378 THE BELL SYSTEM TECHNICAL JOURNAL, MARCH 1957 



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Fig. 23 — PI carrier ac power plant in cabinet for pole mounting. 



acid electrolyte for good low temperature operation and lead calcium 

 alloy electrodes for long life. The battery has 10 cells housed in two jars 

 of five cells each. It is operated at about 23.5 volts and weighs about 

 ten pounds. It provides about six days' reserve for a remote terminal or 

 about two days for a remote repeater. The battery should not freeze at 

 temperatures as low as 40°F, but the storage capacity may be reduced 

 90 per cent at this extreme. The battery is mounted on steps so that the 

 electrolyte level can be seen through the transparent plastic batterj^ 

 jars. Fig. 23 also shows the compact packaging of the entire power supply 

 within the same type of aluminum housing as used for the carrier termi- 

 nal. A tj^pical pole mounted installation is shown in Fig. 20. Fig. 24 is a 



