Thank you,

Thank you,
FREEDOM FIGHTERS FOR AMERICA
"FIGHTING FOR FREEDOM AND LIBERTY" http://www.freedomfightersforamerica.com
10-3-1012
Chris Zucker,Pres.FREEDOM FIGHTERS FOR AMERICA
Is interviewed by Nick Spinner of Electronic Harassment/ organized stalking on Talk shoe
channel # 97862
Chris speaks on targeting issues that people under the govt-mob assasination program
are experiencing , and the subject of the new world order in the targeting system
.http://recordings.talkshoe.com/TC-97862/TS-673423.mp3
1:15mins
AgoraVox : http://www.agoravox.fr/tribune-libre/article/ce-que-les-sectes-revelent-de-23464
Républicain lorrain : http://www.republicain-lorrain.fr/france-monde/2012/09/04/fenech-les-sectes-ont-infiltre-les-lieux-de-pouvoir
Le Point.fr : "Les grandes sectes noyautent les institutions" http://www.lepoint.fr/societe/les-grandes-sectes-noyautent-les-institutions-02-10-2012-1512514_23.php
I miss her very much.
I miss her very much. http://www.komonews.com/news/local/124085174.html#idc-container
<iframe width="640" height="360" src="https://www.youtube.com/embed/DNFy2xFPMIo?feature=player_embedded" frameborder="0" allowfullscreen></iframe>
<iframe width="640" height="360" src="https://www.youtube.com/embed/iU-8VV3aRnw?feature=player_embedded" frameborder="0" allowfullscreen></iframe>
It is normal dream; or, it is telepathy?( Part 2- Scenario 3 )
If this is a real telepathy and if don’t stop it, I will disclose more serious telepathy. So, we can understand how these torturers are not only atrocious but paranoid.
When I fall asleep,
Scenario 1:
One voice was heard with a question in Chinese:
Question:
Why didn’t you become a citizen?
My answer:
After settling this torture case.
Scenario 2:
My eyes were guided to the top view of one complicated mechanical drawing, with left view missing ( without left view) . And, one voice was heard with 2 questions in Chinese:
Question A:
What is this?
My answer:
Top view.
Question B:
What is missing?
My answer:
Left view.
Scenario 3:
A portrait of Chinese former Top Leader Ding Xiao Ping’s was standing and facing me. The voice was heard with one question :
Question:
What level of officer are you now?
My answer:
Middle level ( My answer was totally wrong.)
Hi guys I am wondering if anybody here tried standing near a tesla coil and if anybody has had any experience with Neodymium Magnets I ask this because I am planning to go to the Ontario science centre in Toronto and see a tesla coil demonstration however since I know little about tesla coils and I am going to be in the audience not to near the tesla coil, I don't know if distance would effect my situation.Also with regard to neodymium magnets there is a store in Oakville Ontario that specializes in magnets and I am thinking of travelling there. So any advice would be nice.
Greetings & Blessings
Here is a list of Holy Prayers & Invocations.
I recommend printing this page.
May you find inspiration from this.
∑
Esta Lior
000.
### 444.111. Invocation of the Soul and Monadic Mantrum . Invocation of the Great Invocation 222. Short Version of the Great Invocation 333. Long Version of the Great Invocation 555. The Lord's Prayer 666. Prayer of St. Francis' 777. Traditional Rosary 888. A New Age Rosary 999. The Affirmation of the Disciple ### Written by Dr Joshua David Stone, Posted in Ascension Classes {taken from 'How to Open and Close Each Class Session' http://iamuniversity.org/how-to-open-and-close-each-class-session/}
Invocation of the Soul and Monadic Mantrum
The soul mantrum was brought forth to the Earth through the channelings of Alice Bailey of the Ascended Master Djwhal Khul. In my personal opinion it is one of the most profound mantrums on the entire planet and should be recited every time spiritual work of some kind is about to be ignited. The original soul mantrum goes as follows: I am the Soul, I am the Light Divine, I am Love, I am Will, I am Fixed Design. x3 Since most of you, my beloved readers, have already passed your fourth initiation it is appropriate to change the Soul mantrum to the Monadic mantrum which is the updated version. It is the same as the Soul mantrum but instead of saying, “I am the Soul,” you say, “I am the Monad.”
I am the Monad, I am the Light Divine, I am Love, I am Will, I am Fixed Design. x3 Actually I recommend that you say both of them. First the Soul mantrum and then the Monadic mantrum. The saying of these mantrums will ignite your Higher Self and Mighty I Am Presence (Monad) into action. “Try it, you’ll like it!”
Invocation of the Great InvocationThe next step of the class is to have printed out in advance copies of the Great Invocation which is a prayer that was brought forth by Lord Maitreya, the Planetary Christ, around 1945 or 1950. It is one of the most powerful prayers that has ever been given forth to light workers and the New Group of World Servers. I am first going to give it to you in the short version, and then I am going to give you the longer version. I recommend doing the short version for most of your classes, however on special holidays or Holy days I recommend doing the longer version. Short Version of the Great InvocationFrom the point of Light within the Mind of God Let Light stream forth into the minds of men. Let Light descend on Earth. From the point of Love within the Heart of God Let Love stream forth into the hearts of men. May Christ return to Earth. From the center where the Will of God is known Let purpose guide the little wills of men - The purpose which the Masters know and serve. From the center which we call the race of men Let the Plan of Love and Light work out And may it seal the door where evil dwells. Let Light and Love and Power restore the Plan on Earth. What I would recommend is that you either photocopy this page or type it up on your computer and have this available with the Soul and Monadic mantrum and possibly some other prayers that I am going to suggest in the coming pages.
Long Version of the Great Invocation
Let the Forces of Light bring illumination to mankind Let the Spirit of Peace be spread abroad May men of goodwill everywhere meet in a spirit of cooperation May forgiveness on the part of all men be the keynote at this time Let power attend the efforts of the Great Ones So let it be, and help us to do our part. Let the Lords of Liberation issue forth Let Them bring succor to the sons of men Let the Rider from the Secret Place come forth, And coming, save Come forth, O Mighty One. Let the souls of men awaken to the Light, And may they stand with massed intent Let the fiat of the Lord go forth The end of woe has come! Come forth, O Mighty One The hour of service of the Saving Force has now arrived Let it be spread abroad, O Mighty One. Let Light and Love and Power and Death Fulfill the purpose of the Coming One The will to save is here The love to carry forth the work is widely spread abroad The active aid of all who know the truth is also here Come forth, O Mighty One and blend these three. Construct a great defending wall The rule of evil now must end. From the point of Light within the Mind of God Let Light stream forth into the minds of men. Let Light descend on Earth. From the point of Love within the Heart of God Let Love stream forth into the hearts of men. May Christ return to Earth. From the center where the Will of God is known Let purpose guide the little wills of men - The purpose which the Masters know and serve. From the center which we call the race of men Let the Plan of Love and Light work out. And may it seal the door where evil dwells. Let Light and Love and Power restore the Plan on Earth.
The Lord's Prayer
Our Father, Who art in heaven, Hallowed be Thy Name. Thy Kingdom Come, Thy Will be done on Earth as it is in Heaven. Give us this day our daily bread, and forgive us our debts as we forgive our debtors. And lead us not into temptation, but deliver us from evil. For Thine is the Kingdom and the Power and the Glory, for ever. Amen.
Prayer of St. Francis
LORD, make me an instrument of Your peace. Where there is hatred, let me sow love. Where there is injury, pardon; where there is doubt, faith; where there is despair, hope; where there is darkness, light; and where there is sadness, joy. DIVINE MASTER, grant that I may not so much seek to be consoled as to console; to be understood as to understand; to be loved as to love; for it is in giving that we receive; it is in pardoning that we are pardoned; and it is in dying that we are born to eternal life.
Traditional Rosary
In the name of the Father and the Son and of the Holy Spirit. Amen. I Believe in God, the Father Almighty, Creator of Heaven and Earth; and in Jesus Christ, His only Son, our Lord; who was conceived by the Holy Spirit, born of the Virgin Mary, suffered under Pontius Pilate, was crucified, died, and was buried. He descended into hell; the third day He arose again from the dead; He ascended into heaven, to sitteth at the right hand of God the Father Almighty; from thence He shall come to judge the living and the dead. I believe in the Holy Spirit, the Holy Catholic Church, the communion of Saints, the forgiveness of sins, the resurrection of the body, and life everlasting. Amen. Our Father, who art in Heaven, hallowed by Thy name. Thy kingdom come. Thy will be done on Earth as it is in heaven. Give us this day our daily bread and forgive us our trespasses as we forgive those who trespass against us. And lead us not into temptation, but deliver us from evil. Amen. Hail Mary, full of grace; the Lord is with thee. Blessed art thou among women, and blessed is the fruit of thy womb, Jesus. Holy Mary, Mother of God, pray for us sinners, now and at the hour of our death. Amen. Glory be to the Father and to the Son and to the Holy Spirit; as it was in the beginning, is now, and ever shall be, world without end. Amen. Hail, holy Queen, Mother of Mercy! Our life, our sweetness, and our hope! To thee do we cry, poor banished children of Eve; to thee do we send up our signs, mourning, and weeping in this valley of tears. Turn, then, most gracious Advocate, thine eyes of mercy toward us; and after this our exile show unto us the blessed fruit of thy womb, Jesus; O clement, O loving, O sweet Virgin Mary. Pray for us, O holy Mother of God. That we may be made worthy of the promises of Christ. O God, whose only begotten Son, by His life, death, and resurrection has purchased for us the rewards of eternal life, Grant, we beseech Thee, that meditating upon these mysteries in the most Holy Rosary of the Blessed Virgin Mary, we may imitate what they contain, and obtain what they promise; through the same Christ our Lord. Amen.
A New Age Rosary
First make the sign of the cross five times, honoring our Lord’s five wounds. Sorrowful and Immaculate Heart of Mary, pray for us who see refuge in thee. Holy Mother, save us through your Immaculate Heart’s Flame of Love. At the end, hold the cross and say three times: Glory be to the Father and to the Son and to the Holy Spirit; as it was in the beginning, is now, and ever shall be, world without end. Amen. Close the rosary by saying: Mother of God, send down your grace through your Immaculate Heart’s Flame of Love to the whole human race, now and at the hour of our death. Eternal Father-Mother God, I offer you the Body and Blood the Soul and Divinity of your dearly beloved Son, Our Lord Jesus Christ, in atonement for our sins and the sins of the whole world. For the sake of his most sorrowful Passion, have mercy on us and the whole world. Holy God, Holy Omnipotent One, Holy Immortal One, have mercy on us and on the whole world.
This Rosary is from Earlyne Chaney’s A Book of Prophecy. The Affirmation of the DiscipleI am a point of light within a greater light I am a strand of loving energy within the stream of love divine. I am a point of sacrificial fire, focused within the fiery will of God and thus I stand. I am a way by which men may achieve. I am a source of strength enabling them to stand. I am a beam of light, shining upon their way, and thus I stand. And standing thus, revolve and treat this way, the ways of men, And know the ways of God. And thus I stand.
I strive toward understanding. Let wisdom take the place of knowledge in my life. I strive towards cooperation. Let the master of my life, the soul, and likewise the one I seek to serve, throw light through me on others.
In the center of the Will of God I stand. Naught shall deflect my will from His. I implement that will by love. I turn towards the field of service. I, the triangle divine, work out that will within the square, and serve my fellow men.
I am a messenger of Light. I am a pilgrim on the way of Love. I do not walk alone, but know myself as one with all great souls, and one with them in service. Their strength is mine. This strength I claim. My strength is theirs and this I freely give. A soul, I walk on earth, I represent the One.
I am one with my group of brothers, and all that I have is theirs. May the love which is in my soul pour forth to them. May the strength which is in me lift and aid them. May the thoughts which my soul creates reach and encourage them.
I know the law, and towards the goal I strive. Naught shall arrest my progress on the way. Each tiny life within my form responds. My soul has sounded forth that call, and clearer day by day it sounds.
The glamour holds me not. The path of light streams clear ahead. My plea goes forth to reach the hearts of men. I seek, I try to serve your need. Give me your hand and tread the path with me.
The sons of men are one and I am one with them. I seek to love not hate. I seek to serve and not exact due service. I seek to heal not hurt. Let Pain bring due reward of light and love. Let the soul control the outer form and life, and all events, and bring to light the love which underlies the happenings of the time. Let vision come and insight. Let the future stand revealed. Let inner union demonstrate and outer cleavages be gone. Let love prevail. Let all men love. We know, oh Lord, of life and love, about the need. Touch our hearts anew with love, that we too may love and give.
This affirmation is from Alice Bailey's Ponder On This
§§§
I Am The True Vine Niv Sefatayim
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summa cum laude Mantras and Power Names of GOD That Can Also Be Used in Your ClassesWritten by Dr Joshua David Stone, Posted in Ascension Classes The following list of mantras and power names of GOD I have placed in this book so you, my beloved readers, can have easy access to them, and can utilize this material in your classes if you like. Chanting or repeating the names of GOD is one of the most powerful tools of spiritual growth and spiritual attunement that is available to us. I have enclosed the names of GOD, mantras and words of power of all religions for you to use at your discretion.
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Judy Satori | PO Box 339 | Naples | NY | 1451 |
These torturers torture me , murder me, commit crimes against humanity to me, who have no interests in politics ,who have no political inclination, and who is so naïve to believe they will listen to what I have explained. So, we can see how atrocious they are.
We must think about one important question :
If UN Committee Against Torture concludes they commit acts of torture, what shall I/we do?
Meanwhile, pay attention to some fake victims want to destroy our process ! Many times and many people have found them and their absurd acts.
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In 2012 Jesse Beltran & Lars Drudgaard, founded the ‘International Center Against Abuse of Covert Technologies’ to bring awareness to the general public and the legal systems around the world in regards to serious human rights abuses utilising…
Remote Influencing Technologies.
The invisible – Hidden dangers and usage of theseTechnologies in and around your Home & Neighbourhood.
Often used covertly as Invisible Weapons against YOU!
Organised Crime of Covert Electronic Assault - NZ - Booklet - Public Awareness
Informative Links - that go with the Booklet
http://www.organised-crime-of-covert-electronic-assault-nz.com/informative-links.html
Free E-Book. NOTE: Special thanks to the victims (current & fallen), researchers & honest professionals that have shared their stories and research over the years... Without YOU - This booklet could not have been written - The Author (pseudonym) Wendy Newman
I'm still living in Munich and recently encountered frequent security system beeping at the stores. It started about the beginning of this Month, and it was only beeping at the entrance or at the exit. It started right after the day I went to Karstadt and bought a box of chocolate and dropped my mechanical pen after paying at the cashier. I put the pen in my bag after a woman stood near the cashier pointing me where my pen dropped. The first beeping was at Karstadt in Münchener Freiheit where I visited the supermarket inside. At that time, there was a family with a baby cart going out in the same entrance and I thought they got alarm beeped. Right after visiting Karstadt, I went to DM, a drugstore, near by and after paying at the cashier, the alarm beeped. I bought a pack of toilet paper quickly and that was so strange to find the beeping happened. I tried twice and twice beeped. At the third time, I filmed. At that time, the beeping did not happen. That is on the video GSA 11.
Few days ago, the beeping happened at the entrance of DM in Karlsplatz and at that point, the cashier asked me in English to check my bag. This time, I filmed the beeping at the entrance and as well as the conversation at the cashier. She said that my netbook was the problem. Somehow, the alarm beeped while nothing was around and even the woman after me at the cashier line passed, the alarm beeped. These incidents I recorded in GSA 11 film.
Here is the GSA film link.
http://videobam.com/zGsbn
Few days ago, I went to Tengelmann, a supermarket, at Karlsplatz. At the entrance, the security alarm did not beep but at the cashier it beeped. And at this time, a man came and he opened my bag but he did not do anything. So far, someone checked my bag twice at two different stores in one week. I've been in Munich for few months, but it never happened at all. And here is the video.
http://videobam.com/wlrOW
On Friday, Sep 28, I went to Karstadt at München main train station and I checked the alarms around. This time, I found the one near the S-Bahn station beeped. I entered and went through to another entrance on SW. That one did not beep. Later, I checked ther two security checkpoints and they did not beep. I have no idea how that happened but only one security alarm beeped. From these video, I can prove that I'm not the shoplifter but there are something wrong with the security alarms in the stores in Munich. I thought these evidences are quite interesting for your research as not so many people are claimed as shoplifters in such a strange way.
http://videobam.com/xoWHV
By the way, when I lived in Sarajevo, I experienced the baby pigeons dying one by one at the hostel, Srca Sarajevo. I tried to keep them in safe place, but they died in very short time. One occassion, one black baby pigeon died in less than few hours. It was normal, but suddenly get sick and died. I filmed how it died and later brought the body to the vet. department of Uni Sarajevo. The autopsy in English shows that they could not find the actual cause of death.
http://videobam.com/evgDX
There used to be police cars and Feurwehr cars and amburances frequently showing up on the street. But nowadays, it stopped for awhile.
I found the BlocBag to be one of the most reasonable priced screening to purchase. It is a great investment for any T.I. because the BlocBag is "Portable"! :) You can take it with you anywhere you go. It also has a see through and breathable head cover attached to it to protect your head as well while you sleep. Here is the link below, check it out;
http://www.emfields.org/shielding/overview.asp
T.S. egy
|=---------------------=[ The basics of Radio ]=-------------------------=| |=-----------------------------------------------------------------------=| |=------------------=[ shaun2k2 <shaun at rsc dot cx> ]=----------------=| 0 - Introduction 0.1 - Technical Terms 1 - Radio Basics 1.1 - Radio Waves 1.2 - Carrier 1.3 - (RF) Frequency Bands 1.4 - Wavelength 1.5 - Transmission 1.6 - Receiving 2 - AM Radio 2.1 - What is AM Radio? 2.2 - Modulation 2.3 - Demodulation 2.4 - Circuits 2.4.1 - Receivers 2.4.2 - Transmitters 3 - FM Radio 3.1 - What is FM radio? 3.2 - Modulation 3.3 - Demodulation 3.4 - Circuits 4 - Misc 4.1 - Pirate Radio 4.2 - Wireless Telephone Tapping 4.3 - Jamming 5 - Conclusion 6 - Bibliography --[ 0 - Introduction Ever since our discovery of radio, in around 1902, we have proceeded to utilise it for many different purposes -- from sending others short messages, to transmitting large and critical data sequences to other computer systems. As time has gone on, as useful a technology as radio is, it is barely noticed anymore. When most people think of 'radio', they picture a small black device sitting in their car, which they will use to listen to their local radio stations during car journeys. On the other hand, very few people realise the true usefullness of radio, often forgetting that their cellphones, televisions, satellite TV and alarm systems all too use radio to complete their task on a very regular medium -- radio is not just that boring old thing gathering dust in the corner. This article is divided up into four parts. The first part describes the basic theory of radio, and examples to illustrate some of the common day uses of it. In parts two and three, AM and FM radio details are outlined showing various different circuits to illustrate how these principles can be applied to real-life, functioning circuits. Section four is a misc. section, presenting some miscellaneous interesting points. Some electronics knowledge is useful in radio, though not totally necessary. Most circuits presented here are quite rough, and can be greatly improved upon in many ways. ----[ 0.1 - Technical Terms Below is a description of technical terms used throughout the article: RF -- Any frequency within the radio spectrum, which can be used by to transmit and receive radio signals. Modulation -- A technique used to package data into a radio signal which is of use to the destination radio receiver. AM -- Amplitude Modulation. This involves shifting the amplitude of a radio signal's carrier very slightly in sympathy with a modulating signal. FM -- Frequency Modulation. FM modulation involves shifting the frequency of a radio wave's carrier very slightly in sympathy with a modulating signal. Receiver -- Any device which is capable of receiving radio signals sent by a radio transmitter. Transmitter -- A device which can transmit radio waves into the surrounding environment. Aerial -- A medium to large piece of wire which is used by either a radio transmitter or receiver to propagate or detect an incoming radio signal. In a radio receiver or transmitter, an aerial acts as one plate of a capacitor, whilst the other plate is taken place by the Earth. Antenna -- See aerial. Wireless -- Refers to any technology which communicates data without the need for a wired connection. Most wireless devices, such as cell phones, televisions, and others use radio, but several do use technologies such as infrared, which is not covered here. Radio wave -- A radio wave is an 'electromagnetic' wave, most commonly containing data to be received by a remote radio receiver. Oscillator -- Refers to an electronic circuit which 'oscillates', or 'vibrates', to complete a certain task. Oscillators are used in radio to transmit radio waves at a given frequency -- the rate at which the oscillator oscillates is the RF (see RF) at which the wave is transmitted. Common oscillator circuits, also used in this paper, are LC oscillator circuits, and crystal-controlled oscillators. Crystal-controlled oscillator -- An oscillator circuit whos oscillation frequency is controlled by a 'crystal'. See oscillator. LCoscillator -- An oscillator consisting of a capacitor and an inductor, whos frequency of oscillation is controlled directly by the capacitor, which is usually variable. See oscillator. Capacitor -- Device which stores current as an electrical field. Broadcast -- A term used to describe transmitting radio waves into the atmosphere. Wavelength -- The physical distance between two waves on the same frequency, transmitted successively. Bands -- Frequency Bands are a range of frequencies used interchangeably or commonly for the same type of technology. For example, televisions often use the VHF band. Frequency -- Number of cycles per seconds. Frequency can be used to describe how often an oscillator oscillates. Sidebands -- When modulation of a carrier is applied, two extra bands are generated, both slightly higher and lower than the carrier frequency, equating from the 'sum and difference' of the carrier and audio frequency. These two bands appear at either end of the RF carrier, hence the term 'sidebands'. --[ 1 - Radio Basics ----[ 1.1 - Radio Waves Radio waves, otherwise referred to as 'radio signals', are simply electromagnetic waves. Radio waves are transmitted by devices called 'radio transmitters' or 'transmitters' for short. Despite our wide and many uses for radio waves as a whole, we actually known very little about 'radio'. We do know, however, that radio waves are a form of energy, which act exactly like they have been propagated as any other type of wave we know of. For example, an audio wave. Radio waves are made up of three things; an electric field, a direction, and a magnetic field. Despite our underlying ignorance of radio and its properties, we can predict and use its properties to our advantage to undergo a wide variety of different tasks -- and will probably do so for a long time to come. ----[ 1.2 - Carrier An 'RF carrier' can be thought of as the part of the radio wave which can be modulated to 'carry' a data signal. An analogy to help with understanding this is to think of turning on a flashlight and pointing it towards a wall. The light which is seen on the wall is the 'carrier'. Before and without modulation, the carrier of a radio wave contains no data, and just contains peaks of an RF voltage. peak voltage ||\\ ///\ //\\ || \\ // \\ // \\ || \\\/ \\\/ \\ RF carrier Because sending radio waves with a carrier containing no data would be almost useless, a carrier is 'modulated' to contain data. There are various modulation schemes in wide use, but the two most common schemes are AM (Amplitude Modulation) and FM (Frequency Modulation). These are discussed later. ----[ 1.3 - (RF) Frequency Bands As we can gather from listening to a variety of radio stations, different forms of technology use an entirely different 'band' of radio frequencies on which to send and receive their radio signals. The entire range in which radio signals are transmitted extends from around 30KHz, up to about 30GHz. This whole range of available RFs (Radio Frequencies) is known as the 'radio spectrum'. The radio spectrum's range of frequencies, and their concurrent uses are shown in the below table. +-------------------+----------------------------+---------------------+ | Frequency | Uses | Name | +-------------------+----------------------------+---------------------+ | 30KHz-300KHz | Long-wave radio, useful | Low Frequency (L.F) | | | for long distance | | | | communications | | +-------------------+----------------------------+---------------------+ | 300KHz-3MHz | Medium wave, local radio | Medium Freq (M.F) | | | distant radio stations | | +-------------------+----------------------------+---------------------+ | 3MHz-30MHz | Short wave radio | High (H.F) | | | Communications | | | | Amateur radio | | +-------------------+----------------------------+---------------------+ | 30MHz-300MHz | FM Radio | Very High (V.H.F) | | | Police radio | | | | Meteorology Comms | | +-------------------+----------------------------+---------------------+ | 300MHz-3GHz | Air Traffic Control | Ultra High (U.H.F) | | | TV | | +-------------------+----------------------------+---------------------+ | 3GHz-30GHz | Radar Comms | Microwaves (S.H.F) | | | Satellites | | | | Telecommunications (TV & | | | | telephone) | | +-------------------+----------------------------+---------------------+ Since certain frequency bands are used to accomodate important communications, such as the VHF band, it became illegal to transmit radio waves at certain frequencies without a license. It was made so because transmission of radio signals at important frequencies could interrupt critical communication, such as communication between police officers with their radio transmitter devices. All frequencies within the radio spectrum are invisible to humans. Light frequencies which are visible to humans, i.e frequencies which are present in the light spectrum, operate at *much* lower frequencies. ----[ 1.4 - Wavelength Wavelength is the physical distance between a peak in one radio wave, to the peak in another radio wave transmitted successively -- on the same RF. As a general analogy, the wavelength can be thought of as the distance that the peak in a given wave will have travelled in the space of time for one cycle. This can be calculated using the below simple formula. |\ = V / F * |\ = lamda V = Velocity F = Frequency Using this formula, the wavelength for an example scenario can be calculated, when the RF is 27MHz. The speed of light is 300 million meters/second, which is therefore the velocity of the electromagnetic wave. |\ = 300,000,000 / 27,000,000 = 11.11r Looking at the above calculation, what can be gained? It seems that the wavelength for waves transmitted in the example scenario is 11.11 (recurring) meters, so from this, it can be gathered that a peak in a particular radio wave will have travelled 11.11r meters in the time it took for one oscillation of the transmitting oscillator. But how can we know how long this oscillation period takes? We can calculate this using the formula '1 / f'. 1 / 27,000,000 = 0.0000000370r This means that within the miniscule time frame of 0.0000000370 (recurring) seconds, the peak within the radio wave should have travelled approximately 11.11 (recurring) meters. Wavelength might seem quite a useless thing to calculate on its own, but it comes in very useful when it comes to calculating suitable aerial lengths for both radio transmitters and radio receivers. As a rule of thumb, an ideal length for a radio aerial is around 1/2 of the signals wavelength. This can be calculated very easily. 11.11 / 2 = 5.555 (roughly) From this calculation, we can gain the knowledge that a near ideal radio transmitter/receiver aerial can be constructed to be of around 5.5 meters. Exact precision is not generally critical to the overall operation of the radio transmitter/receiver. For example, where portability of equipment is more of a concern than great efficiency, 1/4, 1/8 or even 1/16 of the wavelength in meters is often used for the length of the radio aerial. 11.11 / 4 = 2.7775 11.11 / 8 = 1.38875 11.11 / 16 = 0.694375 From this little experiment we can see that we can turn a length which is considerably out of question due to portability desires, into a length which is much more suitable, yet efficiency is not affected too much. This technique is very commonly employed to calculate sensible lengths for radio aerials. However, other techniques are also employed, especially in the case of satillite TV. Notice how TV satillite dishes house tiny holes in the body of the dish? These holes are specially sized to ensure that radio waves with wavelengths less than that associated with the desired RFs (3GHz-30GHz) do not create an electrical current in the aerial wire, as suitable radio waves do. Holes based upon the same principle can also be found when looking inside a microwave oven. ----[ 1.5 - Transmission Perhaps one of the most difficult concepts to grasp in radio is how radio waves are actually broadcast into the environment. As touched upon previously, radio waves are transmitted using oscillators in electronic circuits, and the rate at which the oscillator oscillates is the frequency at which the radio waves are transmitted. As an example, we will focus on using an LC tuned oscillator circuit in the radio transmitter circuit. LC oscillators are made up of an inductor (L), and a capacitor (C). If we consider how a capacitor stores current, we can come up with the conclusion that it is stored as an electric field between two plates -- these two plates make up the capacitor. During one oscillation (also known as a 'cycle') of the LC tuned circuit, all available current is stored first in the capacitor as an electric field, and then as a magnetic field associated with the LC circuit's inductor. After a *very* short time period (1/f), the magnetic field is turned back into an electrical current, and begins to recharge the capacitor again. Because the inductor's magnetic field is beginning to change back into electrical charge, the inductor turns another electrical field into a magnetic field in order to counter-act the change. This continuous cycle of quick changes keeps the current in the LC circuit flowing in the same direction, driven by the current stored in the inductor. When the inductor's charge eventually becomes zero, the capacitor becomes charged again, but with the opposite polarity. After each oscillation (cycle), energy loss has occured, but not all of the energy loss can be accounted for as energy lost as heat from the inductor's coil. Thus, we can gather that some energy has been 'leaked' from between the capacitor's plates, as electromagnetic energy -- radio waves. If we consider this, we can conclude that the further apart the plates in the capacitor are, the more energy is broadcast ('leaked') as radio waves. This must mean that if we have a capacitor with plates spaced 1 meter apart, more energy will be broadcast as radio waves than if the capacitor had plates spaced a very small distant apart. By thinking even deeper, we can conclude that to maximise 'leakage' of radio energy, a capacitor is needed in the LC tuned oscillator circuit with plates spaced at quite a distance apart. It just so happens that for this task, to maximise broadcast of radio waves, the world's largest plate can be used to take the place of one plate of the capacitor -- the Earth! The other capacitor plate needs just be a suitably lengthed piece of wire, which is an equally common sight -- this piece of wire is known as an 'aerial'! In real-world radio transmitters, oscillator circuits are used to make a small current 'oscillate' in an aerial wire. Because of the constant change of energy form in the oscillator circuit, the current oscillating in the length of the wire becomes electromagnetic and is radiated as radio energy. Back to the length of the aerial in relation to wavelength; this is where the length calculated earlier comes in handy. From the knowledge gained here, we can assume an adapted LC oscillator circuit as below. Capacitor Inductor ________________ | ) | ) --- )____________ Aerial --- ) | ) |________________) As a concept, using the adapted LC tuned oscillator circuit above, the transmission of radio waves can be thought of like this; radio waves are generated due to the propagation of an electric current in an aerial wire. It is, as we have learnt, the 'leakage' of electromagnetic energy from between the two plates of the capacitor which causes broadcasting of radio waves. As oscillations occur in our LC tuned circuit, all available energy is stored in the capacitor, followed by energy (electrical current) not leaked as electromagnetic waves being fed into the inductor. This whole process measures one oscillation, and once one oscillation is over, the whole process repeats itself again, and each time energy is being lost as radio waves from the acting 'capacitor' (aerial and Earth). Therefore, it is the rate at which the LC circuit is oscillating (the 'frequency') at that determines the frequency at which the radio waves are broadcast at -- thus determining the RF of the radio signals. ----[ 1.6 - Receiving The concept of receiving radio signals is based upon almost the opposite of the concepts of transmitting radio waves. In similarity to radio transmitters, radio receivers also use an aerial, but for a totally different purpose; for detecting the radio signals in the environment. As described previously, radio waves are a form of energy, propagated as electromagnetic waves through the air. Thus, when radio signals transmitted by nearby radio transmitters pass the aerial of the receiver, a *tiny* RF alternating current is generated in the aerial wire. When a signal becomes present in the aerial wire, 'wanted' radio frequencies are 'selected' from the assortment of RF currents in the aerial, using a 'tuned circuit'. As an example, we'll focus on the LC tuned circuit as in the previous section, due to the simplicity of this circuit. RF current of the 'wanted' frequency can be selected from amongst the other RFs by use of an LC tuned circuit, which is set to resonate at the frequency of the 'wanted' radio frequency. This selection is done because the LC tuned circuit has low impedance at any frequencies other than the 'wanted' frequency. Frequencies other than the 'wanted' frequency are prevented from passing through the circuit because they are 'shorted out' due to low impedance of the LC circuit at any other frequency than the resonant frequency (the frequency of the 'wanted' signals). Following the selection of correct radio frequencies from the other RF signals, the radio receiver will usually amplify the signal, ready for demodulating. The technique which is adapted by the receiver for demodulating the radio signal into the modulating signal is totally dependant on the type of modulation being used in the received radio wave. In the case of an AM radio receiver, a selected signal will be 'rectified' and thus demodulated, using a low-drop germanium diode. This process basically turns the alternating RF current back into a direct DC current, which represents the power strength of the AM signal. Next, the RF component is generally removed by using a capacitor. The output product of this process is a recovered modulating signal which can be fed to a pair of high impedance headphones. The diagram below represents how the selected RF current is rectified by the diode. ||\\ //\\ ----------------------|>|--------------- ||\\ //\\ || \\|| \\ || \\|| \\ \/\/\/\/\/\/ AM Modulated Carrier diode Modulating signal (RF carrier present) After being rectified by the diode, the AM radio signal is still not suitable to be fed to an audio output, as the RF carrier is still present. The RF carrier can be removed by using a single capacitor. | | ||\\ //\\ ------------------------| |--------------------- /\ /\ || \\|| \\ | | / \/ \ Modulating signal capacitor Modulating signal (RF carrier removed) The output of the capacitor is a recovered modulating audio waveform which is suitable for passing to an audio output device, such as a set of headphones with a high impedance. This technique is likely to be the simplest way to create an AM radio receiver, commonly known as the 'crystal set', used by the mass in the 1920s. Other receivers are more often used to produce a higher quality of audio output, such as TRFs (Tuned Radio Receivers) and Superhetrodyne receivers. The whole system model of a radio receiver at its most basic level can be thought of as the below diagram. Modulated Radio Signal (electric current generated in aerial wire by radio wave) | \|/ Signal amplified | \|/ Signal demodulated | \|/ Modulating signal Although the techniques and components needed to achieve each step of the diagram are different, most receivers stick to this sort of system. Other types of receivers and their circuits are discussed more indeph in the section they are related to. --[ 2 - AM Radio ----[ 2.1 - What is AM Radio? AM Radio refers to any form of technology which makes use of Amplitude Modulation to modulate the 'carrier' with information. To package a radio wave with often complex signals, the carrier of a radio wave is shifted in power very slightly in sympathy with a modulating audio or data signal. Next to morse code, AM is one of the simplest forms of modulation, and with this, comes its disadvantages. ----[ 2.2 - Modulation AM Modulation involves nothing more than shifting the power of a radio wave's carrier by tiny amounts, in sympathy with a modulating signal. Amplitude, as you probably already knew, is just another word for 'power'. The simplicity of AM modulation can be demonstrated with a simple diagram like the one below. ||\\ ///\ //\\ || \\ // \\ // \\ ---> \ /\ / ---> \\ \\ || \\\/ \\\/ \\ \/ \/ \\ ///\\ \\// \\ RF Carrier Modulating signal AM signal As you can hopefully make out from the diagrams, whenever the modulating signal (the signal which we are modulating) increases in voltage, the amplitude (power) of the RF carrier is increased in sympathy with the modulating signal. When the voltage of the modulating signal declines in voltage, the opposite of above happens. After AM modulating the carrier, the signal has usually twice the 'bandwidth' of the original modulating signal. ----[ 2.3 - Demodulation When an AM designed radio receives a radio wave, as previously noted, a small RF alternating current is generated in the aerial wire. Because of the AM modulation of the carrier applied by the sending transmitter, the voltages in the carrier are larger and smaller than each other, but in equal and opposite amounts. As a result, to recover the modulating signal, either the positive or the negative part of the modulated signal must be removed. In the simplest AM radio receivers, the modulated signal can be 'rectified' by making use of a single germanium low-drop diode. \\/\/\/\/\ \\ /// // ---------------------|>|----------------- \\ /// // \\// \\/ \\// \\// AM radio signal diode Modulating signal Here, part of the carrier has been removed, resulting in recovery, or 'rectification' of the modulating signal. Because the carrier frequency (the RF of the radio wave) is usually significantly greater than the modulating frequency, the RF carrier can be removed from the resultant modulating signal, using a simple capacitor. \\ // | | \\ /// // ----------------| |---------------- \ /\ / \\// \\// | | \/ \/ Modulating signal capacitor Modulating signal (with RF carrier) (without RF carrier) By exposing the rectified signal to a capacitor, the audio signal (or otherwise data signal) is smoothed, producing a higher quality of audible output. At this point, the modulating signal is more or less recovered. Although this technique of AM demodulation can be made to work to a satisfactory level, the vast majority of commercial radio receivers now adopt a design known as 'superhet', which I will explain briefly here. Superhet receivers are based upon the principle of 'mixing' two signals to produce an intermediate frequency. The diagram illustrates a superhet receivers operation. Carrier in ---> Tuned circuit ---> Mixer ---> IF amplifier ---> Detector (selects correct RF) | | | | | | Local oscillator Audio Amp | | +--+ | | +--+ \__/ As we can see, superhet demodulation is significantly more complex than 'rectification'. Superhet receiver systems, like the above system diagram, works basically as follows. First, an RF alternating current becomes present in the circuit, because of the electromagnetic activity around the aerial. Signals of the correct radio frequency are selected via a tuned circuit, and inputted into one input pin of the 'mixer'. In the meantime, the other input of the mixer is occupied by the 'local oscillator', which is designed to be oscillating at a frequency just lower than the inputted radio frequency. The output of the mixer is known as the 'Intermediate Frequency' (IF), which is the difference between the local oscillator frequency, and the frequency of the received AM radio signal. Next, the 'IF' is amplified, and passed to an 'envelope detector'. The output of the envelope detector is the modulating audio signal (an AF -- Audio Frequency), which is in turn amplified, and outputted to the user via a loudspeaker or other audio output device. Since the local oscillator is almost always set to oscillate at a frequency of approximately 465KHz *below* the frequency of the carrier input, the output of the mixer will always be a 'carrier' of 465KHz -- which still carries the modulated information. After the signal is amplified by the IF amplifier(s) (there can be more than one IF amplifier), the signal is now demodulated by the detector -- which is often just a single diode. As mentioned above, the modulating signal recovered by the system can be fed to an amplifier, followed by an audio output device. As well as producing a higher quality of audio signal, superhet receivers also eliminate the need to be able to tune multiple tuned circuits in a TRF (Tuned Radio Receiver). TRF designs become awkward when it comes to tuning them into different radio frequencies because of the many tuned circuits needed -- superhets overcome this problem as they always 'know' what the collector load will be -- a 465KHz signal. Superhet designs can also be adapted to work with FM radio signals, assuming the 'detector' is changed to a suitable detector for FM signals (i.e phase detector). ----[ 2.4 - Circuits Since radio technology is a frequently discussed topic across the Internet, many radio circuit design implementations are readily available, ranging from very simple circuits, to quite complex ones. Here I present some radio related circuits which most people with a bit of electronics knowledge and the right components can build. ------[ 2.4.1 - Receivers Discussed above was the historic 'crystal set' radio receiver, which allows anyone with a long enough aerial wire and a few components to listen to AM radio bands. Below is the basic crystal set radio receiver circuit, which is very easy to construct. Aerial Wire D1 * | Q1 | ____|>|__________________ |_____________|/ | | | |\ | | _______|_____ | | | ( | | | | ( L1 --- C1 * | C2 --- 0 high impedance ( --- | --- 0 headphones ( | | | | (_____________| | | | | | | | |_______________^____________|__________| | | (not joined) |_______________| | GND - C1 should be a variable capacitor to allow the station to tune into other frequency bands. - D1 should be a low-drop germanium diode -- non-germanium diodes won't work. From previous discussion, we can figure out that the above 'crystal set' AM radio receiver works as follows; incoming radio waves generate a tiny alternating current in the aerial wire, from which 'wanted' radio frequencies are selected, by the tuned LC circuit. Selected current passes through a diode, which 'rectifies' the signals, thus demodulating them. Before the diode, there is a simple transistor, which amplifies the 'wanted' frequency. The only reason for this is to make the quality of sound slightly better. Any remaining RF components are removed using a single capacitor -- this consequently has the effect of smoothing out the signal. The product audio signal is passed to a set of headphones -- these *must* be high-impedance, or nothing audible sounds on the headphones. As was noted earlier, this type of receiver was used frequently in the 1920s, and gave even newbie electronic enthusiasts of that time the opportunity to build something that would be considered very useful at that time. To make decent use of the 'crystal set' circuit, around 60-70 turns of wire around a rod of ferrious metal would create a good aerial. Designs like above are never used in commercial radio receivers anymore. Excluding superhet receivers, TRFs are occasionally used to produce low quality radio receivers. Below is a simple TRF receiver schematic. Aerial | C5* C6 +9V | ________________________________________ | | | | ) | | | --- --- ) LC2 |-| | | --- --- ) __| | | | |____|_______) | |_| | | | | | C8 --- C1 | | D1 C7 | |___| |____0 --- _|_ Q1_____________|>|________| |_|_|/ | | 0 LC1 | R1 | | / | | | |\ Q2 _________|__ |_| __|/ | | High impedance | ) | | |\_____ | | headphones | ) | | | | | | ) | | | | | --- C2 * )___| |__|_ | | | --- ) | | | | | | | ) C3 | | | | |___________) | | C4 | | | |_____ | | | | | R4 |-| R6 |-| R2 |-| R3 |-| --- | | | | | | | | --- |_| |_| |_| |_| | | | ____|______|____|_________ |___________| 0V - C2 should be a variable capacitor - C5 and C6 should be variable capacitors - Resistors of sensible values should suffice - Capacitors of sensible values should suffice As in the 'crystal set' receiver, when a radio signal is 'picked up' by the aerial, the proper frequency is selected using the LC tuned circuit. The signal is passed to a transistor amplifier. However, this time, the transistor amplifier has a 'tuned collector load', because of the tuned LC circuit (LC2) at the collector leg of the transistor. Next, the signal is rectified, stored in a few capacitors until enough current has collected, and is eventually fed to the user with the high impedance headphones. The use of the tuned collector load at the transistor causes for the receiver to be more precise, amplifying only the signals which are at the frequency of LC2's resonant frequency. As expected, this causes for a higher quality of audio signal to be fed into the users headphones, making this a much better radio receiver. A few things can be done to improve the above receiver, such as adding yet more tuned amplifiers, and perhaps adding a few more resistors and capacitors for safety and efficiency purposes. ------[ 2.4.2 - Transmitters All that we really need to do when designing a simple radio transmitter is keep in mind that we require an oscillator -- either tuned or crystal controlled -- and a series of amplifier circuits which boost our signal. After these stages, all that is left is to make the signals oscillate in the aerial wire. Below is a simple radio transmitter schematic. Aerial | | ___________________________________________________________________| | | | | | | | | | | | | | L1 ) | | | L3 | | ) R3 |-| C3 | |__ ) |-| R1 Crystal ) | | --- | | ) | |_________|_____________) |_| --- | | C5) |_| ||| | | | | --- ) | |_______| |_______|_AM ___|_______|/ --- | | / | | Modulator |\___|___| |__________| |________|/ C2 Q2 | | | | | |\ Q1 (PNP) | ) | C1 | --- ) | |-| C4 --- ) M | | R4 | L2 ) | |_| | | | | | | | | | | |_______________________|______________________________________|____| - TR2 is a PNP transistor - M is a microphone This circuit works by oscillating at the frequency controlled by the crystal (27MHz would be legal in the UK), amplifying the signal with tuned collector loads at the transistor (TR1), and then by radiating the signal off as radio waves by oscillating the signal in the aerial wire. Amplitude modulation is added to the signal by varying the gain of the transistor driver, by connecting it to the output of a microphone. The above circuit is quite inefficient, and is likely to produce low quality signals, but it can be used as a starting point to building a simple AM radio transmitter. It's probably illegal to operate the above circuit on frequencies requiring a license, so some countries *require* the circuit to be crystal controlled on a 'model radio' RF. One improvement to be made on the schematic is to amplify the output of the microphone before feeding it to the transistor driver. Possible devices which could apply the AM modulation are audio amplifiers, or even op-amps. An audio amp following the oscillator would produce a higher quality, stronger signal, but would also provide power gain (i.e amplitude gain), in sympathy with the audio signal produced by the microphone. This gain of amplitude due to the audio amp has essentially applied Amplitude Modulation of the carrier signal, because the power of the signal has been altered according to the inputted audio signal (at the microphone). An ordinary op-amp could be used in a similar way, but by substituting the non-inverting input pin with a suitable power supply. Essentially, this would cause for an outputted gain from the op-amp, according to the audio signal, because the two inputs to the op-amp are compared, as such. --[ 3 - FM Radio ----[ 3.1 - What is FM radio? FM radio just means any form of technology which makes use of radio with FM modulated signals. To modulate a radio wave's carrier with information, FM transmitters shift the frequency of the carrier very slightly, to be in sympathy with a modulating signal. ----[ 3.2 - Modulation FM modulation consists of little more than shifting a radio wave's carrier frequency very slightly in sympathy with a modulating signal's frequency. Modulation of an example audio signal is shown in the figures below. ||\\ ///\ //\\ || \\ // \\ // \\ ---> \ /\ / ---> ||\\ /\\ // || \\\/ \\\/ \\ \/ \/ ||\\ //\\ // ||\\// \\// RF Carrier Modulating signal FM signal The diagrams show that when the frequency of the modulating signal increases, so does the given carrier frequency, and the opposite when the modulating signal's frequency decreases. This is shown in the FM signal diagram by the bands being spaced widely apart when the modulating signal frequency is increasing, and more closely together when the modulating signal's frequency is decreasing. ----[ 3.3 - Demodulation When an FM modulated carrier signal is detected by the receiver's aerial wire, in order to recover the modulating signal, the FM modulation must be reversed. Most modern FM radio receivers use a circuit called the 'phase-locked loop', which is able to recover FM modulated radio signals by use of a VCO (Voltage Controlled Oscillator), and a 'phase detector'. Below is the system diagram of a PLL suitable for use in FM radio receivers. FM signal in -------------> Phase --------------- Detector | | | | | | | | | VCO | |__________________| | | | | | Modulating signal out The above PLL is able to recover the modulating signal by having one input to a phase detector as the modulated carrier, and the other input as a VCO oscillating at the frequency of the RF carrier. The phase detector 'compares' the two frequencies, and outputs a low-power voltage relative to the difference between the two 'phases', or frequencies. In essence, the outputted voltage will be relative to the frequency by which the carrier's frequency was shifted during modulation by the transmitter. Therefore, the output of the PLL, known as the 'phase error', is the recovered modulating signal. In addition to being outputted from the small system, the voltage is also given to the VCO as 'feedback', which it uses to 'track' the modulation. Acting upon the feedback received, the frequency of oscillation is altered accordingly, and the process is repeated as necessary. In the past, less efficient and reliable circuits were used to demodulate FM radio signals, such as the 'ratio detector'. Although the 'ratio detector' is less sophisticated than PLL methods, a functioning ratio detector circuit is actually a little more complex than PLLs. It should be noted that superhet receivers, touched upon a little earlier, can also be used as FM radio receivers, but their 'detectors' are different to that of an AM superhet -- for example, a PLL circuit or ratio detector discussed here could be used in conjunction with a superhet receiver to make an FM radio. This is the method which is actually adopted by most commercial radio receiver manufacturers. ----[ 3.4 - Circuits ------[ 3.4.1 - Transmitters The same general principles apply to FM radio transmitters as they do to AM radio transmitters, except that information must be modulated in a different way. In AM radio transmitters, the carrier frequency is more or less always constant. However, in FM transmitters, the whole principle is to alter the carrier frequency in small amounts. This means that a tuned oscillator circuit is not appropriate, because we need to alter the frequency accordingly, not transmit at one static frequency. The method used to overcome this problem is discussed a little later. A simple FM transmitter schematic diagram is presented below. Aerial | | | ____________________________________________________________________| | | | | | | | | | | | ) | ) |-| --- C3 | ) | R1 L1 ) R3 | | --- |_ C4 ) |-| ) |_| | | | ) | | ) | | | --- | |_| | Crystal | C2 | | | --- | L2 |_______________|||_____________|___________| |___|____|____|/ | | | / | | |\___|___| |____________| |_____________|/ | | | | |\ Q1 Q2 | | | | | C1 | | M |-| | | | | R2 | | |_| | | | | |______________________________|_____________________________________| When audio signals are produced by the microphone, current carrying audio frequencies are amlified, and are used to modulate the radio wave. Since the microphone does this all for us, there is no need to use modulation modules, ICs, or other technology. In situations where an elecret microphone is not available to do the modulation for us, a varactor diode can be used to vary the capacitance in an oscillator circuit, depending on the amplitude of a modulating signal. This varies the oscillation frequency of the oscillator circuit, thus producing FM modulation. --[ 4 - Misc ----[ 4.1 - Pirate Radio Pirate Radio stations are simply just radio stations ran by individuals who are not licensed amateur radio enthusiasts. Although radio is actually a natural resource, it has been illegal for a significant amount of time in some countries to transmit radio waves on certain frequencies. Although transmitting radio signals on certain frequencies (around 27MHz) is legal in places like the UK, strict FCC regulations kick in, almost limiting the threshold to useless. Because of this limitation, radio enthusiasts all around the globe see fit to set up pirate radio stations, which they use for their enjoyment, playing their favourite music tracks to the 'public', and for a breeding ground for aspiring DJs. Some 'pirate radio' stations keep within the FCC terms, by transmitting at low-power. These types of stations are often referred to as 'free radio', or 'micropower stations'. The legality of pirate radio stations is questionable, but varies from country to country. In some European Countries, you can be arrested for just owning an unregistered transmitter. In Ireland, prosecution rarely takes place if registered radio stations are not affected, but it is still illegal. The US allows transmission of radio signals at *microscopic* power, making the limitations almost useless for unlicensed radio enthusiasts, thus causing them to resort to pirate radio. Contrary to popular belief, setting up a pirate radio station is not necessarily a difficult task. At the minimum, someone wanting to setup a pirate radio station would need the following pieces of equipment: - Stereos, CD Players, Microphones, etc. - Audio Amp - Audio Mixer - Transmitter - Aerial Stations using only the above equipment can sometimes sound quite crude, and might interfere with other legal radio stations. To avoid this, a 'compressor' can be used, which also limits the noise created by sudden loud noises in the background. Although any of the example transmitters in this article probably wouldn't be sufficient enough to transmit music audio signals over the air, but they could be used as a starting point to building your own, more efficient kit. Additionally, FM and AM radio kits can be purchased, which anyone with a soldering iron can build. The length and height of the antenna depends entirely on how far the radio signals need to be transmitted. By reading the previous sections, some information on getting a correctly sized aerial can be gained. For example, a quick and dirty aerial for an AM pirate radio station could be around 15-20 feet tall. To avoid being busted, it is probably a good idea to stay within the legal power limits. Otherwise, a Direction Finding device used by the authorities could easily track down the exact location of the transmitter. ----[ 4.2 - Wireless Telephone Tapping 'Beige boxing' has long been the easiest and most exploited way to tap telephones, interrupt on neighbours conversations, and use enemies phone lines to make long distance calls to your friend in Australia. However, since beige boxing requires the phreak to lurk around like a ninja, a safer method can be used, which doesn't require you to be physically close to the target phone line. As expected, audio signals on a target phone line can be transmitted as radio signals at an arbitrary frequency, and be received by any phreak with an FM radio receiver. Although this concept is not new, it serves as an interesting and useful project for radio newbies to try out. Below is a simple FM phone bug transmitter circuit. __________________________________________________________ | | | | | | IN (green) ___.___|_______ |-| | | | | | | | | /\ LED | |_| | | --- | | |___| | op-amp | | | C1 | | | | |---|\ | | | |__________|/ ____| >------- Aerial | IN (red) _____|___| |\ _____|___|/ | | | | | | | | | | | | | OUT (green) __| | ( | | | /\ ( | /\ varactor | --- ( | --- | | ( | | | OUT (red) ________|____________________|_____|___|__________________________| - inductor should be about 8 turns of wire - aerial should be about 5 inch long By interchanging the varator with a crystal, or by using a variable capacitor, the frequency band on which the bug transmits line activity could be changed accordingly. The varactor making up part of the oscillator circuit is intended to alter the frequency of oscillation, depending on the audio signal inputted from the green wire of the telephone line. The varactor diode can be thought of as an electrically variable capacitor, which in this case alters its capacitance in sympathy with the audio frequency on the telephone line -- causing for change of oscillation frequency, and thus frequency modulation. The following op-amp provides additional strength to the signal, in an attempt to avoid a weak, unreliable signal. For user-friendly purposes, the LED connecting to the red wire of the line pair should illuminate when a signal is present on the line. The above circuit can be modified to be made more efficient, and a longer aerial is an obvious way of lengthening the range of transmission. If a phreak was to contruct and use a device like this, all they would need is an FM radio to tune into the correct frequency. There are much better designs than the minimalistic one above -- if a practical FM telephone bug is required, many plans are available. ----[ 4.3 - Jamming Technically, all it takes to carry out 'radio jamming' is to transmit noise at a desired frequency. For example, if a person in the UK were to transmit RF noise at 30MHz+, police radio communications could possibly disrupted. Although the principles are mostly the same, there are several different types of jamming. - modulated jamming This consists of mixing different types of modulation, and transmitting the results at a desired radio frequency. This is designed to make receiving legimate radio signals hard or next to impossible. - CW (continuous wave) CW jamming only involves transmitting a consistant carrier frequency once tuned into a RF frequency/band you want to jam. This again makes receiving desired radio signals particuarly hard. - Broadband Broadband jammers spread Gaussian noise across a whole band of audio frequencies, blocking legimate audio signals from easy receival. A basic radio transmitter is easily modifiable, by adding a noise generator, to successfully jam arbitrary frequency bands. Many other types of radio jammers exist, and their details are readily available on the World Wide Web. --[ 5 - Conclusion Radio is an extremely useful technology, which is at least as old as the atom. But we are only just beginning to exploit its full usefullness in even new and up and coming technology, and probably will do for the next few hundred years. As we've discovered, contrary to popular belief, employing the use of radio in electronic circuits isn't at all as complicated as one would think. Because of this, the use of radio and be both used and exploitfully abused -- only a few basic principles need to be understood to make use of this wonderful technology. Although the surface has only been scratched, and way forward is open.