CENTRAL BATTERY SWITCHBOARD
With Combined Automatic Calling and Clearing Signals
Equipped with Self-restoring Tubular “Eyeball’’ Indicators, Corresponding
Line Jacks, Plugs and Cords, operator’s Service Plug, Hand Microtelephone, Three-magnet
Calling Generator, Circular Night Bell, Relay, and Two-way On and Off Switch for
cutting in or out the Night Bell. Soldering Tabs are provided at the back of the
Board for connecting to the Line and Battery Wires. Woodwork of well-seasoned Polished Walnut.
The illustration shows a 50-line Secret Service Type of Switchboard. where it is impossible for the operator to listen in oil the
conversation; but combined Ringing and Listening Keys can be fitted if required, to facilitate rapid handling of the connections.
The method of operating is as follows:- To answer a call - Insert Service Plug into Jack corresponding to number of signal displayed, and ascertain by means of the Hand Microtelephone the number required. Withdraw the Service Plug, and insert a disengaged Back-row Plug in Jack of calling station.
To call station wanted - Insert Service Plug into Spring Jack corresponding to the station wanted, and turn handle of Generator.
To connect stations together - When the station required answers, withdraw Service Plug, and insert the Front-row Plug corresponding to the (Inc already connected to the calling station.
To disconnect - During conversation the visual signals of both stations will remain displayed; when the signals return to their normal position conversation is finished, and both Plugs must be withdrawn.
Audible signal - A Switch is fitted under the Plug shelf, to enable the operator to switch the Night Bell on or off as desired.
Taken from the GEC Telephone Catalogue, K Section, 10th Edition, 1908