A 15 mA dc H−multicusp source has been developed for injection into a TR30 cyclotron. This source is also used with a 900 kV tandem accelerator to obtain 10 mA protons at 1.8 MeV. The program is an extension of the 5–7 mA dc H−cusp source developed at TRIUMF during 1989–1990. Major efforts include the search for the optimal filament materials, shape, and location; comparison of cusp line confinement and magnetic filtering of electrons at the extraction region; optimization of extraction lense configuration; and upgrading of vacuum and power systems capability. The source is noncesiated and the maximum arc power available is only 5 kW. After the H−beams pass through an electron suppression grid and a 20 mm collimator, we obtained 15 mA with 0.66 &pgr; mm mrad 4 rms normalized emittance. At this output thee/Hratio was about 4. The best normalized emittance occurs around 5–7 mA, having a value of 0.37 &pgr; mm mrad. Further development in the near future is planned using cesium and multiple apertures in the hope of increasing dc H−currents to 30 mA while holding the normalized emittance below 0.75 &pgr; mm mrad. ©1996 American Institute of Physics.