Patent US2247442A successfully refreshed from Google Patents.
US2247442A
Expired / Lapsed
US
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Neutralizing arrangement for amplifiers
Assignee: AT&T Inc
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Filing: 1940-02-02
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Granted: 1941-07-01
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Expires: 1960-02-02
Abstract
No abstract record available.
Inventors
- 👤 Labin Emile
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:16
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/54; H03C; H03C1/00; H03C1/16; H03C1/18; H03C1/22; H03F1/00; H03F1/08; H03F1/14; H03F1/16; H03F3/50; H03F3/52
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) | 1944-06-30 | 1944-12-30 | 1945-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-06-30 | 1948-12-30 | 1949-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-06-30 | 1952-12-30 | 1953-07-01 | $7700.00 | Window Closed / Lapsed |