Abstract: An optical unit, particularly for use with a composite overhead conductor. The cylindrical, aluminum core of the optical unit has spirally shaped grooves on its surface into which optical fibers are placed. A tape is spirally wound to hold the optical fibers in the grooves. The winding pitch is such that the tape edges overlap. An aluminum pipe encases the spacer, optical fibers and tape. The tape consists of a thermally insulating middle layer and two sheets of aluminum foil sandwiching the middle layer, the aluminum foil contacting the pipe and the core so as to conduct electricity therebetween.

Abstract: Manufacturing of a soft metal sheath formed of aluminum or copper, for example, is improved by suitably selecting the apparatus composing the shaping means employed therein and arranging the capstan and the sinking die in a novel manner. The apparatus selected is made from a wear-resistant synthetic resin such as a molybdenum bisulfide-included nylon. The sheath is manufactured from a metal tape of aluminum or copper through the working stages of applying a cylindrical tube shaped from the tape onto a cable core, butt welding the seam, and then reducing the diameter of the metal tube to connect it to the core.