KENNELLY AND PIERCE. — TELEPHONE RECEIVERS. 



119 



Second, the effect of the motion of the diaphragm." These two effects 

 will be treated in order. 



Change of Damped Resistance, Inductance and Reactance 

 with Change of Frequency. — Figure 2 shows the damped resis- 

 tance, inductance and reactance of the bipolar receiver "Rb" plotted 



OHM 



320 

 300 

 280 



260 



.240 



g 220 



C4 



200 



180 



IGO 



UO 



120 



100 



80 



GO 



40 



20 



HENRY 



i)04 



.OGO 

 .056 

 .052 

 .048 

 .044 



.040 



.036 =4 



.032 "2 



.028 



.024 



.020 



.016 



.0120 



.0080 



.0040 



2000 4000 6000 8000 10000 12000 14000 



Angular Velocity in Radians Per Second 



Figure 2. Curves of damped resistance, inductance, and reactance plotted 

 against angular velocity, for Bell bipolar receiver, with 0.3 volt at terminals. 

 The dots are observed points; circles calculated; crosses belong to reactance 

 curve. 



against the angular velocity of the current used in the measurements. 

 Figure 3 contains the corresponding curves for the bipolar "watch- 

 case" receiver. In each case the resistance and reactance of the 

 telephone when damped increases with increase of frequency, while 

 the damped inductance decreases with increase of frequency. The 

 following empirical relations approximately hold. 



For the bipolar Bell "Rb," at 20° C, and with 0.3 volts at its termi- 



