A Technique for Precise Measurement ot Short- and Long-Term Stability of Oscillators

In the study of frequency and time measurement, it is necessary to measure and often to record the difference between unknown and standard frequency sources. The technique and equipment described are capable of making the measurement and recording the difference directly in parts from 1 in 10⁶ to 1 in 10¹⁰. Neither the standard nor the unknown source need be offset. Variations too rapid to record may be observed on an oscilloscope.