A HIGH PRECISION STANDARD OF FREQUENCY 



503 



plate circuit of the lower frequency oscillator. The frequency of the 

 controlled oscillator remains indefinitely at an exact submultiple of 

 the controlling frequency. 



Two such circuits are used, one to obtain current at 10,000 cycles 

 and one for 1,000 cycles. Of course, additional amplifier circuits are 

 required in order to supply outputs of considerable magnitude at 



Fig. 13 — One complete 100,000-cycle standard frequency unit. 



these frequencies, and in such a way that there can be no reaction on 

 the controlling circuits due to load variations or to stray currents at 

 other frequencies fed backward through the output circuits. 



A 1,000-cycle motor, operated by current controlled at the 100th 

 submultiple of the standard, drives generators for producing current 

 at 100 cycles and 10 cycles. There are available, therefore, frequencies 



