GB877206A - Improvements in and relating to automatic gain control in transistor radio receivers - Google Patents
Improvements in and relating to automatic gain control in transistor radio receiversInfo
- Publication number
- GB877206A GB877206A GB22605/60A GB2260560A GB877206A GB 877206 A GB877206 A GB 877206A GB 22605/60 A GB22605/60 A GB 22605/60A GB 2260560 A GB2260560 A GB 2260560A GB 877206 A GB877206 A GB 877206A
- Authority
- GB
- United Kingdom
- Prior art keywords
- stage
- transistor
- derived
- gain control
- control voltage
- 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
- 230000003111 delayed effect Effects 0.000 abstract 2
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/3052—Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver
- H03G3/3068—Circuits generating control signals for both R.F. and I.F. stages
Landscapes
- Control Of Amplification And Gain Control (AREA)
Abstract
877,206. Transistor automatic gain control circuits. GENERAL MOTORS CORPORATION. June 28, 1960 [July 13, 1959], No. 22605/60. Addition to 836,103. Class 40(6) In a transistor superheterodyne radio receiver, the automatic gain control voltage is derived from a separate detector and applied to an I.F. amplifier, a delayed control voltage being derived from the output of that amplifier and applied to an R.F. stage. The Figure shows a receiver comprising a PNP transistor R.F. stage coupled through a tuned network 14, 18, 20 to a frequency changer 16 which feeds NPN I.F. stages 22 and 40. The latter stage has a double tuned output circuit 38, 112 and feeds a second detector stage 116, D3. The AGC voltage is derived froma separate detector 36, D2 and is applied through a resistor 34 to the first I.F. stage 22 to control its gain. An amplified gain control voltage is obtained from a point B in the collector circuit and applied through a resistor 76 to the R.F. stage. This voltage is derived from a resistance network 58, 60, 78 and a diode D1. When the signal is small, diode Dl conducts and clamps the potential of B to the potential of C but when the signal increases above a certain level the current through transistor 22 is so reduced that diode Dl no longer conducts and the potential at B varies with the level of the incoming signal. Accordingly the application of the control voltage to the R.F. stage is delayed.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US877206XA | 1960-07-13 | 1960-07-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB877206A true GB877206A (en) | 1961-09-13 |
Family
ID=22206872
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB22605/60A Expired GB877206A (en) | 1960-07-13 | 1960-06-28 | Improvements in and relating to automatic gain control in transistor radio receivers |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB877206A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2376557A1 (en) * | 1976-12-29 | 1978-07-28 | Philips Nv | GAIN ADJUSTED SIGNAL AMPLIFIER |
-
1960
- 1960-06-28 GB GB22605/60A patent/GB877206A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2376557A1 (en) * | 1976-12-29 | 1978-07-28 | Philips Nv | GAIN ADJUSTED SIGNAL AMPLIFIER |
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