| 摘要 |
PURPOSE:To compensate the loss of a circuit accurately and economically by controlling automatically the amplification degree of a signal information amplifier in response to the difference between the level of an incoming pilot signal and the reference level of a pilot signal for comparison. CONSTITUTION:A certain kind of signal information is transmitted from an exchange station 1 at the transmission side via an input circuit 7. Then a transmitter 2 supplies a signal information current to a hybrid amplifier 25 via a BPF21. At the same time, the pilot signal is also supplied to the amplifier 25 from a pilot signal oscillator 22 via a level controller 23 and an HPF24. Thus the amplifier 25 transmits both the signal information and the pilot signal at a time to a circuit 3. A receiver 4 obtain a difference level C between the output level B of a pilot signal detecting filter 41 and the reference level A of a level controller 43 through a differential transformer 44. The level C is supplied to a compensating amplifier 48 via an amplifier 45 and a rectifier circuit 46. Therefore the signal information current contained in a signal spectrum sent from the circuit 3 and supplied to the amplifier 48 via a BPF47 is compensated by the amplifier 48 for its circuit loss component and then outputted to an exchange statioin 5 at the reception side via an output circuit 6. |
