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 period

Info

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
Application number
NL7704112A
Other languages
Dutch (nl)
Original Assignee
Oak Industries Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Oak Industries Inc filed Critical Oak Industries Inc
Priority to NL7704112A priority Critical patent/NL7704112A/en
Publication of NL7704112A publication Critical patent/NL7704112A/en

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.
NL7704112A 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 NL7704112A (en)

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)

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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