An elastic vibrator dissipates its energy through its supporting point. When a frequency of an equivalent vibration system of the supporting point becomes near to the frequency of the vibrator, energy dissipation becomes Large. Coupled vibrations between the vibrator itself and the supporting point take place, and consequently energy dissipation can become 5〜10 times larger in comparison with the usual case where the ratio of the frequency to that of the equivalent vibration system of the supporting point is not near to unity.
AT-cut quartz-crystal vibrators with the frequencies higher than l MHz have been utilized recently for clocks. The typical frequency is 4194. 340 kHz. The present paper describes the result of a series of experiments which has been made in order to examine what degree of fine polishing is necessary for the practical use of such kind of quartz-crystal elements, from the point of view of their mass production. The quartz-crystal elements examined here are of AT- cut, 4l94. 304 kHz in frequency and packed in the HC-6 /u type holders.