Owen Duffy wrote in news:Xns9F9850D3A83Anonenowhere@
88.198.244.100:

If you are trying to measure Z at the reference plane in the simplest
manner, then what you propose in your last par should give you the
magnitude and phase of the reflection relative to a s/c (where
Gamma=-1).

I should have explained that this simple approach assumes the coupler etc
to be ideal, the measurement instrument accurate etc.

We make those assumptions in using something like a Bird 43 to find VSWR,
you could use your test setup with comparable accuracy to find more than
just the magnitude of Gamma (and hence VSWR), but also its phase and
therefore complex Z.

Owen