. The Bell System technical journal . g station but the signalingsystem should respond only to signals from the transmitter signalingattachment, irrespective of broadcast speech, music and telegraphsignals which may involve the same frequencies. Visible indicationsshould be provided to show when the receiver is in operating condi-tion. The receiver should respond to a call from the central stationl)y operating another visible indicator, in addition to a bell or otheraudible signal, if desired. Modern Methods in Train Dispatching, by J. C. Latham, Electrical Com-munication, Vol. Ill, No. 1, Jul
. The Bell System technical journal . g station but the signalingsystem should respond only to signals from the transmitter signalingattachment, irrespective of broadcast speech, music and telegraphsignals which may involve the same frequencies. Visible indicationsshould be provided to show when the receiver is in operating condi-tion. The receiver should respond to a call from the central stationl)y operating another visible indicator, in addition to a bell or otheraudible signal, if desired. Modern Methods in Train Dispatching, by J. C. Latham, Electrical Com-munication, Vol. Ill, No. 1, July, 1924. -Radio Telephone Signaling Low-Frequency System, by C. S. Demarest,M. L. Almquist and L. M. Clement, Journal of the A. I. E. E., Vol. XLIII, No. 3March, 1924. lUnrO SIGNALING SYSTEM 331 Description of Aim>aratusTransmitter Attachment A photograph of the transmitter attachment is shown in Fig. 1,and a schematic circuit is given in Fig. 2. The apparatus consistsof a vacuum tube oscillator and a number of calling keys. These. ■^ —Transmitter attachment TRHTiSMITTER flTTfiCHMENTNEW YORK CITY POLICE RdDIO ^IGNBLmC SYSTEM
Size: 1742px × 1435px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
