714 THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1952 



Fig. 24 — Four-channel O terminal. 



plug-in units. Since there is no interference between plug-in units in 

 inserting and removing them, can covers have been eliminated. This 

 fact, and the somewhat wider distribution of units having a high con- 

 centration of vacuum tubes, result in a relatively low temperatvn-e rise 

 for O as compared with N. Blower facilities are not provided in the 

 terminal. 



Typical of the units suspended from the framework is the twin chan- 



