| 摘要 |
PURPOSE:To eliminate a noise pulse by eliminating a reception signal out of an output of a pulse noise detector provided at a former stage than an intermediate frequency amplifier stage by means of a filter and using its output to control the noise gate of the intermediate frequency amplifier stage. CONSTITUTION:An output of a mixer 1 is fed to the noise gate 5 through a common filter 2, an auxiliary filter 3 and a buffer 4. On the other hand, after an output of the common filter 2 is branched and passes through a filter 13 eliminating the reception signal with a band, the noise is amplified (10) and a noise pulse is detected (11). The noise pulse is waveform-shaped (12) and then fed to the said noise gate 5 to control the gate. Thus, even the noise pulse having an amplitude smaller than the signal amplitude is eliminated in this way. |
