The early transmitter for radio broadcasting is so big and bulky that they do occupy numerous spaces. The circuitries are mainly designed with valves, which are big in sizes.

With the advent of semiconductor materials such as transistors electronic equipment are now becoming miniaturized such that small transmitters are now becoming handy and compact.

In line with this we choose to design a complete radio broadcasting equipment tat is compact and existence of semiconductor materials.

The system units are of two categories namely: audio console for the processing and mixing of musicals is basically a condenser microphone.

The transmitter unit is where the center frequency is provided. All these were designed to be in compact and small manner. This project is aimed at serving a community using a small and compact radio broadcasting equipment with a power watt of 1 watt a community of 1 kilometer in radius should be covered comfortable and the audio production very clear unlike the common noisy FM microphone project.

TABLE OF CONTENT

Title page

Approval page

Declaration

Dedication

Acknowledgement

Abstract

Table of content

List of diagram/figures

Introduction

CHAPTER 1 TRANSMITTER FUNDAMENTALS

AND TYPES OF MODULATION

1.1 Transmitters fundamental

1.2 Modulations (analog and digital)

1.3 Amplitude modulation

1.4 Frequency modulation

1.5 Method of fm

1.6 Modulation overview

1.61 Basic reactance modulator

1.62 Theory of reactance modulator

1.70 Types of reactance modulator

1.7.1 Varacto diode modulator

CHAPTER 2 AMPLIFIER EXPLANATIONS

2.10 Amplifier explanations

2.20 Class of amplifier

2.21 Class of amplifier

2.22 Class B amplifier

2.23 Class AB amplifier

2.24 Class c amplifier

2.30 Oscillators

2.31 Types of oscillators

CHAPTER 3.0

TRANSMISSION LINE

3.10 FUNDAMENTALS

3.30 Types of transmission lines

3.31 Rectangular wave guide

3.32 Circular wave guide

3.33 Ridge Wave guide

3.34 Optical fiber

CHAPTER 4

POWER SUPPLY

4.1 Stages of power supply

4.2 Audio console power supply

4.3 Transmitter power supply design

CHAPTER 5 AUDIO CONSOLE UNIT

5.1 Audio console transducer

5.2 Audio console pre-amp stage

5.3 Audio console power amp stage

5.4 Audio console control/mixer

5.5 The operation of the audio console

CHAPTER 6 TRANSMITTER AND ANTENNA DESIGN

6.1 Oscillator stage design for transmitter

6.2 Buffer/power amplifier design

6.3 Tank circuit design

6.4 Antenna design

6.41 Types of antenna and application

6.42 Antenna matching network

6.43 Antenna design

CHAPTER 7 COMPONENT DESCRIPTION AND CONSTRUCTION

7.10 LM 386-power amplifier

7.11 Capacitor

7.12 Transistor

7.2 Specification

7.3 Construction and soldering

7.4 Precautions taken during soldering

7.5 Troubleshooting

7.6 Transmitter strip board

7.7 Audio console strip board

RECOMMENDATION

CONCLUSION

REFERENCE:

LIST OF FIGURES AND DIAGRAM

Fig 1.4 Information signal

Fig 1.62 Reactance modulator circuit

Fig 1.7 Reactance modulator elements

Fig 1.7 Diagram of transistor reactance modulator

Fig 1.8 Varactor diode modulator

Fig 2.1 Amplifier configuration

Fig 2.21 Class a wave form representation

Fig 2.22 Voltage current characteristic of class b amp

Fig 2.3 Block diagram of an oscillator

Fig 3.2 Balanced line

Fig 3.22 Unbalanced wire – line

Fig 3.3 Method of wave propagation in a waveguide

Fig 3.31 Te10 mode in a rectangular waveguide

Fig 3.32 Circular waveguide

Fig 3.33 Rectangular waveguide/ ridge

Fig 3.4 Optical fiber cable

Fig 4.1 Power supply block diagram

Fig 4.2 Audio console power supply regulator

Fig 4.3 Transmitter power supply

Fig 5.2 Audio console pre-amp

Fig 5.3 Audio console power amp

Fig 5.4 Audio console control/ mixer

Fig 6.1 Oscillator stage

Fig 6.2 Buffer amp/power amp

Fig 6.3 Tank circuit

Fig 6.42 Antenna matching network

Fig 7.1 LM 386 (power amp)

Fig 7.11 Capacitor

Fig 7.12 Transistor

Bill of quantity

Block diagram of audio console

Block diagram of transmitter

Audio console schematic

Transmitter schematic

Transmitter casing

Audio console casing

INTRODUCTION

This our project work is all about design and construction of a complete radio broadcasting equipment that is compact and miniaturized. It is capable of delivering a power output of 1 watt and assumed to cover a distance of 400 meters ie 200 meters radius depending on obstructions.

The transmitted signal is frequency modulated stays constant and its frequency varies according to the amplitude variations of the audio signal. When the input signals amplitude increases (ie during the positive half cycle) the frequency of the carrier increases too, on the other hand when the input signal decreases in amplitude (negative half-cycle or no signal) the carrier frequency decreases accordingly.

The output frequency of the transmitter is adjustable from 88 to 108 MHZ, which is the FM band that is used for radio broadcasting. The circuit as we have already mentioned consist of four stages. Three RF stages and one audio preamplifier for the modulation. The first RF stage is an oscillator is