US1978475A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intermediate frequency amplifier
Assignee: RCA Corp
•
Filing: 1932-01-13
•
Granted: 1934-10-30
•
Expires: 1952-01-13
Abstract
No abstract record available.
Inventors
- 👤 Posthumus Klaas
- 👤 Weyers Theodorus Josephus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:27
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/0153; H03H7/0161; H03H7/17; H03H7/1741; H03H7/1775
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) | 1937-10-29 | 1938-04-30 | 1938-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-10-29 | 1942-04-30 | 1942-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-10-29 | 1946-04-30 | 1946-10-30 | $7700.00 | Window Closed / Lapsed |