Measuring The Characteristic Impedance - RigExpert AA-600 User Manual

5.2.6. Measuring the characteristic impedance

The characteristic impedance is one of the main parameters of any coaxial cable.
Usually, its value is printed on the cable by the manufacturer. However, in certain
cases the exact value of the characteristic impedance is unknown or is in question.
To measure the characteristic impedance of a cable,
1. Connect a non-inductive resistor to the far end of the cable. The exact value of
this resistor is not important. However, it is recommended to use 50 to 100 Ohm
resistors.
Example 1: 50-Ohm cable with 100 Ohm resistor at the far end.
Example 2: Unknown cable with 50 Ohm resistor at the far end.
2. Enter the R,X graph mode and make measurement in a reasonably large
frequency range (for instance, 0 to 50 MHz).
Example 1: 50-Ohm cable
Example 2: Unknown cable
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