JPS643343U - - Google Patents
Info
- Publication number
- JPS643343U JPS643343U JP9608487U JP9608487U JPS643343U JP S643343 U JPS643343 U JP S643343U JP 9608487 U JP9608487 U JP 9608487U JP 9608487 U JP9608487 U JP 9608487U JP S643343 U JPS643343 U JP S643343U
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- intermediate frequency
- receiving section
- signal strength
- interference
- 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
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 230000010355 oscillation Effects 0.000 claims description 4
- 230000003321 amplification Effects 0.000 claims description 3
- 238000001514 detection method Methods 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 239000013078 crystal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
Landscapes
- Circuits Of Receivers In General (AREA)
- Superheterodyne Receivers (AREA)
- Noise Elimination (AREA)
Description
第１図はこの考案の一実施例の構成を示すブロ
ツク図、第２図は同実施例の動作を示すフローチ
ヤート、第３図は同実施例における狭帯域バンド
パスフイルタ１３の通過帯域特性を示す特性図で
ある。
７……ＦＭフロントエンド、８……帯域切換回
路（制御手段）、９……ＦＭ中間周波増幅回路、
１３……狭帯域バンドパスフイルタ、２９……Ａ
Ｍ中間周波増幅回路、３２……信号強度検出回路
、３６……ＡＭ第２周波数変換回路、３８……局
部発振回路、３９……切換スイツチ、４９……コ
ントローラ（制御手段）、ＸＬ１〜ＸＬ３……ク
リスタル。
Fig. 1 is a block diagram showing the configuration of an embodiment of this invention, Fig. 2 is a flowchart showing the operation of the embodiment, and Fig. 3 shows the passband characteristics of the narrowband bandpass filter 13 in the embodiment. FIG. 7...FM front end, 8...band switching circuit (control means), 9...FM intermediate frequency amplification circuit,
13...Narrowband bandpass filter, 29...A
M intermediate frequency amplification circuit, 32... Signal strength detection circuit, 36... AM second frequency conversion circuit, 38... Local oscillation circuit, 39... Changeover switch, 49... Controller (control means), XL1 to XL3... …crystal.
Claims (1)
Ｍ第１中間周波数が前記ＦＭ受信部の中間周波数
に等しく設定されているダブルコンバージヨンタ
イプのＡＭ受信部とを有するＦＭ／ＡＭ受信機に
おいて、 前記ＡＭ受信部の第２周波数変換回路の局部発
振周波数として、ＡＭ第１中間周波数をＡＭ第２
中間周波数に変換するための第１局発周波数と、
ＦＭ受信時の正規受信局の上側および下側隣接局
に対応するＦＭ中間周波数を前記ＡＭ第２中間周
波数に変換するための第２、第３局発周波数とを
設定し、さらに、 前記ＦＭ中間周波信号の周波数を中心周波数と
し、かつ隣接局妨害を排除するのに必要な所要通
過帯域特性を有する狭帯域バンドパスフイルタと
、 前記ＡＭ受信部の中間周波増幅回路から出力さ
れる中間周波信号に基づいて、信号強度を検出す
る信号強度検出手段と、 ＦＭ受信時において、前記ＦＭ中間周波信号を
前記ＡＭ第２周波数変換回路に供給するとともに
、前記ＡＭ第２周波数変換回路の局発周波数を順
次切換え、この切換えに従つて前記信号強度検出
手段から得られる信号の変化を相互に比較するこ
とにより、隣接局妨害の有無を判別し、妨害と判
別された場合には前記狭帯域バンドパスフイルタ
を前記ＦＭ受信部の中間周波段に挿入する制御手
段 とを具備することを特徴とするＦＭ／ＡＭ受信
機。[Claims for Utility Model Registration] A superheterodyne FM receiving section,
In an FM/AM receiver having a double conversion type AM receiving section in which the M first intermediate frequency is set equal to the intermediate frequency of the FM receiving section, local oscillation of a second frequency conversion circuit of the AM receiving section is provided. As the frequency, the AM first intermediate frequency is set as the AM second intermediate frequency.
a first local oscillation frequency for converting to an intermediate frequency;
setting second and third local oscillation frequencies for converting the FM intermediate frequencies corresponding to the upper and lower adjacent stations of the regular receiving station during FM reception into the AM second intermediate frequency; a narrowband bandpass filter whose center frequency is the frequency of the frequency signal and which has the required passband characteristics necessary to eliminate adjacent station interference; and an intermediate frequency signal output from the intermediate frequency amplification circuit of the AM receiving section. a signal strength detection means for detecting signal strength based on the signal strength; and at the time of FM reception, supplying the FM intermediate frequency signal to the AM second frequency conversion circuit, and sequentially converting the local frequency of the AM second frequency conversion circuit. By comparing the changes in the signals obtained from the signal strength detection means according to the switching, it is determined whether or not there is interference from an adjacent station, and if interference is determined, the narrowband bandpass filter is switched on. An FM/AM receiver comprising: control means inserted into an intermediate frequency stage of the FM receiving section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9608487U JPH0339953Y2 (en) | 1987-06-23 | 1987-06-23 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9608487U JPH0339953Y2 (en) | 1987-06-23 | 1987-06-23 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS643343U true JPS643343U (en) | 1989-01-10 |
| JPH0339953Y2 JPH0339953Y2 (en) | 1991-08-22 |
Family
ID=31320887
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9608487U Expired JPH0339953Y2 (en) | 1987-06-23 | 1987-06-23 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0339953Y2 (en) |
-
1987
- 1987-06-23 JP JP9608487U patent/JPH0339953Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0339953Y2 (en) | 1991-08-22 |
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