FR840029A - Telephone transmission systems - Google Patents
Telephone transmission systemsInfo
- Publication number
- FR840029A FR840029A FR840029DA FR840029A FR 840029 A FR840029 A FR 840029A FR 840029D A FR840029D A FR 840029DA FR 840029 A FR840029 A FR 840029A
- Authority
- FR
- France
- Prior art keywords
- transmission systems
- telephone transmission
- telephone
- systems
- transmission
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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
- H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR840029T | 1937-12-18 |
Publications (1)
Publication Number | Publication Date |
---|---|
FR840029A true FR840029A (en) | 1939-04-18 |
Family
ID=9299972
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
FR840029D Expired FR840029A (en) | 1937-12-18 | 1937-12-18 | Telephone transmission systems |
Country Status (1)
Country | Link |
---|---|
FR (1) | FR840029A (en) |
-
1937
- 1937-12-18 FR FR840029D patent/FR840029A/en not_active Expired
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