GB380199A - Intercommunicating wired radio high frequency telephone system - Google Patents

Abstract

380,199. Wired wireless systems. INTERNATIONAL RADIOPHONE CORPORATION, 810, Colorado Building, Washington, U.S.A.-(Assignees of Polin, H. S. ; 2, East 54th Street, New York, U.S.A.) July 11, 1931, No. 19993. Convention date, July 19, 1930. [Class 40 (v).] A high frequency intercommunication telephone system particularly for use in buildings ships, aircraft, trains &c., comprises a number of stations each of the same design comprising an oscillating valve circuit associated with a telephone transmitter and receiver, and connected by a single common conductor which provides the sole communication channel and may be the frame of a building, an electric conduit &c. Groups of stations operating at different frequencies may be connected to the same conductor. Tuning is avoided, the circuits of the stations or groups thereof being initially adjusted to oscillate at the desired frequency. The system shown in the Figure comprises two stations interconnected by the conductor 14, 14<1> which is connected to the grid of the valve at each station, although it may connect any electrode (including the filament) of one valve with any electrode of the other. The conductor 14, 14<1> may include an inductive or capacitative coupling. The telephone transmitter 3 and receiver 9 are respectively connected in the grid and plate circuits of the valves.