. The Bell System technical journal . lace, message telephone circuits must be arranged so that toand fro conversations can take place practically transmission circuits on the contrary are single-directiontransmission circuits. They are, therefore, not complicated by prob-lems of electrical echo, singing and the like, which are ever presentwith long message telephone circuits. However, although free fromthe problems of two-way working, the design and operation problemsof program transmission circuits are by no means easy as comparedwith those of message telephone circui
. The Bell System technical journal . lace, message telephone circuits must be arranged so that toand fro conversations can take place practically transmission circuits on the contrary are single-directiontransmission circuits. They are, therefore, not complicated by prob-lems of electrical echo, singing and the like, which are ever presentwith long message telephone circuits. However, although free fromthe problems of two-way working, the design and operation problemsof program transmission circuits are by no means easy as comparedwith those of message telephone circuits. On the contrary, in manyrespects, these problems are considerably more difficult, the reasonbeing that the requirement as to approach to absolute fidelity ofreproduction is much more severe than for message telephone circuits. A frequency band width of 2,500 cycles furnishes, if properly util-ized, a telephone circuit over which speech is transmitted very clearlyso that conversations may be easily carried on. This band is not t^*. 10500 1&900 11,100 n;8oo :^20 ^900 1,700 ZTOO 4S0 700 27,300 44,000 _., INVOLVESp) WHICH Goes UP l/2 HOUR A WEEK ANO INVOLVES40W N0RK4AL DIRECTION OF TRANSMISSIONARE CONNECTED-
Size: 1265px × 1976px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
