ANTENNA CABLE DISCONNECTION DETECTING DEVICE FOR RADIO COMMUNICATION DEVICE FOR CONSTRUCTION MACHINE, AND RADIO COMMUNICATION DEVICE FOR CONSTRUCTION MACHINE

摘要

Provided are an antenna cable disconnection detecting device of a radio communication device for a construction machine, which can detect the disconnection of an antenna cable correctly, and a radio communication device for a construction machine, which is equipped with that antenna cable disconnection detecting device. In the antenna cable disconnection detecting device of the radio communication device for the construction machine, an antenna cable (4) includes a center wire (6), and an armoring line (7) positioned concentrically on the outer side of the center line (6). Each one end of the center line (6) and the armoring line (7) is connected with a communication device (2), and the other end of the center line (6) is connected with an antenna (3) whereas the other end of the armoring line (7) is grounded to the earth. The antenna cable disconnection detecting device comprises DC current blocking means (10a) connected with the armoring line (7) of the antenna cable (4) for blocking a DC current (15) to flow from the armoring line (7) to the communication device (2), and current disconnection detecting means (10c) connected with the armoring line (7) of the antenna cable (4) for detecting the disconnection of the DC current (15) to flow through the armoring line (7).