JPS63177634A - Am receiver - Google Patents
Am receiverInfo
- Publication number
- JPS63177634A JPS63177634A JP25747586A JP25747586A JPS63177634A JP S63177634 A JPS63177634 A JP S63177634A JP 25747586 A JP25747586 A JP 25747586A JP 25747586 A JP25747586 A JP 25747586A JP S63177634 A JPS63177634 A JP S63177634A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- circuit
- pseudo
- stereo
- adjacent
- 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.)
- Granted
Links
- 230000002452 interceptive effect Effects 0.000 claims description 23
- 238000001514 detection method Methods 0.000 claims description 10
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明はＡＭ受信機に係り、特にステレオ感のあるＡＭ
放送の受聴ができ、しかも隣接妨害局信号発生時のＳ／
Ｎ比を改善して良好な受聴ができるＡＭ受信機に関する
。[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an AM receiver, particularly an AM receiver with a stereo effect.
You can listen to broadcasts, and when an adjacent interfering station signal occurs, S/
The present invention relates to an AM receiver that improves the N ratio and allows good listening.
〈従来技術〉
通常、ＡＭ受信機においてはＡＭチューナの出力である
モノラル信号を左右両チャンネルのスピーカに入力して
音声を出力する。しかし、かかる方式では音の広がりを
有するステレオ感のある受聴ができない。そこで、従来
ＡＭステレオという方式を採用してステレオ感のあるＡ
Ｍ受聴が可能となるようにしている。<Prior Art> Typically, in an AM receiver, a monaural signal, which is the output of an AM tuner, is input to speakers of both left and right channels to output audio. However, with such a system, it is not possible to listen with a stereophonic sound with a wide sound. Therefore, we used a conventional method called AM stereo to create an A
It is possible to listen to M.
〈発明が解決しようとしている問題点〉しかし、ステレ
オのＳ／Ｎ比はモノラルに比べて２０ｄＢ程度悪化する
ため、隣接局から妨害信号（隣接妨害局信号）が発生す
ると良好な受聴ができないという問題がある。<Problem to be solved by the invention> However, since the S/N ratio of stereo is about 20 dB worse than that of monaural, there is a problem that good listening cannot be achieved if an interfering signal (adjacent interfering station signal) is generated from an adjacent station. There is.
以上から、本発明の目的はステレオ感のあるＡＭ放送の
受聴ができ、しかも隣接妨害局信号が発生しても良好な
ＡＭ放送の受聴ができるＡＭ受信機を提供することであ
る。In light of the above, an object of the present invention is to provide an AM receiver that can listen to AM broadcasts with a stereophonic effect and can also listen to AM broadcasts in good condition even when an adjacent interfering station signal occurs.
く問題点を解決するための手段〉
第１図は本発明にかかるＦＭステレオ受信機のブロック
図である。Means for Solving the Problems> FIG. 1 is a block diagram of an FM stereo receiver according to the present invention.
１１はアンテナ、１２はＡＭチューナ、１３は擬似ステ
レオ回路、１４は切替回路、１５は隣接妨害局検出回路
、１６は時定数回路である。11 is an antenna, 12 is an AM tuner, 13 is a pseudo-stereo circuit, 14 is a switching circuit, 15 is an adjacent interfering station detection circuit, and 16 is a time constant circuit.
く作用〉
擬似ステレオ回路１３は、ＡＭチューナ１２の出力であ
るモノラル信号ＳＭを入力されてＬ、Ｒ両チャンネルの
擬似ステレオ信号ｓＬ’ 、 Ｓ、’ を出力する。Function> The pseudo-stereo circuit 13 receives the monaural signal SM which is the output of the AM tuner 12, and outputs pseudo-stereo signals sL', S,' of both L and R channels.
切替回路１４は、隣接妨害局信号が発生していない場合
には擬似ステレオ信号ＳＬ′、ＳＲ′を出力し、隣接妨
害局信号が発生している場合にはモノラル信号ＳＭを出
力する。The switching circuit 14 outputs pseudo stereo signals SL' and SR' when no adjacent interfering station signal is generated, and outputs a monaural signal SM when an adjacent interfering station signal is generated.
〈実施例〉
第１図は本発明にかかるＡＭ受信機のブロック図である
。<Embodiment> FIG. 1 is a block diagram of an AM receiver according to the present invention.
図中、１１はアンテナ、１２はＡＭチューナ、１３は擬
似ステレオ回路、１４は切替回路、１５は隣接妨害局検
出回路、１６は時定数回路である。In the figure, 11 is an antenna, 12 is an AM tuner, 13 is a pseudo-stereo circuit, 14 is a switching circuit, 15 is an adjacent interfering station detection circuit, and 16 is a time constant circuit.
擬似ステレオ回路１３は第２図に示すように、アンプ１
３ａと、第３図に示す周波数特性を有するくしば型フィ
ルタ１３ｂと、＜シば型フィルタ出力とアンプ出力の差
分を出力する差動回路１３Ｃとを有し、＜シば型フィル
タ１３ｂの出力をＬ−チャンネルの擬似信号ＳＬ′ と
し、差動回路１３Ｃの出力をＲ−チャンネルの擬似信号
３ 、７ とするものであり、モノラルに比べてステレ
オ感が得られる。The pseudo-stereo circuit 13 is connected to the amplifier 1 as shown in FIG.
3a, a comb-shaped filter 13b having the frequency characteristics shown in FIG. 3, and a differential circuit 13C that outputs the difference between the comb-shaped filter output and the amplifier output. is an L-channel pseudo signal SL', and the output of the differential circuit 13C is an R-channel pseudo signal 3, 7, which provides a stereo feeling compared to monaural signals.
隣接妨害局検出回路１５は第４図に示すようにに上側隣
接局信号検出回路１５ａと、下側隣接局信号検出回路１
５ｂと、検波器１５ｃ、１５ｄと、オア回路１５ｅを有
している。尚、第４図において、１２ａは高周波増幅器
、局部発振器、混合回路等で構成されたＡＭ高周波回路
、１２ｂは中間周波増幅器である。As shown in FIG. 4, the adjacent interfering station detection circuit 15 includes an upper adjacent station signal detection circuit 15a and a lower adjacent station signal detection circuit 1.
5b, detectors 15c and 15d, and an OR circuit 15e. In FIG. 4, 12a is an AM high frequency circuit composed of a high frequency amplifier, a local oscillator, a mixing circuit, etc., and 12b is an intermediate frequency amplifier.
各局の周波数が１０ＫＨｚ間隔であるとすれば、ＡＭ高
周波回路１２ａの混合回路出力ＭＳには希望局に応じた
４５５ＫＨｚの中間周波数成分と、上側隣接局に応じた
４４５ＫＨｚの周波数成分と、下側隣接局に応じた４６
５ＫＨｚの周波数成分が含まれている。Assuming that the frequency of each station is 10 KHz apart, the mixing circuit output MS of the AM high frequency circuit 12a contains an intermediate frequency component of 455 KHz corresponding to the desired station, a frequency component of 445 KHz corresponding to the upper adjacent station, and a frequency component of 445 KHz corresponding to the lower adjacent station. 46 depending on the station
Contains a frequency component of 5KHz.
そこで、混合回路出力ＭＳを上側及び下側隣接局信号検
出回路１５ａ、１５ｂにそれぞれ入力して４４５ＫＨｚ
成分及び４６５ＫＨｚ成分を抽出して次段の検波器１５
ｃ、１５ｄに入力する。各検波器１５ ｃ、 １５ ｄ
は入力された信号をそれぞれ直流に変換してダイオード
ＤＩ、Ｄ２で構成されたオア回路１５ｅに入力し、オア
回路１５ｅは入力信号のうち大きいほうの検波信号を隣
接妨害局信号ＮＯＢとして出力する。Therefore, the mixed circuit output MS is inputted to the upper and lower adjacent station signal detection circuits 15a and 15b, respectively, to generate a signal at 445KHz.
component and the 465KHz component are extracted and sent to the next stage detector 15.
c, input to 15d. Each detector 15c, 15d
converts the input signals into direct current and inputs them to an OR circuit 15e composed of diodes DI and D2, and the OR circuit 15e outputs the larger detected signal of the input signals as an adjacent interfering station signal NOB.
時定数回路１６は、隣接妨害局検出回路１５の出力であ
る隣接妨害局信号ＮＯＢが所定のレベル以上になると直
ちに切替信号ＳＷをハイレベルからローレベル（「１」
→ｒＯ」）にし、また所定時間Ｔ１以上継続して前記所
定レベル以下になると切替信号ＳＷをｒ ＯＪ −ｒ
Ｉ Ｊに反転する。尚、前記所定時間Ｔ１は時定数回路
１６の時定数により決定される。The time constant circuit 16 changes the switching signal SW from a high level to a low level (“1”) as soon as the adjacent jamming station signal NOB, which is the output of the adjacent jamming station detection circuit 15, reaches a predetermined level or higher.
→rO''), and when the level remains below the predetermined level for a predetermined period of time T1 or more, the switching signal SW is changed to rOJ -r
Flip to I J. Note that the predetermined time T1 is determined by the time constant of the time constant circuit 16.
さて、第１図において、隣接妨害局信号ＮＯＢがない場
合（隣接妨害局信号が所定レベル以下の場合）には切替
信号ＳＷはハイレベル（ｒｌＪ）となっている。従って
、この場合切替回路１４は擬似ステレオ回路１３から入
力されている擬似ステレオ信号３ＬＬ、３．７を出力す
る。この結果、ステレオ感のある（音の広がりがある）
ＡＭ放送の受聴ができる。Now, in FIG. 1, when there is no adjacent interfering station signal NOB (when the adjacent interfering station signal is below a predetermined level), the switching signal SW is at a high level (rlJ). Therefore, in this case, the switching circuit 14 outputs the pseudo stereo signals 3LL and 3.7 input from the pseudo stereo circuit 13. As a result, there is a stereo feeling (the sound is spacious)
You can listen to AM broadcasts.
しかし、隣接妨害局信号ＮＯＢが発生してそのレベルが
所定値以上になれば時定数回路１６の出力である切替信
号ＳＷは直ちにローレベルとなる。However, when the adjacent interfering station signal NOB is generated and its level exceeds a predetermined value, the switching signal SW, which is the output of the time constant circuit 16, immediately becomes a low level.
この結果、切替回路１４はＡＭチューナ１２の出力であ
るモノラル信号Ｓ０を出力する。尚、モノラル４８号を
出力する理由は、隣接妨害局信号（雑音）ＮＯＢの発生
によりＳ／Ｎ比が悪くなるためセあり、モノラル信号を
出力するとＳ／Ｎ比が改善される。As a result, the switching circuit 14 outputs the monaural signal S0 that is the output of the AM tuner 12. Note that the reason for outputting monaural No. 48 is that the S/N ratio deteriorates due to the generation of the adjacent interfering station signal (noise) NOB; outputting a monaural signal improves the S/N ratio.
しかる後、隣接妨害局信号ＮＯＢが所定時間Ｔ。After that, the adjacent interfering station signal NOB continues for a predetermined time T.
以上継続して所定レベル以下になれば切替信号ＳＷがハ
イレベルとなるため切替回路１４は再び擬似ステレオ信
号Ｓ、′、Ｓ１．１′を出力する。If the level continues to fall below the predetermined level, the switching signal SW becomes high level, and the switching circuit 14 again outputs the pseudo stereo signals S,', S1.1'.
尚、弱電界時には雑音レベルが増大するが隣接妨害局信
号も増大するから、モノラル状態となりＳ／Ｎ比が改善
されて放送が聴きやすくなる。Note that when the electric field is weak, the noise level increases, but the signal from the adjacent interfering station also increases, resulting in a monaural state, which improves the S/N ratio and makes it easier to listen to the broadcast.
〈発明の効果〉
以上本発明によれば、隣接妨害局信号の有無に応じて適
宜擬似ステレオ状態からモノラル状態にし、あるいはモ
ノラル状態から擬似ステレオ状態にしたから、隣接妨害
のない良好な状態においてはステレオ感のあるＡＭ放送
の受聴ができ、隣接妨害のある状態にはＳ／Ｎ比を改善
して良好なＡＭ放送の受聴ができる。<Effects of the Invention> According to the present invention, the pseudo-stereo state is changed to a monaural state, or the monaural state is changed to a pseudo-stereo state, as appropriate depending on the presence or absence of an adjacent interfering station signal. It is possible to listen to AM broadcasts with a stereo feeling, and when there is adjacent interference, the S/N ratio is improved and AM broadcasts can be listened to in good condition.
第１図は本発明にかかるＡＭ受信機のブロック図、
第２図は擬似ステレオ回路のブロック図、第３図は擬似
ステレオ回路におけるくしば型フィルタの周波数特性図
、
第４図は隣接妨害局検出回路のブロック図である。
１１・・アンテナ、１２・・ＡＭチューナ、１３・・擬
似ステレオ回路、
１４・・切替回路、
１５・・隣接妨害局検出回路、
１６・・時定数回路
特許出願人 アルパイン株式会社代理人
弁理士 齋藤千幹ぐ
さ
、−羽
Ｊ ０−Fig. 1 is a block diagram of an AM receiver according to the present invention, Fig. 2 is a block diagram of a pseudo-stereo circuit, Fig. 3 is a frequency characteristic diagram of a comb filter in the pseudo-stereo circuit, and Fig. 4 is an adjacent interfering station. FIG. 2 is a block diagram of a detection circuit. 11... Antenna, 12... AM tuner, 13... Pseudo stereo circuit, 14... Switching circuit, 15... Adjacent interfering station detection circuit, 16... Time constant circuit Patent applicant Alpine Co., Ltd. Agent Patent attorney Saito Senkigu
Sa--wing J 0-
Claims (1)
、 ＡＭチューナ出力であるモノラル信号Ｓ＿Ｍを入力され
てＬ、Ｒ両チャンネルの擬似ステレオ信号Ｓ＿Ｌ′、Ｓ
＿Ｒ′を出力する擬似ステレオ回路と、隣接妨害局信号
が発生していない場合に擬似ステレオ信号Ｓ＿Ｌ′、Ｓ
＿Ｒ′を出力し、隣接妨害局信号が発生している場合に
モノラル信号Ｓ＿Ｍを出力する切替回路を備えてなるＡ
Ｍ受信機。(1) An AM tuner, an adjacent interfering station detection circuit that detects interfering signals from adjacent stations, and receiving the monaural signal S_M, which is the output of the AM tuner, and generating pseudo-stereo signals S_L', S_L' and S_L', S_L' and S_M for both L and R channels, respectively.
A pseudo-stereo circuit that outputs _R' and pseudo-stereo signals S_L', S when no adjacent interfering station signal is generated.
_R' and a switching circuit that outputs a monaural signal S_M when an adjacent interfering station signal is generated.
M receiver.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25747586A JPS63177634A (en) | 1986-10-29 | 1986-10-29 | Am receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25747586A JPS63177634A (en) | 1986-10-29 | 1986-10-29 | Am receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63177634A true JPS63177634A (en) | 1988-07-21 |
| JPH0426571B2 JPH0426571B2 (en) | 1992-05-07 |
Family
ID=17306820
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25747586A Granted JPS63177634A (en) | 1986-10-29 | 1986-10-29 | Am receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63177634A (en) |
-
1986
- 1986-10-29 JP JP25747586A patent/JPS63177634A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0426571B2 (en) | 1992-05-07 |
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