| 摘要 |
PURPOSE:To attain stable adjustment of th RF-AGC, by inserting a capacitor between a slider of the RF-AGC adjusting potentiometer and a ground and making the set point unchanged even if a conductive adjusting rod is used. CONSTITUTION:The RF-AGC amplifier circuit 14 of an integrated video intermediate frequency amplifier stage 1 is connected to a terminal 4, to which a slider of an RF-AGC adjusting potentiometer 2 is connected. One end of the potentiometer 2 is grounded via a resistor, and the other end is connected to a terminal 8 of the amplifier stage 1 and a power supply +B. A bypass capacitor 3 is connected between the slider of the potentiometer 2 and a ground. The potentiometer is grounded with the capacitor 3 in terms of high frequency and the use of the conductive adjusting rod is made possible in the RF-AGC adjustment of an amplifier circuit 14 with the adjustment of the potentiometer 2, allowing to make the adjustment of the RF-AGC easy and stable. |
