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BELL SYSTEM TF.CILMCAL JOURNAL 



mounted the batteries, the vacuum pump with its motor, and the 

 tracker bar with paper roll mechanism. The arrangement is clearly 

 shown in Figs. 6 and 7 taken with the protecting panels remo\-ed. 

 In Fig. 6, a is a moisture-proof box containing the input and tuned 

 circuits. The inductance coil is placed in the center of the upper 

 half of this bo.\ together with the switch for connecting the^windings 



\'ic\v of Analyzer with I'limp Side Uncovered 



a — Input and tuned circuits 



B — .'\niplificr-rcrtificr 



c — Source-alternating relay 



d — Recording meter 



E — Paper roll 



/ — Plate battery 

 n — Pump motor 

 Q — Reversing solenoid 

 / — Series-parallel coil switch 

 I' — Vacuum [)unip 

 -Tracker har 



in scries or parallel. The smaller ca|)acitaiices are of mica and are 

 arranged around the coil and switch assembly in such a way that 

 they may be connected with a minimum length Oi lead to the air 

 relays which are' located on one side of tlir box. The larger capac- 

 itance units are made up of paper condensers and are placed in the 

 lower half of the box. The metal linetl box h contains the amplifier- 

 rectifier, and at d is shown the recording meter. Box e contains the 

 control circuits with the necessary relays. The method of mount- 

 ing the air relays, main vacuum header (attached to underside of 



