PRESENT STATUS OF TRANSISTOR DEVELOPMENT 



433 



electrical characteristics. Vibration of point-contact and junction tran- 

 sistors o\(M- tlic tro(|uency range from 20 to 5000 cps at accelerations of 

 lOOg produces no detectable modulation of any of the transistor elec- 

 trical characteristics, i.e., such modulalion, if it exists, is far loelow the 

 inherent noise level. At a few spot frequencies in the audio range, vi- 

 bration tests up to lOOOg accelerations similarly failed to produce dis- 

 cernible modulation of the transistor characteristics. 



Fig. 25 — Miniaturization in space and power drain. 



MINIATURIZATION STATUS 



Space Requirements 



In smallness of size, the transistor is entering new fields previously 

 inaccessible to electron devices. The cartridge structure (see Fig. 25), 

 such as the type A, has a volume of 5V cubic inch, compared to about -g^ 

 cubic inch for a sub-miniature tube and about 1 cubic inch for a minia- 

 ture tube. Under current development, the M1689 bead point-contact 

 transistor has substantially similar electrical characteristics to the M1698* 

 cartridge switching unit but occupies only about -2^00 cubic inch. The 

 M17.52 junction bead transistor has a volume of approximately 5^ cubic 

 inch but this may be reduced to the same order as the point-contact bead 

 if necessary. For further substantial size reductions in equipment, the 

 next move must comprise the passive components. It should be pointed 

 out that the low voltages, low power drain, and correspondingly lower 

 ec[uipment temperatures should make possible further reductions in 

 passive component size. 



* The M1698 transi.stor is a cartridge tyjje point-contact transistor witli elec- 

 trical characteristics designed for switching and pulse applications. This unit is 

 ])roving u.seful in the laboratory development of new circuits or in cases where 

 miniature j)ackages are unnccessarj'. 



