US3808540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loudness control
Assignee: GATES RADIO CO
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Filing: 1971-03-11
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Granted: 1974-04-30
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Expires: 1991-03-11
Abstract
Abstract A device for reducing the apparent loudness of the output signal in a broadcasting system which includes a frequency selective gain reduction network connected between an automatic gain control amplifier and the output section. Means are provided for amplifying the energy content at the output of the automatic gain control amplifier. Pre-emphasis means are provided to increase the signal level of the sampling means within a given frequency range. The output of the sampling means is then used to actuate the frequency selective gain network for decreasing the gain at the output section in response to increases in gain at the output of the sampling means.
Inventors
- 👤 W Kabrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:56
CPC Classifications
H; H03; H03G; H03G5/00; H03G5/16; H03G5/18; H03G5/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
214 words
In a broadcast transmitter including an automatic gain control amplifier through which the audio frequency intelligence signal passes and which controls the signal level as a function of the total energy in the audio frequency spectrum, comprising an attenuating network receiving the output of said automatic gain control network to pass the audio to an output and having a variable impedance for audio frequencies in a small portion of the audio band and low impedance for audio frequencies other than said small portion of the audio band, a detecting and control means connectEd to said attenuating network to vary its impedance as a function of energy content of the audio signal in said small portion of the audio band, said detecting and control means connected to the output of said automatic gain control amplifier and detecting the energy level of the audio signal in said small portion of the audio band, and said detecting and control means connected to said variable attenuating network so as to adjust its impedance to signals in said small portion of the audio band without substantially affecting audio signals outside said small portion of the audio bands so as to prevent unusually high levels of energy in said small portion of the audio band from passing to said output.
Claim 2
Dependent Claim
214 words
In a broadcast transmitter including an automatic gain control amplifier through which the audio frequency intelligence signal passes and which controls the signal level as a function of the total energy in the audio frequency spectrum, comprising an attenuating network receiving the output of said automatic gain control network to pass the audio to an output and having a variable impedance for audio frequencies in a small portion of the audio band and low impedance for audio frequencies other than said small portion of the audio band, a detecting and control means connectEd to said attenuating network to vary its impedance as a function of energy content of the audio signal in said small portion of the audio band, said detecting and control means connected to the output of said automatic gain control amplifier and detecting the energy level of the audio signal in said small portion of the audio band, and said detecting and control means connected to said variable attenuating network so as to adjust its impedance to signals in said small portion of the audio band without substantially affecting audio signals outside said small portion of the audio bands so as to prevent unusually high levels of energy in said small portion of the audio band from passing to said output.
Claim 3
Dependent Claim
20 words
In a broadcast transmitter according to claim 1 wherein said small portion of the audio band extends from 2-4 kilohertz.
Claim 4
Dependent Claim
72 words
In a broadcast receiver according to claim 1 wherein said attenuating network comprises a capacitor, an inductance and a variable resistance connected in parallel and said detecting and control means connected to said variable resistance to vary the impedance of said network to said small portion of the audio frequency band and said capacitor and inductance having values such that they are resonant in said small portion of the audio frequency band.
Claim 5
Dependent Claim
23 words
In a broadcast transmitter according to claim 3 wherein said capacitor and inductance have values such that they are resonant between 2-4 kilohertz.
Claim 6
Dependent Claim
99 words
In a broadcast transmitter according to claim 4 wherein said detecting control means comprises a push-pull amplifier including first and second transistors connected in push-pull and receiving the output signal from said automatic gain control network on their base electrodes, a second capacitor and a second inductance connected in series between the emitters of said first and second transistors and having values so as to have a series resonance within said small portion of said audio band, and adjustment means connected to the collectors of said first and second transistors and controlling said variable resistance of said attenuating network.
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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) | 1977-04-29 | 1977-10-29 | 1978-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-29 | 1981-10-29 | 1982-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-29 | 1985-10-29 | 1986-04-30 | $7700.00 | Window Closed / Lapsed |