Abstract: A radio relay system including a water-proof conductor housing on which is located a pair of antennas, one antenna being used for transmitting and receiving radio carrier wave signals of a first and a second frequency, respectively, while the other antenna is used for transmitting and receiving radio carrier wave signals of a third and a fourth frequency, respectively. A skirt for each of the antennas is located adjacent the antennas on the housing, one skirt has a length equal to a quarter of the wavelength of the first frequency while the other skirt has a length equal to a quarter wavelength of the third frequency.

Abstract: A radio relay system which comprising an external conductor, a first antenna installed on the externals conductor for transmitting and receiving a first radio carrier wave, a second antenna installed on the external conductor for transmitting and receiving a second radio carrier wave, a skirt provided around the second antenna, the skirt having a length equal to a quarter of the wavelength of the second radio carrier signal, and a relay device which includes a branching filter for extracting a part of the second radio carrier wave as a carrier wave, an adjusting unit for adjusting the amplitude and phase of the carrier wave extracted by the branching filter, and a combining unit for combining the carrier wave extracted by the branching filter with the second radio carrier wave received through the first antenna, and the relay device transmitting as the second radio carrier through the second antenna the first radio carrier wave received through the first antenna.

Abstract: A base station for a mobile communications system including an antenna for transmitting a radio carrier wave to a mobile communications device and receiving signals therefrom, a coaxial external conductor including a skirt in the form of a sun shade having a length equal to a quarter wavelength of the radio carrier wave, a radio section located inside the coaxial external conductor for providing radio communication with the mobile communication device via the antenna, and a connecting section connecting the radio section to a telephone line and where the antenna is configured in the form of an upper disk of a discone antenna and where the skirt is a lower conical member of the discone antenna.

Abstract: Apparatus for measuring and analyzing the swing of a baseball player. The apparatus includes devices for emitting a plurality of spaced light beams projected in directions to be intersected by the swing plane of a bat and a corresponding plurality of light receiving elements arranged to receive light beams reflected from the bat. Signals received by the light receiving elements are collected and supplied to a processing apparatus and the results of this processing are displayed on a display unit which provides indication of angle, speed, level, etc. of the swing. The information may also be provided to a printer. The apparatus indicates whether the swing is performed normally and if it deviates from normal indicates the error involved.