fixture that was made to be a pure real impedance?

While fooling around a couple of days ago, I decided to follow the cal procedure, but when the VNA asked for the load to be connected to the port, I connected the bad coax cable from post #54.

Then I connected the 50 ohm cal fixture and instead of a dot in the middle of the Smith chart, I got a blob that looked like the one in post #54 for the cable, but offset up and to the left.

The VNA was then showing impedances using the cable impedance as the normalizing impedance. It didn't seem too useful.

 

Have you ever seen the impedance used for normalizing be anything other than a pure real? Have you ever calibrated your VNA with anything other than a fixture that was made to be a pure real impedance?

No, I think the answer to this is clear - these affects are not significant for transmission lines that are relatively low loss. Now if you had to achieve some impedance matching using your coax from your old scope probe then you may well have to consider them. The line reflection coefficient would not go around the circles you expect on the smith chart normalised to a real impedance, as your posting 57 demonstrated.