IT972344B - SECRETITY UNIT IN PHONY FOR INTERCOM SYSTEMS - Google Patents

SECRETITY UNIT IN PHONY FOR INTERCOM SYSTEMS

Info

Publication number
IT972344B
IT972344B IT52512/72A IT5251272A IT972344B IT 972344 B IT972344 B IT 972344B IT 52512/72 A IT52512/72 A IT 52512/72A IT 5251272 A IT5251272 A IT 5251272A IT 972344 B IT972344 B IT 972344B
Authority
IT
Italy
Prior art keywords
secretity
phony
unit
intercom systems
intercom
Prior art date
Application number
IT52512/72A
Other languages
Italian (it)
Original Assignee
Boeing Co
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 Boeing Co filed Critical Boeing Co
Application granted granted Critical
Publication of IT972344B publication Critical patent/IT972344B/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication
    • H04K1/003—Secret communication by varying carrier frequency at or within predetermined or random intervals

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radio Relay Systems (AREA)
  • Mobile Radio Communication Systems (AREA)
IT52512/72A 1971-09-07 1972-09-02 SECRETITY UNIT IN PHONY FOR INTERCOM SYSTEMS IT972344B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US17800071A 1971-09-07 1971-09-07

Publications (1)

Publication Number Publication Date
IT972344B true IT972344B (en) 1974-05-20

Family

ID=22650774

Family Applications (1)

Application Number Title Priority Date Filing Date
IT52512/72A IT972344B (en) 1971-09-07 1972-09-02 SECRETITY UNIT IN PHONY FOR INTERCOM SYSTEMS

Country Status (7)

Country Link
JP (1) JPS4837003A (en)
CH (1) CH567843A5 (en)
DE (1) DE2243113A1 (en)
FR (1) FR2152161A5 (en)
GB (1) GB1399365A (en)
IT (1) IT972344B (en)
NL (1) NL7212139A (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2416597A1 (en) * 1971-12-09 1979-08-31 Berger Claude Signal coding system for secret transmission - uses transposition of signal frequency with applied pseudo-random bias using locally generated analog signal
US4167700A (en) * 1977-05-02 1979-09-11 Motorola, Inc. Digital voice protection system and method
JPS5961242A (en) * 1982-09-30 1984-04-07 Fujitsu Ltd Secret communication system
CA1226914A (en) * 1984-01-26 1987-09-15 The University Of British Columbia Modem for pseudo noise communication on a.c. lines
JPS61199341A (en) * 1985-02-28 1986-09-03 Tamura Electric Works Ltd Cordless telephone set
CN105071886B (en) * 2015-08-24 2017-12-19 苏州华启智能科技有限公司 A kind of vehicle-mounted broadcasting system audio bus-sharing system
CA3073322A1 (en) * 2017-08-18 2019-02-21 David Hegarty A device for operating a sounder to produce a plurality of different sounds, and a method for operating a sounder to produce a plurality of different sounds

Also Published As

Publication number Publication date
CH567843A5 (en) 1975-10-15
FR2152161A5 (en) 1973-04-20
DE2243113A1 (en) 1973-03-15
GB1399365A (en) 1975-07-02
NL7212139A (en) 1973-03-09
JPS4837003A (en) 1973-05-31

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