Abstract: The channel selector shaft of a 70 channel mechanically detented UHF tuner is provided with mechanical stops which prevent the shaft from moving above UHF channel No. 69 so that the upper twenty-four UHF channels are unused. Also, a dial driving arrangement is provided for driving an expanded UHF dial having only 56 channel indicia so that the 56 channel indicia cover substantially the same area on the dial as the 70 channel indicia of prior art arrangements.

Abstract: A pair of stator contacts, which are positioned inside the tuner housing and are internally connected to the AFT circuit within the tuner housing, are positioned so that unused tuning coils carried by the station selector shaft of the tuner are momentarily connected to this pair of stator contacts as the station selector shaft is moved from one detented channel position to the next. Each time a tuning coil is connected to the AFT circuit it defeats the AFT operation thereof and prevents the AFT circuit from controlling the local oscillator until the next detented channel position is reached. When the station selector shaft reaches a detented channel position at least one of the pair of stator contacts is not connected to any of the tuning coils of the tuner so that the AFT circuit is free to control the local oscillator in a conventional manner.

Abstract: A combination VHF and UHF tuner is provided in which a common station selector shaft may be rotated a number of revolutions to cover the seventy stations in the UHF band. The common selector shaft is provided with twenty-four detent positions per revolution and in alternate positions of the shaft the twelve VHF stations in the VHF band are received. As the common selector shaft is rotated through several revolutions the VHF stations are repeatedly received but are interspersed with different individual stations in the UHF band. Accordingly, no matter what UHF station is being received, all of the VHF stations are always within one turn of the common selector shaft. In many mixed UHF-VHF reception areas a single turn of the common selector shaft is sufficient to select all of the UHF stations as well as all of the VHF stations which are broadcasting in that area.

Abstract: A switching arrangement for VHF-UHF tuners is provided wherein changeover from VHF operation to UHF operation is accomplished by employing wiping action stator contacts and with a minimum of connections between the VHF and UHF tuners.

Abstract: An operator-controllable detent mechanism is provided for a combination VHF-UHF television tuner. Separate torsionally-loaded detent springs are provided for two detent wheels which are mounted on the common station selector shaft of the tuner. A manually-operable control member concentric with the selector shaft is employed selectively to remove the torsional load on one detent member or the other so that the common selector shaft may be detented for combined VHF-UHF reception, VHF only reception or UHF only reception.

Abstract: A detent type tuning mechanism for a UHF tuner having a continuously variable tuning shaft includes a detented selector shaft, and a fine tuning mechanism including a rotatable turret having mounted thereon a plurality of cams, each adjustable by a fine tuning shaft when the selector shaft is positioned in a predetermined position. A variable impedance element, operated by the fine tuning mechanism, is provided for fine tuning the tuner independently of the position of the selector shaft and the tuning shaft to permit a precise numerical display of the UHF channel selected in each position of the detented selector shaft.

Abstract: A highly accurate UHF television tuner utilizes an improved housing and an improved mounting system for securing the tuning rotor and stator within the housing. The housing is fabricated from sheet metal that is welded at the corners to provide mechanical rigidity, and soldered at the corners to provide a good electrical contact. A cover is placed over an open end of the housing and soldered at the corners further to increase the mechanical rigidity of the housing. The depth of the housing is increased to reduce the effects of the housing on the tuner elements. An eyelet is mounted in one end of the housing for supporting the rotor shaft, and the stator is mounted by insulating posts that are inserted through sleeves integrally formed in the housing. An improved contact for more effectively grounding the rotor shaft to the housing is provided, and an improved detenting system is provided for the selector shaft to reduce the effects of inertial creep.

Abstract: A digital display indicator for a television tuner utilizes a tape or other record medium having each of the television channel numbers disposed thereon in a seven-segment type font. A mechanism is provided for moving the tape past a display window to simulate a seven-segment digital display. In an alternative embodiment, the channel numbers may be displayed on one or more circular discs.

Abstract: A UHF television tuner utilizes a mechanical fine tuning mechanism that alters the operation frequency of the oscillator of the tuner independently of the position of the main tuning shaft. The mechanical fine tuning mechanism utilizes a tuning slug disposed inside a tunable coil of the oscillator, and a rotary to linear motion translating mechanism is disposed within the fine tuning shaft for converting a rotational motion of the fine tuning shaft to a linear motion of the slug inside the coil.

Abstract: A continuously variable UHF tuner arrangement is provided wherein a single channel selector shaft is provided with a detent position for each of the 70 UHF television stations and a highly accurate detent mechanism is employed to return the channel selector shaft to any one of the detent positions with extreme accuracy. As a result, the tuning elements of the tuner may be accurately aligned to different UHF stations corresponding to said detent positions and a nonambiguous digital dial arrangement may be employed to indicate to the operator exactly which UHF station is being received. Electronic fine tuning is provided to permit the UHF tuner to be fine tuned independently of the position of the selector shaft.

Abstract: A highly accurate UHF television tuner utilizes an improved housing and an improved mounting system for securing the tuning rotor and stator within the housing. The housing is fabricated from sheet metal that is welded at the corners to provide mechanical rigidity, and soldered at the corners to provide a good electrical contact. A cover is placed over an open end of the housing and soldered at the corners further to increase the mechanical rigidity of the housing. The depth of the housing is increased to reduce the effects of the housing on the tuner elements. An eyelet is mounted in one end of the housing for supporting the rotor shaft, and the stator is mounted by insulating posts that are inserted through sleeves integrally formed in the housing. An improved contact for more effectively grounding the rotor shaft to the housing is provided, and an improved detenting system is provided for the selector shaft to reduce the effects of inertial creep.

Abstract: A mechanism for driving a television tuner channel indicator located behind a panel and mounted concentrically with a selector shaft and a concentric fine tuning shaft. The driving mechanism includes a two-piece gear housing mounted on the selector shaft for rotation therewith, a driving gear affixed to the fine tuning shaft, a driven gear, and three planetary gears mounted within the housing and engaging the driving and driven gears. The selector shaft passes through the gear housing and engages the coarse tuning mechanism of the tuner. The driven gear engages the fine tuning mechanism of the tuner, and the indicator is attached to the gear housing. The driving mechanism may be provided with apparatus for actuating an AFC defeat switch when the television tuner is being fine tuned or tuned between channels.

Abstract: A detent type tuning mechanism for a UHF tuner having a continuously variable tuning shaft includes a detented selector shaft, a gear train interconnecting the tuning shaft and the selector shaft, and a memory type fine tuning mechanism including a rotatable turret having mounted thereon a plurality of cams each engageable by a fine tuning shaft when the selector shaft is positioned in predetermined ones of the detent positions. A Geneva mechanism is employed to rotate the turret a predetermined increment to bring a different one of the cams into engagement with the fine tuning shaft when the selector shaft is rotated a predetermined number of detent positions. Each cam thereby serves as a memory fine tuning member for a predetermined group of adjacent UHF channels corresponding to a like number of detent positions of the selector shaft. An indicator dial provides a numerical display of the precise UHF channel selected at each position of the detented selector shaft.

Abstract: A continuously variable UHF tuner arrangement is provided wherein a single channel selector shaft is provided with a detent position for each of the seventy UHF television stations and a highly accurate detent mechanism is employed to return the channel selector shaft to any one of said detent positions with extreme accuracy. As a result, the tuning elements of the UHF tuner may be accurately aligned to different UHF stations corresponding to said detent positions and a nonambiguous digital dial arrangement is employed to indicate to the operator exactly which UHF station is being received. A masking member concentric with the selector shaft is provided with a viewing area in which only one member from cooperating tens and units dial members is simultaneously visible.

Abstract: An isolation network for isolating a pair of balanced antenna terminals from a tuner located in a receiver of the type having a line connected chassis includes an isolating capacitor connected in series with each one of the antenna terminals. A high value bleeding resistor is connected in a direct current conductive circuit across one of the isolating capacitors for discharging the static charge accumulated on the isolating capacitor. A second lower value resistor is connected between the high value resistor and the other isolating capacitor for discharging the other isolating capacitor through the high value resistor.

Abstract: A compact speed reduction mechanism for driving a tuning indicator dial of a UHF television tuner or the like includes a harmonic drive unit having a rigid fixed spline and a movable flexible spline member. The indicator dial is mechanically coupled to the flexible spline member and a wave generator is attached to the selector shaft. The number of teeth on each spline is selected to give approximately a 7:1 reduction ratio between the selector shaft and the indicator dial. More teeth are provided on the flexible spline than the rigid spline to prevent binding between the splines which normally occurs when reduction ratios of less than approximately 20:1 are used.

Abstract: A compact dial indicator arrangement is provided for a UHF tuner of the type having a continuously variable main tuning shaft and a station selector shaft provided with detent means for establishing a separate detent position for each of the 70 television stations in the UHF band. An elongated strip of material bearing numbers corresponding to each one of the 70 UHF television stations is moved past a viewing position at which the selected channel numbers may be viewed by means interconnected with the detented selector shaft so that the number on the elongated strip corresponding to each stop position of the continuously variable main tuning shaft is automatically viewable at the viewing position in response to rotation of the selector shaft to each detented position thereof.