GB237638A - Improvements in or relating to reception apparatus for wireless telephony and the like - Google Patents

Abstract

237,638. Capon, A. L. H. April 4, 1924. Tuning-apparatus, construction and control of; thermionic amplifiers and detectors. - The aerial and intervalve circuits of a multivalve receiver are simultaneously tuned by means of a system of press-button switches, which may also be used to control the number of low frequency amplifiers in circuit, or to throw the set as a whole m or out of action. As shown in Fig. 1 the aerial inductance 8 is divided into several sections 8<0>. 8<1>, 8<2> &c. A series of push-buttons 9, 9<1> are mounted on a control box as shown in Fig. 6 so that when, say, the button 9 is depressed contact is made between the points 10, 12, and the segments 8<1>, 8<2> &c. are shorted to earth, leaving the segment 8<0> alone in circuit. Normally the segments are held in series through a contact 11. Similar contacts 13, 13<1> are arranged to control the plate resistances such as r through a second series of push-buttons mounted on the same control box (not shown) and interconnected with the push-buttons 9. Associated switch buttons 14, 15 insert the telephone receiver 21 in the plate circuit of the amplifiers 4 or 5 at will. When the button 14 is depressed, the contacts 16, 17, Fig. 4, are closed to ignite the filaments of valves 1 to 4; the contacts 18 and 19 bring the telephone into the plate circuit of valve 4: whilst the contact at 19, leading to the primary of the transformer between valves 4 and 5 is broken. Each series of push-buttons A, Fig. 6, is so arranged that as any one of that series is depressed it moves outwardly a swinging plate L, and so automatically releases the other buttons. A master button shaped as shown in Fig. 7 switches off all the valves simultaneously and so puts the receiver out of action.