US3881155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting the multi-path of FM stereo broadcasted waves
Assignee: TRIO ELECTRONICS Inc
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Filing: 1973-07-05
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Granted: 1975-04-29
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Expires: 1993-07-05
Abstract
Abstract After receiving the FM stereo broadcasted wave the amplitude modulated component of the intermediate frequency component of the received wave caused by the multipath is detected, and an amplitude modulated component associated with the pilot signal is selectively amplified by means of a selective amplifier or an amplitude modulated component having a predetermined frequency is detected for use to operate display means or to adjust the position of the receiving antenna.
Inventors
- 👤 Noboru Saikaishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:56
CPC Classifications
H; H04; H04H; H04H40/00; H04H40/18; H04H40/27; H04H40/36; H04H40/45; H04H40/72; G; G01; G01R; G01R29/00; G01R29/06; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/1027
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
111 words
In a method of detecting the effect of multi-path transmission of a FM stereo broadcasted wave transmitted with FM modulation components including a pilot signal of predetermined frequency with constant amplitude modulation wherein the wave received by a FM stereo receiver is converted into an intermediate frequency signal, and the amplitude modulated wave caused by said multi-path transmission is detected from said intermediate frequency signal, the improvement which comprises the steps of selecting only said pilot signal from said amplitude modulated wave, further detecting the selected said pilot signal to recover a detected value of said constant amplitude modulation and utilizing said detected value as a measure of said multi-path transmission.
Claim 2
Dependent Claim
111 words
In a method of detecting the effect of multi-path transmission of a FM stereo broadcasted wave transmitted with FM modulation components including a pilot signal of predetermined frequency with constant amplitude modulation wherein the wave received by a FM stereo receiver is converted into an intermediate frequency signal, and the amplitude modulated wave caused by said multi-path transmission is detected from said intermediate frequency signal, the improvement which comprises the steps of selecting only said pilot signal from said amplitude modulated wave, further detecting the selected said pilot signal to recover a detected value of said constant amplitude modulation and utilizing said detected value as a measure of said multi-path transmission.
Claim 3
Dependent Claim
25 words
The method according to claim 1 wherein said step of utilizing said detected value comprises the step of applying said detected value to display means.
Claim 4
Dependent Claim
27 words
The method according to claim 1 wherein said step of selecting comprises the step of frequency selective tuning of said pilot signal from said amplitude modulated wave.
Claim 5
Dependent Claim
108 words
In apparatus for detecting the effect of multi-path transmission of a FM stereo broadcasted wave transmitted with FM modulation components including a pilot signal with constant amplitude modulation comprising receiving means for receiving said FM stereo broadcasted wave, means responsive to said received wave for forming an intermediate frequency signal, detector means for deriving the amplitude modulated components out of said intermediate frequency signal, a selective amplifier coupled to receive said amplitude modulated components for selectively amplifying only an amplitude modulated component associated with the pilot signal, and means coupled to the output of said selective amplifier for utilizing said amplitude modulated component associated with said pilot signal.
Claim 6
Dependent Claim
108 words
In apparatus for detecting the effect of multi-path transmission of a FM stereo broadcasted wave transmitted with FM modulation components including a pilot signal with constant amplitude modulation comprising receiving means for receiving said FM stereo broadcasted wave, means responsive to said received wave for forming an intermediate frequency signal, detector means for deriving the amplitude modulated components out of said intermediate frequency signal, a selective amplifier coupled to receive said amplitude modulated components for selectively amplifying only an amplitude modulated component associated with the pilot signal, and means coupled to the output of said selective amplifier for utilizing said amplitude modulated component associated with said pilot signal.
Claim 7
Dependent Claim
35 words
The apparatus according to claim 4 in which said means for utilizing Comprises a rectifier for rectifying the output from said selective amplifier and a DC indicating meter energized by the output of said rectifier.
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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) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |