| 摘要 |
408,903. Valve detecting and modulating circuits. HAZELTINE CORPORATION, 15, Exchange Place, Jersey City, New Jersey, U.S.A.-(Assignees of Wheeler, H. A. ; 18, Melbourne Road, Great Neck, New York, U.S.A.) Nov. 11, 1933, No. 31489. Convention date, Jan. 14. [Class 40 (v).] A pentode valve 12 (which, however, may have further screening electrodes) is employed as a detector-oscillator in a superhetorodyne receiver. Incoming signals are applied between the cathode and the inner grid 12<1> while oscillations are produced with the aid of the cathode, suppressor grid 12<3> and anode 12<a> connected as a triode oscillator, a mixed electromagnetic and electrostatic coupling being provided between the anode and grid circuits to ensure a constant amplitude at different tuning settings. Intermediate frequency oscillations appear in circuit 16. The screening grid 12<2> which is held at a constant voltage higher than the average voltage of the anode minimizes coupling between the oscillator and input circuits. Resistance 19 governs the average anode voltage and the degree of electrostatic coupling between the output and oscillator circuits. |
