System for the emission of sustained waves, of variable frequencies, in electric guide cables or lines

摘要

250,933. Soc. Industrielle des ProcÚdÚs W. A. Loth. April 15, 1925, [Convention date]. Leader gear for assisting navigation; wiredwireless systems. - Guide-conductors are fed simultaneously or successively with alternating currents of different frequencies, from a single generator, such as a thermionic valve, thus permitting the simultaneous use of different receivers variously located on the vessel or craft under guidance. As shown in Fig. 1, a backcoupled valve 1 is associated with a choice of tuning-condensers 4, which are brought into circuit at will by means of a rotating switch 5. The generated currents are fed either to a submarine cable 9, or to aerial lines 11 or 12, the return circuit being closed through the armouring 10 of the cable, through an insulated wire 13, or through ground, or sonorous or unsonorous frequencies may be transmitted as described in Specification 219,726. Alternatively the oscillation-generator may be a Poulsen arc. Several generators may be employed to feed currents of different frequency simultaneously to the guidelines, or successive impulses of different frequencies may be fed from the same source by means of the switch 5 and key 2. The intensity of the magnetic-field radiation may be controlled by means of a rheostat 15, 16 in a definite timecycle, so that the incoming navigator can gauge his distance from the guide-lines by the relative duration of the sending and spacing intervals of the received signals. Fig. 4 shows various endconfigurations of the guide-lines or cables 9 when used for guiding a ship or aeroplane to a definite spot. Fig. 3 shows an arrangement in which means for telegraphic or telephonic communication are incorporated with the cable leader gear. Carrier currents from the generator 1 on the lefthand side of the Figure are modulated by a microphone 22, whilst incoming signals are received by telephones 20 when the switch 7 is in the position 7'. When the switch is in position 7" a telegraphic recorder 23 and sending key 25 are placed in circuit with the cable 9. The station on the right-hand side of the Figure is similarly equipped except that amplifiers 26, 27 are mounted in the telephonic and telegraphic receiving circuits respectively.