Battery operated, portable transmitter having coil surrounding tubular, ferromagnetic housing

摘要

A compact portable transmitter includes a ferromagnetic tubular housing. A electro-magnetic coil is wrapped around an exterior surface of the housing, such that the housing serves as a transmitter core. A protective covering is positioned over the electro-magnetic coil. Batteries are positioned within the housing to supply power to the electro-magnetic coil and associated transmitting electronics.