| 摘要 |
PURPOSE:To improve an AFT sensitivity without dropping an oscillating output level by applying an AFT voltage and a tuning voltage to the anode of one of two variable capacity diodes of a resonance circuit provided on a small current part, and the cathode of the other, respectively. CONSTITUTION:Variable capacity diodes 38, 40, are provided in series and also at a position where a current level is small. Accordingly, an influence exerted to an oscillating output level by a resistance component of the diodes 38, 40, etc. is reduced. Also, a tuning voltage is applied to a terminal 41 and an oscillating operation for tuning is obtained, and in this case, when a low positive reference voltage is impressed to a terminal 43 and a drift of an oscillation frequency by a peripheral variation is generated, an AFT voltage is impressed from an AFC circuit of the outside and the frequency is stabilized. |
