US4001695A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic deviation analysis meter
Assignee: Systron Donner Corp
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Filing: 1975-03-24
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Granted: 1977-01-04
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Expires: 1995-03-24
Abstract
Abstract A system for automatically measuring frequency deviation without manual tuning or frequency selection includes a transfer oscillator circuit which is switchable between fast and slow loop response modes by use of a squelch indication. In addition, a varactor in the voltage controlled oscillator is conditionally operated in the less sensitive portion of its tuning range. This is accomplished by inhibiting the squelch, thus preventing a frequency lock in the undesired portion of the varicap tuning range when the higher frequencies are applied to the input.
Inventors
- 👤 Benny A. Hrbacek
- 👤 Lewis F. Grovenstein, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:05
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
181 words
An automatic deviation analysis meter for indicating the frequency deviation of an unknown frequency modulated carrier signal comprising: automatic transfer oscillator means including a harmonic mixer, a voltage controlled oscillator (VCO) for producing a local oscllator (L.O.) signal, a negative feedback loop including said harmonic mixer coupled to and responsive to the L.O. signal of said VCO to produce an intermediate frequency (I.F.) signal, said loop including a discriminator coupled to said harmonic mixer and responsive to said I.F. signal for producing a d.c. voltage determined by any I.F. signal frequency change, said d.c. voltage driving said VCO after acquisition of said carrier signal; search means for scanning said VCO during a scanning mode and before acquisition of said carrier signal; means for controlling the frequency response of said loop and responsive to acquisition of said carrier signal for providing a relatively slow loop response to maintain the L.O. signal substantially constant with relatively low audio frequency modulation on said acquired carrier such means also coupling said search means to said VCO during said scanning mode and providing a fast response.
Claim 2
Dependent Claim
181 words
An automatic deviation analysis meter for indicating the frequency deviation of an unknown frequency modulated carrier signal comprising: automatic transfer oscillator means including a harmonic mixer, a voltage controlled oscillator (VCO) for producing a local oscllator (L.O.) signal, a negative feedback loop including said harmonic mixer coupled to and responsive to the L.O. signal of said VCO to produce an intermediate frequency (I.F.) signal, said loop including a discriminator coupled to said harmonic mixer and responsive to said I.F. signal for producing a d.c. voltage determined by any I.F. signal frequency change, said d.c. voltage driving said VCO after acquisition of said carrier signal; search means for scanning said VCO during a scanning mode and before acquisition of said carrier signal; means for controlling the frequency response of said loop and responsive to acquisition of said carrier signal for providing a relatively slow loop response to maintain the L.O. signal substantially constant with relatively low audio frequency modulation on said acquired carrier such means also coupling said search means to said VCO during said scanning mode and providing a fast response.
Claim 3
Dependent Claim
39 words
An automatic deviation analysis meter as in claim 1 where said controlling means include low pass filter means having a rolloff frequency or less than 50 Hz for filtering said d.c. driving voltage for providing said slow loop response.
Claim 4
Dependent Claim
28 words
An automatic deviation analysis meter as in claim 1 together with means coupled to said harmonic mixer for signalling the presence of said carrier signal during said scanning.
Claim 5
Dependent Claim
33 words
An automatic deviation analysis means as in claim 3 together with means for inhibiting said carrier presence means in response to said VCO producing a local oscillator signal in a predetermined frequency range.
Claim 6
Dependent Claim
37 words
An automatic deviation analysis meter as in claim 4 where said inhibiting means is responsive to said harmonic mixer operating at a relatively high harmonic number to produce said I.F. signal for inhibiting said carrier presence means.
Claim 7
Dependent Claim
68 words
An automatic deviation analysis meter as in claim 3 where said controlling means includes filter means for filtering said d.c. driving voltage and for coupling said search means to said VCO said filter means being switchable between fast and slow response modes said controlling means being responsive to said carrier presence signal means for gradually switching to said slow response mode to allow said filter means to stabilize.
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) | 1980-01-04 | 1980-07-05 | 1981-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-04 | 1984-07-05 | 1985-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-04 | 1988-07-05 | 1989-01-04 | $7700.00 | Window Closed / Lapsed |