US3970974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Trimmer for a tuned UHF line
Assignee: Oak Industries Inc
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Filing: 1974-04-24
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Granted: 1976-07-20
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Expires: 1994-04-24
Abstract
Abstract A UHF tuner employing resonant cavities with tuned lines has a discrete air trimmer capacitor which includes a fixed electrode connected to the tunable line with one or more insulated turns of silver wire and a movable electrode guided into the fixed electrode to provide characteristics of lower minimum capacity, higher maximum to minimum capacity ratio, smaller physical size, higher Q and lower cost than conventional capacitor trimmers.
Inventors
- 👤 Elmer Bastian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:55
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0007; H05K9/006; H03; H03J; H03J3/00; H03J3/02; H03J3/16; H03J3/18; H03J3/185
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
131 words
In a UHF tuner, a chassis, at least two cavities in the chassis, shields between said cavities, one of said cavities including an antenna resonator, another of said cavities including mutually coupled RF amplifier and mixer resonators, a shield between said mutually coupled RF amplifier and mixer resonators, a trimmer capacitor having minimum capacity near the upper end of the UHF band in each of said cavities having a resonator, said trimmer capacitor including a fixed electrode connected to said resonator and formed from a plurality of helically arranged insulated turns of wire, an insulating sleeve mounted inside said turns of wire and defining a central passage, a movable electrode positioned to move in and out of the central passage of said fixed electrode, and support means for said movable electrode.
Claim 2
Dependent Claim
131 words
In a UHF tuner, a chassis, at least two cavities in the chassis, shields between said cavities, one of said cavities including an antenna resonator, another of said cavities including mutually coupled RF amplifier and mixer resonators, a shield between said mutually coupled RF amplifier and mixer resonators, a trimmer capacitor having minimum capacity near the upper end of the UHF band in each of said cavities having a resonator, said trimmer capacitor including a fixed electrode connected to said resonator and formed from a plurality of helically arranged insulated turns of wire, an insulating sleeve mounted inside said turns of wire and defining a central passage, a movable electrode positioned to move in and out of the central passage of said fixed electrode, and support means for said movable electrode.
Claim 3
Dependent Claim
37 words
The structure of claim 1 further characterized by a sleeve mounted inside said central passage of said fixed electrode and including a central passage in which said movable electrode is positioned as it moves in and out.
Claim 4
Dependent Claim
15 words
The structure of claim 2 further characterized in that said movable electrode is a screw.
Claim 5
Dependent Claim
24 words
The structure of claim 3 further characterized in that said support means of said movable electrode is a tapped extruded hole in said chassis.
Claim 6
Dependent Claim
30 words
The structure of claim 4 further characterized by a tension nut threaded on said movable electrode for securing said movable electrode after it has been positioned at the desired point.
Claim 7
Dependent Claim
83 words
In a resonant cavity usable at UHF frequencies, a resonator, a trimmer capacitor having minimum capacity near the upper end of the UHF band and including a fixed electrode connected to said resonator and formed from a plurality of helically arranged insulated turns of wire, an insulating sleeve mounted inside said turns of wire and defining a central passage, a movable electrode positioned to move in and out of the central passage of said fixed electrode, and support means for said movable electrode.
Claim 8
Dependent Claim
83 words
In a resonant cavity usable at UHF frequencies, a resonator, a trimmer capacitor having minimum capacity near the upper end of the UHF band and including a fixed electrode connected to said resonator and formed from a plurality of helically arranged insulated turns of wire, an insulating sleeve mounted inside said turns of wire and defining a central passage, a movable electrode positioned to move in and out of the central passage of said fixed electrode, and support means for said movable electrode.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |