| 摘要 |
PURPOSE:To correct automatically damping frequency characteristics of a transmission line by selectively giving desired amplification characteristics by making a receiver compare two signals of different frequencies transmitted from a transmitter. CONSTITUTION:At a transmission side, reference signal 1 of a fixed frequency and signal 2 of a different frequency to be compared with it are alternated 3 and sent out to a transmission line. A reception side is provided with several amplifying methods (composed of a parallel circuit of a capacitor and resistance, change-over circuit 4 and amplifier 5) which have equal amplification characteristics at signal frequency 1 and different amplification characteristics with comparison signal 2, and holding circuit 9 for the peak value of signal 2 obtained by those methods and when the output of circuit 8 is greater than signal 1, one of parallel circuits of capacitors 11a to 11m and resistances 12a and 12m is selected by switch circuit 4 and then connected to the transmission line so that switch control circuit 10 will provide desired amplification characteristics. |
