US3922608A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic interference locator
Assignee: United States Department of the Army
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Filing: 1973-11-29
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Granted: 1975-11-25
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Expires: 1993-11-29
Abstract
Abstract A two terminal probe has two low-pass filters in series with each terminal, so as to prevent the probe and the associated circuitry from acting as an antenna and prevent the unwanted pickup of high level RF signals. A coaxial cable connects the probe to a signal processor where the normal frequencies of the unit being tested are filtered out, and the interference signal is amplified and connected to a speaker for audio detection.
Inventors
- 👤 Hugh W Denny
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 23:23
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/145; G01R29/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
105 words
A device comprising first and second wires each having one end adapted to be connected across a circuit to be tested; first and second filters each having an input and an output; the other end of said first and second wires being connected respectively to the inputs of said first and second filters; a shield means enclosing said first and second filters; an output connector having first and second terminals; said first terminal being connected to said shield means; said second terminal being connected to the output of said second filter means; and the output of said first filter being connected to said shield means.
Claim 2
Independent Claim
105 words
A device comprising first and second wires each having one end adapted to be connected across a circuit to be tested; first and second filters each having an input and an output; the other end of said first and second wires being connected respectively to the inputs of said first and second filters; a shield means enclosing said first and second filters; an output connector having first and second terminals; said first terminal being connected to said shield means; said second terminal being connected to the output of said second filter means; and the output of said first filter being connected to said shield means.
Claim 3
Dependent Claim
79 words
A device as set forth in claim 1 and further comprising a signal processor which comprises a high impedance amplifier having an input and an output; connection means connecting the input of said amplifier to the terminals of said connector; filtering means having an input and an output; an indicating means having an input; and said filtering means having its input connected to the output of said amplifier and its output connected to the input of said indicating means.
Claim 4
Dependent Claim
65 words
A device as set forth in claim 2 further comprising an active bandpass filter having an input and an output; a second amplifier having an input connected to the output of said bandpass filter and an output; the output of said second amplifier being connected to said indicating means; and the input of the bandpass filter is connected to the output of said filtering means.
Claim 5
Dependent Claim
139 words
A device as set forth in claim 3 wherein said connection means is a coaxial cable; said output connector is a coaxial connector; said signal processor being inclosed by a shield means; a second coaxial connector connected through said shield means to said coaxial cable; said coaxial connectors each having a center connector connected to each other by the coaxial cable and a shield connection connected to each other by the coaxial cable; the shield of said second coaxial connector being connected to the shield of the signal processor; the center connector of said second connector being connected to the input of the high impedance amplifier; and further comprising a notch filter having an input and an output connected between the filtering means and the input of said active bandpass filter; and said indicating means being an audio speaker.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |