Abstract: A slewing assembly comprises a cylindrical main body and a shackle member, it is characterized that the cylindrical main body includes a pedestal-like member with a terminal to be connected to a radio set or the like and a hollowed cylindrical section for rotatably receiving the shackle member; the shackle member comprises a forked portion containing a slot and a screw hole for pivotally securing an extensile rod antenna or the like and a hollowed cylindrical section to be rotatably received in the hollowed section of the main body, a plurality of grooves surrounding the outer surface thereof are provided for lubricating purpose, one slit extends axially on the entire outer surface of the same, the other one slit extends more than a hemicircumference around the outer surface of the same at the end abutting against the flange of the forked portion, said two slits intersect at right angle to form an integral cross slit so that the hollowed cylindrical section of the shackle member is contractable and expandable