Noise Figure Rating for Marginal Oscillators

The concept of noise figure is extended to marginal oscillators, devices which are commonly used in nuclear resonance experiments for detecting small changes in coil Q. This permits the absolute sensitivity of the circuit to be evaluated, without regard to extraneous factors, such as coil Q and sample material. The method is illustrated by applying it to a new FET oscillator built for use in a low temperature nuclear resonance thermometer.