[go: up one dir, main page]

GB764428A - Improvements in or relating to radio broadcast receivers - Google Patents

Improvements in or relating to radio broadcast receivers

Info

Publication number
GB764428A
GB764428A GB1720/55A GB172055A GB764428A GB 764428 A GB764428 A GB 764428A GB 1720/55 A GB1720/55 A GB 1720/55A GB 172055 A GB172055 A GB 172055A GB 764428 A GB764428 A GB 764428A
Authority
GB
United Kingdom
Prior art keywords
transistor
impedance
collector
emitter
transistors
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
GB1720/55A
Inventor
Arthur Edward Brewster
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 GB1720/55A priority Critical patent/GB764428A/en
Priority claimed from GB5695/55A external-priority patent/GB764175A/en
Publication of GB764428A publication Critical patent/GB764428A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/34—Negative-feedback-circuit arrangements with or without positive feedback
    • H03F1/36—Negative-feedback-circuit arrangements with or without positive feedback in discharge-tube amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/181—Low-frequency amplifiers, e.g. audio preamplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/26—Push-pull amplifiers; Phase-splitters therefor
    • H03F3/28—Push-pull amplifiers; Phase-splitters therefor with tubes only
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G1/00—Details of arrangements for controlling amplification
    • H03G1/0005—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal
    • H03G1/0035—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements
    • H03G1/0082—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements using bipolar transistor-type devices
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/22—Automatic control in amplifiers having discharge tubes
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Control Of Amplification And Gain Control (AREA)
  • Circuits Of Receivers In General (AREA)
  • Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)

Abstract

764,428. Transistor gain and selectivity control circuits. STANDARD TELEPHONES & CABLES, Ltd. Jan. 20, 1955, No. 1720/55. Classes 40(5) and 40(6) The impedance of a transistor 20 shunting the coupling 9 between two stages 1, 2 is varied to control the gain of an amplifier in a radio receiver, the variation in damping also affecting the selectivity. The controlled stage may be a transistor or discharge tube amplifier. The I.F. signal is amplified in transistors 1 and 2 and applied to transistors 3, 4 in push-pull to cause each to conduct on alternate halfcycles of carrier. The modulation signal is fed out over filter 16 while the pulses of current cause the emitters and base to go more negative with increased carrier input. The transistor 20 is normally biased off by battery 24 which gives a delay to the A.G.C., but when this voltage is exceeded, the base of transistor 20 becomes negative with respect to the emitter, thereby lowering the emitter-collector impedance. The resistor 13 is chosen to give the desired band-width to the coupling when the transistor 20 is presenting its high impedance. The resistor 10 limits the collector current of transistor 20 when in its low impedance condition, the low collector potential of transistor 1 introducing little distortion since the transistor 20 has such a low impedance. In a modification, Fig. 2 (not shown) the capacitor 12 is tapped on to a parallel tuned circuit replacing inductor 9.
GB1720/55A 1950-08-02 1955-01-20 Improvements in or relating to radio broadcast receivers Expired GB764428A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1720/55A GB764428A (en) 1950-08-02 1955-01-20 Improvements in or relating to radio broadcast receivers

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
NL700129X 1950-08-02
GB1720/55A GB764428A (en) 1950-08-02 1955-01-20 Improvements in or relating to radio broadcast receivers
GB5695/55A GB764175A (en) 1950-08-02 1955-02-25 Improvements in or relating to safe-guarding arrangements for electric communicationsystems

Publications (1)

Publication Number Publication Date
GB764428A true GB764428A (en) 1956-12-28

Family

ID=32397621

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1720/55A Expired GB764428A (en) 1950-08-02 1955-01-20 Improvements in or relating to radio broadcast receivers

Country Status (1)

Country Link
GB (1) GB764428A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2895045A (en) * 1957-09-26 1959-07-14 Avco Mfg Corp Radio receiver with transistorized audio - detector and automatic gain control circuitry
US2939950A (en) * 1957-07-01 1960-06-07 Rca Corp Combined manual and automatic gain control circuit
US2965848A (en) * 1956-01-28 1960-12-20 Philips Corp Detector circuit arrangement
US3360735A (en) * 1963-07-17 1967-12-26 Sony Corp Automatic gain control circuit having means for compensating for capacitive effect
JPS488101U (en) * 1971-06-10 1973-01-29

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2965848A (en) * 1956-01-28 1960-12-20 Philips Corp Detector circuit arrangement
US2939950A (en) * 1957-07-01 1960-06-07 Rca Corp Combined manual and automatic gain control circuit
US2895045A (en) * 1957-09-26 1959-07-14 Avco Mfg Corp Radio receiver with transistorized audio - detector and automatic gain control circuitry
US3360735A (en) * 1963-07-17 1967-12-26 Sony Corp Automatic gain control circuit having means for compensating for capacitive effect
JPS488101U (en) * 1971-06-10 1973-01-29

Similar Documents

Publication Publication Date Title
US3328714A (en) Automatic gain control system for cascaded transistor amplifier
GB1172366A (en) Transistor Circuits
US4366450A (en) Automatic gain control circuit
FR2376557A1 (en) GAIN ADJUSTED SIGNAL AMPLIFIER
US3052853A (en) Attenuator for strong signals in a radio receiver
GB1138417A (en) Video signal processing circuits
GB764428A (en) Improvements in or relating to radio broadcast receivers
GB1330988A (en) Receiver for pulse modulated signals
GB937536A (en) Automatic-gain and bandwidth control system for transistor circuits
GB671305A (en) Improvements in high input impedance transistor amplifiers
US2507432A (en) Squelch or muting of amplifiers
US3509468A (en) Transistorized squelch circuit for an fm receiver
GB1022081A (en) Automatic gain control circuits
US2997656A (en) Gain control for transistor detector or amplifier
GB1073206A (en) Improvements in or relating to amplifier circuit arrangements
US2148604A (en) Signal-translating system
GB840976A (en) Improvements in or relating to electrical circuit means employing transistors
US2912572A (en) Automatic-gain-control system utilizing constant current source
US3173099A (en) Transistor amplifier with automatic gain control
GB923371A (en) Transistor radio receivers
GB726633A (en) Circuit arrangement for controlling a tuning indicator tube in combined amplitude modulation- frequency modulation broadcast receivers
GB1127137A (en) Signal translating circuits
GB997908A (en) Improvements in or relating to volume compression circuits
GB759665A (en) Automatic gain control system for semi-conductor devices
GB949431A (en) Automatic gain control system