GB665951A - Improvements in or relating to automatic gain control arrangements for carrier current communication systems - Google Patents

Improvements in or relating to automatic gain control arrangements for carrier current communication systems

Info

Publication number
GB665951A
GB665951A GB2708849A GB2708849A GB665951A GB 665951 A GB665951 A GB 665951A GB 2708849 A GB2708849 A GB 2708849A GB 2708849 A GB2708849 A GB 2708849A GB 665951 A GB665951 A GB 665951A
Authority
GB
United Kingdom
Prior art keywords
amplifier
gain control
bridge
gain
resistance
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
GB2708849A
Inventor
Bert Bulow Jacobsen
Charles Trevor Daly
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.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
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 Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB2708849A priority Critical patent/GB665951A/en
Publication of GB665951A publication Critical patent/GB665951A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/04—Control of transmission; Equalising
    • H04B3/10—Control of transmission; Equalising by pilot signal
    • H04B3/11—Control of transmission; Equalising by pilot signal using pilot wire

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

665,951. Automatic volume control. STANDARD TELEPHONES & CABLES, Ltd. Oct. 21, 1949, No. 27088/49. Class 40 (iv). In a carrier current communication system the gain of certain amplifiers is controlled in accordance with the resistance variations of a conductor included in the transmission cable and more accurate gain control is effected in a later amplifier by a pilot current transmitted with the communication signals. In Fig. 1, stations 2 and 6 are controlled by a pilot current and the intermediate stations are controlled according to the impedance of auxiliary cables 12, 13 and 14 which are stranded up in the same cable with the main signal circuit and shortcircuited at the preceding station. The gain control devices 9, 10 and 11 at the intermediate stations comprise an oscillator 18 which is an amplifier having a bridge network 19, which is slightly unbalanced so that the loss through the feed-back path is equal to the gain of the amplifier. A change in the resistance of the line 12 causes the bridge 19 to become unbalanced so that a change occurs in the amplifier output level to change the resistance of a thermistor 17 in the signal amplifier feed-back path and of a thermistor 20 to restore the bridge to its original condition. Specification 510,379, [Group XL], is referred to.
GB2708849A 1949-10-21 1949-10-21 Improvements in or relating to automatic gain control arrangements for carrier current communication systems Expired GB665951A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2708849A GB665951A (en) 1949-10-21 1949-10-21 Improvements in or relating to automatic gain control arrangements for carrier current communication systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2708849A GB665951A (en) 1949-10-21 1949-10-21 Improvements in or relating to automatic gain control arrangements for carrier current communication systems

Publications (1)

Publication Number Publication Date
GB665951A true GB665951A (en) 1952-02-06

Family

ID=10253993

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2708849A Expired GB665951A (en) 1949-10-21 1949-10-21 Improvements in or relating to automatic gain control arrangements for carrier current communication systems

Country Status (1)

Country Link
GB (1) GB665951A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4271503A (en) * 1977-11-15 1981-06-02 Thomson-Csf Automatic control device for a receiver using a pilot

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4271503A (en) * 1977-11-15 1981-06-02 Thomson-Csf Automatic control device for a receiver using a pilot

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