GB405124A - Wireless and like receiving systems - Google Patents

Abstract

405,124. Valve circuits for wireless reception. HAZELTINE CORPORATION, 15, Exchange Place, Jersey City, New Jersey, U.S.A.-(Assignees of Johnson, J. K. ; 61, Halls Lane, Rye, New York, U.S.A.) Feb. 25, 1933, Nos. 5804 and 5805. Convention dates, April 6, 1932. [Class 40 (v).] In a wireless or like receiver signals below a pre-determined level are suppressed by means as by an auxiliary suppressor valve 14, to remove a prohibitive bias from low frequency amplifier 13 under control of rectifier 12. The Figure shows an arrangement in which the direct current voltage developed across the load resistance 22 is wholly applied to the grid of the valve 14 through smoothing condenser 18 and resistance 17 and in part used for the control of the grid bias of preceding amplifying valves to regulate their gain. The audio-frequency sig nals are applied through condenser 31 to th potentiometer 32 and the amplifier 13. With no signal anode current of the valve 14 will produce voltage in resistances 28, 32 which with the voltage drop between points 53, 54 will bias valve 13 to cut-off. Signal voltage will bias valve 14 to cut-off and permit the operation of valve 13 with normal bias. Adjustment of the screen grid voltage of the valve 14 serves to adjust the signal cut-off level. Specification 398,882 is referred to.