Design And Construction Of A Noise Muting FM Receiver

ABSTRACT

The tuning of a frequency modulated (FM) receiver to a FM radio station frequency involves a lot of ‘hissing’ noise in between the stations, which is very irritating for the operator and as such undesirable. Digital FM receivers are free from this problem, because in them the output is automatically clipped during off-station gaps. However, digital FM receivers are comparatively much costlier than their analogue counterparts.

Analogue FM receivers employ an LC tuning system that generates ‘hiss’ noise at the output, which remains unclipped during off-station tuning. However, when the received signal level is adequate (i.e., when the receiver frequency is very close to an FM transmitting station frequency), the limiter circuit preceding the ratio detector circuit in an analogue FM receiver will clip/limit any noise riding the FM carrier.

This work is on simple noise muting FM receiver circuit described here eliminates this ‘hissing’ noise from the output of an analogue FM receiver circuit when it is not resonating to any FM transmitting station’s frequency. In other words, this circuit mutes the output from an analogue FM receiver when its tuner circuit is sweeping in between FM stations.

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

1.0      INTRODUCTION

1.1      BACKGROUND OF THE PROJECT
1.2      AIM OF THE PROJECT
1.3      OBJECTIVE OF THE PROJECT
1.4      SIGNIFICANCE OF THE PROJECT
1.5      PURPOSE OF THE PROJECT
1.6      APPLICATION OF THE PROJECT
1.7      ADVANTAGES OF THE PROJECT
1.8      PROBLEM/LIMITATION OF THE PROJECT
1.9      PROJECT ORGANISATION

CHAPTER TWO

2.0     LITERATURE REVIEW

2.1      REVIEW OF RELATED STUDIES

2.2      REVIEW OF RELATED TERMS

CHAPTER THREE

3.0     CONSTRUCTION METHODOLOGY

3.1      SYSTEM CIRCUIT DIAGRAM

3.2     SYSTEM OPERATION

3.3      CIRCUIT DESCRIPTION

3.4      SYSTEM CIRCUIT DIAGRAM

3.5      CIRCUIT OPERATION

3.6  IMPORTANCE AND FUNCTION OF THE MAJOR COMPONENTS USED IN THIS CIRCUIT

3.7      POWER SUPPLY UNIT

CHAPTER FOUR

RESULT ANALYSIS

4.0      CONSTRUCTION PROCEDURE AND TESTING

4.1      CASING AND PACKAGING

4.2      ASSEMBLING OF SECTIONS

4.3      TESTING

4.4.1 PRE-IMPLEMENTATION TESTING

4.4.2  POST-IMPLEMENTATION TESTING

4.5      RESULT

4.6      COST ANALYSIS

4.7      PROBLEM ENCOUNTERED

CHAPTER FIVE

5.1      CONCLUSION

5.2      RECOMMENDATION

5.3      REFERENCES