GB419795A - Superheterodyne radio receiver and the like - Google Patents

Abstract

419,795. Valve circuits for wireless reception. 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.) June 8, 1934, No. 17001. Convention date, Nov. 16, 1933. [Classes 40 (iii) and 40 (v).] In a superheterodyne receiver operating over more than one frequency band, the frequency range of the oscillator is minimized by tuning to a frequency higher than the signal in the lower frequency band and to a frequency lower than the signal in the higher frequency band. The Figure shows a four wave-range receiver in which wave-range changing is effected by ganged switches and tuning by ganged condensers. A separate oscillator valve 14 is used and the oscillator voltage is injected into the cathode circuit of the detector 10 by means of the common cathode resistance 13. The reaction circuit of the oscillator includes the feedback coils 31, 32 and one of the condensers 40, while resistance 36, condenser 37 are provided in shunt to the coil 31 to limit the amplitude of oscillation on the shortest waveband. The signal input circuit includes a coupling 15 for image frequency suppression as described in Specification 412,942, while the aerial circuit includes a trap circuit 17 tuned to the intermediate frequency used. The Specification gives the values of components used in a receiver operating over a range of 550-20,000 Kc. with an intermediate frequency of 450 Kc.