An FM monitor type radio having indicator lights on its front face to indicate the particular frequency to which the radio is tuned. A digital counter driven by a multivibrator cycles the radio in order, through its various frequencies. The multivibrator is switchable from a free running state to a state in which it is actuated to drive the counter one position by means of a manual selector switch. The number of frequencies to which the radio tunes can be controlled by opening or closing one or ...

A received signal vector (X(t)) from an array antenna (#1 to #4) is subjected to frequency offset correction by a frequency offset correction part (6) and thereafter subjected to adaptive array processing. An error signal (e(t)) is referred to on the basis of an output signal (y(t)) from the adaptive array and a reference signal (d(t)) held in a memory (30) in a reference signal section or a replica signal (d'(t)) output from a forced phase-locking processing part (20) in a section having no ref...

This invention relates to radio antennae, and in particular to dielectric-clad antennae of the kind comprising a length of conductor the electrical length of which is effectively increased by a cladding of dielectric material. The disclosure describes how the physical height of an antenna, typically an HF or VHF wire monopole antenna can be reduced in relation to its electrical length by means of a thin cladding of dielectric material having a relative magnetic permeability substantially greater...

Compact radio antennae are disclosed which comprise an extended conductor, such as a wire, arranged to form an elongated structure. The conductor is arranged in a plurality of windings comprising windings of opposite senses positioned coaxially in proximate relation. In one form the conductor is arranged in a series of helical windings all coaxial, to form a cylindrical structure, and successive windings in the series are alternately left-handed and right-handed. In another form the conductor is...

A cassegrain aerial having a primary feed, an auxiliary reflector which transmits or reflects according to the plane of polarisation of energy incident on it from the primary feed, and a main, twist reflector which receives energy reflected from the auxiliary reflector, rotates its plane through 90.degree. and re-reflects it into free space through the intervening auxiliary reflector. The main, twist reflector consists of a sheet reflector in front of which two, parallel, wire grids are arranged...

A radio interferometer for measuring vertical angle in which the effect of ground reflections upon the phase angle measured by the interferometer is reduced. A linear vertical interferometer aerial array has a common aerial element and elements spaced from it by distances s, 2s, 4s ... m s where m is an integral power of two, the widest spacing m s being repeated in a vertically-extending space diversity pattern. This repetition may be effected by additional elements spaced (16+1)s, (16+2)s, (16...

A radio receiver having a cabinet consisting of a plurality of cabinet sections, which are joined to one another and can be brought to and held in a doughnut-like state. Adjacent sections of the cabinet are rotatably joined together by means of a coupling member penetrating aligned holes formed in respective walls of adjacent cabinet sections. The outer shape or appearance of the receiver cabinet can thus be varied according to the user's taste. The receiver is very unique and can be used both a...

An interferometer system for measuring the elevation angle of a remote radio source, comprising a linear array of equallyspaced aerial elements, a series of phase discriminators, each coupled to a common aerial and to one of the other aerials in order to measure phase differences between the incident waves, and signal processing units for averaging out the measured phase differences and to derive therefrom an indication of the elevation angle of the radiation incident on the aerial array.

A radio receiver has an antenna casing provided separately of the chassis and printed circuit board of the receiver and housing a rod-like antenna. The antenna casing has a stem portion rotatably and slidably extending through a bearing portion formed in the cabinet of the receiver to mount the antenna casing rotatably on the cabinet whereby the antenna may be oriented in a direction at which a desired radio wave is received best regardless of the orientation of the receiver relative to the radi...

A self-contained, fully operational radio device adapted in size and configuration for implacement and retention at the entrance to an ear canal, said device being fully self-supported by surrounding ear cartilage, thereby eliminating any need for connecting wires or other radio circuitry. The device includes a casement having an outward and an inward housing for containing the respective radio circuitry and speaker means for the radio device. A battery is also contained within the outward housi...