CARRIER-CURRENT COMMUNICATION 



M9 



desired stabilit\-, it is evident tliat the balance which may be secured 

 determines the over-all gain which is possible. In this case the cir- 

 cuit equivalent for all channels between Los Angeles and Avalon 

 was set at five T. V. As the loaded cable between Los Angeles and 

 San Pedro is approximately nine T. U., it may be seen that the carrier 

 system actually introduces a gain and performs the function of a 



Fig. i: 



repeater besides increasing the number of circuits. Fig. 10 gives 

 a frequency characteristic of one of the channels which is typical 

 of all of them. Balancing equipment has been provided for both 

 cables as is shown in Fig. 5. With this arrangement, the carrier 

 system may be operated over either cable. The transfer from one 

 cable to the other is so simple that it can be made with practically 

 no traffic interruption. 



