Abstract: A corona generating device including a coronode in the form of a wire supported between insulating end block assemblies. The coronode may take the form of a thin wire coated with a dielectric coating which may be glass or other suitable material, the coating being formed into enlarged beads adjacent the ends thereof. The coronode beads rest jointly on the floors of the cavities provided in each end block assembly and may also be supported on a thin pedestal or elongated support which spans the end block assemblies. The pedestal serves as a continuous support for the coronode intermediate the end block assemblies. One end block assembly includes a member movable into abutment with the bead to apply an adjustable tensioning force to the coronode.