GB513656A - Improvements in or relating to electrical oscillation generators - Google Patents

Abstract

513,656. Valve generating circuits. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. March 30, 1938, No. 9778. Convention date, March 30, 1937. [Class 40 (v)] Automatic amplitude limitation is obtained in a generator comprising a pair of crosscoupled valves by deriving a control voltage from the control electrode of one valve and applying it to the other valve. The Figure shows a triode-pentode in which coupling is effected by condenser C7 between the anode P1 and the grid G<1>2 and the bias developed on the grid G1 is applied through a filter R5, R7, C6 to grid G<1>2 to maintain the amplitude generated constant. The Specification as open to inspection under Sect. 91 comprises also an arrangement, Fig. 1 (Cancelled) in which valves T1, T2, are connected in series to the supply and the grid G2 is biassed by a resistance R3 which is in series with inductance L4 to correct for phase shift. The two valves may be in a common envelope and in a modification a double valve is employed with a common cathode. In a two valve arrangement the grid of the first valve is biassed by a resistance in the cathode lead Fig. 5 (Cancelled and not shown) instead of by the use of a grid condenser and leak to avoid causing grid current and harmonic production. The tuned circuit may be in the anode circuit of the first valve instead of in the grid circuit Fig. 6 ( Cancelled and not shown). This subject-matter does not appear in the Specification as accepted.