ANALYZER FOR THE VOICE FREQUENCY RANGE 



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In addition to its use for determining the relative magnitudes of the 

 components in an electrical wave, the analyzer is also useful in making 

 acoustic measurements. It was primarily developed for the study of 

 what we may term the frequency distortion of transmitters; it may 

 also be used in the measurements of non linear distortion. As may be 



Fig. 5 — Portable analyzer unit 



inferred, frequency distortion is a departure of the wave form of the 

 electrical output from that of the acoustic input due to the fact that 

 the transmitter does not respond equally to acoustic forces of the same 

 magnitude over the frequency range under consideration. Non-linear 

 distortion is the distortion produced by the fact that the voltage across 

 the transmitter at any particular frequency is not a linear function of 

 the magnitude of the impressed acoustic force. This type of distor- 

 tion usually manifests itself by the production of frequency components 

 in the electrical output which are not present in the acoustic input. 

 The analyzer may be used for quantitative determinations of this non- 

 linear distortion and in such measurements high frequency discrimina- 

 tion and ability to measure frequency components of widely different 

 magnitudes are very valuable. 



