GB579972A - Secrecy communication system - Google Patents
Secrecy communication systemInfo
- Publication number
- GB579972A GB579972A GB10109/42A GB1010942A GB579972A GB 579972 A GB579972 A GB 579972A GB 10109/42 A GB10109/42 A GB 10109/42A GB 1010942 A GB1010942 A GB 1010942A GB 579972 A GB579972 A GB 579972A
- Authority
- GB
- United Kingdom
- Prior art keywords
- irregular
- secrecy
- speech
- phase
- signal
- 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
- 230000001788 irregular Effects 0.000 abstract 3
- 230000005540 biological transmission Effects 0.000 abstract 2
- 230000000873 masking effect Effects 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
- H04K1/00—Secret communication
Abstract
579,972. Secret transmission. HAZELTINE CORPORATION. July 20, 1942, No. 10109. Convention date, June 25, 1941. [Class 40 (iv)] In a secret transmission system, speech or telegraph signals are passed to a balanced modulator 15 which is fed by a phase-inverter 34 with one or other of two potentials which vary in an irregular manner in accordance with the arrangement of transparent and opaque portions on a card 28 interposed between the fluorescent end of a cathode-ray tube 27 and a photo-electric cell 30. The cathode beam is controlled by apparatus 33 which also sends synchronizing impulses to the distant station. The signal in the output of apparatus 15 is thus repeatedly reversed in phase in an irregular way as shown at C, Fig. 2. Alternatively, the system may be regarded as one in which the signal is modulated by a current with an irregular frequency-variation. Secrecy may be improved by limiting the output of the modulator 15 to the useful portion of the lower sideband resulting from this operation by means of a filter 22. Further secrecy may be given by superimposing a masking tone at 13. This is arranged to be disconnected during the intervals in speech. Converse operations are performed at the receiving end.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US399637A US2402058A (en) | 1941-06-25 | 1941-06-25 | Secrecy communication system |
Publications (1)
Publication Number | Publication Date |
---|---|
GB579972A true GB579972A (en) | 1946-08-22 |
Family
ID=23580331
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB10109/42A Expired GB579972A (en) | 1941-06-25 | 1942-07-20 | Secrecy communication system |
Country Status (2)
Country | Link |
---|---|
US (1) | US2402058A (en) |
GB (1) | GB579972A (en) |
Families Citing this family (42)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2733358A (en) * | 1956-01-31 | Signal | ||
US2734100A (en) * | 1956-02-07 | Kendall | ||
US3470323A (en) * | 1944-06-30 | 1969-09-30 | Bell Telephone Labor Inc | Signaling system |
US2705901A (en) * | 1946-01-15 | 1955-04-12 | Chalmers W Sherwin | Oscillographic integrator |
US2543116A (en) * | 1946-07-08 | 1951-02-27 | Bell Telephone Labor Inc | Means and method for the secret transmission of message intelligence |
US2636936A (en) * | 1946-09-10 | 1953-04-28 | Rca Corp | Television secrecy system |
US2489883A (en) * | 1946-12-28 | 1949-11-29 | Bell Telephone Labor Inc | Pulse code modulation receiver employing cathode-ray tube demodulators |
BE481448A (en) * | 1947-02-07 | |||
US2547598A (en) * | 1947-09-13 | 1951-04-03 | Zenith Radio Corp | Subscription image transmission system and apparatus |
IT454079A (en) * | 1948-07-02 | |||
NL147062B (en) * | 1948-07-21 | Prowse Co Ltd D H | SAWING DEVICE. | |
US2596741A (en) * | 1948-08-28 | 1952-05-13 | Eastman Kodak Co | External memory device for electronic digital computers |
US2525156A (en) * | 1949-01-31 | 1950-10-10 | Robert M Tink | Method of and means for electrically generating tones |
US2557691A (en) * | 1949-03-19 | 1951-06-19 | Geovision Inc | Electronic function generator |
FR986834A (en) * | 1949-03-22 | 1951-08-06 | S E D A C Soc | Process for acting on the cathode beam of a television tube in order to ensure its secrecy |
US2703150A (en) * | 1949-09-29 | 1955-03-01 | Lu Garda Rieber | Geophysical display system |
US2705740A (en) * | 1949-12-14 | 1955-04-05 | Zenith Radio Corp | Subscription type signalling system |
CA888373A (en) * | 1949-12-21 | 1971-12-14 | Her Majesty The Queen In Right Of Canada As Represented By The Minister Of National Defence Of Her Majesty's Canadian Government | Secret signalling system |
ZA13752B (en) * | 1950-04-05 | |||
GB705510A (en) * | 1951-02-09 | 1954-03-17 | Nat Res Dev | Improvements in and relating to the electrostatic storage of digital information |
US2769025A (en) * | 1951-05-04 | 1956-10-30 | Internat Telemeter Corp | Prepaid entertainment distribution system |
US2770803A (en) * | 1951-10-31 | 1956-11-13 | Zenith Radio Corp | Subscription television system |
US2809231A (en) * | 1951-11-09 | 1957-10-08 | Zenith Radio Corp | Subscriber television system |
US2727157A (en) * | 1951-12-22 | 1955-12-13 | Westinghouse Electric Corp | Fluorescent tube |
US2847501A (en) * | 1952-02-06 | 1958-08-12 | Zenith Radio Corp | Subscription television system |
US2795705A (en) * | 1952-08-26 | 1957-06-11 | Rabinow Jacob | Optical coincidence devices |
US3274333A (en) * | 1952-10-23 | 1966-09-20 | Skiatron Elect & Tele | Scrambled television system |
USRE34004E (en) * | 1953-03-30 | 1992-07-21 | Itt Corporation | Secure single sideband communication system using modulated noise subcarrier |
US2909592A (en) * | 1953-04-15 | 1959-10-20 | Zenith Radio Corp | Subscription television system |
NL187162B (en) * | 1953-05-26 | Texaco Development Corp | QUATERNAIRE ACRYLAMIDES AND METHACRYLAMIDES AND METHOD OF PREPARATION. | |
US2896071A (en) * | 1954-03-01 | 1959-07-21 | Zenith Radio Corp | Secrecy communication system |
US2994739A (en) * | 1955-04-13 | 1961-08-01 | Zenith Radio Corp | Subscription television receiver and method of operating the same |
US2982952A (en) * | 1955-06-28 | 1961-05-02 | Zenith Radio Corp | Subscription television |
DE1010997B (en) * | 1955-07-23 | 1957-06-27 | Boelkow Entwicklungen Kg | Method and device for encrypting messages for wired or wireless transmission |
GB825052A (en) * | 1956-01-11 | 1959-12-09 | Rank Cintel Ltd | Improvements in or relating to control circuits for cathode ray tubes |
BE556930A (en) * | 1956-04-27 | 1900-01-01 | ||
US2924645A (en) * | 1956-09-04 | 1960-02-09 | Skiatron Elect & Tele | Scrambled television transmission |
US3071762A (en) * | 1956-11-09 | 1963-01-01 | North American Aviation Inc | Analog-to-digital converter |
US3180927A (en) * | 1961-09-07 | 1965-04-27 | Itt | Cryptosecure transmission system |
CA1054407A (en) * | 1975-10-22 | 1979-05-15 | Hiroshi Ichigaya | Signal generating system utilizing a cathode ray tube |
US4389671A (en) * | 1980-09-29 | 1983-06-21 | Harris Corporation | Digitally-controlled analog encrypton |
US4888799A (en) * | 1986-01-03 | 1989-12-19 | Scientific Atlanta, Inc. | Scrambling of signals by inversion |
-
1941
- 1941-06-25 US US399637A patent/US2402058A/en not_active Expired - Lifetime
-
1942
- 1942-07-20 GB GB10109/42A patent/GB579972A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US2402058A (en) | 1946-06-11 |
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