Ham Radio

CAPSTONE PROJECT (PART –I) REPORT

(Project Term August-December, 2012)

AMATEUR RADIO

(Communication / Super Spice, PCB Designing)

Submitted by

D. S. Charan Registration Number: 10900627

Lokesh Mandhyan Registration Number: 10903024

Nitin Gaba Registration Number: 10901820

Praveen Kumar Registration Number: 10905371

Vidhita Gholap Registration Number: 10905133

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Project Group Number G089.

Under the Guidance of

Mr. R.Madhusudhan Goud,Assistant Professor

Discipline of Electronics & Communication Engineering

Lovely Professional University, Phagwara

August to December, 2012

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DECLARATION

We hereby declare that the project work entitled “Amateur Radio” is an authentic record of our

own work carried out as requirements of Capstone Project (Part-I) for the award of degree of

B.Tech in Electronics & Communication( ECE ) from Lovely Professional University,

Phagwara, under the guidance of Mr. R.Madhusudhan Goud, during August to December,

2012).

Project Group Number: G089

Name of Student 1: D.S. Charan Registration Number:10900627

Name of Student 2: Lokesh Mandhyan Registration Number:10903024

Name of Student 3: Nitin Gaba Registration Number:10901820

Name of Student 4: Praveen Kumar Registration Number: 10905371

Name of Student 5: Vidhita Gholap Registration Number:10905133

(Signature of Student 1)

(Signature of Student 2)

(Signature of Student 3)

(Signature of Student 4)

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(Signature of Student 5)

CERTIFICATE

This is to certify that the declaration statement made by this group of students is correct to the

best of my knowledge and belief. The Capstone Project Proposal based on the technology / tool

learnt is fit for the submission and partial fulfillment of the conditions for the award of B.Tech in

Electronics & Communications (ECE) from Lovely Professional University, Phagwara.

Name : Mr. R.Madhusudhan Goud

U.ID : 15777

Designation :Assistant Professor

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Signature of Faculty Mentor

ACKNOWLEDGEMENT

It is our proud privilege to have Mr. MADHUSUDHAN SIR as our mentor for this

project, AMATEUR RADIO (HAM RADIO). He has been an immense help to us

since the beginning of the project. He guided us at tough times and helped us achieve

this goal. We are very thankful to him for his help and support.

We would also like to extend our thanks to our H.O.D NARINDER KUMAR for his

undying faith in us and making us believe in ourselves. His guidance has been the

reason we could complete this project.

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ABSTRACT

The final year project aims at exposing the students undergoing higher technical studies to

the thoughts and logic that must be developed to ensure that one is able to integrate his/her

ideas into something concrete.

This generally is initiated by the inception of an idea or a concept, which not only aims at

developing a product (Hardware or Software), but also the in-depth study of the earlier

existing products in the same category and their deficiencies. Accordingly an approach is

taken to propose a solution, which is better from the previous ones in one respect or the

other.

With the same approach in mind, we, the final year students of Bachelor of Technology

(Electronics and communication), have taken up the AMATEUR RADIO (HAM

RADIO) as our final year project.

Amateur radio is the use of designated radio frequency spectrum for purposes of private

recreation, non-commercial exchange of messages, wireless experimentation, self-training,

and emergency communication. The term "amateur" is used to specify persons interested in

radio technique solely with a personal aim and without direct pecuniary interest, and to

differentiate it from commercial broadcasting, public safety (such as police and fire), or

professional two-way radio services (such as maritime, aviation, taxis, etc.).

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List of Contents

Page no

Chapter 1 Introduction 8-9

Chapter 2 Review of Literature 10-11 Rationale/Scope of the study 12-13

Chapter 3 Objectives of the study 14 System Block diagram and logical diagram 15

Chapter 4 Complete work Plan with timelines 16 Expected outcome of the study 17 Preliminary research 17 Experimental work done 18-29 Conclusions 30 Bibliography 31

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CHAPTER 1

1.1 INTRODUCTION

Amateur radio is a community of people that use radio transmitters and receivers to communicate with other Amateur radio operators. If you were to ask a dozen different amateurs what ham radio meant to them chances are you would get 12 different answers. Amateur radio operators are often called ham radio operators or simply "hams" and frequently the public is more familiar with this term than with the legal term Radio Amateur.

Amateur radio (ham radio) is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication. The term "amateur" is used to specify persons interested in radio technique solely with a personal aim and without direct pecuniary interest, and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.).

The amateur radio service is established by the International Telecommunication Union (ITU) through the International Telecommunication Regulations. National governments regulate technical and operational characteristics of transmissions and issue individual stations licenses with an identifying call sign. Prospective amateur operators are tested for their understanding of key concepts in electronics and the host government's radio regulations.

Radio amateurs use a variety of voice, text, image, and data communications modes and have access to frequency allocations throughout the RF spectrum to enable communication across a city, region, country, continent, the world, or even into space.

Amateur radio is officially represented and coordinated by the International Amateur Radio Union (IARU), which is organized in three regions and has at its members the national amateur radio societies which exist in most countries. According to an estimate made in 2011 by the American Radio Relay League, two million people throughout the world are regularly involved with amateur radio.

Amateur radio communication utilizes HF, UHF and VHF frequencies bands Amateurs use a variety of voice, text, image, and data communications modes over radio. Generally new modes can be tested in the amateur radio service, although national regulations may require disclosure of a new mode to permit radio licensing authorities to monitor the transmissions.

Encryption, for example, is not generally permitted in the Amateur Radio service except for the special purpose of satellite vehicle control uplinks. The following is a partial list of the modes of communication used, where the mode includes both modulation types and operating protocols.

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An amateur radio operator uses a call sign on the air to legally identify the operator or station. In some countries, the call sign assigned to the station must always be used, whereas in other countries, the call sign of either the operator or the station may be used. In certain jurisdictions, an operator may also select a call sign although these must also conform to the issuing government's allocation and structure used for Amateur Radio call signs.

Fig 1.1 shows the international Sign of Amateur Radio.

Fig 1.2 shows typical RM96 Transceiver.

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CHAPTER 2

2.1 REVIEW OF LITERATURE 1909 – First Amateur Radio Club, the Junior Wireless Club is formed (later

renamed the Radio Club of America) 1912 – Amateur Radio licensing begins under the Radio Act of 1912. Radio

is regulated by the Department of Commerce. Irving Vermilya, 1ZE isgranted “Skill Certificate # 1”, making him the first U.S. licensed AmateurRadio Operator

1914 – Hiram Percy Maxim organizes the American Radio Relay League 1915 - Emma Candler, 8NH, becomes the first woman radio amateur 1917 – 6000 Licensed Hams in the US. Amateur Radio is temporarily shut

Down as America enters World War I

IN Early 1920 HAM Radio station

Fig 2.1 TRANSMITTER SECTION

Fig 2.2 RECEIVER SECTION

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The 1980’s

By 1980 more commercial ham equipment is made in Japan than in the USA.

Computers and Radios become a natural combination.

Cell phones introduced in early 80’s.

Fig 2.3 1980’S RADIO SECTION

21st Century

Majority of ISS astronauts are Hams who talk regularly with hams here on Earth.

FCC drops Morse requirements for all Amateur license classes. Consumer electronics (cell phones, I-pods, WI-FI) overshadowing the “Gee

Whiz” aspect of Amateur Radio. Ham Radio still has draw for people who are interested in the inner

Workings of radio equipment and signal propagation.

2.2 SCOPE OF STUDY

“HAM RADIO” OUR NATION'S BACKUP COMMUNICATION SYSTEM!”

Ham Radios are known for their handy use in times of disasters. The scope of ham radio lies in the same. In times of crisis and natural disasters, amateur radio is often used as a means of emergency communication when wire line, cell phones and other conventional means of communications fail. Unlike commercial systems, Amateur radio is not as dependent on

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terrestrial facilities that can fail. It is dispersed throughout a community without "choke points" such as cellular telephone sites that can be overloaded.

Amateur radio operators are generally experienced in improvising antennas and power sources and most equipment today can be powered by an automobile battery. Annual "Field Days" are held in many countries to practice these emergency improvisational skills and usually they held in Tamil Nadu in India. Amateur radio operators can use hundreds of frequencies and can quickly establish networks tying disparate agencies together to enhance Communication.Recent examples include the 2001 attacks on the World Trade Center in Manhattan, the 2003 North America blackout and Hurricane Katrina in September 2005, where amateur radio was used to coordinate disaster relief activities when other systems failed.On September 2, 2004, ham radio was used to inform weather forecasters with information on Hurricane Frances live from the Bahamas. On December 26, 2004, an earthquake and resulting tsunami across the Indian Ocean wiped out all communications with the Andaman Islands, except for a DX-pedition that provided a means to coordinate relief efforts. Recently, Amateur Radio operators in the People's Republic of China provided emergency communications after the 2008 Sichuan earthquake and US hams did similar work following Hurricane Ike.

The largest disaster response by Indian Amature Radio operaters was in 2004 at the time of tsunami. In the Southern States of India government has established new ham radio stations to tackle the disasters in the Coastal Areas. Amateur radio as a hobby has reached an important turning point. Many can point to various examples of why things are changing; however, some of these examples are real and some are only periodic in nature, but the trend of activity and interest now as compared to five or even ten years ago is changing.

The real issue which we must face is 'does the amateur radio service (ARS) base its future on the precepts created and tested over the last twenty years or do we look at new and novel ways of growing, sustaining, and protecting the hobby that we love?' Amateur radio has prospered over the last twenty years as commercial manufactures were able to grow radio sales in all over the World, with the amateur radio community as a secondary market to their already existing commercial markets. This resulted in a tremendous growth and usage of VHF/UHF and to some extent, HF, over the last several decades.

Amateur radio is in the midst of a paradigm shift from the vast majority of communicators currently on the bands to a more balanced population representing technical, experimental, and hobbyist who just like to communicate with radios.Now day’s e-hams are becoming popular too. E-hams are an internet version of ham radio and it is helping to reach people about ham radios.

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CHAPTER 3

3.1 OBJECTIVES OF THE STUDY

We are introduced to the Scientific activity at a very young age and will create an awareness on the importance of Information Technology and Communications in their life.

We will possess a license from the Ministry of Communications, Government of India and are encouraged to construct their own Transceiver or Purchase or Operate a Amateur Radio Station including Information Technology through Computers.

We joins the fraternity and interact with other Students, Teachers, Scientists, Doctors, Lawyers, Politicians, Kings and Prime Ministers from all over the World. plan ahead for their future carriers in their lives.

We can take part or share information on the latest developments in various technologies.

We can win a lot of Awards and Certificates by participating in various events all over the world sitting in their own room.

We can discuss their views and ideas freely and can educate themselves & others to improve their knowledge on the Subject.

We will inculcate the communication and leadership skills.

To provide emergency or public service communications when normal means of communications are disrupted.

To advance the state of the Amateur Radio art through individual and collective research

.

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3.2 SYSTEM BLOCKS AND LOGICAL DIAGRAM

Fig 3.1 BLOCK DIAGRAM OF AMETEUR RADIO

Fig 3.2 CIRCUIT DIAGRAM OF RM-96

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CHAPTER 4

4.1 COMPLETE WORKPLAN WITH TIMELINESS

In our project yet we have design some important blocks and study all blocks of circuit diagram.

We come to know about rules and regulations and guidelines of Indian government(department of telecommunication) about Amateur radio that we have to follow.

We are also go through antenna design and hardware and in presentation we are show the hardware of antenna.

In next term first we will give the license exam in December.

After becoming the license holder we will do the PCB design of all blocks In next semester.

After designing every blocks we will check it on CRO to know about its performance.

Then we assemble the whole blocks and other circuits.

After assembling we will check the performance of amateur radio using spectron analyzer.

After checking the performance of ham radio we will transmit voice over frequency band allocated to us.

In the end we will submit the final report and we will give whole description about project and we will also give the demo of our project by transmitting and receiving voice from other amateur radio license holder.

4.2 EXPECTED OUTCOMES OF THE PROJECT

The outputs and deliverables from this project are manifold and designed to establish communication in times of disasters and to gain technical knowledge about the working of Receivers and Transmitters along with the knowledge of spectrum.

The expected output of the project is to establish real time communication for free.

We expect to develop a ready-to-use Ham Radio.

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We expect to document the process that will be useful for anyone to develop a ham radio.

We expect this project will help to spread the awareness of ham radio.

4.3 PRELIMINARY RESEARCH

Preliminary Work of the project started from deciding what kind of ham radio we must develop. After examining the various types of ham radios that are available in the market we have decided to develop a RM96 Low Power Transmitter.

The reasons for choosing RM96 are as follows.

1. RM 96 is Consumes Low power and we can run it with the help of battery unless other ham radios require Generators to run them.

2. RM 96 is cost effective and can be is less complex when compared to other ham radios.3. Unless other ham radios the antenna size is low and in our case it is of 2 meters. One may

increase the size of antenna up to 16 meters but with a 2 meter antenna we can communicate over a reasonable area without any difficulties.

As we need to have a Ham License to operate a ham radio we have approached the “Wireless Monitoring Station” Jalandhar. But due to certain complications as per the guidelines of the officer we are using the spectrum for time being and we will appear in Delhi to take the test.

As the RM96 circuit is a bit complex and we can’t find all the Components in PSPICE software we have tried to simulate these circuits in Super Spice Software and we have verified the blocks individually.

4.4 EXPERIMENTAL WORK DONE

4.4.1 RF AMPLIFIER

An RF power amplifier is a type of electronic amplifier used to convert a low-power radio-frequency signal into a larger signal of significant power, typically for RF AMPLIFIER. An RF power amplifier is a type of electronic amplifier used to convert a low-power radio-frequency signal into a larger signal of significant power, typically for driving the antenna of a transmitter. It is usually optimized to have high efficiency, high output Power(P1dB) compression, good return loss on the input and output, good gain, and optimum heat dissipation.

RF Power Amplifiers are used in a wide variety of applications including Wireless Communication, TV transmissions, Radar, and RF heating. The basic techniques for RF power amplification can use classes as A, B, C, D, E, and F, for frequencies ranging from VLF (Very Low Frequency) through Microwave Frequencies. RF Output Power can range from a few mW to MW, depend by application. The introduction of solid-state RF power devices brought the use of lower voltages, higher currents, and relatively low load resistances.

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Most important parameters that defines an RF Power Amplifier are:1. Output Power2. Gain3. Linearity4. Stability5. DC supply voltage6. Efficiency7. RuggednessChoosing the bias points of an RF Power Amplifier can determine the level of performance ultimately possible with that PA. By comparing PA bias approaches, can evaluate the tradeoffs for: Output Power, Efficiency, Linearity, or other parameters for different applications.

The Power Class of the amplification determines the type of bias applied to an RF power transistor.

The Power Amplifier’s Efficiency is a measure of its ability to convert the DC power of the supply into the signal power delivered to the load.

The definition of the efficiency can be represented in an equation form as: or Power Added Efficiency:

Power that is not converted to useful signal is dissipated as heat. Power Amplifiers that has low efficiency have high levels of heat dissipation, which could be a limiting factor in particular design.

In addition to the class of operation, the overall efficiency of a Power Amplifier is affected by factors such as dielectric and conductor losses. First quantify any loss in the circuit, then attempt to minimize it, and finally ensure that the mechanical and thermal design is adequate under all conditions.

4.4.2 IF AMPLIFIER

In communications and electronic engineering, an intermediate frequency (IF) is a frequency to which a carrier frequency is shifted as an intermediate step in transmission or reception.  The intermediate frequency is created by mixing the carrier signal with a local oscillator signal in a process called heterodyning, resulting in a signal at the difference or beat frequency. Intermediate frequencies are used in super heterodyne radio receivers, in which an incoming signal is shifted to an IF for amplification before final detection is done.

Conversion to an intermediate frequency is useful for several reasons. When several stages of filters are used, they can all be set to a fixed frequency, which makes them easier to build and to tune. Lower frequency transistors generally have higher gains so fewer stages are required. It's easier to make sharply selective filters at lower fixed frequencies.

There may be several such stages of intermediate frequency in a super heterodyne receiver; two or three stages are called double or triple conversion.

Reason for using IF

Intermediate frequencies are used for three general reasons. At very high (gigahertz) frequencies, signal processing circuitry performs poorly. Active devices such as transistors cannot deliver

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much amplification. Ordinary Circuits using capacitors and inductors must be replaced with cumbersome high frequency techniques such as strip lines and waveguides. So a high frequency signal is converted to a lower IF for more convenient processing. For example, in satellite television receivers, converting the microwave downlink signal to a much lower intermediate frequency at the dish allows a relatively inexpensive coaxial cable to carry the signal to the rest of the receiver inside the building.

A second reason, in receivers that can be tuned to different frequencies, is to convert the various different frequencies of the stations to a common frequency for processing. It is difficult to build amplifiers, filters, and detectors that can be tuned to different frequencies, but easy to build tunable oscillators. Super heterodyne receivers tune in different frequencies by adjusting the frequency of the local oscillator on the input stage, and all processing after that is done at the same fixed frequency, the IF. Without using an IF, all the complicated filters and detectors in a radio or television would have to be tuned in unison each time the frequency was changed, as was necessary in the early tuned radio frequency receivers.

The main reason for using an intermediate frequency is to improve frequency selectivity. In communication circuits, a very common task is to separate out or extract signals or components of a signal that are close together in frequency. This is called filtering. Some examples are, picking up a radio station among several that are close in frequency, or extracting the chrominance subcarrier from a TV signal. With all known filtering techniques the filter's bandwidth increases proportionately with the frequency. So a narrower bandwidth and more selectivity can be achieved by converting the signal to a lower IF and performing the filtering at that frequency.

4.4.3 MIXER

In electronics a mixer or frequency mixer is a nonlinear electrical circuit that creates new frequencies from two signals applied to it. In its most common application, two signals at frequencies f1 and f2 are applied to a mixer, and it produces new signals at the sum f1 + f2 and difference f1 - f2 of the original frequencies. Other frequency components may also be produced in a practical frequency mixer.

Mixers are widely used to shift signals from one frequency range to another, a process known as heterodyning, for convenience in transmission or further signal processing. For example, a key component of a super heterodyne receiver is a mixer used to move received signals to a common intermediate frequency. Frequency mixers are also used to modulate a carrier frequency in radio transmitters.

TYPES OF MIXER

Passive mixers use one or more diodes and rely on the non-linear relation between voltage and current to provide the multiplying element. In a passive mixer, the desired output signal is always of lower power than the input signals.

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Active mixers can increase the strength of the product signal. Active mixers improve isolation between the ports, but may have higher noise and more power consumption; an active mixer can be less tolerant of overload.

Mixers may be built of discrete components, may be part of integrated circuits, or can be delivered as hybrid modules.

Fig 4.1 Schematic diagram of a double-balanced passive diode mixer.

.Mixers may also be classified by their topology.

Unbalanced mixers allow some of both input signals to pass through to the output.

A single balanced mixer is arranged so that either the local oscillator (LO) or signal input (RF) is suppressed at the output, but not both.

A double balanced mixer has symmetrical paths for both inputs, so that neither input signal appears at the output, only the product (IF) signal. 

Double balanced mixers are more complex and require higher drive levels than unbalanced and single balanced designs. Selection of a mixer type is a trade off for a particular application. Mixer circuits are characterized by conversion gain, and noise figure.

4.4.4 BALANCED MODULATOR

A balanced modulator mixes the audio signal and the radio frequency carrier, but suppresses the carrier, leaving only the sidebands. The output from the balanced modulator is a double sideband suppressed carrier signal and it contains all the information that the AM signal has, but without the carrier. It is possible to generate an AM signal by taking the output from the balanced modulator and reinserting the carrier.

In a balanced modulator two audio signals are processed to create the sum of the two frequencies with the difference of the two frequencies called the upper and lower sidebands. USB = f1 + f2 LSB = f1 - f2

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Two frequencies of 1000 Hz and 100 Hz are input to the module. So the resultant output frequencies will be:

USB = 1000 Hz + 100 Hz = 1100 HzLSB = 1000 Hz - 100 Hz = 900 Hz

Notice that the two input frequencies have disappeared. This is true with only sinusoidal (pure fundamental) waveform inputs when the recover carrier control is fully counter-clockwise. When inputs of complex harmonic structure are used the individual component frequencies are processed to create sums and differences of the component frequencies. This creates many upper and lower sideband frequencies that will be predictable ( as in the case of sine and square wave signals) or unpredictable (guitar and violin modulated together). The module will also serve as an amplitude modulator. In amplitude modulation the carrier signal does not get lost (suppressed) in the modulation process. Mathematically expressed:

F1, (f1 + f2 ) , ( f1 - f2 )Once again two frequencies of 1000 Hz (carrier) and 100 Hz (modulation) are processed with the module when the recover carrier control is rotated clockwise. This produces the carrier frequency (1000 Hz), the lower sideband (900 Hz) and the upper side band (1100 Hz) at the output. The recovery control may be used to vary the amount of the carrier signal injected into the output creating an increasingly chromatic sounding output.

4.4.5 TRANSMITTER

In electronics and telecommunications a transmitter or radio transmitter is an electronic device which produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves. In addition to their use in broadcasting, transmitters are necessary component parts of many electronic devices that communicate by radio, such as cell phones, wireless computer networks, Bluetooth enabled devices, garage door openers, two-way radios in aircraft, ships, and spacecraft, radar sets, and navigational beacons. The term transmitter is usually limited to equipment that generates radio waves for communication purposes; or radiolocation, such as radar and navigational transmitters. Generators of radio waves for heating or industrial purposes, such as microwave ovens or diathermy equipment, are not usually called transmitters even though they often have similar circuits.

The term is popularly used more specifically to refer to a broadcast transmitter, a transmitter used in broadcasting, as in FM radio transmitter or television transmitter. This usage usually includes both the transmitter proper, the antenna, and often the building it is housed in.An unrelated use of the term is in industrial process control, where a "transmitter" is a telemetry device which converts measurements from a sensor into a signal, and sends it, usually via wires, to be received by some display or control device located a distance away.

The purpose of most transmitters is radio communication of information over a distance. The information is provided to the transmitter in the form of an electronic signal, such as an audio (sound) signal from a microphone, a video (TV) signal from a video camera, or in wireless networking devices a digital signal from a computer.

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4.4.6 RECEIVER

In radio communications, a radio receiver is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an  antenna. The antenna intercepts radio waves (electromagnetic waves) and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the wanted radio frequency signal from all other signals, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation. The information produced by the receiver may be in the form of sound (an audio signal), images (a video signal) or data (a digital signal).  A radio receiver may be a separate piece of electronic equipment, or an electronic circuit within another device. Devices that contain radio receivers include television sets, radar equipment, two-way radios, cell phones, wireless computer networks, GPS navigation devices, satellite dishes, radio telescopes, bluetooth enabled devices, garage door openers, and baby monitors.

4.4.7 VARIABLE FREQUENCY OSCILLATOR

A variable frequency oscillator (VFO) in electronics is an oscillator whose frequency can be tuned (i.e. varied) over some range. It is a necessary component in any tunable radio receiver or transmitter that works by the super heterodyne principle, and controls the frequency to which the apparatus is tuned. In a simple superhet radio receiver, the incoming radio frequency signal (at frequency  ) from the antenna is mixed with the VFO output signal tuned to  , producing an intermediate frequency (IF) signal that can be processed downstream to extract the modulated information. The IF signal frequency is chosen to be either the sum of the two frequencies at the mixer inputs (up-conversion),   or more commonly, the difference frequency (down-conversion),  , depending on the receiver design.

In addition to the desired IF signal and its unwanted image (the mixing product of opposite sign above), the mixer output will also contain the two original frequencies,   and   and various harmonic combinations of the input signals. These undesired signals are rejected by the IF filter. If a double balanced mixer is employed, the input signals appearing at the mixer outputs are greatly attenuated, reducing the required complexity of the IF filter.

The advantage of using a VFO as a hetrodyning oscillator is that only a small portion of the radio receiver (the sections before the mixer such as the preamplifier) need to have a wide bandwidth. The rest of the receiver can be finely tuned to the IF frequency.

In a direct-conversion receiver, the VFO is tuned to the same frequency as the incoming radio frequency and   Hz. Demodulation takes place at baseband using low-pass filters and amplifiers.

In a radio frequency (RF) transmitter, VFOs are often used to tune the frequency of the output signal, often indirectly through a hetrodyning process similar to that described above. Other uses include chirp generators for radar systems where the VFO is swept rapidly through a range of

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frequencies, timing signal generation for oscilloscopes and time domain reflectometers, and variable frequency audio generators used in musical instruments and audio test equipment.

4.4.8 ANTENNA

A Simple 2 m/70 cm Vertical Dipole Antenna 

This easy to build dual band VHF/UHF antenna makes a great project for the new ham that is ready to get on the 2 meter and 70 centimeter amateur radio bands. It can be mounted on a roof top for use as a fixed antenna and it also folds conveniently for travel making it an excellent backpack antenna. The design is simple and so is construction.

The antenna elements are made of 1/8" diameter stainless steel rod. Each rod is bent into a tight "U" shape and fastened to the acrylic plexi glass boom with stainless steel hardware. Flat washers large enough to fit across the gap in each element are used to hold the elements in place. A piece of 1/4" thick cast acrylic plexiglass, 18" long and 2-1/2" wide, is used for the boom.

Drill the holes in the boom as shown in the diagram. The position and hole size for the mast mounting clamp is determined by the size and width of the clamp or U-bolt that you use. I used a TV antenna mast clamp that fits a 1-1/4" mast.

Fig 4.2 2m/70cm VERTICAL DIPOLE ANTENNA

Probably the hardest part in making this antenna is bending the stainless steel rod. But the rod can be bent without heating it first with a torch. I was able to bend the rod by placing it in a bench vise. The tricky part is to bend two pieces of rod that come out looking similar is shape. Use two pieces of stainless steel rod that are longer than needed then trim them to correct lengths after the rod has been folded into a U shape. Make each element section as shown in the next diagram.

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Fig 4.3 2m/70cm ANTENNA SPECIFICATIONS

The hardware for mounting the antenna elements to the boom is also used to connect the feed line to the antenna. The coaxial cable center and shield are separated and the leads kept as short as possible. Crimp-on ring connectors, with the plastic insulation removed, are soldered to the ends of the cable. The coaxial cable center lead is connected to the top section and the shield is connected to the bottom section of the antenna. This antenna was fed with RG-8X (Mini 8) 50 ohm coaxial cable. The feed line used was a random length and was not cut to any specific length.

 TUNING THE ANTENNA

To tune the antenna for minimum SWR simply loosen the wing nuts and slide the antenna elements in or out as needed. Keep in mind that changes made to one band will affect the other band. For example if you shorten the 2 meter length then you also shorten the 70 cm length. Some fine tuning by again trimming either the 2 meter or 70 cm sections may be done if desired but this should not be needed.

PARTS LISTS

All stainless steel element mounting hardware. Use larger size hardware if flat washers do not extend across both sides of the antenna element.

2 each 1/8" Stainless steel rod, 3' (.9 m) long.

Acrylic Plexiglass, 18" x 2-1/2" x 1/4" (45.7 cm x 6.4 cm x 7 mm).

2 each #6 x 32 x 1" (25 mm) Machine screws.

2 each #6 x 32 Wing nuts.

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4 each #6 Large flat washers.

2 each #6 Split lock washers.

2 each #6 External tooth lock washers.

2 each #6 Crimp-on ring connectors.

Mast mount clamp.

Plastic cable tie or small U-bolt.

4.5 SOFTWARE IMPLEMENTATION:

SPICE is a general-purpose circuit simulation program for nonlinear dc, nonlinear transient, and linear ac analyses. Circuits may contain resistors, capacitors, inductors, mutual inductors, independent voltage and current sources, four types of dependent sources, lossless and lossy transmission lines (two separate implementations), switches, uniform distributed RC lines, and the five most common semiconductor devices: diodes, BJTs, JFETs, MESFETs, and MOSFETs.The SPICE3 version is based directly on SPICE 2G.6. While SPICE3 is being developed to include new features, it continues to support those capabilities and models which remain in extensive use in the SPICE2 program.

4.5.1 AUTOMATIC GAIN CONTROL

FIG 4.4 AUTOMATIC GAIL CONTROL

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FIG 4.5 OUTPUT OF AGC

4.5.2 MIXER:

FIGURE 4.6 IMPLEMENTATION OF MIXER

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FIG 4.7 OUTPUT OF MIXER

4.5.3 OSCILLATOR

FIG 4.8 IMPLEMENTATION OF OSCILLATOR

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FIG 4.9 OUTPUT OF OSCILLATOR

4.5.4 BALANCED FREQUENCY OSCILLATOR

FIG 4.10 IMPLEMENTATION OF BFO

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FIG 4.11 OUTPUT OF BFO

4.5.5 SSB FILTER

FIG 4.12 IMPLEMENTATION OF SSB FILTER

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FIG 4.13 OUTPUT OF SSB FILTER

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CONCLUSIONS

1. Amateur radio in India is still under developed.

2. So that it still has space to develop and it is developing with its highest speed than ever.

3. It is very important to simulate all circuits before working on PCB

4. it is important to have keen knowledge about different ham radios before selecting one.

5. Government should take necessary steps to spread awareness regarding Ham Radio and its working in coastal areas as it might remain only way for communication in times of disasters.

6. By implementing ham radio we have gained knowledge about how communication system really works.

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BIBILOGRAPHY

1. Harishankar, VU3NSH (HAM CALL SIGN)

2. S. Rama Mohan Rao ,VU2RM (HAM CALL SIGN)

3. "What is Ham Radio?". ARRL.org. Archived from the original on 4 May 2010. (http://www.arrl.org/what-is-ham-radio-1)

4. Gernsback, H (May 1909) (PDF). First Annual Official Wireless Blue Book of the Wireless Association of America. New York: Modern Electrics Publication. (http://www.seas.upenn.edu/~uparc/documents/First%20Annual%20Official%20Wireless%20Blue%20Book%20-%201909.pdf)

5. "FCC.gov, About Amateur Stations ''They design, construct, modify, and repair their stations. The FCC equipment authorization program does not generally apply to amateur station transmitters. ''". Wireless.fcc.gov. 2002-02-19.( http://wireless.fcc.gov/services/index.htm?job=about&id=amateur)

6. Haag, Jerry. "Principles of Amateur Radio Net Control". SCC-AREA-RACES.org.http://www.scc-ares-races.org/mtnview/principles-of-net-control.html

7. Sumner, David (August, 2011). "How Many Hams?". QST (American Radio Relay League)

8. "Amateur and Amateur-satellite service". International Telecommunication Union.Archived from the original on 22 August 2010. http://life.itu.int/radioclub/ars.html

9. Wilson, Mark J; Reed, Dana G (2006). The ARRL Handbook for Radio Communications 2007 (84th ed.). Newington, CT: American Radio Relay League.

10. "'Inventor of IC "chip", Nobel Prize Winner Jack S. Kilby Credits Amateur Radio for His Start in Electronics.''". Nobelprize.org. 2005-06-20.http://nobelprize.org/nobel_prizes/physics/laureates/2000/kilby-autobio.html

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