GB707373A - Improvements in or relating to multiplex communication systems - Google Patents

Abstract

707,373. Thermionic distributers. POSTMASTER GENERAL. July 20, 1950 [March 7, 1949], No. 6163/49. Class 40 (3). [Also in Group XL(c)] The interlaced channel pulses in a multiplex system are produced by first multiplexing the channels in groups, in such a way that the outputs from some groups overlap in time those from other groups, the group outputs then being multiplexed to a single channel or a lower number of groups. Distribution of the channel pulses to their indvidual channels at a receiver is effected by an inverse process. The receiver of a 20-channel system, comprises four normally blocked valves a ... d, which are unblocked cyclically by negative pulses P6 . . . P9, applied to valves a1 ... d1 respectively. The incoming pulse train from the channel MC is applied to the grids of valves a1 . . . d1, so that channel pulses 1, 5, 9 &c. are applied to the control grids of valves A; 2, 6, 10 &c. to the grids of valves B; 3, 7, 11. &c. to the grids of valves C and 4, 8, 12 &c. to the grids of valves D. These sets of five valves are cyclically unblocked at their suppressor grids in columns of four by longer positive puises P1 ... P5, each of which lasts four channel periods, to pass individual channel pulses to the anode circuit output transformers, only one of which is shown. In the similar transmitting arrangement, Fig. 5 (not shown), valves A . . . D receive the channel input signals and valves a ... d feed the common output channel. The pulses necessary to operate a 100- channel system using 30 pulse sources are discussed, Fig. 7 (not shown). Specifications 694,092, [Group XXXIX], and 707,379, [Group XL(c)], are referred to.