6. Practical Applications of PM and FM
1. Radio Transmitting
Radio is device that use technology of using radio waves to transfer information, such as sound, by using the properties of electromagnetic energy waves transmitted through space, such as their phase, amplitude, frequency, or pulse width. If radio waves passing an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be get back into its original form.
Radio systems must have transmitter to modulate some property of the energy produced to impress a signal on it. To using amplitude modulation or angle modulation ,which can be frequency modulation or phase modulation. Radio systems have antenna to convert
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The frequency of an oscillator is altered or distorted.
FM synthesis can generate both harmonic and in harmonic sounds. For synthesizing harmonic sounds, the modulating signal must have a harmonic relationship to the original carrier signal. IF the amount of frequency modulation increases, the sound grows progressively more complex. Through the use of modulators with frequencies that are non-integer multiples of the carrier signal , atonal and tonal bell-like and percussive sounds can easily be create
FM synthesis using analogy oscillators may result in pitch instability. FM synthesis can also be implemented digitally, the latter proving to be more 'reliable' and is currently seen as standard practice. Digital FM synthesis (using the more frequency-stable phase modulation variant) was the basis of several musical instruments beginning as early as 1974. FM synthesis had also become the usual setting for games and software until the
The radio has had a huge impact on bringing information to the public about war and other government issues. Advertising and broadcasting on the airwaves was a major step in bringing war propaganda to a level where people could be easily touched nationally. Broadcasting around the clock was being offered everywhere. Before there was television people relied on the radio as a way to be entertained, the means of finding out what was going on in the world, and much more. During the World War II time period, 90 percent of American families owned a radio, and it was a part of daily life. So it was an obvious means of spreading war propaganda. During this time period, propaganda was spread throughout the radio by means of news programs, public affairs broadcasts, as well as through Hollywood and the mainstream. The average person had not even graduated high school at the time, and the average reading level of the American was somewhat low. The radio made it possible for stories and news to be delivered to everyone in plain simple English. The radio served as a medium that provided a sense of national community. Although it took time, the radio eventually rallied people together to back up the American war effort.
Television has affected every aspect of life in society, radically changing the way individuals live and interact with the world. However, change is not always for the better, especially the influence of television on political campaigns towards presidency. Since the 1960s, presidential elections in the United States were greatly impacted by television, yet the impact has not been positive. Television allowed the public to have more access to information and gained reassurance to which candidate they chose to vote for. However, the media failed to recognize the importance of elections. Candidates became image based rather than issue based using a “celebrity system” to concern the public with subjects regarding debates (Hart and Trice). Due to “hyperfamiliarity” television turned numerous people away from being interested in debates between candidates (Hart and Trice). Although television had the ability to reach a greater number of people than it did before the Nixon/Kennedy debate, it shortened the attention span of the public, which made the overall process of elections unfair, due to the emphasis on image rather than issue.
Polyphonic is operating on a “shoestring budget” of $150,000. The company is not helped by initial discussions about HSS with potential customers, which have resulted in cold receptions, at best, about the product’s potential application to the music processes despite its multiple strengths.
War of the Worlds is an out of the box radio play that changed the world of mass communication forever and allowed the entire nation to see power of imagination and the unique power of radio over its audience. The creators of this nationwide hysteria were Orson Welles and the Mercury group. Orson Welles was a famous American actor, producer, director and radio broadcaster. In an effort to increase the shows audience, Orson Wells catered the idea of a Halloween public scare. The War of the Worlds radio play was a dramatization of H.G. Well’s novel The War of the worlds (1898 novel relating the story of an alien invasion on Earth) and performed as a scary Halloween episode on of the radio show Mercury Theater On The Air. The episode was aired over the Columbia Broadcasting System (CBS) on October 30th, 1938. The first two thirds of the 62-minute broadcast were presented as a series of simulated news bulletins, which suggested to many listeners that an actual alien invasion by Martians was currently in progress. Orson Welles’s scripted act was so convincing that the broadcast caused hysteria throughout the nation as several listeners believed that the nation was actually being invaded by Martians in a seemingly unstoppable attack. Many people were terrified by the news, and they left their homes in panic and fled. The aftermath of the broadcast was so disastrous that even Welles and his team were shocked. This 1938, 62 minute broadcast truly changed the meaning of mass media and everybody came to realize the true potential and power of mass communication.
The radio works because of sound waves being transmitted from one receptor to the next. Electrons moving through a wire create a magnetic field and when a second wire is placed next to the first the electrons are transmitted. The second wire is then able to turn the moving electrons into an electrical current which produces the same sound that created the moving electrons in the first wire (Gugliotta). Italian inventor, Gulielmo Marconi received the British patent for the radio in 1897. In 1901, Marconi discovered that radio wires did not have to be close to each other to work and that radio signals could be transmitted over very large distances. On December 13, 1901 Marconi successfully transmitted a radio wave 2,000 miles across the ocean from Poldhu, England to St. John’s, Newfoundland. U...
Wishart, Trevor. "From Sound Morphing to the Synthesis of Starlight. Musical experiences with the Phase Vocoder over 25 years." Musica/Tecnologia Music , 2013: 65-67.
Music is transmitted through sound waves, which are very similar to the sine waves studied in Trigonometry. The differences in the waves result in a different sounds that are transmitted. Vibrating objects travel through a medium (the material that the disturbance is moving through) to create sounds at a given frequency. The frequency is how often the particles vibrate when a wave passes through the medium. The unit that is most used to measure frequencies is the Hertz (Hz) and 1 Hz is equivalent to 1 vibration per second. The frequency affects the pitch of the note that is being played; The higher the frequency the higher the pitch and the lower the frequency the lower the pitch.
The Radio was introduced to society because of the telegraph and the telephone. These inventions don’t do the same things but their similar branch of technology. “Radio technology began as “wireless telegraphy”. “It all started with the discovery of radio waves, electromagnetic waves that have the capacity to transmit music, speech, pictures and other data invisibly through air.” [Bellis] Majority of technology uses electromagnetic waves to send data information or TV broadcasts. During the 1860’s, Scottish physicist, James Clerk Maxwell predicted the existence of radio waves; and in 1886, German physicist, Heinrich Rudolph Hertz showed how fast the variation of electric current could be placed into space in the form of radio waves similar to light and heat. “Guglielmo Marconi, an Italian inventor, proved the feasibility of radio communication”. [Bellis]1 He sent and received his first radio signal in Italy in 1895. "By 1899 he flashed the wireless signal across the English Channel and two years later received the letter “S” telegraphed from England to Newfoundland.” This was just the beginning of something so popular that Marconi himself just wouldn’t believe. “Lee Deforest invented space telegraphy, the triode amplifier and the Audion.” In the early 1900’s, the great requirement for further development of radio was and efficient and delicate detector. This made it possible to amplify the radio frequency signal picked up by the antenna before application to the receiver detector; thus, much weaker signals could be utilized than had previously been possible. Deforest was also the person who first used the word “radio”. The result of Deforest’s work was the invention of amplitude-modulated or AM radio tha...
Analog communication employs continuous transmission of an electromagnetic wave form that varies in frequency and amplitude.
Radio was invented in 1896 as a form of wireless telegraphy, which transmits the Morse code without the need for fixed stations and cables; this system was initially used at sea. Radio in the UK and US took a Eurocentric approach, which was the view from the west.
The radio was the first invention to allow mass communication to different parts of the world. It enabled information to be transferred thousands of miles. The development of the radio began in 1893 with Nikolai Tesla’s demonstration of wireless radio communication in St. Louis, Missouri. Nikolai Tesla’s work set the foundation for later scientists who worked to perfect the radio we now use in our daily lives. The man most associated with the invention of the radio is an Italian man named Guglielmo Marconi, who in 1986 was awarded the official patent for the radio by the British Government. The reason Marconi is most know for the invention of the radio is because he was the first to broadcast a transmission, which he did in 1899 and it was a mile long. Thanks to these great inventors and their brilliant minds we can now listen to sports nearly anywhere and everywhere we are in the world, due to the radio.
Every invention ever known to man had pioneers or people who contributed to the creation of the product. Radio had many pioneers that allowed for its creation and their names are Heinrich Hertz, Nikola Tesla, Ernst Alexander, Edwin Armstrong, Guglielmo Marconi, Lee DeForest, Frank Conrad, Reginald Fessenden, and Edward Armstrong. It all started with a German physicist named Heinrich Hertz who in 1884 proved that you could transmit and receive electric waves wirelessly. Hertz thought that the work he had done had no use whatsoever but little did he know that what he done is considered the fundamental building block of radio, and that is the reason why every frequency measurement is named after him (Short). In that same year a Serbian-American inventor named Nikola Tesla came to the U.S and sold patents to his inventions to a man named George Westinghouse. After that Tesla established his own lab which is where he built the tesla coil , an induction coil that is still used in radio today (Short). The next progression of radio focused on more than just the transmission of waves, the new focus was transmission of speech. The first to begin to add speech into the radio mix was Ernst Alexander, a Sweden born inventor who developed the first alternator to make speech transmission possible (Short). This was so new to the s...
Frequency modulation is, of course, used on the FM band. And it is used for
Impact of the Radio The invention of the radio had an immense impact, revolutionizing the unity of society. “I live in a strictly rural community, and people here speak of ‘The Radio’ in the large sense, with an over-meaning,” said E.B. White in 1933. “When they say ‘The Radio’ they don’t mean a cabinet, an electrical phenomenon, or a man in a studio, they refer to a pervading and somewhat godlike presence which has come into their lives and homes” (Lewis). The radio became a mighty weapon whose power involved spreading ideas to millions of listeners, who may otherwise never have heard those inspirational messages. Religious fanatics used to stand at the back of churches shouting radical nonsense, while others would ignore it.
I personally have always enjoyed the different and unique sounds of the instruments that the musicians in rock & roll bands could make using the synthesizer, their electric guitars, th...