JPS5768933A - Fm receiver - Google Patents

Fm receiver

Info

Publication number
JPS5768933A
JPS5768933A JP14491080A JP14491080A JPS5768933A JP S5768933 A JPS5768933 A JP S5768933A JP 14491080 A JP14491080 A JP 14491080A JP 14491080 A JP14491080 A JP 14491080A JP S5768933 A JPS5768933 A JP S5768933A
Authority
JP
Japan
Prior art keywords
detector
output
muting
signal level
detecting
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
JP14491080A
Other versions
JPS6213853B2 (en
Inventor
Hidekazu Ishii
Original Assignee
Nec Corp
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 Nec Corp filed Critical Nec Corp
Priority to JP14491080A priority Critical patent/JPS6213853B2/ja
Publication of JPS5768933A publication Critical patent/JPS5768933A/en
Publication of JPS6213853B2 publication Critical patent/JPS6213853B2/ja
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03GCONTROL OF AMPLIFICATION
    • H03G3/00Gain control in amplifiers or frequency changers without distortion of the input signal
    • H03G3/20Automatic control
    • H03G3/30Automatic control in amplifiers having semiconductor devices
    • H03G3/34Muting amplifier when no signal is present or when only weak signals are present, or caused by the presence of noise signals, e.g. squelch systems
    • H03G3/341Muting when no signals or only weak signals are present

Abstract

PURPOSE:To improve the tracking performance to the reception level change of muting operation, by detecting a minimum value of reception signal level and giving muting to the FM detection output when this minimum value is smaller than the specified value. CONSTITUTION:The output of a signal level detector 11 detecting a signal level of an intermediate frequency signal is inputted to a minute voltage detector 31. This detector 31 detects the lowest voltage from a variable voltage applied to the input and stores the result for a set time. If the output of the detector 11 falls down through the variance by the interference on electromagnetic wave propagation, the output of the detector 31 follows it for reduction, and muting can be given to a switch circuit 19 via an AND circuit 13, allowing to avoid unpleasant noise from an FM receiver. The time constant is selected so that the output of the detector 31 is stored for the set time and since the muting is released so that output can be made gradually without rapid release of muting, audible unpleasantness is made less.
JP14491080A 1980-10-16 1980-10-16 Expired JPS6213853B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14491080A JPS6213853B2 (en) 1980-10-16 1980-10-16

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14491080A JPS6213853B2 (en) 1980-10-16 1980-10-16

Publications (2)

Publication Number Publication Date
JPS5768933A true JPS5768933A (en) 1982-04-27
JPS6213853B2 JPS6213853B2 (en) 1987-03-30

Family

ID=15373115

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14491080A Expired JPS6213853B2 (en) 1980-10-16 1980-10-16

Country Status (1)

Country Link
JP (1) JPS6213853B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4525868A (en) * 1982-03-23 1985-06-25 Nippon Electric Co., Ltd. Interference wave detection circuit for use in radio receiver

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4525868A (en) * 1982-03-23 1985-06-25 Nippon Electric Co., Ltd. Interference wave detection circuit for use in radio receiver

Also Published As

Publication number Publication date
JPS6213853B2 (en) 1987-03-30

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