BATTERY INTERCOMMUNICATION TELEPHONES
"REPLY-AND-CALL" SUB-STATION AUTOMATIC
Pattern No. B600
Comprises Granular Carbon transmitter Watch Receiver, Cord, Automatic Switch-hook (with automatic device for changing over the call line), Induction Coil, Bell, and Push Button.
The act of pressing the call button rings the bell at the Central Station, and automatically changes over the call line, no matter whether the receiver is on, or off the hook. Directly the receiver is replaced the connection is automatically restored to the reply line. The great advantage claimed with this instrument is that auxiliary 2-way switches at the side stations are dispensed with, thus doing away with the old trouble of replacing the switch to the calling line after speaking, and the confusion caused by leaving the switch in the wrong position.