摘要 |
An antenna is pivoted on a mounting about a first axis (3) and is driven by a screw threaded drive member (5) to which it is pivoted about a second axis (4). The drive member (5) engages a drive mechanism (6) which is pivoted about a third axis (7) which is fixed inspace all the axes being parallel. At one position of adjustment the second and third axes (4,7) are in line with each other enabling the drive member (5) to be pivoted through 180 DEG thereby doubling the size of the arc through which the antenna can be rotated. <IMAGE> |