[en] The heating of plasmas by waves in the ion cyclotron frequency regime is now the preferred approach for driving tokamak reactors to ignition conditions. Among the notable advantages of this approach are ready penetration into a thermonuclear plasma and an established technology for power generation. An ICRF power system for DIII-D (Doublet III reconfigured with a large dee-shaped vacuum vessel) has been designed to test the feasibility of employing such heating in a reactor. The system proposed is a narrow band rf generator operating at 55 and 40 MHz constructed in modules capable of delivering 1.25 MW each. A 20 MW, 10 s system is planned for the program envisioned. A system description is presented inclusive of rf excitation through final power amplifiers. The system layout of equipment within the D-III facility is also described. The modular nature of the total system facilitates meaningful testing at intermediate power levels, future system enlargement, and even reuse of the hardware on other facilities