A NEW KEY WEST^HAVANA CARRIER TELEPHONE CABLE 209 



sistance attenuator which is introduced in the circuit to give flexibihty 

 in control. This loss can be reduced in value to improve transmission 

 in the case of connections to distant points. As the speech currents 

 enter the carrier apparatus they receive, in addition to the frequency 



Fig. 10 — Rear view of carrier terminal apparatus at Key West 

 showing special amplifier and transformers. 



change, an amplification of from 5 to 10 db in the modulator unit and 

 from 10 to 20 db in the transmitting amplifier. The highest frequency 

 channel receives the highest gain and leaves the common transmitting 

 amplifier at a level about 20 db higher than at the toll switchboard. 



