1054 THE BELL SYSTEM TECHNICAL JOURNAL, OCTOBER 1951 



Fig. 10— Main IF amplifier. 



OUTPUT COUPLING 

 APERTURE TUNING 



AIR SUPPLY 



TRANSDUCER PROBE 



DC PLATE 

 CONNECTION 



MOVABLE COAXIAL 

 TRANSFORMER 



PLATE TUNING 



PLATE CAVITY 



GRID 



INPUT CAVITY 



INPUT APERTURE 



CATHODE 

 RF CONNECTION 



Fig. 11— 416A tube cavity. 



the modulator and the transmitter ampUfiers and can best be described with 

 the aid of a sectional view as shown in Fig. 11. The tube screws into the 



