Abstract: A theodolite that includes a stand, a telescope, a friction gear and a worm gear. The telescope is pivotally secured to the stand. The clutch plate is secured to the telescope for at least limited rotational movement upon pivoting of the telescope. The friction gear is mounted for rotation about substantially the same axis as rotation of the clutch plate. The worm gear is mounted to the stand and is in constant mesh with the friction gear so that rotation of the worm gear causes rotation of the friction gear. A device engages the friction gear with the clutch plate with a frictional force. The frictional force is adjustable to allow for adjustment of the telescope separately from the worm gear.

Abstract: An antenna comprises a base plate forming a ground plane, a coaxial feed serving as a mast connected to the base plate and extending along an axis that is normal to the ground plane, and two orthogonal dipoles each formed of two elements. Each dipole element has a first end connected to and supported by the mast at a first location spaced apart from the ground plane by a predetermined distance and a second end closer to the ground plane and exhibits a curvature in a plane containing the mast.