DESIGN FACTORS OF THE 1553 TRIODE 



519 



case of the grid-return triode of Fig. 1 it begins somewhere in the 

 input wave guide at 0-0' where only the dominant wave exists, 

 includes the input external cavity and that portion of the tube in- 

 terior right up to but not including the cathode-grid gap adjacent 

 to the electron stream at 1-1'. 



The output passive transducer, extending from the externally avail- 

 able output terminals located in the output wave guide through the 

 output part of the bulb right up to the internal output electrodes at 

 the boundary of the electron stream. Call this To ; in the triode it 



Y,2V2 Y2,V, 



t \ 2' N2:i 3' 



Fig. Al-2. — Amplifier representations. 



extends from somewhere in the output wave guide at 3-3' where 

 only the dominant wave exists, includes the external coupling window, 

 resonator cavity and output portion of the bulb, right up to the 

 grid-anode gap adjacent to the electron stream at 2-2'. 

 3. The active electron transducer enclosing everything between the 

 internal terminals of the above two passive coupling transducers — 

 call this Te — in the triode it extends from the cathode-grid gap 

 adjacent to the electron stream at 1-1' to the grid-anode gap adja- 

 cent to the electron stream at 2-2'. Geometrically it includes the 

 stream and active portions of the electrodes. The term "active" 

 will be applied to the electron stream and to those portions of the 

 electrodes which interact directly with the stream. 



