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GB979825A - Amplifier for two way speech transmission - Google Patents

Amplifier for two way speech transmission

Info

Publication number
GB979825A
GB979825A GB830163A GB830163A GB979825A GB 979825 A GB979825 A GB 979825A GB 830163 A GB830163 A GB 830163A GB 830163 A GB830163 A GB 830163A GB 979825 A GB979825 A GB 979825A
Authority
GB
United Kingdom
Prior art keywords
channels
amplifiers
signal
microphone
control
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
GB830163A
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.)
Gylling and Co AB
Original Assignee
Gylling and Co AB
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 Gylling and Co AB filed Critical Gylling and Co AB
Publication of GB979825A publication Critical patent/GB979825A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/001—Two-way communication systems between a limited number of parties

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)

Abstract

979,825. Two-way transmission systems. A. B. GYLLING & CO. March 1, 1963 [March 9, 1962], No. 8301/63. Heading H4R. In a two-way transmission system having separate amplifiers for each direction of transmission and a control device differentially varying the gains in the two channels in accordance with the relative signal strengths in the two channels, the control signal is derived from the higher frequency components of the signals being amplified in the channels in order that the control arrangement will discriminate against noise picked up by the microphone, which will generally originate at a distance from the microphone and will therefore have its low frequencies emphasized, as against the speech signals originating from close to the microphone, and therefore having a normal frequency distribution. The Figure shows a two-way transmission system having amplifiers 6a, 7a, 8a and 6b, 7b, 8b for the respective directions of transmission, amplifiers 8a and 8b being of variable gain controlled by the gain controlling device 9 which derives a control signal in accordance with the signal strengths in the two channels, the signal strength being determined before and/or after the control amplifier and with high pass, or band-pass, filters 12a, 13a, 12b and 13b between the signal amplifiers and the control device 9. The filters having an attenuation at 300 c/s. at least 6dB greater than at 3000 c/s.
GB830163A 1962-03-09 1963-03-01 Amplifier for two way speech transmission Expired GB979825A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE260362 1962-03-09

Publications (1)

Publication Number Publication Date
GB979825A true GB979825A (en) 1965-01-06

Family

ID=20260273

Family Applications (1)

Application Number Title Priority Date Filing Date
GB830163A Expired GB979825A (en) 1962-03-09 1963-03-01 Amplifier for two way speech transmission

Country Status (3)

Country Link
DE (1) DE1188145B (en)
DK (1) DK110112C (en)
GB (1) GB979825A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2137458A (en) * 1983-03-01 1984-10-03 Standard Telephones Cables Ltd Digital handsfree telephone

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1298572B (en) * 1967-03-17 1969-07-03 Siemens Ag Intercom or intercom

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE504122C (en) * 1929-01-28 1930-11-11 Siemens & Halske Akt Ges Transmission system with two-way traffic and feedback barriers
DE958935C (en) * 1954-02-08 1957-02-28 Telefunken Gmbh Circuit arrangement for voice-controlled echo and feedback barriers in intercom systems with loudspeaker operation
DE1058563B (en) * 1956-02-22 1959-06-04 Siemens Ag Circuit arrangement for whistling reduction in loudspeaker systems
NL245570A (en) * 1958-12-29
DE1066625B (en) * 1963-09-30 1959-10-08

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2137458A (en) * 1983-03-01 1984-10-03 Standard Telephones Cables Ltd Digital handsfree telephone

Also Published As

Publication number Publication date
DK110112C (en) 1968-12-16
DE1188145B (en) 1965-03-04

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