NL7704112A - Cable TV system with converter, coder and de-scrambler - has suppressor for audio and video scrambling signal during time base period - Google Patents
Cable TV system with converter, coder and de-scrambler - has suppressor for audio and video scrambling signal during time base periodInfo
- Publication number
- NL7704112A NL7704112A NL7704112A NL7704112A NL7704112A NL 7704112 A NL7704112 A NL 7704112A NL 7704112 A NL7704112 A NL 7704112A NL 7704112 A NL7704112 A NL 7704112A NL 7704112 A NL7704112 A NL 7704112A
- Authority
- NL
- Netherlands
- Prior art keywords
- signal
- audio
- cable
- converter
- signal during
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/16—Analogue secrecy systems; Analogue subscription systems
- H04N7/167—Systems rendering the television signal unintelligible and subsequently intelligible
- H04N7/171—Systems operating in the amplitude domain of the television signal
- H04N7/1713—Systems operating in the amplitude domain of the television signal by modifying synchronisation signals
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Details Of Television Systems (AREA)
Abstract
A cable television system where the receiving end has a converter fitted with a coding or descrambling system. The transmission side of the cable has equipment which mixes the scrambling signal with the television signal. The decoding circuit incorporates an automatic amplification control detector in a closed loop with an amplifier in the converter. The carrier wave of the audio signal has a larger amplitude superimposed on the carrier wave of the video signal than the amplitude of the scrambling wave. There is a circuit at the receiving end which suppresses the audio and video scrambling signal during part of the vertical interval of the television signal. There is also a high frequency amplifier with an input for the scrambled television signal and an input for the descrambled sign wave of constant frequency.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL7704112A NL7704112A (en) | 1974-03-15 | 1977-04-14 | Cable TV system with converter, coder and de-scrambler - has suppressor for audio and video scrambling signal during time base period |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US45149074A | 1974-03-15 | 1974-03-15 | |
NL7704112A NL7704112A (en) | 1974-03-15 | 1977-04-14 | Cable TV system with converter, coder and de-scrambler - has suppressor for audio and video scrambling signal during time base period |
Publications (1)
Publication Number | Publication Date |
---|---|
NL7704112A true NL7704112A (en) | 1978-10-17 |
Family
ID=26645314
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NL7704112A NL7704112A (en) | 1974-03-15 | 1977-04-14 | Cable TV system with converter, coder and de-scrambler - has suppressor for audio and video scrambling signal during time base period |
Country Status (1)
Country | Link |
---|---|
NL (1) | NL7704112A (en) |
-
1977
- 1977-04-14 NL NL7704112A patent/NL7704112A/en active Search and Examination
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
BA | A request for search or an international-type search has been filed | ||
A85 | Still pending on 85-01-01 | ||
BB | A search report has been drawn up | ||
BC | A request for examination has been filed | ||
CNR | Transfer of rights (patent application after its laying open for public inspection) |
Free format text: OCI COMMUNICATIONS INC. |
|
BN | A decision not to publish the application has become irrevocable |