GB466082A - Improvements in or relating to arrangements for modulating high frequency oscillations - Google Patents

Abstract

466,082. Valve modulating circuits. LORENZ AKT.-GES., C. Aug. 14, 1936. No. 22463. Convention date, Aug. 19, 1935. [Class 40 (v)] Modulation of short-wave oscillators is effected by a split-anode tube placed in a magnetic field and with its anode sections connected across the oscillatory circuit to form a variable leak. As shown, a reaction oscillator R has its tuned circuit coupled to an aerial D, and across the circuit condenser C1 is connected a Lecher pair S1 S2. A magnetron tube H has its split anode connected to the respective wires Sl, S2, and the modulation voltage is applied through a transformer T to the anode-cathode circuit. The magnetic field is supplied by an electromagnet M energized by a source B. The magnetic field and the anode voltage are such that with no modulation the anode current is zero or very small; and the rotational frequency of the electrons in the tube is approximately the wave frequency. The tube H may be connected across the aerial inductance L2, Fig. 4 (not shown). The oscillator R may be replaced by a magnetron wave generator, Fig. 5 (not shown). Modulation voltage may be applied to a grid in the magnetron H, Fig. 7 (not shown). According to the Specification as open to inspection under Sect. 91, the magnetron H may be replaced by a diode valve with modulating voltage applied across its electrodes, or by a triode valve with modulation applied to its grid, the valve being placed in a magnetic field in both cases. This subject-matter does not appear in the Specification as accepted.