GB366921A - Improvements in or relating to secret signalling systems - Google Patents

Improvements in or relating to secret signalling systems

Info

Publication number
GB366921A
GB366921A GB33560/30A GB3356030A GB366921A GB 366921 A GB366921 A GB 366921A GB 33560/30 A GB33560/30 A GB 33560/30A GB 3356030 A GB3356030 A GB 3356030A GB 366921 A GB366921 A GB 366921A
Authority
GB
United Kingdom
Prior art keywords
cams
synchronous
synchronism
strap
nov
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
Application number
GB33560/30A
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.)
Electrical Research Products Inc
Original Assignee
Electrical Research Products 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 Electrical Research Products Inc filed Critical Electrical Research Products Inc
Publication of GB366921A publication Critical patent/GB366921A/en
Expired 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Respiratory Apparatuses And Protective Means (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Abstract

366,921. Electric synchronous movements. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York,U.S.A. -(Assignees of Chesnut, R. W. ; 155, Inwood Avenue, Upper Montclair, New Jersey, Fisher, H. J. ; Davis Road, Port Washington, and Sanial, A. J. ; 365, West 20th Street, both in New York, both in U.S.A.) Nov. 7, 1930, No. 33560. Con. vention date, Nov. 8, 1929. [Class 40 (iii).] In a secret telephone transmission system the secrecy scheme is varied periodically under the control of cams driven by a synchronous motor 72 driven by a valve oscillator 70. When it is desired to check the synchronism, keys 120 are operated at both stations and a 1000-cycle generator is connected up at the controlling station. This results in the transmission of a signal from the controlling station {at which strap 19 is omitted) during the half second that 75 makes its upper contacts. At the controlled station (at which strap 170 is omitted) the circuits are fit to receive while the cam 74 makes its lower contacts. Consequently if the cams are synchronous, no signal is heard. The cams are brought into synchronism by means of the apparatus shown in Fig. 5.
GB33560/30A 1929-11-08 1930-11-07 Improvements in or relating to secret signalling systems Expired GB366921A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US405602A US1829783A (en) 1929-11-08 1929-11-08 Method and system of secret signaling

Publications (1)

Publication Number Publication Date
GB366921A true GB366921A (en) 1932-02-08

Family

ID=23604372

Family Applications (1)

Application Number Title Priority Date Filing Date
GB33560/30A Expired GB366921A (en) 1929-11-08 1930-11-07 Improvements in or relating to secret signalling systems

Country Status (2)

Country Link
US (1) US1829783A (en)
GB (1) GB366921A (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2539556A (en) * 1941-07-11 1951-01-30 Bell Telephone Labor Inc Variable delay speech privacy system
US3967066A (en) * 1941-09-24 1976-06-29 Bell Telephone Labor Inc ecret telephony
US3967067A (en) * 1941-09-24 1976-06-29 Bell Telephone Laboratories, Incorporated Secret telephony
US2466390A (en) * 1944-03-30 1949-04-05 Bell Telephone Labor Inc Secret telegraph system
CH248975A (en) * 1946-02-04 1947-05-31 Patelhold Patentverwertung Process and device for disguising the individual calls in a multi-channel system.
US2565525A (en) * 1947-11-26 1951-08-28 Int Standard Electric Corp Two-way electric pulse communication system
US3289152A (en) * 1964-02-06 1966-11-29 Gen Dynamics Corp Acoustic signaling system
US4020285A (en) * 1972-09-29 1977-04-26 Datotek, Inc. Voice security method and system
US4278840A (en) * 1979-03-23 1981-07-14 Datotek, Inc. Dynamic frequency and time voice encryption system and method

Also Published As

Publication number Publication date
US1829783A (en) 1931-11-03

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