US3909727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data signaling noise suppression system
Assignee: RCA Corp
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Filing: 1974-04-19
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Granted: 1975-09-30
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Expires: 1994-04-19
Abstract
Abstract The suppression of speaker noise caused by data signaling in a mobile radio system is achieved by detecting the presence of a single audio tone frequency over a time period and when the presence of such a tone is detected causing muting of the speaker of the mobile radio receiver.
Inventors
- 👤 Carroll Duane Hughes
- 👤 Walter Charles Painter
- 👤 Chandos Arthur Rypinski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:35
CPC Classifications
H; H04; H04W; H04W88/00; H04W88/02; H04W88/022; H04W88/025; H04W88/027; H03; H03G; H03G3/00; H03G3/005; H03G3/20; H03G3/30; H03G3/34
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
136 words
A receiver system responsive to a carrier wave modulated by either voice audio intelligence signals or data audio tone intelligence signals at a given frequency within the voice band of frequencies for detecting said audio signals at a detector and providing the output thereof to an audio speaker wherein said data signals cause highly objectional noise in the output of said speaker, the improvement therewith comprising: means for normally coupling the output from said detector to said speaker, and timed means including a clipper, a bandpass filter, an AC/DC converter and a timer coupled between said audio detector and said audio speaker responsive to the presence of a tone of said given frequency over a given time period for disconnecting said normally coupling means and thereby muting said speaker only during the presence of said tone.
Claim 2
Dependent Claim
136 words
A receiver system responsive to a carrier wave modulated by either voice audio intelligence signals or data audio tone intelligence signals at a given frequency within the voice band of frequencies for detecting said audio signals at a detector and providing the output thereof to an audio speaker wherein said data signals cause highly objectional noise in the output of said speaker, the improvement therewith comprising: means for normally coupling the output from said detector to said speaker, and timed means including a clipper, a bandpass filter, an AC/DC converter and a timer coupled between said audio detector and said audio speaker responsive to the presence of a tone of said given frequency over a given time period for disconnecting said normally coupling means and thereby muting said speaker only during the presence of said tone.
Claim 3
Dependent Claim
21 words
The combinatin claimed in claim 1 wherein said bandpass filter is centered at said given audio frequency of said data signals.
Claim 4
Dependent Claim
26 words
The combination claimed in claim 2 wherein said time period is of sufficient length beyond 50 milliseconds to distinguish said data signal from a voice signal.
Claim 5
Dependent Claim
29 words
The combination claimed in claim 3 wherein said timed means includes an attenuator preceding the bandpass filter to limit the amplitude of the input signal to the bandpass filter.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |