// 1 'PER- FREQ UENC V WA VE [G UIDES 



303 



insulated bindinji posts. The oscillator unit shown carries on its 

 exterior a plug connector leading by cable to a nearby d-c. power 

 supply unit. 



If an oscillator similar to that described above were connected into 

 the middle of a long hollow pipe, waves, would of course, be propagated 

 in both directions. Those that would ordinarily be propagated to the 

 left may be reflected by a suitably located reflecting wall or piston so 



(A) 



PARALLEL PLATE 

 CONDENSER PROVIDING 

 LEADS TO FILAMENT 

 AND PLATE 



TO POWER (a.\ BY-PASS 



^iiDDrv ^^' CONDENSER 



PISTON ASSEMBLY 



OSCILLATOR 

 UNIT 

 (B>\ t^/ f O 



ADJUSTABLE 

 IRIS 



(c) 



F"ig. 12 — Various component parts of a wave guide generator. (.1) Schematic 

 representation. (B) The oscillator unit. (C) Complete generator including oscil- 

 lator piston and iris. 



as to reinforce those being propagated to the right. Also an iris of 

 suitable proportions may be so located in front of the generator as to 

 further enhance oscillations. As has been pointed out above the sec- 

 tion of pipe bounded by the piston and iris together approximate in 

 behavior a tuned circuit. It is convenient to regard the chamber as a 

 load impedance characteristic of the tube itself or perhaps it should 

 more properly be regarded as a transformer by which the oscillator is 

 matched to the line. 



