Rabu, 14 Januari 2009
PROGRESS technology also impact on radio broadcasting.
Once we can only enjoy with radio waves AM (amplitude modulation). But now the audience was spoiled by the emergence of FM radio waves (frequency modulation) is voiced more clearly. The person credited with finding the FM wave is the Edwin Howard Armstrong, who is known as the "Father of the inventor of FM radio". Armstrong was born on December 18, 1890 in New York City, United States (U.S.). Ingenuity and tenacity have appeared since childhood. In fact, when he was barely 14 years old, he had aspired to become an inventor. As a teenager, he began trying to become a service equipment at home without wires (wireless), and while in high school, he had begun to experiment with making an antenna mast in front of his house to learn about wireless technology that frequently experienced at that time interference. He was quickly able to understand the problems in the communications tool. He also can find the weaknesses in the receiver signal transmission end of the communication. In fact, there is no other way to strengthen the delivery of energy at the end. To develop knowledge on issues of communication waves, after graduating from high school, Armstrong went to Columbia University majoring in engineering. At the university that he continued his research in the field of wireless. In the third year at Columbia University, Armstrong introduced his findings, a first radio wave amplifier (radio amplifier). Radio itself was first found by Lee De Forest Audion tube that uses a tube named Lee De Forest. However, the waves it emits are too weak. Armstrong learned how to work the tube Lee DeForest and then redesigned by taking the electromagnetic waves coming from a radio transmission and signal quickly back through the tube. Just a moment, the signal strength will increase as much as 20,000 times per second. This phenomenon is by Armstrong called the "regeneration of the radio", which is an important and necessary discovery when the radio was the first time. With this development, the radio technician does not need another 20 tons of generators for their radio station broadcasts. Single circuit design becomes the key findings of Armstrong's survival of the wave transmitter became operational core of the radio. And he graduated engineering degree in 1913. On these findings, Armstrong patented his creation and gives license to the Marconi Corporation in 1914. Six years later, Westinghouse bought the patent Armstrong superheterodyne receiver, and starting their work becomes the first radio station KDKA in Pittsburgh named. Begin radio became very popular at that time, ranging from entertainment to important news, no that does not use the radio service. After that, appearing on other radio waves. RCA (the Radio Corporation of America) immediately bought all the radio patents as well as other radio go buy it. After World War I ended, Armstrong returned to Columbia University and worked as a professor at the university. In 1923 he married Marion MacInnes, secretary to the President of RCA, David Sarnoff. In that decade he was involved in corporate wars to control radio patents. This continued until early 1930, and Armstrong defeated in court. Nevertheless, he continued research to solve the problem of radio statistics. He concluded, there is only one solution to the work that has been stolen can be appreciated, the system design entirely new. Study after study was done to keep him further refine the radio voice. In 1933 Armstrong introduced the system of FM radio (frequency modulation), which provides clear reception even though there was a storm and offers high-precision sound that did not previously exist. The system also provides a single wave with two radio programs with a single carrier. This development is called multiplexing. About the difference between AM and FM waves, can be explained as follows. Voice signals can not be directly emitted as sound signals rather than electromagnetic waves. If the voice signal is converted into electromagnetic waves though, how long the antenna is needed. To be able to send voice signals more easily, the voice signal is superimposed on the first radio signals with higher frequencies than the voice signal. Method for laying the voice signal on a radio signal is called modulation. Modulation of the radio is often used amplitude modulation (AM - amplitude modulation) and frequency modulation (FM - frequency modulation) The main difference between the wave AM with FM is a way of modulating his voice. FM wave has a range of plus an additional $ 455 KHz. So, if there is frekeensi radio FM 88.00, he was actually using the frequency 88.00 MHz + 455 KHz. Why is there an additional 455 KHz? Well, it modulates the FM wave of digital sound. Thus, the audio sound waves digitally chopped appropriate audio frequency (ear threshold between 6 Hz - 20 KHz). After digitally chopped (455 KHz was added, as a digital audio buffer), digital signal tsb. on-mix with radio waves (carrier) which frequency was 88.0 MHz, and then thrown into the open air. Important Bagaian FM transmitter system is the antenna, transmission line, and the transmitter itself. To introduce the findings to the world, in 1940, Armstrong received permission to set up the first FM radio station established in Alpine, New Jersey. Thanks to these findings, in 1941, the Franklin Institute awarded the medal of Franklin Armstrong, who is one of the highest award the scientific community. Defeat in the dispute over the years with companies that have used the copyright, does not affect the provision of the Franklin medal. Unfortunately, Armstrong had to end his life in a tragic way. The inventor of FM radio waves are found dead of suicide in the year 1954. His wife, Marion MacInnes, who became heir to the findings of Armstrong's continued struggle to fight him in court and won millions of dollars. Clarity on the resulting sound in the early '60s, dominating the channel FM radio system, and even used for communications between Earth and outer space by the U.S. National Space Agency, NASA. (Desy Natalia / various sources) ***
