The use of the cathode-ray tube as a wattmeter and phase difference measurer for high-frequency electric currents

This paper contains an account of the manner in which a cathode-ray tube can be employed to measure high-frequency power, i.e. as a wattmeter, by the delineation and measurement of the ellipse formed on a phosphorescent screen by a cathode-ray spot, which is oscillated in two directions at right angles by the current and voltage of the circuit under test.