Abstract: A linearly polarized omnidirectional antenna includes one or more dipoles having an elongated tubular conductive radiator of a length that is about half the wavelength of the midband frequency, and an elongated inner conductive member extending longitudinally through the interior of the radiator and spaced therefrom. A coaxial cable or other feed means conducts signals to and from one end of the radiator and to and from the inner conductive member. The impedances of the dipole and the feed means are matched over a selected frequency band, such as by the use of a series inductive reactance between the feed means and the radiator. Two such dipoles can be connected to a colinear, center-fed pair, and two or more such dipole pairs can be arranged in a colinear array having a common inner conductive member.

Abstract: A device for mounting an antenna on a surface or object, and is particularly suitable for use on a motive vehicle. The device is rotatable to a fixed operative-position for the antenna, which may have the antenna projecting in an upright or vertical direction, eventhough the surface on which the device is mounted, is inclined with respect to ground. The fixed operative-position for the antenna may be incrementally varied. Upon the application of an external force, the antenna may be released from the fixed position and rotated to a non-operative position for protecting the antenna, in the event the over head space is limited; and thereafter, the antenna may be returned to the precise operative-position.