GB628648A - Improvements in or relating to television or like systems - Google Patents

Abstract

628,648. Television. CINEMA-TELEVISION, Ltd., and YOUNG, R. E. March 10, 1947, No. 6653. [Class 40 (iii)] [Also in Group XL (c)] Relaying-apparatus for television &c. signals comprises at least one pulse generator triggered by received synchronizing impulses and adapted to produce impulses for transmission which simulate the synchronizing impulses transmitted at the originating end of the relaying system. The object of the invention, which is to overcome the disadvantage, with ordinary relaying systems, that the wave-shape of the synchronizing signals progressively deteriorates whilst the picture signals retain their quality, is realized by the arrangement shown in the drawing in which television signals received on aerial 1 are fed to a receiver 2 and then to a separator stage 3, the separated synchronizing signals from which are employed to trigger pulse generators 5, 6 supplying line and frame synchronizing signals respectively which are mixed in a circuit 9 with the separated vision signals amplified in video amplifier 4, the composite waveform being fed to a D.C. restoration stage 10 and thence to a modulator and transmitter 11 for radiation from aerial 12. Additional pulse generators 7, 8 may be employed to supply further pulses under the control of other recurrent pulses (e.g. for control and supervisory intelligence) which are transmitted separately from the line and frame synchronizing pulses.