Topband: RG-179 Coax

[Jim Brown]

On 2/14/2020 11:40 AM, Fred Moeves wrote:
> Can you figure out impedance of coax with a device like the Rig Expert?

Yes, if it's a model that can be calibrated, and if the calibration is 
properly done, and if it's a model that can export measurements to a 
computer. Calibration requires of Standard Short, Open, and Load parts. 
Once you've calibrated, sweep a length of the coax with the far end open 
and again with it shorted. Export the data to a computer, then import it 
into AC6LA's free ZPlots Excel spreadsheet and follow his instructions. 
For the measurements, the coax must be connected at precisely the same 
point as where the calibration was done.

Before attempting this, study parts of the manual for the equipment that 
talks about the "measurement plane."

73, Jim K9YC