JPS5735425A - Squelch device - Google Patents

Squelch device

Info

Publication number
JPS5735425A
JPS5735425A JP11195480A JP11195480A JPS5735425A JP S5735425 A JPS5735425 A JP S5735425A JP 11195480 A JP11195480 A JP 11195480A JP 11195480 A JP11195480 A JP 11195480A JP S5735425 A JPS5735425 A JP S5735425A
Authority
JP
Japan
Prior art keywords
detector
output
gate circuit
amplifier
noise
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
JP11195480A
Other languages
Japanese (ja)
Inventor
Katsuzo Tomita
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.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric 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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP11195480A priority Critical patent/JPS5735425A/en
Publication of JPS5735425A publication Critical patent/JPS5735425A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/34—Muting 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
    • H03G3/344—Muting responsive to the amount of noise (noise squelch)

Landscapes

  • Noise Elimination (AREA)

Abstract

PURPOSE:To achieve a stable squelch operation against a small signal with a low modulation, by providing a gate circuit which switches a voice signal with the ratio of carrier wave to noise of an amplitude modulation signal. CONSTITUTION:An amplitude modulation signal received from an input termnal 1 is detected at a detector 3 to be voice signal, which is amplified at an audio amplifier and gate circuit 4 and outputted to a voice output terminal 5. On the other hand, an output of the detector 3 being an output proportional to a carrier level is amplified at a DC amplifier 20 and applied to a comparator 11. The noise component is picked up for the output of the detector 3 through a band pass filter 8 and applied to an attenuator 9 and a detector 10. A comparison circuit 11 compares the output of a DC amplifier 20 with that of the detector 10, and if noise, i.g., the output of the detector 10 is increased, the gate circuit 4 is closed, and if smaller, the gate circuit 4 is opened.
JP11195480A 1980-08-11 1980-08-11 Squelch device Pending JPS5735425A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11195480A JPS5735425A (en) 1980-08-11 1980-08-11 Squelch device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11195480A JPS5735425A (en) 1980-08-11 1980-08-11 Squelch device

Publications (1)

Publication Number Publication Date
JPS5735425A true JPS5735425A (en) 1982-02-26

Family

ID=14574314

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11195480A Pending JPS5735425A (en) 1980-08-11 1980-08-11 Squelch device

Country Status (1)

Country Link
JP (1) JPS5735425A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6330036U (en) * 1986-08-12 1988-02-27
WO1992016056A1 (en) * 1991-02-27 1992-09-17 Fujitsu Ten Limited Circuit for sensing pulse-like noise in am receiver

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6330036U (en) * 1986-08-12 1988-02-27
JPH0427228Y2 (en) * 1986-08-12 1992-06-30
WO1992016056A1 (en) * 1991-02-27 1992-09-17 Fujitsu Ten Limited Circuit for sensing pulse-like noise in am receiver
US5303415A (en) * 1991-02-27 1994-04-12 Fujitsu Ten Limited Pulse noise detecting circuit of AM receiver

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