The work contains an experimental confirmation and a theoretical study of broadband power transfer in wire medium slabs. The motivation of this work is a set of novel thermophotovoltaic devices suggested earlier. The key element of these devices is a wire medium slab which electromagnetically connects hot and cold parts without touching them due to a small gap between the ends of the wires and these parts of the system. The electromagnetic connection implies radiative heat transfer. This transfer presumably holds in a very wide band of infrared frequencies. However, this theory was never confirmed experimentally. Even the conceptual possibility of broadband electromagnetic power transfer through a wire medium layer was obtained only in numerical simulations. In the present work, the authors propose a test-bed system, qualitatively mimicking the radiation by a thermal emitter in the radio frequency range. The thermal emitter is replaced by an input waveguide and the photovoltaic (cold) part - by an output waveguide. They are separated by a substantial air gap in which an array of parallel wires is introduced, not touching the waveguide walls.