| 摘要 |
PURPOSE:To prevent the decrease in an output level by a synthesizer and to obtain excellent S/N by connecting one terminal of a diode to each of plural oscillators, connecting other terminals in common, using the result as an output terminal as the synthesizer, varying selectively the bias voltage in a forward direction of the diodes and making one of them conductive. CONSTITUTION:Each crystal oscillator 1(a-h) is connected to the synthesizer 6. The synthesizer 6 consists of plural diodes 7(a-h), one of each diode 7 (anode side) is connected to the output terminal of the crystal oscillator 1, the other ends (cathode) are connected in common to form the output terminal Vout. A switch 9(a-h) comprising a resistor 9 and a transistor(TR) 10 is provided between the crystal oscillator 1 and the diodes 7. When a base voltage turning on the TR 10 is supplied to a selection signal source 3. The base voltage turning on the TR 10 is supplied to a selection signal source 3, the diode 7 is interrupted to turn off the switch 9. Moreover, when a base voltage turning off the TR 10a is fed to the selection signal source 3a only, the diode 7a is conductive, the switch 9a is turned on and only the output of the crystal oscillator 1a is outputted at the output terminal Vout of the synthesizer. |
