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Foundations of radio

Foundations of radio. Fundamentals of a/v: Radio, TV & film. The medium of radio. For people in most countries of the world, radio represents the number one source of news and information. The medium of radio.

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Foundations of radio

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  1. Foundations of radio Fundamentals of a/v: Radio, TV & film

  2. The medium of radio For people in most countries of the world, radio represents the number one source of news and information.

  3. The medium of radio In the U.S. where people depend more on TV and the Internet for news, radios still outnumber people by about three-to-one.

  4. But let’s not get ahead of our story… Our story has its roots in the Telegraph. This device was the first widely used electronic form of communication.

  5. The beginning of electronic communications Telegraphs operate with a “hardwire” set-up, utilizing Morse Code to communicate. Combinations of dots and dashes represent letters of the alphabet. Samuel Morse of Morse Code fame invented this system in 1836 and sends the first message in 1844 from Washington, DC, to Baltimore.

  6. Still in place today… Morse Code is still used as a medium of communication—primarily because for long distance communication, the dots and dashes survive interference and radio static much better than the human voice.

  7. Electronic communications are here to stay With the help of wires strung from pole-to-pole across the country, the Telegraph eventually put the Pony Express out of business.

  8. The more things change… The Telegraph was just the first of a string of inventions throughout history that threatened the existing order of things.

  9. The more they stay the same… Telegraph made the Pony Express obsolete. Radio endangered the telegraph and telephone. Film threatened radio. Television took a bite out of films. The Internet looms large over TV and film.

  10. The telephone is invented Not too long after the Telegraph was invented, Alexander Graham Bell was credited with inventing an even better way of communicating: the Telephone.

  11. The telephone is invented March 10, 1876 First successful experiment with the Telephone. “Mr. Watson—come here—I want to see you.”

  12. …and life hasn’t been the same since This version of the telephone was used in hundreds of thousands of U.S. homes up to the mid-1900s.

  13. “PARTY LINE” All phones on the party line rang at the same time, no matter who the call was for. Each home had its own ring pattern. It was pretty hard to keep a good secret in those days.

  14. “number please” There were no dials or pushbuttons; you had to place every call through an operator at the town’s central switchboard. Before leaving the line, the operator would wait until someone picked up—or inform you that there was no answer.

  15. Point-to-point communication Given the ability of any number of people to listen in on interesting conversations, the early Telephone medium actually ended up being a limited form of “broadcasting” in some communities.

  16. The foundation of radio The Telegraph and the Telephone both laid the foundation for RADIO.

  17. The foundation of radio In 1887, Heinrich Hertz demonstrated that electromagnetic waves could be transmitted through the air. In recognition of his achievement, the term “Hertz” is now used as a term for cycles per second, a common unit for the frequency of both sound and radio waves.

  18. Transmitting signals by radio waves Guglielmo Marconi is commonly credited for inventing Radio in 1895. Once he proved that wireless transmissions could work, he patented the invention and set up the Marconi Wireless Telegraph Company.

  19. Early signals wimpy What was needed was a way of electrically amplifying signals—including the human voice.

  20. Vacuum tube amplifier invented In 1906, the audion tube, a vacuum tube that amplified signals was created. Ship radio operators who had never heard anything but boring Morse Code beeps, had a Twilight Zone experience at sea when they heard Christmas carols on their radios! Music and even the human voice had been successfully sent via radio.

  21. Early broadcasts Shortly after that first radio broadcast, broadcasts were transmitted from the Eiffel Tower in Paris and the Metropolitan Opera House in New York. Mostly just PR stunts, the success of these broadcasts did prove that radio could be an entertainment medium with the potential for mass appeal.

  22. Titanic makes “radio” a household word Meanwhile, out at sea, something happened that shook the nation. The “Titanic” set out on its maiden voyage in April 1912. It hit an iceberg—and sank.

  23. Titanic makes ‘radio’ a household word About 2,200 people were on-board, and most of them perished that night. But, it could have been worse. Thanks to the new invention of Radio, about 800 were saved.

  24. Titanic makes ‘radio’ a household word A young radio operator, safely on land, was in charge of monitoring oceanic radio transmissions that night. David Sarnoff [foreshadowing major player in radio and TV] had just started his first day on the job. He received the SOS signal from the Titanic and immediately relayed the information to the nearest ships.

  25. Audio recording developed In the early days of radio there was no way to record sound. Everything had to be done “live.” In 1877, Thomas Edison designed the “tinfoil phonograph,” credited to be the first practical device to record and play back sound.

  26. Audio recording developed The first recordings were made on strips of tinfoil and on wax cylinders, both of which had a very limited life.

  27. Audio recording developed In 1898, the Telegraphone, the first practical magnetic sound recorder was patented. They were sold as dictation machines and general purpose sound recorders. It was not until WW2 that magnetic tape, common to tape recorders, was developed.

  28. First u.s. broadcast station KDKA in Pittsburgh, Pa., was the first radio station to be officially licensed by the Dept. of Commerce as a commercial radio station. They played music by holding a microphone up to a phonograph. And marketed these radios for $10 each. By 1920, radio was officially on the scene in the U.S.

  29. Government regulation The U.S. Congress passed the Radio Act of 1927, which created the Federal Radio Commission (FRC). The FRC’s purpose was to organize the licensing of transmitters, including assigning radio station frequencies, call letters, and power limits.

  30. Government regulation Stations to the east of the Mississippi started with “W,” and stations west start with the letter “K.” In 1934, the FRC was reorganized into the agency that now controls U.S. broadcasting: the Federal Communications Commission (FCC). The FCC’s regulatory powers expanded to include telephone and telegraph—and years later, television.

  31. The golden age of radio The Golden Age of Radio—the period when radio reached its peak popularity—was in the 1930s and 1940s. Part of this period was during the Great Depression. Radio and its wide range of live music, comedy, variety shows, and dramatic programming served as a welcome escape from those troubled times.

  32. Stay tuned: tomorrow… The Golden Age of Radio! The “War of the Worlds” Broadcast! How Radio Works!

  33. The early history of radio Once radio broadcasting was launched, people began to realize just how significant this new medium could be. KDKA, along with at least one other station, broadcast the 1920 Harding-Cox presidential election returns—well in advance of the newspapers.

  34. The early history of radio People took note of all the free music, information and commentary that was suddenly available to anyone with a radio set. But…scores of people were building their own personal radio stations, which created a major problem.

  35. The early history of radio Soon there were too many stations for the number of frequencies available to separate them on the dial.

  36. The dawn of broadcast advertising In 1922, a station in New York, WEAF, ran a 10-minute talk on the merits of some co-op apartments --and charged $50 for their effort. That was deemed a toll broadcast – now better known as a commercial. Things haven’t been the same since.

  37. Government regulation The U.S. Congress passed the Radio Act of 1927, which created the Federal Radio Commission (FRC). The FRC’s purpose was to organize the licensing of transmitters, including assigning radio station frequencies, call letters, and power limits. Stations to the east of the Mississippi started with “W,” and stations west start with the letter “K.” In 1934, the FRC was reorganized into the agency that now controls U.S. broadcasting: the Federal Communications Commission (FCC). The FCC’s regulatory powers expanded to include telephone and telegraph—and years later, television.

  38. The golden age of radio The Golden Age of Radio—the period when radio reached its peak popularity—was in the 1930s and 1940s. Part of this period was during the Great Depression. Radio and its wide range of live music, comedy, variety shows, and dramatic programming served as a welcome escape from those troubled times.

  39. The golden age of radio Even though people couldn’t afford payments on their washing machines, vacuum cleaners or Model A Fords, they desperately struggled to keep up payments on their radios.

  40. The early history of radio By 1935, more than 22 million American homes had radios, and automobiles were being sold with radios.

  41. Radio = major advantage in news Radio had a major advantage in being able to “be first with the news.” Not only were radio stations scooping newspapers on major stories, they also were siphoning off advertising revenue.

  42. Radio = major advantage in news Radio did especially well in bringing the news and drama of World War 2 into the homes of Americans. Edward R. Murrow was the most notable news personality of this era. He once did a live report from London with the sounds of bombs falling around him.

  43. The “war of the worlds” broadcast October 1938 Orson Welles, a young, controversial genius of radio, stage and film, had come up with a radio drama for Halloween night involving an invasion from Mars.

  44. The “war of the worlds” broadcast The show was in the form of a mock radio newscast featuring supposedly live reports from various parts of the U.S., tracing the destructive advance of the Martians across the country Keep in mind that this was during the time when “radio was king.” The show caused panic across the country.

  45. Am, fm waves and sound To understand some of the concepts we’ve talked about as well as some of the strange things that happen to broadcast signals, we need to take a look at how radio works.

  46. Am, fm waves and sound AM stands for amplitude modulation. AM radio ranges from 530 to 1710 kHz (kilohertz, or thousands of cycles per-second of electromagnetic energy). These are the numbers you see on your AM radio dial.

  47. Am, fm waves and sound You can see that AM radio waves are of a lower frequency than either FM radio or TV waves. They behave differently too.

  48. Am, fm waves and sound Because the signals of AM stations tend to be limited in their range, you can use some of the frequencies many times –as long as the stations are far enough apart geographically. This is why we can have nearly 5,000 AM radio stations on only 117 different frequencies.

  49. Am, fm waves and sound How far the AM station’s signal travels depends on such things as the station’s frequency, the power of the transmitter in watts, how good their antenna is, and a thing called ionospheric refraction. Ionospheric refraction is a big deal because AM radio waves can end up hundreds, even thousands, of miles away and interfere with other stations on the same frequency.

  50. Am, fm waves and sound During the daytime, the distance the AM radio signal travels is the distance the ground wave travels based upon the power of the transmitter. Notice the ground wave doesn’t go very far. This means stations can be put on the same frequency without interfering with each other. The signal also reaches the ionosphere –and it is much more effective in reflecting radio waves at night.

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