| 摘要 |
PURPOSE:To enable response in a short time, by providing the main detection circuit and controlling VCO with the output of the circuit, in multi frequency FSK demodulator. CONSTITUTION:The tone detection circuit 71, 72...7n which can detect the carriers f1, f2...fn incoming to the terminal 10 are connected to the terminal 10. The output of the tone detection circuits 71, 72...7n is fed to the VCO control circuit 6, and the output corresponding to the frequency detected is fed to VCO5. The output of VCO5 is fed to the frequency converter 4 and the frequency of carrier incoming is converted to the intermediate frequency. |
