Measure Zo - how to use

[Charles]

Bob,
Thanks for the update to version 685. I'm a little confused about how to use the new Measure Zo function. Most of the time I received an error message saying that 'Impedance could not be measured. Try repositioning......'. Could you describe the steps involved? Maybe I'm not thinking clearly, but it would seem that you could place the cursor at any point on the scan and the function would return Zo, but that doesn't seem to be the case.
Thanks, Charlie, K4ZRJ

[Bob]

Yes, this is not really clear. I need to add something to the manual

The trick is to set the scan limits so you get at least two theta zero crossings on the graph. For example, the quarter wave and half wave points. More zero crossings are ok, but use the first two at the lower frequencies. Position the cursor anywhere between these zero crossings and, while pressing the left mouse button to freeze the cursor, select the Measure Zo function.

-- Bob