Calibration and Automation of Transmission Line Discriminators for FM Noise Measurement

The use of a calibrated noise source is shown to be an improved method for calibrating the simple transmission line discriminator for FM noise measurements. The value for excess noise in the source, a simple power measurement, and a frequency read from the baseband spectrum analyzer can be used to determine discriminator slope and all of the other calibration factors. The the theory and operation of the new methods are discussed.