| 摘要 |
PROBLEM TO BE SOLVED: To most suitably maintain the expected call quality after a change from a metal cable to an optical cable by providing an electric characteristic equal to an existing metal cable to a signal attenuator, inserting it between an electric communication line equipment and a terminal equipment or connecting it to the terminal equipment. SOLUTION: A signal attenuator has the electric characteristic equal to that of the existing metal cable. In the respective attenuation circuits of the signal attenuator, first resistors 3a and 3b, coils 4a and 4b, second resistors 5a and 5b and capacitors 6a and 6b have the electric characteristics equal to the existing metal cable. One or plural attenuation circuits are connected between the electric communication line equipment and the analog telephone terminal or to the analog telephone terminal so as to set call quality to optimum. Thus, a communication fault can be avoided at the time of changing to the optical fiber. Then, the call and communication between analog telephone terminals are terminated and the adjusting work of a transmission loss is terminated. |
