Abstract: An insulated coupling usable with a television tuner shaft or the like for electrically isolating the tuner shaft from the chassis of the television receiver includes a pair of flanged insulating bushings pressed into axially extending chambers formed in the ends of two coupled sections of the tuner shaft. A knurled pin fabricated from hardened steel or other strong material is pressed into the two bushings to hold the two sections of the shaft together with the two flanges of the bushings abutting to form an insulated section between the two coupled sections of the shaft.

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 limited tuning range tuning unit useable with a television tuner of the turret type includes a user tunable coil having a tuning slug extending from an end of the tuning unit. A pinion gear engageable by a drive train coupled to a user operated fine tuning shaft is attached to the end of the tuning slug. The pinion gear is provided with a stop tooth for limiting the adjustment range of the slug to approximately one revolution. In one embodiment, the slug is also longitudinally movable with respect to a coil in the coil unit to provide a factory adjustment for centering the tuning range available to the user. Alternatively, the factory adjustment may be provided by making the slug rotatable with respect to the pinion gear.