JPS6438037U - - Google Patents
Info
- Publication number
- JPS6438037U JPS6438037U JP13036987U JP13036987U JPS6438037U JP S6438037 U JPS6438037 U JP S6438037U JP 13036987 U JP13036987 U JP 13036987U JP 13036987 U JP13036987 U JP 13036987U JP S6438037 U JPS6438037 U JP S6438037U
- Authority
- JP
- Japan
- Prior art keywords
- bias voltage
- reception input
- frequency
- transformer
- tuning
- 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.)
- Pending
Links
- 238000001514 detection method Methods 0.000 claims description 6
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 239000003990 capacitor Substances 0.000 claims 1
- 230000003247 decreasing effect Effects 0.000 claims 1
- 230000000694 effects Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 3
Landscapes
- Control Of Amplification And Gain Control (AREA)
- Circuits Of Receivers In General (AREA)
Description
第１図は本考案の一実施例に係るＡＭヘテロダ
イン検波型のＡＭラジオ受信機の要部の回路図で
ある。第２図は従来例のＡＭラジオ受信機の要部
の回路図、第３図は第２図のＡＭラジオ受信機の
ＡＧＣ動作の説明に供するＡＭ変調波とバイアス
電圧との波形図、第４図は過変調時における第２
図のＡＭラジオ受信機による検波出力波形の説明
に供する図である。
ＴＲ……高周波増幅用トランジスタ、ＴＣ……
同調回路、Ｄ……検波ダイオード、ＲＣ……バイ
アス抵抗回路、Ｒ５……バイアス電圧制御用抵抗
。
FIG. 1 is a circuit diagram of a main part of an AM heterodyne detection type AM radio receiver according to an embodiment of the present invention. FIG. 2 is a circuit diagram of the main part of a conventional AM radio receiver, FIG. 3 is a waveform diagram of an AM modulated wave and bias voltage to explain the AGC operation of the AM radio receiver of FIG. 2, and FIG. The figure shows the second waveform during overmodulation.
It is a figure provided for explanation of the detected output waveform by the AM radio receiver of a figure. TR...Transistor for high frequency amplification, TC...
Tuning circuit, D...detection diode, RC...bias resistance circuit, R5...bias voltage control resistor.
Claims (1)
ジスタと、 同調用コンデンサとトランスの１次コイル（同
調用コイル）との並列回路で構成されて前記高周
波増幅用トランジスタで増幅された受信入力を同
調出力する同調回路と、 前記トランスの２次コイルの一端に接続されて
前記同調回路からの受信入力を検波する検波ダイ
オードと、 弱受信入力のときは前記高周波増幅用トランジ
スタの利得を大きくし、また強受信入力のときは
前記高周波増幅用トランジスタの利得を小さくす
る方向にあらわれる前記検波ダイオードの出力部
のバイアス電圧を、その高周波増幅用トランジス
タのベースに供給するバイアス抵抗回路とを具備
し、 前記２次コイルの他端と接地部との間に弱受信
入力時における前記バイアス電圧を低くする作用
を有するバイアス電圧制御用抵抗を設け、 前記バイアス電圧制御用抵抗により弱受信入力
時における過変調歪を抑制することを特徴とする
ＡＭへテロダイン検波型のＡＭラジオ受信機。[Scope of Claim for Utility Model Registration] A high-frequency amplification transistor that amplifies the received input to a high frequency, and a parallel circuit consisting of a tuning capacitor and a primary coil (tuning coil) of a transformer, and is amplified by the high-frequency amplification transistor. a detection diode connected to one end of the secondary coil of the transformer to detect the reception input from the tuning circuit; and a detection diode connected to one end of the secondary coil of the transformer to detect the reception input from the tuning circuit; and a bias resistor circuit that supplies a bias voltage at the output section of the detection diode, which appears in the direction of increasing the gain of the high-frequency amplifying transistor and decreasing the gain of the high-frequency amplifying transistor when there is a strong reception input, to the base of the high-frequency amplifying transistor. A bias voltage control resistor is provided between the other end of the secondary coil and a grounding portion, and the bias voltage control resistor has an effect of lowering the bias voltage when the reception input is weak, and the bias voltage control resistor lowers the bias voltage when the reception input is weak. An AM heterodyne detection type AM radio receiver characterized by suppressing overmodulation distortion in an AM radio receiver.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13036987U JPS6438037U (en) | 1987-08-27 | 1987-08-27 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13036987U JPS6438037U (en) | 1987-08-27 | 1987-08-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6438037U true JPS6438037U (en) | 1989-03-07 |
Family
ID=31385475
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13036987U Pending JPS6438037U (en) | 1987-08-27 | 1987-08-27 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6438037U (en) |
-
1987
- 1987-08-27 JP JP13036987U patent/JPS6438037U/ja active Pending
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