JPS56120239A - Simple privacy telephone system - Google Patents

Simple privacy telephone system

Info

Publication number
JPS56120239A
JPS56120239A JP2365780A JP2365780A JPS56120239A JP S56120239 A JPS56120239 A JP S56120239A JP 2365780 A JP2365780 A JP 2365780A JP 2365780 A JP2365780 A JP 2365780A JP S56120239 A JPS56120239 A JP S56120239A
Authority
JP
Japan
Prior art keywords
signal
telephone system
voice signal
privacy telephone
constitution
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.)
Pending
Application number
JP2365780A
Other languages
Japanese (ja)
Inventor
Shinjiro Suzuki
Tadashi Yoshikawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP2365780A priority Critical patent/JPS56120239A/en
Publication of JPS56120239A publication Critical patent/JPS56120239A/en
Pending legal-status Critical Current

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

Abstract

PURPOSE:To constitute the privacy telephone set with low cost, by synthesizing the audio frequency signal in which the frequency changes with time, with voice signal. CONSTITUTION:An oscillator 11 produces the audio frequency signal in which the frequency changes with time. This signal is fed to a hybrid circuit 13 via a comb type filter 12. Voice signal is fed to the circuit 13, which synthesizes and transmits the signals. At the reception side, the voice signal is reproduced by passing the reception signal in a comb type filter 14. Thus, a number of filters are not required, allowing the constitution with low cost.
JP2365780A 1980-02-27 1980-02-27 Simple privacy telephone system Pending JPS56120239A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2365780A JPS56120239A (en) 1980-02-27 1980-02-27 Simple privacy telephone system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2365780A JPS56120239A (en) 1980-02-27 1980-02-27 Simple privacy telephone system

Publications (1)

Publication Number Publication Date
JPS56120239A true JPS56120239A (en) 1981-09-21

Family

ID=12116577

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2365780A Pending JPS56120239A (en) 1980-02-27 1980-02-27 Simple privacy telephone system

Country Status (1)

Country Link
JP (1) JPS56120239A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59191952A (en) * 1983-04-15 1984-10-31 Fujitsu Ltd Secret transmission system of information

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59191952A (en) * 1983-04-15 1984-10-31 Fujitsu Ltd Secret transmission system of information
JPH0237145B2 (en) * 1983-04-15 1990-08-22 Fujitsu Ltd

Similar Documents

Publication Publication Date Title
ES8604378A1 (en) Apparatus for and methods of scrambling voice signals.
JPS56120239A (en) Simple privacy telephone system
GB1525330A (en) Transmit-receive switching signal generator for radio telephone equipment
JPS5361903A (en) Unnecessary signal sound suppressor for telephone set
JPS5220801A (en) Automatic voice frequency elimination and control system
JPS56111400A (en) Sound field expanding apparatus
JPS5283114A (en) Gathering receiver
JPS5628548A (en) Talking set system of voice packet
JPS5413714A (en) Multi-frequency signal reception system
JPS5773554A (en) Button telephone set
JPS56106437A (en) Am receiver
JPS55133156A (en) Compensation circuit for cross polarized wave
JPS5313810A (en) Audio frequency signal telephone receiver
JPS645250A (en) Howling prevention circuit for loudspeaker system telephone set
JPS5247606A (en) Signal receiving circuit of switchboard equipment
JPS55133142A (en) Estimation system for gain of communication line
JPS5696571A (en) Signal transmission system
JPS56120278A (en) Frequency discriminating circuit
JPS545318A (en) Rejection system of interferring distortion caused in demodulation signal due to interference between fm signals
JPS5421214A (en) Automatic clarifier adjusting system of ssb
JPS5351947A (en) Electronic circuit
JPS5224427A (en) Frequency converter circuit
JPS5235515A (en) Tv receiver
GB1526974A (en) Transmission and reception of composite electrical signal
JPS5319703A (en) Simultaneous call and its unit