BE471744A - - Google Patents
Info
- Publication number
- BE471744A BE471744A BE471744DA BE471744A BE 471744 A BE471744 A BE 471744A BE 471744D A BE471744D A BE 471744DA BE 471744 A BE471744 A BE 471744A
- Authority
- BE
- Belgium
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
- H04M1/62—Constructional arrangements
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M9/00—Arrangements for interconnection not involving centralised switching
- H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Telephone Set Structure (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB730146A GB614638A (en) | 1946-03-08 | 1946-03-08 | Improvements in and relating to loudspeaking telephone systems |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| BE471744A true BE471744A (en:Method) |
Family
ID=9830490
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE471744D BE471744A (en:Method) | 1946-03-08 |
Country Status (3)
| Country | Link |
|---|---|
| BE (1) | BE471744A (en:Method) |
| FR (1) | FR942664A (en:Method) |
| GB (1) | GB614638A (en:Method) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3102169A (en) * | 1959-12-14 | 1963-08-27 | Modern Telephones Great Britai | Loudspeaking telephones |
-
0
- BE BE471744D patent/BE471744A/xx unknown
-
1946
- 1946-03-08 GB GB730146A patent/GB614638A/en not_active Expired
-
1947
- 1947-03-05 FR FR942664D patent/FR942664A/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR942664A (fr) | 1949-02-15 |
| GB614638A (en) | 1948-12-20 |