A radiating antenna system for a self-contained sensor module mounted on a power transmission line. The module is capable of measuring various parameters such as line current, voltage, conductor temperature, and ambient temperature. The parameter values are processed by sensor electronics and the processed values are transmitted to a ground receiver. The antenna system includes the power transmission line itself, the housing of the sensor module and an impedance matching network. The impedance matching network couples the output of the transmitter to the housing which radiates at the operating frequency of the transmitter. The housing includes apparatus for capacity coupling the hub of the housing to the transmission line at high frequencies.