GB764428A - Improvements in or relating to radio broadcast receivers - Google Patents
Improvements in or relating to radio broadcast receiversInfo
- 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
Links
- 230000008878 coupling Effects 0.000 abstract 2
- 238000010168 coupling process Methods 0.000 abstract 2
- 238000005859 coupling reaction Methods 0.000 abstract 2
- 239000003990 capacitor Substances 0.000 abstract 1
- 238000013016 damping Methods 0.000 abstract 1
- 230000004048 modification Effects 0.000 abstract 1
- 238000012986 modification Methods 0.000 abstract 1
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)
- Circuits Of Receivers In General (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
- Control Of Amplification And Gain Control (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.
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)
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 |
-
1955
- 1955-01-20 GB GB1720/55A patent/GB764428A/en not_active Expired
Cited By (5)
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 | |
US3052853A (en) | Attenuator for strong signals in a radio receiver | |
GB1017759A (en) | Improvements in or relating to variable gain transistor amplifiers | |
GB764428A (en) | Improvements in or relating to radio broadcast receivers | |
GB1330988A (en) | Receiver for pulse modulated signals | |
GB1101488A (en) | Improvements in and relating to electric signal amplifiers | |
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 | |
US2926308A (en) | Transistor biasing circuit | |
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 | |
GB876042A (en) | Improvements in or relating to transistor circuit arrangements for demodulating and amplifying signals | |
GB726633A (en) | Circuit arrangement for controlling a tuning indicator tube in combined amplitude modulation- frequency modulation broadcast receivers | |
GB1127137A (en) | Signal translating circuits | |
GB759665A (en) | Automatic gain control system for semi-conductor devices |