| 摘要 |
PURPOSE:To simplify the control of each supergroup level by time-sharingly controlling the gain of a modulator by each pilot current from the output point of a frequency division multi-carrier transmitting device having pilot current in every occupied band. CONSTITUTION:A frequency division multiplex signal with pilot current inputted from a terminal 11 is frequency-converted into standard supergroup signals by a supergroup receiver 12 and sent to a supergroup transmitter 14 through filters 131-134. Each standard supergroup signal is frequency-converted into the original line frequency band by a modulator and sent out from an output terminal 19. An transmitting output from the output terminal is inputted to a terminal 16 of a control device 15 and pilot current is extracted from the input signal. The extracted current is converted into DC voltage, which is inputted to the gain control terminal of each supergroup modulator through a terminal 17. An address corresponding to each pilot current is outputted from a terminal 18 to select a gain control terminal connecting to each modulator time-sharingly. Thus, the level of each supergroup can be automatically controlled by simple configuration. |
