Acceleration Effects on Electron Tubes 



By F. W. STUBNER 



(Manuscript received June 19, 1953) 



This paper discusses methods of measuring shock and vibratory accel- 

 erations to which electron tubes may be subjected in various equipments^ 

 and the influence of these disturbances on the performance of the tubes. 

 An outline is given of the design problems connected with the elimination 

 of tube damage or faulty operation of tubes under adverse shock or vibra- 

 tion conditions, and of the methods used for simulating these conditions 

 by means of production test machines and test methods. 



INTRODUCTION 



The rapid expansion of the use of electronic equipment by industry 

 and the armed services has created increasingly new demands on both 

 the electrical and mechanical characteristics of electron tubes. Since 

 these tubes are electronic devices, it is only natural that their structural 

 designs are dictated to a large extent by electrical requirements. How- 

 ever, the experience gained with conventional tubes in some of the new 

 equipment applications has revealed certain mechanical shortcomings 

 which reflect on the proper functioning or life of the tubes. The realiza- 

 tion of the increasing importance of mechanical design has resulted in 

 an increased effort for structural improvements to assure more reliable 

 tube performance. The term ''reliable", as used here, denotes that a tube 

 has a high degree of dependability when subjected to specific conditions, 

 either electrical or mechanical. Thus, the requisites for reliability may 

 differ for various applications. Although, in designing a tube, many re- 

 quirements must be taken into consideration, only some of the problems 

 connected with dependable tube performance under mechanical distur- 

 bances, i.e., shocks and vibrations, will be discussed here. 



Since the performance of a tube depends on the geometry of its com- 

 ponent parts, minute changes in element spacing may produce variations 

 in its characteristics. Because of the necessarily delicate stmcture of 

 some tube elements, permanent or transient dimensional changes may be 

 produced by mechanical forces acting on the tube unless the tube is 



1203 



