FR977153A - Secret telephone communication system - Google Patents
Secret telephone communication systemInfo
- Publication number
- FR977153A FR977153A FR977153DA FR977153A FR 977153 A FR977153 A FR 977153A FR 977153D A FR977153D A FR 977153DA FR 977153 A FR977153 A FR 977153A
- Authority
- FR
- France
- Prior art keywords
- communication system
- telephone communication
- secret telephone
- secret
- telephone
- 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
- H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
- H04K1/00—Secret communication
- H04K1/04—Secret communication by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR977153T | 1948-10-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
FR977153A true FR977153A (en) | 1951-03-28 |
Family
ID=9519452
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
FR977153D Expired FR977153A (en) | 1948-10-27 | 1948-10-27 | Secret telephone communication system |
Country Status (1)
Country | Link |
---|---|
FR (1) | FR977153A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2217875A1 (en) * | 1973-02-13 | 1974-09-06 | Gretag Ag | |
FR2236321A1 (en) * | 1973-07-02 | 1975-01-31 | Gretag Ag |
-
1948
- 1948-10-27 FR FR977153D patent/FR977153A/en not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2217875A1 (en) * | 1973-02-13 | 1974-09-06 | Gretag Ag | |
FR2236321A1 (en) * | 1973-07-02 | 1975-01-31 | Gretag Ag |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
NL150641B (en) | DATA TRANSMISSION SYSTEM. | |
CH291689A (en) | Telegraph receiver. | |
CH275635A (en) | Automatic telephone registration system. | |
CH274389A (en) | Telephone system with loudspeakers and two separate channels. | |
CH283262A (en) | Loudspeaker bilateral telephone system. | |
CH282893A (en) | Communication facility. | |
CH295259A (en) | Powerline communication installation. | |
FR977153A (en) | Secret telephone communication system | |
FR65373E (en) | All-relay telephone system | |
FR970914A (en) | Telephone intercom system | |
FR988281A (en) | Telephone switching system | |
CH304203A (en) | Telecommunication system. | |
CH280332A (en) | Telephone station. | |
CH271526A (en) | Telephone. | |
BE486835A (en) | Telecommunication system. | |
FR992007A (en) | Telegraphy system | |
FR1010457A (en) | TV system | |
CH271784A (en) | Telephone. | |
FR985680A (en) | Telecommunications office system | |
CH285300A (en) | Loudspeaker bilateral telephone system. | |
FR987599A (en) | Secret phone device | |
CH301277A (en) | Telephone installation. | |
DK75049C (en) | Telephone subscriber device. | |
FR978646A (en) | Telephone intercom system | |
ES181833A1 (en) | IMPROVEMENTS IN TELECOMMUNICATION SYSTEMS |