Improvements relating to wired radio broadcasting systems

摘要

365,791. Impedance networks ; wiredwireless systems. KOLSTER-BRANDES, Ltd., Cray Works, Sidcup, Kent.-(Kolster Radio Corporation; 200, Mount Pleasant Avenue, Newark, New Jersey, U.S.A.) Jan. 24, 1931, No. 2423. [Classes 40 (iii) and 40 (v).] In a polyphase system of wired-wireless broadcast transmission, a number of filter circuits with common elements are interposed between the high-frequency generator and the transmission lines, in order to pass only a predetermined band of frequencies, the ratio of inductance to capacity of the series and parallel branches of one of the filter networks being greater than in the other filter networks. As shown in a three-phase system, in the Figure, two filter lines 19, 20 are combined to form a third. The ratio of inductance to capacity in the series-connected elements of the first and last meshes of both the filters 19 and 20 is one-fourth that of the combined filter unit 19, 20. Similarly the series inductance to capacity ratio for the intermediate mesh in each of the separate filters 19, 20 is onefourth that of the combined filter 19, 20. The ratio of inductance to capacity of the parallelconnected elements is also four times greater across the points 24, 26 and 27, 29 than it is across any of the pairs of points 24, 25 or 25, 26 or 27, 28, or 28, 29. The same type of filter may be applied to a three-wire two-phase system.