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1436 THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1953 



the hundreds tens of milliseconds. For other oscillator frequencies the 

 times indicated are scaled in proportion. Thus for a 40-kc oscillator, the 

 indicated times are divided by 4 and the fine steps become 25 micro- 

 seconds. 



The start of the A cycle is marked by L500 and the stop by R500, the 

 500 tube itself serving as the memory circuit, and no coincidence circuit 

 is needed. 



The C cycle is wired permanently with a phase to close just before 

 500 and open just before 0. By choosing 480 and 980, access to the units 

 decade is unnecessary and only four coincidence circuits are provided. 



The start of the B cycle is marked by six coincidences, the end by five 

 of these and the alternate connection to the 500 tube. The hundreds 

 switch is simplified because the B relay always operates between and 

 500 and releases between 500 and 1000. Therefore, the start and stop 

 coincidence circuits can be wired permanently to the 500 tube and only 



COUNTER LAMP DISPLAY 



TO TIME SELECTOR 



SWITCHES 



(SEE FIG. 14) 



RESET 



Fig. 13 — Inte 



