| 摘要 |
<p>PURPOSE:To facilitate periodical inspection, etc., after a transmission system is installed, by enabling level adjustment without a level measuring instrument, by indicating the operation state of AGC by an indication device. CONSTITUTION:A signal from an input terminal is amplified by an AGC additional amplifier 2, and then the signal is outputted from an output terminal 4 through a directional coupler 3. It is detected by a detector 5 and amplified by a DC amplifier 6, whose output is fed back to the amplifier 2 to perform gain control. At the same time, the output of the DC amplifier 6 is sent to an indication device 8 through an indication controlling circuit 7, thus obtaining an indication value which corresponds to the gain.</p> |
