Abstract: A bushing is provided for placement on a cable to be held between an upper cover and a lower cover of an apparatus. The bushing has a flange on an outer peripheral surface thereof, and the flange extends perpendicular to the cable on which the bushing is put. The upper cover and the lower cover of the apparatus are attached to form a unit, and the upper cover comprises a flange receiving portion. The flange comes closely into contact with the flange receiving portion to fix the cable against the upper cover and serve as a watertight packing. As a result, a simple watertight structure is provided.

Abstract: A helical antenna includes a hollow cylindrical member having an inner peripheral surface and an outer peripheral surface, an antenna pattern film wound around the outer peripheral surface of the hollow cylindrical member, a center rod coaxial with a center axis of the hollow cylindrical member, and at least three ribs disposed between the center rod and the inner peripheral surface of the hollow cylindrical member. The ribs symmetrically extend in a radial manner at equal angular intervals. The hollow cylindrical member, the center rod, and the ribs preferably may be integrally molded out of plastic. The antenna pattern film may include a flexible insulator film and a conductive pattern formed on the flexible insulator film. The conductive pattern has at least one antenna lead member which is wound around the outer peripheral surface of the hollow cylindrical member in a helix fashion.

Abstract: In order to transmit a signal received in a GPS antenna (20) to a GPS receiver body (30) through a glass plate (40), a signal transmission circuit (10) is divided into first and second signal transmission parts (11, 12). The first signal transmission part (11) is for transmitting a high frequency signal from an output terminal (20out) of the GPS antenna (20) to a first surface (41) of the glass plate (40). The second signal transmission part (12) is for transmitting the high frequency signal from a second surface (42) of the glass plate (40) to an input terminal (30in) of the GPS receiver body (30). The first signal transmission part (11) includes a first coaxial cable (111), a first electrode pair (112), a first balanced line (113), and a first balun (114). The second signal transmission part (12) includes a second coaxial cable (121), a second electrode pair (122), a second balanced line (123), and a second balun (124).

Abstract: In a helical antenna comprising a hollow cylindrical member having an inner peripheral surface and an outer peripheral surface and an antenna pattern film wound around the outer peripheral surface of the hollow cylindrical member, the helical antenna further comprises a center rod coaxial with a center axis of the hollow cylindrical member and at least three ribs disposed between the center rod and the inner peripheral surface of the hollow cylindrical member. The ribs symmetrically extends in a radial manner at equal angular intervals. The hollow cylindrical member, the center rod, and the ribs preferably may be integrally molded out of plastic. The antenna pattern film may comprise a flexible insulator film and a conductive pattern formed on the flexible insulator film. The conductive pattern has at least one antenna lead member which is wound around the outer peripheral surface of the hollow cylindrical member in a helix fashion.

Abstract: A bushing has a flange on an outer peripheral surface thereof. The flange extends perpendicular to a cable on which the bushing is put. An apparatus to which the cable is connected comprises a cover providing a cavity as a flange receiving portion. When the flange is inserted in the cavity, the bushing is fixed to the cover and serves as a watertight packing.

Abstract: In a helical antenna comprising a hollow cylindrical member having an inner peripheral surface and an outer peripheral surface and an antenna pattern film wound around the outer peripheral surface of the hollow cylindrical member, the helical antenna further comprises a center rod coaxial with a center axis of the hollow cylindrical member and at least three ribs disposed between the center rod and the inner peripheral surface of the hollow cylindrical member. The ribs symmetrically extends in a radial manner at equal angular intervals. The hollow cylindrical member, the center rod, and the ribs preferably may be integrally molded out of plastic. The antenna pattern film may comprise a flexible insulator film and a conductive pattern formed on the flexible insulator film. The conductive pattern has at least one antenna lead member which is wound around the outer peripheral surface of the hollow cylindrical member in a helix fashion.

Abstract: In order to transmit a signal received in a GPS antenna (20) to a GPS receiver body (30) through a glass plate (40), a signal transmission circuit (10) is divided into first and second signal transmission parts (11, 12). The first signal transmission part (11) is for transmitting a high frequency signal from an output terminal (20out) of the GPS antenna (20) to a first surface (41) of the glass plate (40). The second signal transmission part (12) is for transmitting the high frequency signal from a second surface (42) of the glass plate (40) to an input terminal (30in) of the GPS receiver body (30). The first signal transmission part (11) comprises a first coaxial cable (111), a first electrode pair (112), a first balanced line (113), and a first balun (114). The second signal transmission part (12) comprises a second coaxial cable (121), a second electrode pair (122), a second balanced line (123), and a second balun (124).

Abstract: A plurality of copper wires are disposed between coaxially arranged an inner cylindrical member and an outer cylindrical member, with one end of each copper wire being fixed at a predetermined position. The remaining portion of each copper wire is spirally bent so as to wind itself around the inner cylindrical member, with the center axes of both the inner cylindrical member and the outer cylindrical member serving as a winding center. Then, an amount of insulative resin is poured into an annular space formed between the inner cylindrical member and the outer cylindrical member. In this way, the spirally deformed copper wires are sealed within the wall portion of a hollow cylindrical insulative resin member.

Abstract: In a helical antenna comprising a hollow cylindrical member having an inner peripheral surface and an outer peripheral surface and an antenna pattern film wound around the outer peripheral surface of the hollow cylindrical member, the helical antenna further comprises a center rod coaxial with a center axis of the hollow cylindrical member and at least three ribs disposed between the center rod and the inner peripheral surface of the hollow cylindrical member. The ribs symmetrically extends in a radial manner at equal angular intervals. The hollow cylindrical member, the center rod, and the ribs preferably may be integrally molded out of plastic. The antenna pattern film may comprise a flexible insulator film and a conductive pattern formed on the flexible insulator film. The conductive pattern has at least one antenna lead member which is wound around the outer peripheral surface of the hollow cylindrical member in a helix fashion.

Abstract: To provide an antenna unit that can always provide good broadcast transmission reception and a signal switching circuit to be used therein. A first antenna element for receiving satellite broadcast transmissions, a second antenna element for receiving VHF terrestrial broadcast transmissions, and a switching means for selectively switching output of either a reception signal of the satellite broadcast transmissions received by the first antenna element or a reception signal of the VHF terrestrial broadcast transmissions received by the second antenna element and supplying that output to the receiver unit via the signal supply cable in response to a direct-current bias level supplied from a receiver unit via a signal supply cable are provided inside a single identical casing.