“…Rapid measurement of impedance or transmission properties over a wide range of frequencies continues to be of great interest. A system for measuring phase and attenuation through a component [Linker and Grimm, 1958] from 8.7 to 9.6 kMc/s and an automatic impedance plotter [Watts and Alford, 1957] covering the frequency ranges 180 to 900 Mc/s and 50 to 250 Mc/s were developed.…”