GB362478A - Trunk communicating installation with harmless cross talk - Google Patents

Trunk communicating installation with harmless cross talk

Info

Publication number
GB362478A
GB362478A GB23724/30A GB2372430A GB362478A GB 362478 A GB362478 A GB 362478A GB 23724/30 A GB23724/30 A GB 23724/30A GB 2372430 A GB2372430 A GB 2372430A GB 362478 A GB362478 A GB 362478A
Authority
GB
United Kingdom
Prior art keywords
line
speech
talk
cross
currents
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
GB23724/30A
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.)
Siemens and Halske AG
Siemens AG
Original Assignee
Siemens and Halske AG
Siemens AG
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 Siemens and Halske AG, Siemens AG filed Critical Siemens and Halske AG
Publication of GB362478A publication Critical patent/GB362478A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M5/00—Manual exchanges
    • H04M5/04—Arrangements for indicating calls or supervising connections for calling or clearing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/32—Reducing cross-talk, e.g. by compensating
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/68—Circuit arrangements for preventing eavesdropping

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

362,478. Preventing overhearing. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. Aug. 7, 1930, No. 23724. Convention date, Aug. 23, 1929. [Class 40 (iv).] Two methods are described for rendering the cross-talk between lines transmitting in opposite directions unintelligible. In Fig. 1, speech over one line causes a buzzer or other noise producer G1, G2 to be applied to the other line to mask the cross-talk currents by means of a relay or other switching arrangement R1, R2, which is rendered ineffective by means of apparatus A1, A2 when speech starts over the other line. In Fig. 2, the speech currents in one line are inverted as regards frequency by means of apparatus U, the lower side-band resulting from the modulation of a carrier frequency equal to the highest speech frequency being transmitted, so that the cross-talk currents in the other line, which are inverted only once, are unintelligible.
GB23724/30A 1929-08-22 1930-08-07 Trunk communicating installation with harmless cross talk Expired GB362478A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE538837T 1929-08-22

Publications (1)

Publication Number Publication Date
GB362478A true GB362478A (en) 1931-12-07

Family

ID=34122368

Family Applications (1)

Application Number Title Priority Date Filing Date
GB23724/30A Expired GB362478A (en) 1929-08-22 1930-08-07 Trunk communicating installation with harmless cross talk

Country Status (4)

Country Link
DE (2) DE538837C (en)
FR (1) FR703983A (en)
GB (1) GB362478A (en)
NL (1) NL32155C (en)

Also Published As

Publication number Publication date
DE604196C (en) 1934-10-19
FR703983A (en) 1931-05-08
NL32155C (en)
DE538837C (en) 1931-11-19

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