GB217238A - Improvements in directional reception and transmission in wireless telegraphy - Google Patents

Abstract

217,238. Latour, M. June 5, 1923, [Convention date]. Directive signalling; relaying systems; thermionic modulating systems; aerials.-Relates to directive systems in which a number of frame or other receiving aerials are arranged in line with or across the signal wave-front, and are spaced apart by some uneven multiple of a quarter or half the signal wave-length, and comprises special means for combining the different receptions at a given point in the complex aerial system. For example if the reception on two frame aerials 1, 2 placed half a wave length apart across the wave front, a.s shown in Fig. 1, is transmitted at light velocity to a point 3 midway between the two frames, a flattened curve of reception 5, Fig. 2, is secured in place of the usual curve 4. With an extended aerial system of this character, particularly in populated districts, difficulty arises in combining the various receptions at the collecting point and with the necessary light velocity over a wire conductor. According to the invention, the combination is effected by re-radiating received long-wave signals on a shorter wave-length. As shown in Fig. 5 the original signals received or a frame aerial 11 are amplified by a valve 13, the output of which is then utilized to modulate the emission from a short-wave generator 14 feeding the local aerial.16, for retransmission to the collecting point. This local transmission may be made directional by energizing a series of suitably-spaced aerials such as 16 deposed with regard to time by an amount equivalent to their displacement in space, the necessary control being effected either by a line conductor or by radiated energy. At the collecting point the different modulated short-wave transmissions are detected so as to reproduce the original longwave signal and combined thereby producing the desired directional effect.