摘要:
A VHF television tuner circuit for selection of a television signal through mechanical selection of inductance coils comprises a first terminal for receiving a VHF television signal comprising a high and low VHF channel signals; a second terminal for receiving a UHF/VHF converted television signal; a mechanical channel selection switch arrangement for selection of a plurality of channel positions by rotation of a channel selection shaft said mechanical channel selection switch arrangement comprising a radio frequency coil switching stage and an oscillation coil switching stage; a radio frequency coil means coupled to the radio frequency coil switching stage; an oscillation coil coupled to the oscillation coil switching stage; a radio frequency amplifier coupled to the radio frequency coil switching stage for selectively amplifying a desired radio frequency signal; a local oscillator coupled to the oscillation coil switching stage for providing a local oscillation frequency, the frequency of which is different by a given frequency difference from the selectively amplified radio frequency signal; and a mixer responsive to the radio frequency amplifier and the local oscillator for providing an intermediate frequency signal. The radio frequency coil switching stage comprises a first stage radio frequency coil switch for selectively grounding or disconnecting the transmission path from said first terminal and for selecting a radio frequency coil corresponding to each VHF channel, and a second stage radio frequency coil switch selectably connectable to the radio frequency coil selected by the first stage radio frequency coil switch for selectively connecting said second terminal to said radio frequency amplifier, and for selectively connecting various capacitors in various ways to form a resonance circuit for selecting a desired radio frequency.
摘要:
A VHF television tuner for selection of a broadcasting television signal through mechanical switching selection of inductance coils, comprising; a tuner casing; a mechanical channel selection switch arrangement provided in said casing and including a rotatably mounted channel selection shaft for selection of inductance coils by rotation of said shaft; a radio frequency amplifier operatively coupled to the selected inductance coils for selectively amplifying a desired radio frequency signal; a local oscillator operatively coupled to said selected inductance coils for providing a local oscillation frequency signal, the frequency of which is different by a given frequency difference from said selectively amplified radio frequency signal; a mixer responsive to the radio frequency signal from said radio frequency amplifier and the local oscillation frequency signal from said local oscillator for providing an intermediate frequency signal; and an intermediate frequency tuned circuit for selectively withdrawing said intermediate frequency signal, said intermediate frequency tuned circuit comprising an intermediate frequency transformer, said intermediate frequency transformer comprising an intermediate frequency coil wound around a bobbin having a given axis and a magnetic core threadably inserted in said bobbin for adjustment of the inductance value of said intermediate frequency coil by rotation of said magnetic core about said axis of said bobbin, said intermediate frequency transformer being provided in said casing such that the axis of said bobbin is oriented in the direction substantially parallel to the axial direction of said channel selection shaft, said casing being formed of an aperture at the position in alignment with the axis of said bobbin, whereby access to said intermediate frequency transformer is allowed from the outside of said casing for adjustment of the inductance value of said intermediate frequency transformer.
摘要:
A feedthrough capacitor arrangement which comprises a frame having a first recess, printed circuit boards disposed in the vicinity of the frame, a feedthrough capacitor having an outer electrode and a central electrode placed in the first recess and a shield member for pressing the feedthrough capacitor placed in the first recess thereby to hold the feedthrough capacitor in association with the frame. In this arrangement, the outer electrode of the feedthrough capacitor is soldered to the frame and to the shield member while the central electrode is soldered to conductor patterns on the printed circuit boards.
摘要:
A television tuner comprises a rotary switching shaft, switching plates associated with the rotary switching shaft, and an input tuning portion, an interstage tuning portion and a frequency converting portion coupled to the switching plates and adapted for channel selection by means of the rotary switching shaft. An additional plate is provided between one switching plate associated with the interstage tuning portion and another switching plate associated with the frequency converting portion. The additional plate is provided with a surface acoustic wave device performing the function of a video intermediate frequency filter and with an integrated circuit including a video intermediate frequency amplifier and a video detector.
摘要:
A CATV system comprises two coaxial cables (11, 12) for transmitting information obtained from a center unit, a slide switch (1), and a CATV converter (30). As a slider (73) of the slide switch is slided in one direction with the same in contact with a common contact (101) connected to the CATV converter, the slider is placed in contact with a first fixed contact (104) connected to one coaxial cable while a first terminating contact (110) connected to a first terminating resistor (13) is separated from the first fixed contact. When the slider is slided in the other direction, the slider is placed in contact with a second fixed contact (107) connected to the other coaxial cable, while a second terminating contact (111) connected to the second terminating resistor (14) is separated from the second fixed contact. Accordingly, each of the coaxial cables is not opened through selection of the slide switch, whereby mixing of an image is prevented from occurring due to mismatching.
摘要:
A shield case having openings at both ends is fabricated by drawing a blank and the opening at one end of the shield case is formed at the periphery thereof as a flat annular receiving portion, with a portion intermediate the receiving portion and the case side surface curved with a gentle curvature. A capacitor including a doughnut shaped dielectric unit is disposed inside the shield case contiguous to the receiving portion and a metallic cylinder is provided extending through the aperture of the dielectric unit of the capacitor and the one end opening of the shield case. One electrode is formed on one main surface of the doughnut shaped dielectric unit, while the other electrode is formed on the other main surface of the unit and a lead out electrode is also formed around the aperture on the other main surface of the unit electrically isolated from the said other electrode. A resistor film is formed between the other electrode and the lead out electrode, and electrical connection is made between the metallic cylinder and the one electrode, and an electrical connection is also made between the metallic cylinder and the lead out electrode, while these are mechanically fixed.
摘要:
A rotary type television tuner includes a chassis and a channel changing shaft extending through the chassis and having an operating knob mounted on the front end thereof for rotating the shaft. The channel changing shaft is made of a synthetic resin reinforced with glass fiber and is circular in cross-section over the greater part, the knob mounting section being formed with a flat portion and having a cross-section that is nearly semicircular. The root of the flat portion of the knob mounting section is rounded. A reinforcing rod assembly comprising a reinforcing rod made of a metal and a reinforcing rod made of a rigid synthetic resin which are connected together as by threads is embedded in the channel changing shaft including its knob mounting section. The length of the reinforcing rod of metal is such that when it is assembled as the tuner, it extends from the front end nearly to the chassis plate.
摘要:
A coaxial cable connector receptacle comprises a cylindrical shield casing made of a metallic plate and having openings at both ends, and an inner casing made of an insulating material and housed inside the shield casing and having apertures at both ends corresponding to the openings of the shield casing. The inner casing is formed of a protruding portion at the side surface thereof, the protruding portion being formed of a groove communicating with the inside of the inner casing and receiving a contact of an external circuit. A contact member having a first and second contact is provided inside the inner casing and the first contact is positioned for receiving a center conductor of a coaxial cable at the position opposing one aperture of the inner casing, while the second contact is formed at the position opposing the groove of the protruding portion in the direction orthogonal to the longitudinal direction for receiving a contact of the external circuit. The center conductor of the coaxial cable is placed in contact with the first contact of the contact member through the opening of the shield casing and the aperture of the inner casing, while the contact from the external circuit is placed in contact with the second contact of the contact member through the groove of the protruding portion.
摘要:
A coaxial cable is electrically connected to a connector receptacle by means of a coaxial cable connector plug. The coaxial cable connector plug comprises a clip which acts as an elastic pressure contact connected to a central conductor of the coaxial cable, and a plug pin electrically connected to the clip and adapted to be inserted into a receptacle opening of the connector receptacle. The clip and the plug pin are integrally formed in a single metallic plate. The clip is formed by folding the metallic plate at one end portion, while the plug pin is formed at the other end portion of the metallic plate by curling the same, with engaging portions being formed at the joint portion of the clip and the plug pin and protruding in the direction orthogonal to the longitudinal direction. The clip is housed in an insulating inner casing, while the pin is guided outward extending therefrom. The inner casing is covered with a shield casing. The inner casing is formed with an aperture for insertion of a center conductor of a coaxial cable at the position corresponding to the clip and the shield casing is formed with an aperture for insertion of an inner insulation of the coaxial cable at the corresponding portion. An outer conductor of the coaxial cable is pressure fixed to the side surface of the shield casing.
摘要:
The present invention relates to a rotary switch which is an improved stator provided with a plurality of projections extending outwardly from its edges to confront the corresponding surfaces of an improved chassis or the like to which the stator is to be secured. The improved chassis is formed, in positions corresponding to the positions of the projections of the stator, with openings or cutout portions each having a claw which can be deformed or bent. By bending the claws toward the projections after inserting the projections into the openings in the chassis, the projections of the stator are firmly held between the chassis and the claws and rigidly secure the stator to the chassis.