FM stereo tone detector
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United States of America Patent
Stats
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Mar 19, 1991
Grant Date -
N/A
app pub date -
Dec 22, 1989
filing date -
Dec 22, 1989
priority date (Note) -
Expired
status (Latency Note)
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Abstract
A stereo FM radio transmission system with FMX transmission and reception capability includes a transmitter that transmits a pilot-coherent FMX-tone indicator signal at a frequency of an exact integer submultiple of the pilot frequency. The system also includes a receiver for dividing the frequency of the received pilot signal by various submultiples, nearly equal to the exact submultiple, toward quickly finding a match in phase of the received tone and the received pilot and finally dividing the pilot by the exact submultiple to establish an operational lock mode of the receiver tone detector to keep-on an FMX-indicator lamp, to change the receiver decoder to an FMX-reception operating mode and to stand by to quickly recapture the pilot and FMX-tone in the event of multipath or other interfering signals.

First Claim
Family

- 15 United States
- 10 France
- 8 Japan
- 7 China
- 5 Korea
- 2 Other
Patent Owner(s)
Patent Owner | Address | |
---|---|---|
ALLEGRO MICROSYSTEMS INC A DE CORP | 363 PLANTATION STREET WORCESTER MA 01605 |
International Classification(s)
Inventor(s)
Inventor Name | Address | # of filed Patents | Total Citations |
---|---|---|---|
Field, Thomas L | Rutland, MA | 3 | 24 |
Richards, Jr Oliver L | N. Grosvenor Dale, CT | 9 | 151 |
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Maintenance Fees
Fee | Large entity fee | small entity fee | micro entity fee | due date |
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Fee | Large entity fee | small entity fee | micro entity fee |
---|---|---|---|
Surcharge after expiration - Late payment is unavoidable | $700.00 | $350.00 | $175.00 |
Surcharge after expiration - Late payment is unintentional | $1,640.00 | $820.00 | $410.00 |
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