PRESENT STATUS OF TRANSISTOR DEVELOPMENT 



419 



Fig. 7 — The M1752 junction transistor. 



and regular spacing of these curves persists down to voltages as low 

 as 0.1 volt and currents of a few microamperes. Thus, essentially linear 

 Class A amplification is possible for as little collector power as a few 

 microwatts. Constant collector power dissipation curves of 10, 50 and 

 100 microwatts are shown dotted for reference. 



Reproducibility of Linear Characteristics 



In describing progress in the reproducibility of those transistor char- 

 acteristics pertinent to small-signal linear applications, one possible 

 method is to give the statistical averages and dispersions in the linear 

 open-circuit impedances of the transistor as defined by Messrs. Ryder 

 and Kircher.^ Such a procedure, of course, implies a state of statistical 

 control in the processes leading to a reasonably well behaved normal dis- 

 tribution for which averages and control limits can be defined. This 

 situation can be said to be in effect for most transistors under current 

 development. 



However, for the old type A unit, control simply was not in evidence; 

 so that in quoting figures on type A's, ranges for commensurate fractions 

 of the total family will be given. In order that symbols and terminology 



