GB410674A - Radio receiving systems - Google Patents

Abstract

410,674. Valve circuits for wireless reception. RADIO FREQUENCY LABORATORIES, Inc., 708, Main Street, Boonton, New Jersey, U.S.A.-(Assignees of Farnham, P.O. ; Boonton, New Jersey, U.S.A.) Oct. 4, 1933, No. 27300. Convention date, Nov. 4, 1932. [Class 40 (v).] A diode rectifier is prevented from rectifying impressed radio frequency voltages until the peak rises to a valve substantially greater than the D.C. potential between its electrodes. The diode is shown applied to a receiver for producing delayed automatic volume control. The valve 9 comprises a filament F, two grids G1, G2, and a plate P. Signals from the tuned input coil are applied through condensers 6, 7, 8 to the grids and the plate. The electrodes G1, F act as a diode signal rectifier, low frequency currents being developed across a resistance 10 connected therebetween and led to a L.F. amplifier over the lead 11. The plate P is biassed negatively from a tapping 13 on a source 14 through a resistance 12 and, with the filament, acts as a delayed gain control diode rectifier, the gain control potentials being taken from the plate P through a filter 15, 16 and feed resistances 20 to the grids G of high frequency amplifying valves 3 which thus normally receive the same bias as the plate P. The diode P F is prevented from rectifying the H.F. input until the bias on the grid G2 is overcome. This grid is biassed more negatively than the plate P through a resistance 23 from the source 14.