GAIN CONTROL AMPLIFIER CIRCUITS OF CATV CONVERTER

摘要

The circuit comprises a filter unit (1) trapping a chnnel signal which selects the channel adjacent to the channel selected by a second IF signal, an amplifier unit (2) amplifying the output signal of the filter unit, and a feedback circuit (3) returning output signal of the amplifier to input part and adjusting the magnitude of output signal with a variable registr (R4). The filter unit (1) comprises a lower channel trapping circuit (4) trapping the andio carrier signal (s') of channel lower than the selected channel and a higher channel trapping circuit (5) trapping the vides carrier signal of the channel higher than the selected channel.