| 摘要 |
<p>646,331. Super - regenerative circuits. HAZELTINE CORPORATION. Oct. 22, 1948, No. 27537. Convention date, Nov. 28, 1947. [Classes 40 (v) and 40 (vi)] In a self-quenched super-regenerative receiver operating in the saturation mode the gain of the super-regenerative valve is varied in response to changes in the control electrode current flowing during.the saturation period, in order to maintain the average quench frequency constant. Changes in tuning, signal level, H.T. supply &c. tend to vary the oscillation build up period and thus the quench frequency but the resulting increase in number of grid current pulses produces a greater bias voltage in a grid leak and condenser circuit and so reduces the gain of the valve and therefore the oscillation build up period. The cathodefeedback oscillator 10 can be quenched either by the R.C. network 28, 29 in the grid circuit, or by the R.C. network 21 in the cathode circuit or the R.C. network 22, 25 in the anode circuit. When not required the first two of these networks are shorted by the switches 51 and 20, the anode resistor when not required being used to adjust the anode voltage and the anode capacitor being adjusted to act a byepass capacitor. An R.C. network 32, 38 in the grid circuit having a time constant preferably longer than the quench repetition period integrates the grid current pulses during the saturation period to provide the quench frequency controlling bias. An increased or decreased control may be obtained by moving switch 31 to increase or decrease respectively the positive grid bias from source +B. The audio frequency output may be taken from the anode or control grid by setting switches 41 and 51 to the appropriate positions. Specification 654,887 is referred to.</p> |
