REFLEX OSCILLATORS 



555 



One of these has a re-entrant shape to minimize stray capacitance in the 

 resonant circuit. These discs are sealed to glass tubing which provides a 



ELECTRODE 



Fig. 59. — X-ray view of the W.E. 707-A shows the method of applying an external 

 cavity tuned with a piston. 



vacuum envelope. The discs extend beyond the glass to permit attach- 

 ment to the external resonant chamber. The shape of the repeller is chosen 



