GB315671A - Improvements in secret telegraphy - Google Patents

Improvements in secret telegraphy

Info

Publication number
GB315671A
GB315671A GB21779/29A GB2177929A GB315671A GB 315671 A GB315671 A GB 315671A GB 21779/29 A GB21779/29 A GB 21779/29A GB 2177929 A GB2177929 A GB 2177929A GB 315671 A GB315671 A GB 315671A
Authority
GB
United Kingdom
Prior art keywords
subdivided
secrecy
frequency band
arrangements
secret
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
GB21779/29A
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of GB315671A publication Critical patent/GB315671A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

315,671. Koomans, N. July 14, 1928, [Convention date]. Void [Published under Sect. 91 of the Acts]. Secret transmission.- Secrecy is obtained when transmitting complex frequency signals, such as speech or photo-telegraphic currents, by variably retarding the frequency components of the signal at the transmitter, e.g. as shown in the Figure in which the ordinates t<1> represent speeds of propagation and the abscissae w frequencies, and providing compensating arrangements at the receiver. The frequency band may be subdivided and the phasevarying arrangements be applied to the subdivisions. In the case of wireless transmission additional secrecy may be secured by suppressing the carrier or one of the side bands or by changing the order when the frequency band is subdivided.
GB21779/29A 1928-07-14 1929-07-15 Improvements in secret telegraphy Expired GB315671A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE315671X 1928-07-14

Publications (1)

Publication Number Publication Date
GB315671A true GB315671A (en) 1930-05-29

Family

ID=6150251

Family Applications (1)

Application Number Title Priority Date Filing Date
GB21779/29A Expired GB315671A (en) 1928-07-14 1929-07-15 Improvements in secret telegraphy

Country Status (3)

Country Link
FR (1) FR678378A (en)
GB (1) GB315671A (en)
NL (1) NL25801C (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3157874A (en) * 1959-06-22 1964-11-17 Thompson Ramo Wooldridge Inc Signalling systems

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3157874A (en) * 1959-06-22 1964-11-17 Thompson Ramo Wooldridge Inc Signalling systems

Also Published As

Publication number Publication date
NL25801C (en)
FR678378A (en) 1930-03-21

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