| 摘要 |
PURPOSE:To make level frequency characteristic measurement of a transmission line easy by switching the transmission line to the position of a level meter only when a measuring signal arrives. CONSTITUTION:A measuring frequency of a specific level is given to one of optional transmission lines 7 desired to be measured from a output terminal 3 of an exchange 1 from an oscillator 4 toward a remote exchange 2 for a prescribed time or over. When the specific frequency comes for a prescribed time or over, a split device 8 of the exchange side 2 having a BPF10 of high impedance reads the frequency to actuate a transmission line switching relay in the device 8 corresponding to the transmission line receiving the measuring frequency. The measuring transmission line is connected automatically to the level meter 6 by this operation. |
