222 



BELL SYSTEM TECHNICAL JOURNAL 



FREQUENCY IN C.P-S. 



RESONANT 



-ZO FREQOENCY +20 



Fig. i — Response-frequency characteristics of resonant bar 



One of the two heterodyne frequency analyzers is built as a self- 

 contained unit mounted on wheels and contains its own "A" and "B" 

 batteries for the vacuum tubes. Fig. 4 shows the top view of the 

 panel where the necessary controls and meters are situated and Fig. 5 

 shows the complete assembly with some of the compartments open. A 

 schematic diagram of the complete circuit is shown in Fig. 6. 



Fig. 4 — Top view of panel 



