A Phase Curve Tracer for Television

This phase curve tracer is a system for showing on the screen of a cathode-ray tube the phase curve of any network, plotted on a linear frequency scale from 0.1 to 5 megacycles. The test frequency is changed to a fixed frequency of 50 kilocycles for phase comparison, and the phase shift is converted to a time shift. A rectangular field on the screen is scanned in vertical lines, one for each test frequency. A bright spot is produced on each line at a vertical distance proportional to the phase angle of the circuit under test. Frequency and phase coordinate lines are superimposed. The full scale of phase indication is adjustable in multiples of 360 degrees by switching.