US3820018A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for locating electromagnetic radiation in the vhf and uhf range from direct or alternating current electric power lines
Assignee: Research Corp
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Filing: 1971-11-04
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Granted: 1974-06-25
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Expires: 1991-11-04
Abstract
Abstract Method and apparatus for locating electromagnetic radiation from sparks on electric power lines carrying direct or alternating current. A receiver is provided that includes a variable threshold by which signals are detected only when they exceed the threshold. During a search for a noise source, as the receiver is moved toward the source the threshold is raised to avoid detecting spurious noise signals from directions other than from the noise source being located.
Inventors
- 👤 W Beasley
- 👤 J German
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:07
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/08; G01R31/081; G01R31/085; H; H02; H02H; H02H1/00; H02H1/0007; H02H1/0015
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
118 words
In a method of locating the source of electromagnetic radiation in the VHF and UHF range radiated by an electric power line, in which a receiver is used to detect said electromagnetic radiation that exceeds a threshold, and the receiver is moved toward the source of radiation, the improvement comprising initially setting the threshold at a minimum value when a search for a source of electromagnetic radiation is commenced and then raising the threshold of said receiver during the time that the receiver is moved toward said source, with said threshold being raised such that said electromagnetic radiation from said source is just detected in said receiver during the time that said receiver is moved toward said source.
Claim 2
Dependent Claim
118 words
In a method of locating the source of electromagnetic radiation in the VHF and UHF range radiated by an electric power line, in which a receiver is used to detect said electromagnetic radiation that exceeds a threshold, and the receiver is moved toward the source of radiation, the improvement comprising initially setting the threshold at a minimum value when a search for a source of electromagnetic radiation is commenced and then raising the threshold of said receiver during the time that the receiver is moved toward said source, with said threshold being raised such that said electromagnetic radiation from said source is just detected in said receiver during the time that said receiver is moved toward said source.
Claim 3
Dependent Claim
87 words
A method according to claim 1, in which the receiver includes a movable directional antenna, and comprising the initial steps of fixing the location of the receiver, moving the antenna until a maximum signal representing electromagnetic radiation in the VHF and UHF range is detected, raising the threshold until the signal is just detected, and then moving the receiver towards said source in the direction in which said antenna is pointing while raising the threshold of the receiver still further so that said signal is just detected.
Claim 4
Independent Claim
222 words
A method of locating the source of electromagnetic radiation in the VHF and UHF range radiated by an electric power line, in which a receiver is used to detect said electromagnetic radiation that exceeds a threshold, in which the receiver includes separate channels tuned to receive different frequencies of electromagnetic radiation, one of said channels being operative at any time, and a plurality of movable directional antennas each for a different one of said channels and each tuned to receive signals of a frequency of the corresponding channel, one of said directional antennas being coupled to said receiver at any time to supply signals to the receiver, comprising the steps of initially selecting an antenna and channel of a lower one of the available frequencies in commencing a search, fixing the location of the receiver, moving the selected antenna until a maximum signal representing electromagnetic radiation in the VHF and UHF range is detected, raising the threshold until the signal is just detected, and then moving the receiver towards said source in the direction in which said antenna is pointing while raising the threshold of the receiver still further so that said signal is just detected, and changing to an antenna and corresponding channel of higher frequency when the receiver has been moved closer to the source following commencement of the search.
Claim 5
Independent Claim
222 words
A method of locating the source of electromagnetic radiation in the VHF and UHF range radiated by an electric power line, in which a receiver is used to detect said electromagnetic radiation that exceeds a threshold, in which the receiver includes separate channels tuned to receive different frequencies of electromagnetic radiation, one of said channels being operative at any time, and a plurality of movable directional antennas each for a different one of said channels and each tuned to receive signals of a frequency of the corresponding channel, one of said directional antennas being coupled to said receiver at any time to supply signals to the receiver, comprising the steps of initially selecting an antenna and channel of a lower one of the available frequencies in commencing a search, fixing the location of the receiver, moving the selected antenna until a maximum signal representing electromagnetic radiation in the VHF and UHF range is detected, raising the threshold until the signal is just detected, and then moving the receiver towards said source in the direction in which said antenna is pointing while raising the threshold of the receiver still further so that said signal is just detected, and changing to an antenna and corresponding channel of higher frequency when the receiver has been moved closer to the source following commencement of the search.
Claim 6
Dependent Claim
126 words
A testing instrument for locating electromagnetic radiation in the VHF and UHF range from direct or alternating current electric power lines, comprising directional receiving means for sensing electromagnetic radiation in said range radiated by a power line and generating signals thereby; a diode connected to pass signals from said receiving means and provided with a bias potential variable upwardly from electrical ground level to vary upwardly from zero the threshold level of said diode which must be exceeded by said signals from said receiving means in order to pass through said diode; and indicating means coupled to said diode and comprising an audio amplifier with adjustable gain and a loudspeaker for providing an audible indication of signals passing through said diode and exceeding said threshold level.
Claim 7
Dependent Claim
126 words
A testing instrument for locating electromagnetic radiation in the VHF and UHF range from direct or alternating current electric power lines, comprising directional receiving means for sensing electromagnetic radiation in said range radiated by a power line and generating signals thereby; a diode connected to pass signals from said receiving means and provided with a bias potential variable upwardly from electrical ground level to vary upwardly from zero the threshold level of said diode which must be exceeded by said signals from said receiving means in order to pass through said diode; and indicating means coupled to said diode and comprising an audio amplifier with adjustable gain and a loudspeaker for providing an audible indication of signals passing through said diode and exceeding said threshold level.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |