US4236254A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio receiver blanker inhibit circuit
Assignee: Motorola Solutions Inc
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Filing: 1978-03-27
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Granted: 1980-11-25
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Expires: 1998-03-27
Abstract
Abstract The noise blanker of a conventional FM radio is inhibited for several seconds upon closing of the receiver's squelch gate. Following the inhibit period, the blanker is reactivated and again inhibited for the full period upon a subsequent squelch gate closing. Thus, the blanker is inhibited for those signal conditions in which its operation would degrade the overall intelligibility of the processed signal as determined by the squelch control setting.
Inventors
- 👤 Michael J. Augustin
- 👤 Wade Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:40
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/34; H03G3/345
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
115 words
An improved blanker circuit for a radio receiver for processing a received signal having a blanker gate and blanking circuitry, the improvement comprising: sense means for sensing, after the blanking gate, the relative signal to noise ratio of the receiver processed signal wherein said sense means comprises a squelch gate for squelching audio output of the receiver, said squelch gate responding to a predetermined degradation in said relative signal to noise ratio of said receiver processed signal to block said audio output; and inhibitor means for inhibiting blanking action for a predetermined time period in response to said squelch gate sensing said predetermined degradation in said signal to noise ratio and blocking the audio output.
Claim 2
Dependent Claim
115 words
An improved blanker circuit for a radio receiver for processing a received signal having a blanker gate and blanking circuitry, the improvement comprising: sense means for sensing, after the blanking gate, the relative signal to noise ratio of the receiver processed signal wherein said sense means comprises a squelch gate for squelching audio output of the receiver, said squelch gate responding to a predetermined degradation in said relative signal to noise ratio of said receiver processed signal to block said audio output; and inhibitor means for inhibiting blanking action for a predetermined time period in response to said squelch gate sensing said predetermined degradation in said signal to noise ratio and blocking the audio output.
Claim 3
Dependent Claim
34 words
The improvement of claim 1 wherein said inhibitor means is comprised of a monostable multivibrator which responds to said predetermined signal to noise degradation to apply a predetermined duration inhibit signal to the blanker.
Claim 4
Dependent Claim
29 words
The improvement of claim 2 further comprising; clock means for inhibiting operation of the blanker at predetermined intervals during periods when the squelch gate is blocking the audio signal.
Claim 5
Independent Claim
93 words
A method for inhibiting operation of the blanker circuit of a radio receiver comprising the steps of: (a) monitoring, after the blanker circuit, the signal to noise ratio of a signal being processed by the receiver, using squelch circuitry which acts to block the receiver's output in response to the receiver processed signal falling below a predetermined signal to noise ratio threshold, to perform said monitoring, and to produce a control signal upon said squelch circuit blocking said receiver output; and (b) inhibiting blanker circuit operation in response to said produced control signal.
Claim 6
Independent Claim
93 words
A method for inhibiting operation of the blanker circuit of a radio receiver comprising the steps of: (a) monitoring, after the blanker circuit, the signal to noise ratio of a signal being processed by the receiver, using squelch circuitry which acts to block the receiver's output in response to the receiver processed signal falling below a predetermined signal to noise ratio threshold, to perform said monitoring, and to produce a control signal upon said squelch circuit blocking said receiver output; and (b) inhibiting blanker circuit operation in response to said produced control signal.
Claim 7
Dependent Claim
30 words
The method of claim 4 wherein step (b) further comprises the step of: inhibiting the blanker circuit for a predetermined time period following the occurrence of said produced control signal.
Claim 8
Dependent Claim
27 words
The method of claim 5 further comprising the step of: (c) periodically inhibiting the blanker during intervals in which the squelch circuit is blocking the audio signal.
Claim 9
Dependent Claim
27 words
The method of claim 4 further comprising the step of: (c) periodically inhibiting the blanker during intervals in which the squelch circuit is blocking the audio signal.
References Cited (Backward Citations)
US3079558A
Cited
US3140446A
Cited
US3140445A
Cited
US3699457A
Cited
US3958181A
Cited
US3978412A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |