Experiments characterizing the coaxial helicity source and helicity injection current drive on the Prototype Helicity Injected Tokamak (Proto-HIT) have been performed. Toroidal currents over 30 kA can be sustained for times much greater than the plasma resistive time. The coaxial source operates with a large toroidal field that greatly enhances the source impedance, allowing a high rate of helicity injection (high source voltage) at a low source current (high efficiency), with results showing good agreement with a simple analytical model