Propagating wave resistivity of a surrounding earth formation is measured by apparatus in a well bore being formed while drilling. The apparatus has a sonde (310) positioned within a drill collar (302) that has its exterior proximate the earth formation during passage of a drill device. The sonde has one or more transmitting antennae (315-1, 315-4) on the housing exterior at first positions that transmit interrogating signals to the earth formation and one or more receiving antennae (315-2, 315-3) that receive signals corresponding to the interrogating signals from the earth formation. The housing (330) has a substantially smooth exterior surface and the antennae are wound in recesses (312-1, 312-2, 312-3, 312-4) in the housing which are filled to be flush with the smooth exterior surface. The drill collar (302) is structured to pass the interrogating signals from the transmitting antennae on the sonde to the earth formation and to pass the signals from the earth formation corresponding to the interrogating signals to the receiving antennae on the sonde. |