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BELL SYSTEM TECHNICAL JOURNAL 



already crowded gun director. These indicators are shown in Figs. 16, 17 

 and 19. Fig. 16 shows the range operator's oscilloscope, called the Control 

 and Indicator, which was located near the optical range finder. Adjacent 

 to this unit was mounted the range unit, sliown in Fig. 17 by means of 

 which the operator could select the target to be followed and continuously 



Fig. 16 — Control & indicator — Radars Mark 2, 3 & 4 



maintain accurate range readings. A typical installation of these two 

 units is shown in Fig. 18. The third unit, shown in Fig. 19, is called a 

 Train or Elevation Indicator and, in Radar Mark 3 (which was for sur- 

 face fire only) this indicator was mounted adjacent to the Train (azimuth) 

 Operator's telescope. 



In addition to the Train Indicator, the azimuth operator was provided 



