Some developments of the piezo-electric crystal as a frequency standard

Part (1) deals with some observed errors in quartz piezo-electric resonators employed as frequency standards. It is shown that these are due to (a) frictional loading, and (b) losses arising from atmospheric humidity. The methods adopted to eliminate these are discussed, and the development of calibration apparatus employing the resonators as reference standards is dealt with. Part (2) is in the main concerned with the use of the improved quartz crystal as a control element in a valve-maintainted source of oscillations. The frequency-stability characteristic of such a system is investigated, the errors are found to be largely due to the valve system, and methods designed to eliminate these are discussed. Finally a complete calibration equipment consisting of a multivibrator system with a range of 1¿6 000 kilocycles per sec. in steps of 1 kilocycle per sec., centrally controlled by a quartz crystal, is shown.