GB156230A - Improved means for determining the distance and direction of a source of wireless and submarine sound signals - Google Patents

Abstract

156,230. Sõrnmark, A. U. Dec. 1, 1919, [Convention date]. Determining distances acoustically.-The distance of a station which emits wireless signals simultaneously with submarine sound signals is determined by the known method of observing the difference in the time of arrival of the two signals, and a thermionic valve is employed both for detecting the wireless signals and for amplifying the sound signals. Known methods are used for determining the direction of the signals, such as the employment of port and starboard microphones 1, 2, or the binaural method, or loop aerials for determining the direction of the wireless signals. With the circuits in the condition shown in the Figure, the coil 6 in the aerial circuit is connected to the grid circuit of the valve 10 the plate circuit of which is connected to the telephone 20 through a retro-active coupling 9. The local oscillating circuit of the coil 9 is slightly mistuned to produce beats. When the operator hears the first or last of a series of wireless signals he starts the stop-watch 23, thereby throwing a switch 22, which disconnects the valve 10 from the wireless circuits and connects the grid circuit to the secondary 18 of a transformer, the primary of which is connected to the microphone 1 or 2, so that the operator can note the time of arrival of the first or last of the series of sound signals. A switch 19 enables the microphones to be connected direct to the telephone 20. Several valves may be used, in parallel or cascade. The switching apparatus may be dispensed with, the wireless and sound-receiving apparatus being both permanently in circuit, or both mav be in circuit until the stop-watch is started. The valves may have cathodes of radio-active material instead of heated filaments.