US2545871A
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Apparatus for compressing or expanding the frequency bands of electric oscillations
Assignee: British Telecommunications PLC
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Filing: 1948-06-05
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Granted: 1951-03-20
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Expires: 1968-06-05
Abstract
No abstract record available.
Inventors
- 👤 Bell David Arthur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:33
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/30; H03H7/34
Claims Analysis
Total Claims: 0
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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) | 1954-03-19 | 1954-09-18 | 1955-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-03-19 | 1958-09-18 | 1959-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-03-19 | 1962-09-18 | 1963-03-20 | $7700.00 | Window Closed / Lapsed |