Patent US3207990A successfully refreshed from Google Patents.
US3207990A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Unilaterally-transmissive frequency-selective triode converter
Assignee: Standard Kollsman Industries Inc
•
Filing: 1961-08-10
•
Granted: 1965-09-21
•
Expires: 1981-08-10
Abstract
No abstract record available.
Inventors
- 👤 Nestlerode Clifford Dale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:44
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/06; H03D7/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
133 words
IN A RADIO RECEIVER, THE COMBINATION WITH A RADIO TUBE OF AN RF AMPLIFIER STAGE AND A TRIODE TUBE OF AN OSCILLATOR MIXER STAGE, OF A COUPLING CIRCUIT BETWEEN SAID TUBES OF THE TWO STAGES SAID COUPLING CIRCUIT COMPRISING A FIRST CIRCUIT TUNABLE TO THE RF INPUT SIGNAL FREQUENCY AND SIMULTANEOUSLY TUNABLE TO AN OSCILLATOR FREQUENCY, AND A SECOND CIRCUIT TUNABLE TO A VARIABLE OSCILLATOR FREQUENCY THAT SHALL HAVE A RELATIVELY FIXED DIFFERENCE RELATION TO THE FREQUENCY OF THE INPUT SIGNAL, THEREBY TO PROVIDE A DIFFERENCE FREQUENCY OUTPUT FROM THE TUBE OF THE OSCILLATOR MIXER STAGE, WHICH OUTPUT FROM THE TUBE OF THE OSCILCONSTANT FREQUENCY TO SERVE AS AN IF SIGNAL AND SAID FIRST R.F. TUNED CIRCUIT HAVING CIRCUIT MEANS TO BLOCK THE OSCILLATOR FREQUENCY FROM FEEDING BACK TO SAID R.F. AMPLIFIER STAGE.
Claim 2
Dependent Claim
133 words
IN A RADIO RECEIVER, THE COMBINATION WITH A RADIO TUBE OF AN RF AMPLIFIER STAGE AND A TRIODE TUBE OF AN OSCILLATOR MIXER STAGE, OF A COUPLING CIRCUIT BETWEEN SAID TUBES OF THE TWO STAGES SAID COUPLING CIRCUIT COMPRISING A FIRST CIRCUIT TUNABLE TO THE RF INPUT SIGNAL FREQUENCY AND SIMULTANEOUSLY TUNABLE TO AN OSCILLATOR FREQUENCY, AND A SECOND CIRCUIT TUNABLE TO A VARIABLE OSCILLATOR FREQUENCY THAT SHALL HAVE A RELATIVELY FIXED DIFFERENCE RELATION TO THE FREQUENCY OF THE INPUT SIGNAL, THEREBY TO PROVIDE A DIFFERENCE FREQUENCY OUTPUT FROM THE TUBE OF THE OSCILLATOR MIXER STAGE, WHICH OUTPUT FROM THE TUBE OF THE OSCILCONSTANT FREQUENCY TO SERVE AS AN IF SIGNAL AND SAID FIRST R.F. TUNED CIRCUIT HAVING CIRCUIT MEANS TO BLOCK THE OSCILLATOR FREQUENCY FROM FEEDING BACK TO SAID R.F. AMPLIFIER STAGE.
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) | 1968-09-20 | 1969-03-22 | 1969-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-20 | 1973-03-22 | 1973-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-20 | 1977-03-22 | 1977-09-21 | $7700.00 | Window Closed / Lapsed |