Patent US2390794A successfully refreshed from Google Patents.
US2390794A
Expired / Lapsed
US
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Frequency response control
Assignee: Zenith Electronics LLC
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Filing: 1944-02-21
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Granted: 1945-12-11
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Expires: 1964-02-21
Abstract
No abstract record available.
Inventors
- 👤 Knight Cosler Donald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:28
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/38; H03F1/40; H04; H04R; H04R25/00; H04R25/50; H04R25/502
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1948-12-10 | 1949-06-11 | 1949-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1952-12-10 | 1953-06-11 | 1953-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1956-12-10 | 1957-06-11 | 1957-12-11 | $7700.00 | Window Closed / Lapsed |