I've always taken it for grunted

I have often grunted when taking transmission line measurments, but I try to
keep it to a low volume.
Your ohmmeter will budge if you terminate the line with a short, or some
resistance. The Characteristic Impedance (300/75/50 ohms) is an AC or RF
measurement, and can not be done with a DC VOM. The devices that the average
Ham has on hand include, antenna analyzer, grid dip meter, and rf signal
generator. Transmission line measurements with these devices can been found in
the ARRL books or with the instruction books with the instruments.
73 Gary N4AST