Abstract: In a small satellite earth station a directional antenna is rocked about a single axis, corresponding to an oscillatory change in declination, but constant hour angle. The rocking is approximately sinusoidal and has a period of one sidereal day. In a preferred arrangement the antenna is mounted on a rocking axis pivot which is fixed at right angles to, and rotatable for adjustment about, a polar axis member. The polar axis member is set up parallel to the earth's axis and the pivot is rotated about the polar axis member to set the hour angle. The rocking of the antenna is achieved by a crank and tie-rod arrangement driven by a clock motor mounted on the polar axis member. The arrangement is particularly simple and will, when set up, track a synchronous satellite without needing frequent adjustment.