| 摘要 |
<p>Two picture search heads (CH1',CH2') are deposited on a head drum of VCR to eliminate the noise of picture search mode. FM signal picked up by the picture search heads are switched by a switch (SW2), amplified by a preamplifier (8) and applied to a FM AGC amplfier (7,9). The output signals of the FM AGC amplifier (7,9) are mixed by a mixer (10) and applied to a double limiter (11). The switch (SW1) is controlled by a control signal generated by a flip flop (4) and the switch (SW2) is switched by a phase shifted signal by a phase shifter (5). The output signals of the FM AGC amplifier (7) and the mixer are selected by the switch (SW4) controlled by external control signal and applied to the double limiter (11).</p> |
