A directional antenna mechanism of a mobile radio tracking receiver,
includes four antenna elements pivotably fastened to the body of the
receiver. In use, the elements are turned to an operating position, in
which they are pointed away from the body. After use, the elements can be
turned to a transport position, in which they are placed inside the body
in the direction of its longitudinal axis. At least two elements are
connected to each other by a mechanism such that moving the first antenna
element to the operating transport position also causes the second
antenna element to move to the same position simultaneously. The
mechanism includes a movable transmission rod inside the body, with
toothings and toothed discs fastened to the ends of the elements,
contacting the toothings. The rod is moved either manually by a lever
fastened to the rod or by an actuator arranged inside the body.