dansawyeror wrote:
The analyzer also shows the response of an open coax to follow the same
circle at the edge of the chart. Is this accurate?

It is accurate for lossless lines. Actual coax
values will tend to spiral in to a Z0 limit.
200 feet of open-circuit RG-58 used on 440 MHz
gets pretty close to 50 ohms after hundreds of
spirals.
--
73, Cecil http://www.w5dxp.com