NEW SINGLE CHANNEL CARRIER TELEPHONE SYSTEM 171 



attenuation-frequency characteristics for four commonly employed 

 gauges of open-wire line under dry and wet weather conditions, re- 

 spectively, at a temperature of 68° F. These curves are for 12-inch 

 spaced copper wires equipped with the type of insulators ordinarily 



Fig. 9 — Repeater panel — front view. 



■zO.06 



8 10 12 2 4 6 



FREQUENCY IN KILOCYCLES PER SECOND 



Fig. 10 — Attenuation of open-wire side circuits — 12-inch spaced copper wire with 

 double petticoat glass insulators. 



employed for toll circuits. Changes in temperature also afifect the 

 attenuation, the loss increasing as the temperature rises. The varia- 

 tions due to changes in temperature are, however, smaller than those 

 due to changes from dry to wet weather and are more likely to occur 



