Test set for impedance-frequency measurement on coaxial cables
01 June 1950
The characteristic impedance, attenuation and velocity ratio of a long length of cable are determined at frequencies between 5 and 30 Mc/s by measurements of its max. and min. input impedance and the frequency change required to produce a phase change of npi. The impedances are measured in terms of a resistor and a voltage ratio and the set is calibrated by means of a tuned circuit and resistor. The accuracy is 0.1% for characteristic impedance and less for attenuation.