US3913038A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic radiation filter for coaxially fed hot chassis television receiver
Assignee: RCA Licensing Corp
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Filing: 1974-08-21
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Granted: 1975-10-14
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Expires: 1994-08-21
Abstract
Abstract A radio frequency filter for a television receiver adapted for coupling to an alternating current source having an earth ground and including a conductive chassis which, upon energization of the receiver by the current source, is coupled to one terminal of the current source and a radio frequency tuner coupled to the chassis. A coaxial cable utilized to couple radio frequency signals between a source of radio frequency signals and the tuner has inner and outer conductors. Capacitors are provided between the outer conductor and the chassis of the television receiver at a first point, a second point and a third point along the coaxial cable, the first point being adjacent the tuner and the second and third points being progressively further from the tuner. First means for elevating the impedance associated with at least the outer conductor of the coaxial cable while maintaining the characteristic impedance of the coaxial cable as a whole is associated with the outer conductor between the first point and the second point. Second means for elevating the impedance associated with at least the outer conductor of the coaxial cable is associated with the outer conductor between the second point and the third point. The combination of the means for elevating the impedance of the outer conductor and the capacitors provide for a reduction of undesirable radio frequency signals coupled to the tuner which are developed between the outer conductor and earth ground by electromagnetic radiation coupled to the coaxial cable between the source of radio frequency signals and the third point.
Inventors
- 👤 George William Carter
- 👤 Stephen Earl Hilliker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:45
CPC Classifications
H; H03; H03H; H03H1/00; H03H1/0007
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
249 words
In a television receiver adapted for coupling to an alternating current source for supplying operating power to said receiver, said source having an earth ground potential reference, said receiver including a conductive chassis coupled to said current source, a radio frequency tuner coupled to said chassis and coaxial cable means having inner and outer conductors for supplying radio frequency signals to said tuner, a radio frequency filter comprising: first impedance means coupled between said chassis and said outer conductor at a first point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; second impedance means coupled between said chassis and said outer conductor of said coaxial cable at a second point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; means coupled at least to said outer conductor between said first point and said second point on said coaxial cable for providing an increase in series impedance associated with at least said outer conductor while maintaining the characteristic impedance of said coaxial cable; and means coupled between said inner conductor and said radio frequency tuner for coupling said radio frequency signals existing between said inner conductor of said coaxial cable and said chassis to said tuner, said last-named means having a relatively high impedance to said alternating current source.
Claim 2
Dependent Claim
249 words
In a television receiver adapted for coupling to an alternating current source for supplying operating power to said receiver, said source having an earth ground potential reference, said receiver including a conductive chassis coupled to said current source, a radio frequency tuner coupled to said chassis and coaxial cable means having inner and outer conductors for supplying radio frequency signals to said tuner, a radio frequency filter comprising: first impedance means coupled between said chassis and said outer conductor at a first point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; second impedance means coupled between said chassis and said outer conductor of said coaxial cable at a second point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; means coupled at least to said outer conductor between said first point and said second point on said coaxial cable for providing an increase in series impedance associated with at least said outer conductor while maintaining the characteristic impedance of said coaxial cable; and means coupled between said inner conductor and said radio frequency tuner for coupling said radio frequency signals existing between said inner conductor of said coaxial cable and said chassis to said tuner, said last-named means having a relatively high impedance to said alternating current source.
Claim 3
Dependent Claim
35 words
The combination as in claim 1 wherein said means coupled at least to said outer conductor between said first point and said second point comprises a material having high permeability at said radio frequency signals.
Claim 4
Dependent Claim
25 words
The combination as in claim 2 wherein said material having high permeability is of a tubular form and is concentrically mounted on said cOaxial cable.
Claim 5
Dependent Claim
15 words
The combination as in claim 1 wherein said first impedance means comprises a first capacitor.
Claim 6
Dependent Claim
22 words
The combination as in claim 4 wherein said first impedance means further comprises a resistor coupled in parallel with said first capacitor.
Claim 7
Dependent Claim
15 words
The combination as in claim 1 wherein said second impedance means comprises a second capacitor.
Claim 8
Dependent Claim
30 words
The combination as in claim 6 wherein said second capacitor is of a tubular form having metalization on the inner and outer cylindrical surfaces forming plates of said second capacitor.
Claim 9
Dependent Claim
23 words
The combination as in claim 1 wherein said means coupled between said inner conductor and said radio frequency tuner comprises a third capacitor.
Claim 10
Dependent Claim
30 words
The combination as in claim 8 wherein said means coupled between said inner conductor and said radio frequency tuner further comprises a resistor coupled in parallel with said third capacitor.
Claim 11
Dependent Claim
340 words
In a television receiver adapted for coupling to an alternating current source for supplying operating power to said receiver, said source having an earth ground potential reference, said receiver including a conductive chassis coupled to said current source, a radio frequency tuner coupled to said chassis and coaxial cable means having inner and outer conductors for supplying radio frequency signals to said tuner, a radio frequency filter comprising: first impedance means coupled between said chassis and said outer conductor at a first point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; second impedance means coupled between said chassis and said outer conductor of said coaxial cable at a second point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; third impedance means coupled between said chassis and said outer conductor of said coaxial cable at a third point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; means coupled at least to said outer conductor between said first point and said second point on said coaxial cable for providing an increase in series impedance associated with at least said outer conductor while maintaining the characteristic impedance of said coaxial cable; means coupled at least to said outer conductor between said second point and said third point on said coaxial cable for providing an increase in series impedance associated with at least said outer conductor while maintaining the characteristic impedance of said coaxial cable; and means coupled between said inner conductor and said radio frequency tuner for coupling said radio frequency signals existing between said inner conductor of said coaxial cable and said chassis to said tuner, said last-named means having a relatively high impedance to said alternating current source.
Claim 12
Dependent Claim
340 words
In a television receiver adapted for coupling to an alternating current source for supplying operating power to said receiver, said source having an earth ground potential reference, said receiver including a conductive chassis coupled to said current source, a radio frequency tuner coupled to said chassis and coaxial cable means having inner and outer conductors for supplying radio frequency signals to said tuner, a radio frequency filter comprising: first impedance means coupled between said chassis and said outer conductor at a first point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; second impedance means coupled between said chassis and said outer conductor of said coaxial cable at a second point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; third impedance means coupled between said chassis and said outer conductor of said coaxial cable at a third point for providing a relatively low impedance between said outer conductor and said chassis for radio frequency signals and for providing a relatively high impedance to said alternating current source; means coupled at least to said outer conductor between said first point and said second point on said coaxial cable for providing an increase in series impedance associated with at least said outer conductor while maintaining the characteristic impedance of said coaxial cable; means coupled at least to said outer conductor between said second point and said third point on said coaxial cable for providing an increase in series impedance associated with at least said outer conductor while maintaining the characteristic impedance of said coaxial cable; and means coupled between said inner conductor and said radio frequency tuner for coupling said radio frequency signals existing between said inner conductor of said coaxial cable and said chassis to said tuner, said last-named means having a relatively high impedance to said alternating current source.
Claim 13
Dependent Claim
53 words
The combination as in claim 10 wherein said means coupled at least to said outer conductor between said first point and said second point and said means coupled at least to said outer conductor between said second point and said third point comprise a material having high permeability at said radio frequency signals.
Claim 14
Dependent Claim
25 words
The combination as in claim 11 wherein said material having high permeability is of a tubular form and is concentrically mounted on said coaxial cable.
Claim 15
Dependent Claim
15 words
The combination as in claim 10 wherein said first impedance means comprises a first capacitor.
Claim 16
Dependent Claim
22 words
The combination as in claim 13 wherein said first impedance means further comprises a resistor coupled in parallel with said first capacitor.
Claim 17
Dependent Claim
24 words
The combination as in claim 10 wherein said second impedance means comprises a second capacitor and said third impedAnce means comprises a fourth capacitor.
Claim 18
Dependent Claim
34 words
The combination as in claim 15 wherein said second capacitor and said fourth capacitor are of a tubular form having metalization on the inner and outer cylindrical surfaces forming plates of said second capacitor.
Claim 19
Dependent Claim
23 words
The combination as in claim 10 wherein said means coupled between said inner conductor and said radio frequency tuner comprises a third capacitor.
Claim 20
Dependent Claim
30 words
The combination as in claim 17 wherein said means coupled between said inner conductor and said radio frequency tuner further comprises a resistor coupled in parallel with said third capacitor.
References Cited (Backward Citations)
US2419907A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |