REFLEX OSCILLATORS 681 



diligent and painstaking efforts were a direct contribution to the successful 

 completion of most of the designs described herein. 



The NDRC Radiation Laboratories at the Massachusetts Institute of 

 Technology extended very close cooperation both on problems of design and 

 applications of the tubes. A. G. Hill and J. B. H. Kuper were particularly 

 helpful with technical advice and support. H. V. Neher was responsible 

 for the initial design of the 2K50 and assisted on its final development at 

 the Bell Laboratories. G. Hobart assisted on the 2K50 at M.I.T. and also 

 on the final development as a resident at Bell Laboratories. 



Professor R. D. Mindlin on leave from Columbia University served as a 

 consultant on vibration and stress analysis problems particularly on the 

 design of diaphragms and mechanical and thermal tuning mechanisms. 



In the preparation of the manuscript the authors are particularly in- 

 debted to R. M. Ryder for his extension of the simple bunching theory 

 which is included as a part of this paper. L. A. MacColl provided the 

 solution for several mathematical problems. 



