In modern society, radio is the most widely used medium of broadcasting and electronic communication. Radio can be broadcasted with both microwaves and longer radio waves. These are transmitted in two ways: amplitude modulation (AM) and frequency modulation (FM). Amplitude radio is created by combining a sound wave from a microphone, tape, record, or CD with a "carrier" radio wave. This results in a wave that transmits voice or programming as its amplitude (intensity) increases and decreases. Frequency modulation conveys information, voice, and music on a radio wave is to slightly change, or modulate, the frequency. One big advantage of frequency modulation is that it is static free.
AM radio works by changing the amplitude of the carrier wave and FM radio works by changing the frequency of the carrier wave.
In amplitude modulation the amplitude of a carrier wave on one specific frequency is modified. The antenna sends out two kinds of Am waves: ground waves and sky waves. From the antenna ground waves spread out horizontally and they travel through the air along the earth's surface. On the other hand sky waves spread up into the sky. When these waves reach the ionosphere, they may be reflected back to earth. This reflection enables AM radio waves to be received at great distances from the antenna.
From this picture it is evident that ground waves don't go very far. This means numerous stations can be put on the same frequency without interfering with each other — assuming they are far enough apart. Problems found are that sky waves can end up in other states, provinces, or even in other countries.
FM Radio waves also go horizontally along the ground and skyward. However, due to the higher frequency of the carrier w...
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Hetrodyning is a method of transferring a broadcast signal from a carrier to a fixed frequency in a reciever so most of the reciever does not have to be returned when you change the channel/station on the radio. A superhetrodyne reciever is fitted to most modern radios in order to use the method of hetrodyning. Hetrodyning is used with AM and FM radio to ensure a more convenient and efficient experience.
There are many differences between AM and FM radio such as AM has the capability to have a larger number of channels but has not got the best quality. FM does not have the same capability of the number of channels but the space between the channels is much wider which makes the quality much better. Although FM radio is limited to 100 radio channels this is made up for in the quality of the radio broadcasted and is therefore the better option.
Lee Wilson
Has anyone ever wondered how radio communications changed society during the 1930’s? According to the research done by the Education Foundation, many people believe that the most important development in the radio at that time was entertainment; this is entirely false. In fact, radio communications not only made an impact in the way people received their news, but also brought together a nation that got out of a brutal depression. Together, the nations as one made radio communications the commanding form of media in the 1930’s. As stations and businesses were beginning to establish themselves, companies from across the nation were taking notice in the department of advertisement. This new realm ignited a spark for the nation’s new economy which later boomed and gave rise to an economically and socially powerful country.
By the late sixties FM radio had replaced AM radio as the focal points being Rock and Roll music, then into the seventies psychedel...
We originally partnered with HCJB to broadcast two programs a week. Recently, the broadcast was moved from HCJB to Trans World Radio (TWR), which will open additional station opportunities as the TWR syndication network becomes aware of ANC.
However, satellite radio is banking on a commercial free format to steal listeners away from terrestrial radio. Sirius offers 65 commercial free channels of music and 55 news, sports and talk stations. And the one thing that satellite has over its less lofty competitor is that you can’t loose the signal as you drive across America. The two major competitors for the satellite radio listeners are Sirius and XM.
Traditional (AM/FM) Radio - it is currently free, but only offers a homogenous shallow play lists with medium audio quality.
The radio grew in popularity and was as successful as it was because it was able to reach all across the nation, helped the American people interpret the Great Depression, and was a universal place of communication and entertainment. Although the first radio-wave theorem was developed in 1864 by James Clerk Maxwell, it was not until the 1920s and 1930s that the device really gained popularity in the U.S. During the Great Depression, families, advertisers, and even politicians used the radio for purposes such as entertainment, news, and a forum to the American people.1
Traditional AM/FM Radio. Sirius’s competition also includes traditional AM/FM radio. Unlike SIRIUS radio, traditional AM/FM radio has had a well established market for its services for many years and generally offers free broadcast reception paid for by commercial advertising rather than by a subscription fee. Also, many radio stations offer information programming of a local nature, such as local news and sports, which Sirius does not offer as effectively as local radio. Some radio stations also have begun reducing the number of commercials per hour, expanding the range of music played on the air and experimenting with new formats in order to compete more directly with satellite radio services.
Cell phones use radio frequencies to transmit signals. Radio Frequencies (RF) are a form of electrical waves similar to those used in radios, microwaves, radars or satellite stations. They are emitted from a transmitter, and received using an antenna. This telephony technology is restricted geographically to small zones called “Cells”. Every cell has a base station capable of sending and receiving radio waves. When a call is started a signal leaves the handheld unit headed to the closest base station. This station answers by allocating a specific channel to the unit. When this “channel” is established, modulated radio frequency signals are both received and transmitted. The head of the user is in the near field of use because the distance from the antenna to the head is a few centimeters. (Blettner & Berg 2000) If the antenna is inside the body of the phone, the exposure to Radio Frequencies is greater. The antenna might be requesting a stronger signal to contest with the interference of the battery or the actual shell of the phone’s body.
Analog communication employs continuous transmission of an electromagnetic wave form that varies in frequency and amplitude.
"Short History of Radio A Short History of Radio With an Inside Focus on Mobile Radio." fcc.gov. Version 2003-2004. N.p., n.d. Web. 4 Dec. 2013. .
Frequency modulation is, of course, used on the FM band. And it is used for
The radio is the oldest use of media for music. It has not lost its importance in spreading music though. Bands today still rely on the radio to help spread their music so people will want to but their albums. For a band to gain an audience and to get people to buy their albums they first need to let the people hear their music. The radio is the simplest media to spread music, but it is very effective. All that has to happen is a person starts driving in their car or sits at home and then they turn on the radio. If they hear a song that they like then they might go buy the album.
A cell phone is essentially a two-way radio consisting of a radio transmitter and a radio receiver. When you talk to your friend on your mobile phone, your mobile transfers your voice into an electrical signal, which is then transmitted through radio waves to the nearest cell tower. The network of cell phone towers then replays the radio wave to friend’s cell phone, which converts it to an electrical signal and back to sound. Cell phones transmit radio waves in all directions.
Radio broadcasting was introduced to the public in the early 1920s (Potter 226). There was only one type of broadcast protocol in the 1920’s and 30’s being AM radio(The Early Years). In 1921 there were only five AM radio stations, and only about 1% of all households in this country had a receiver (Potter 226). A receiver was basically another name for a radio because at this time radios were very expensive and there were not enough radio stations to make the system work. However, in 1923 there were over 500 stations to pop up which in turn led to increased sales of receivers to the general public (Potter 226). With the popping up of more radio stations the more receivers were being bought which meant that many people in the public were tuning into these various radio stations for information and entertainment. Radio was on the rise and it seemed that there was nothing slowing it down.
Once again, radio is currently at a crucial stance. FM radio was once the means in which someone could find out about new music artists, hear their favorite top songs, and catch up on local/world news. However, with the surge of the Internet at the turn of the century, the role of the radio starts to diminish. The Internet can now be used for gathering local news or weather in a fast and efficient manner. It can also be used as a way for music fans to find new artists similar to ones that they currently like, and (although not legal) ease in the process of downloading complete albums in high-quality formats for free. CD and MP3 players are now very popular for the person “on-the-go,” and as a result, it’s very easy to find people that remark: “I don’t listen to radio.” The reason for this is that radio has lost its niche. No longer is radio as convenient of a means to get news and experience new or popular music. Radio is forced, once again, to innovate itself in order to keep from being eliminating by the more popular types of med...