JPS564921A - Frequency selecting circuit - Google Patents

Frequency selecting circuit

Info

Publication number
JPS564921A
JPS564921A JP8020479A JP8020479A JPS564921A JP S564921 A JPS564921 A JP S564921A JP 8020479 A JP8020479 A JP 8020479A JP 8020479 A JP8020479 A JP 8020479A JP S564921 A JPS564921 A JP S564921A
Authority
JP
Japan
Prior art keywords
tuning circuit
coupling
terminal
voltage
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
Application number
JP8020479A
Other languages
Japanese (ja)
Inventor
Toshifumi Shibuya
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP8020479A priority Critical patent/JPS564921A/en
Publication of JPS564921A publication Critical patent/JPS564921A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G5/00—Tone control or bandwidth control in amplifiers
    • H03G5/02—Manually-operated control
    • H03G5/14—Manually-operated control in frequency-selective amplifiers

Abstract

PURPOSE:To vary frequency band width and an insertion loss by coupling the 1st and 2nd tuning circuits with each other by a variable capacity element and by controlling its capacity value. CONSTITUTION:While the 1st parallel tuning circuit consists of capacitor C14 and coil L16, the 2nd parallel tuning circuit is also composed of C15 and L17 and two tuning circuits are coupled with each other through variable capacity diode 12 and C13 connected in series. Then, input coupling C18 is connected to the 1st tuning circuit, and output coupling C19 to the 2nd tuning circuit to constitute a composite tuning circuit. Input terminal 20 for control over the index of coupling of the composite tuning circuit is connected to the cathode of diode 12 via resistance 28. As a voltage at terminal 20 is increased, the index of coupling decreases and an insertion loss increases, reducing passing band width. On the other hand, as the voltage at terminal 20 is decreased, the reverse result is obtained. For the purpose, an automatic gain control voltage is applied to terminal 20, and consequently when the input level is high, the loss increases to narrow the frequency passing band, so that disturbance of mutual modulation will be improved.
JP8020479A 1979-06-27 1979-06-27 Frequency selecting circuit Pending JPS564921A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8020479A JPS564921A (en) 1979-06-27 1979-06-27 Frequency selecting circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8020479A JPS564921A (en) 1979-06-27 1979-06-27 Frequency selecting circuit

Publications (1)

Publication Number Publication Date
JPS564921A true JPS564921A (en) 1981-01-19

Family

ID=13711844

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8020479A Pending JPS564921A (en) 1979-06-27 1979-06-27 Frequency selecting circuit

Country Status (1)

Country Link
JP (1) JPS564921A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6268331U (en) * 1985-10-18 1987-04-28
JPH0346826A (en) * 1989-07-15 1991-02-28 Marantz Japan Inc Communication equipment and agc circuit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6268331U (en) * 1985-10-18 1987-04-28
JPH0346826A (en) * 1989-07-15 1991-02-28 Marantz Japan Inc Communication equipment and agc circuit
JPH0783281B2 (en) * 1989-07-15 1995-09-06 日本マランツ株式会社 AGC circuit

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