US3294912A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stereophonic fm receivers having automatic switching means for stereo reception
Assignee: RCA Corp
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Filing: 1963-02-27
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Granted: 1966-12-27
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Expires: 1983-02-27
Abstract
No abstract record available.
Inventors
- 👤 James F Merritt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:51
CPC Classifications
H; H03; H03D; H03D1/00; H03D1/22; H03D1/2209; H03D1/2218
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
117 words
A CIRCUIT FOR FREQUENCY-MODUALTION STEREOPHONIC RECEIVERS COMPRISING: AN INPUTE CIRCUIT FOR CONNECTIONTO A SOURCE OF DEMODULATED FREQUENCY-MODULATION SIGNALS WHICH DURING MONOPHONIC RECEPTION COMPRISE AUDIO-FREQUENCY SIGNALS AND WHICH DURING STEREOPHONIC SIGNAL RECEPTION INCLUDES: (1) AUDIO-FREQUENCY SIGNALS, (2) SUBCARRIER SIDEBAND SIGNALS. (3) A PILOT SIGNAL, MEANS FOR SEPARATING SAID PILOT SIGNAL FROM THE REMAINDER OF SAID COMPOSITE SIGNAL, A FREQUENCY DOUBLER CIRCUIT INCLUDING A PAIR OF TRANSISTORS EACH HAVING BASE, EMITTER AND COLLECTOR ELECTRODES, MEANS FOR APPLYING SAID SEPARATED PILOT SIGNAL IN PUSHPULL RELATION BETWEEN THE BASE ELECTRODES OF SAID PAIR OF TRANSISTORS, AN OUTPUT CIRCUIT COUPLED TO THE COLLECTOR ELECTRODES OF SAID TRANSISTORS FOR DEVELOPING A DEMODULATING SIGNAL WHOSE FREQUENCY IS TWICE THE FREQUENCY OF SAID PILOT SIGNAL,
Claim 2
Dependent Claim
117 words
A CIRCUIT FOR FREQUENCY-MODUALTION STEREOPHONIC RECEIVERS COMPRISING: AN INPUTE CIRCUIT FOR CONNECTIONTO A SOURCE OF DEMODULATED FREQUENCY-MODULATION SIGNALS WHICH DURING MONOPHONIC RECEPTION COMPRISE AUDIO-FREQUENCY SIGNALS AND WHICH DURING STEREOPHONIC SIGNAL RECEPTION INCLUDES: (1) AUDIO-FREQUENCY SIGNALS, (2) SUBCARRIER SIDEBAND SIGNALS. (3) A PILOT SIGNAL, MEANS FOR SEPARATING SAID PILOT SIGNAL FROM THE REMAINDER OF SAID COMPOSITE SIGNAL, A FREQUENCY DOUBLER CIRCUIT INCLUDING A PAIR OF TRANSISTORS EACH HAVING BASE, EMITTER AND COLLECTOR ELECTRODES, MEANS FOR APPLYING SAID SEPARATED PILOT SIGNAL IN PUSHPULL RELATION BETWEEN THE BASE ELECTRODES OF SAID PAIR OF TRANSISTORS, AN OUTPUT CIRCUIT COUPLED TO THE COLLECTOR ELECTRODES OF SAID TRANSISTORS FOR DEVELOPING A DEMODULATING SIGNAL WHOSE FREQUENCY IS TWICE THE FREQUENCY OF SAID PILOT SIGNAL,
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) | 1969-12-26 | 1970-06-27 | 1970-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-12-26 | 1974-06-27 | 1974-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-12-26 | 1978-06-27 | 1978-12-27 | $7700.00 | Window Closed / Lapsed |