Some practical applications of quartz resonators

Reference is made to the pioneer work of Prof. Cady and other early investigators. It is suggested that, in their practical application, quartz resonators may be almost invariably classified as ¿frequency standards¿or¿frequency stabilizers,¿ but reference is made to other possible uses. A distinction is drawn between the case in which the resonator is used merely to interfere withthe oscillations of an electrical circuit and the case in which the resonator is employed as a means of controlling the frequency of such oscillations. Reference is made to the various modes of vibration, to the effects of temperature, and to the shapes and dimensions of the resonators commonly used. The methods of cutting and grinding are referred to, and mention is made of the sources of supply. The various methods of mounting are considered. The manner in which frequency measurements have been made is described; and a comparison is made with other types of frequency standard. A résumé is given of some of the applications of quartz resonators that have already been described in the technical Press. An account is given of the practical application of quartz resonators carried out by the authors at the Army´s Signals Experimental Establishment, Woolwich. Some of the instruments containing them are described; and conclusions are drawn.