I've recently noticed something on overhead HV transmission lines that I can't think of a purpose for. Close to each tower, there issomething hanging down below each conductor, including the Earth conductor at the top of the tower. Where the conductors consist of bundles of cables, each one will have these things fitted. They are shaped like a letter 'L' turned on its side, with the short part vertical and attached to the cable, and the horizontal longer part running parallel to the cable, and below it by a few cable diameters. the horizontal part looks like a foot or two long, but it's difficult to judge from ground level, some distance away, These things are fitted in pairs, pointing in opposite directions, and are fitted a few metres from where the conductors are attached to the insulator strings at each tower. There is usually one pair on each conductor on each side of each tower, but occasionally a second or even third pair can be found, at roughly equal spacings. They look almost like small radio dipoles, but that wouldn't make any sense. Does anybody know what they are?