A dipole antenna may be created by surrounding a portion of the continuous conductor with a nonconductive magnetic bead, and then applying a power source to the continuous conductor across the nonconductive magnetic bead. The nonconductive magnetic bead creates a driving discontinuity without requiring a break or gap in the conductor. The power source may be connected or applied to the continuous conductor using a variety of preferably shielded configurations, including a coaxial or twin-axial inset or offset feed, a triaxial inset feed, or a diaxial offset feed. A second nonconductive magnetic bead may be positioned to surround a second portion of the continuous conductor to effectively create two nearly equal length dipole antenna sections on either side of the first nonconductive magnetic bead. The nonconductive magnetic beads may be comprised of various nonconductive magnetic materials, and preformed for installation around the conductor, or injected around the conductor in subsurface applications. Electromagnetic heating of hydrocarbon ores may be accomplished.