A coaxial guided wave radar apparatus includes a central conductor configured as a wire rope. One or more spacers can be positioned and held in place about the central conductor at predetermined lengths along the central conductor, wherein each spacer is positioned and held in place along the central conductor by one or more respective retainers that are crimped to the central conductor. A tensioner can be attached to the end of the wire rope of the central conductor. The tensioner allows for a proper tension to be applied to maintain a spacing of the wire rope from an outer conductor.