Patent GB-499877-A (GB)
Title: Improvements in thermionic valve and like circuits
IPC: H01J25/68
Filed: 1937-07-27
Abstract: 499,877. Valve generating, amplifying, and receiving circuits ; thermionic valves. TELEFUNKEN GES. FUR DRAHTLOSE TELEGRAPHIE. July 27, 1937, No. 20741. Convention date, July 27, 1936. [Classes 39 (i) and 40 (v)] In valve circuits and devices for generating, transmitting and receiving high - frequency currents of the kind in which a primary electrode system, constituting for example an oscillation generator, is electron-coupled to a secondary system constituting an output to the load, the output is increased by electron-multiplier action within the valve. In Fig. 1, the electrodes B, G are at such voltages that the system K, B, G acts as an electronic oscillator. The third grid D is coated suitably to produce secondary emission, and electrons passing the grid B strike the electrode D and produce an amplified current to the anode. Received oscillations may be applied to the circuit E, and a demodulated output, amplified by the secondaryemitting electrode D, may be detected in the resistance W in the anode circuit. The grid D may be omitted, and the electrode B may constitute the secondary emitter. The electronic oscillation is tuned to the received wave by adjustment of the voltage of the grid G, and the voltage of the grid B is adjusted to give rectification. The grid D constitutes a screen between the input and output circuits. Fig. 2 shows a push-pull detector operating on the same principle as Fig. 1. The two inner grids constitute a single helix W half a wavelength long, connected at its ends to a tuned Lecher system LW. The braking-electrodes B1, B2 are separate rings connected in push-pull to the receiving-aerial E, and having separatelyadjustable connections to the supply battery. The secondary emitter electrode D and the anode A are not divided, and the latter is connected to the battery through a resistance Wa, across which the detected signals are taken off. By suitable adjustment of the voltages of the braking-electrodes B1, B2, the system operates as a short-wave amplifier, for which purpose the anode A is divided and is connected in push-pull relation to the output circuit. Such an arrangement may be employed in a transmitter as an oscillator-amplifier, the braking-electrodes B1, B2 being then connected directly to the cathode, and the anode output circuit being tuned to the generated oscillation or to a harmonic, Fig. 3 (not shown). The Specification as open to inspection under Sect. 91 comprises an oscillator, Fig. 2 (Cancelled), in which the grids G, Gs of a pentode valve are associated in back-coupling connection with a tuned circuit LC, the output being taken from the anode circuit tuned to the fundamental or a harmonic frequency, and either the grid Gs or a further grid D being coated to give secondary emission. Fig. 6 (Cancelled) shows an oscillation generator comprising an anode ring A intermediate between secondaryemitting electrodes K1, K2 which are connected to a tuned Lecher system Ll. Electrons oscillate between the electrodes K1, K2 giving rise at each impact to secondary electrons. Some of these pass outwards through the mesh of the electrodes K1, K2 either to further secondary emitters D1, D2 or direct to the anodes A1, A2. Amplified output oscillations are generated in the circuit La which is tuned to the fundamental or an harmonic frequency. The invention may be applied to dynatron and magnetron oscillators. This subject - matter does not appear in the Specification as accepted.