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KENNELLY, TAYLOR— PROPERTIES OF 



erly clamped diaphragm, in order to simulate the localized distor- 

 tional behavior of an irregularly clamped diaphragm. 



With this object in view, a small piece of bent hard copper strip 

 was fastened by sealing wax to the center of the diaphragm, as 

 shown in Fig. 13. The weight of this spring was 0.6 gm. in all, 

 of which the free portion weighed only 0.2 gm. The free period 



Fig. 13. Plan and Longitudinal Section of the Test Receiver with Secondary 

 Vibrational System Attached to Center of Diaphragm. 



of this spring, when mounted on the diaphragm, was adjusted, by 

 trial, to approximately 750^, which is nearly the same as the 

 diaphragm thus loaded. Fig. 14 shows the motional-impedance 

 diagram of receiver B with the diaphragm and its spring load. It 

 will be observed that between 660 '-' and 866 r-^, the diagram forms 

 a large reentrant loop, and the actual amplitude, at 753 '-', is only 

 about 4 per cent, of the inferred undistorted diameter OA. It is 

 evident that, in this case, the form of the diagram is completely 



