| 摘要 |
PURPOSE:To improve economy by connecting radio base stations, which correspond to radio equipments mounted on moving bodies, to a central dispatching center by a couple of bare-wire channels, and providing a line-loss compensating amplifier, whose direction is variable, to a halfway point of the bare-wire channels being is service. CONSTITUTION:When a radio wave is transmitted from a train in the service area of some radio base station, e.g. 2', the receiver of the transmitter-receiver 4 of the base station 2' performs squlch operation to close an audio signal switch 7. Then, the received audio signal passes through a two-wire bare conductor 3 and after line loss is compensated by an amplifier 8, it is inputted to a control board 1 to flow the audio signal in a speaker. For answering from an operator, on the other hand, the individual number of the base station 2' is dialed on the control board 1 and a speech is made with a transmission pressed. While the transmission button is pressed, a direction changeover switch 10 is changed over to change the direction of the amplifier 8 from the control board 1 over to a radio base station. |
