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![Page 1: Foundations of radio](https://reader038.fdocuments.net/reader038/viewer/2022103006/56813359550346895d9a6dd7/html5/thumbnails/1.jpg)
FOUNDAT
IONS O
F RADIO
F UN
DA
ME
NT A
L S O
F A/ V
: R
AD
I O,
TV
& F
I LM
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THE MEDIUM OF RADIO
For people in most countries of the world, radio represents the number one source
of news and information.
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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.
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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.
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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.
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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.
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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.
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THE MORE THINGS CHANGE…
The Telegraph was just the first of a string of inventions throughout history that
threatened the existing order of things.
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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.
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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.
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THE TELEPHONE IS INVENTED
March 10, 1876First successful experiment with the Telephone.
“Mr. Watson—come here—I want to see
you.”
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…AND LIFE HASN’T BEEN THE SAME SINCEThis version of the telephone was used in
hundreds of thousands of U.S. homes up to the mid-1900s.
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“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.
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“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.
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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.
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THE FOUNDATION OF RADIO
The Telegraph and the Telephone both laid the foundation for RADIO.
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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.
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TRANSMITTING SIGNALS BY RADIO WAVESGuglielmo 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.
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EARLY SIGNALS WIMPY
What was needed was a way of electrically amplifying signals—including the human
voice.
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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.
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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.
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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.
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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.
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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.
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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.
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AUDIO RECORDING DEVELOPED
The first recordings were made on strips of tinfoil and on wax cylinders, both of
which had a very limited life.
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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.
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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.
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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.
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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.
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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.
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STAY TUNED: TOMORROW…
The Golden Age of Radio!The “War of the Worlds” Broadcast!
How Radio Works!
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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.
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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.
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THE EARLY HISTORY OF RADIO
Soon there were too many stations for the number of frequencies available to separate
them on the dial.
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THE DAWN OF BROADCAST ADVERTISINGIn 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.
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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.
![Page 38: Foundations of radio](https://reader038.fdocuments.net/reader038/viewer/2022103006/56813359550346895d9a6dd7/html5/thumbnails/38.jpg)
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.
![Page 39: Foundations of radio](https://reader038.fdocuments.net/reader038/viewer/2022103006/56813359550346895d9a6dd7/html5/thumbnails/39.jpg)
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.
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THE EARLY HISTORY OF RADIO
By 1935, more than 22 million American homes had radios, and automobiles were
being sold with radios.
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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.
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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.
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THE “WAR OF THE WORLDS” BROADCAST
October 1938Orson 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.
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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.
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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.
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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.
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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.
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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.
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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.
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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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AM, FM WAVES AND SOUND
That’s why, at sunset, most AM radio stations in the U.S. have to:
• Reduce power• Directionalize their signal, or
• Go off the air.
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AM, FM WAVES AND SOUND
FM stands for frequency modulated.The FM radio band ranges from 88 to 108 MHz
(megahertz, or millions of cycles per second of electromagnetic energy).
These are the numbers you see on your FM radio dial.
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AM, FM WAVES AND SOUND
Unlike AM radio stations, FM stations –at least in the U.S.—don’t end up being assigned frequencies with nice round numbers like
610 or 1320. Thus, an FM station may be at 105.9 on the dial.
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AM, FM WAVES AND SOUND
You may have noticed that FM (and TV) stations don’t reduce power or sign off the
air at sunset. Because of their higher frequency, ionospheric refraction doesn’t
appreciably affect FM or TV signals.
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AM, FM WAVES AND SOUND
For the most part, FM and TV signals are line of sight. These waves go in a straight line
and don’t bend around the Earth as AM ground waves do. Thus, they can quickly
disappear into space.FM and TV signals can be stopped or reflected
by things like mountains or buildings.The higher you place an FM or TV transmitter
antenna, the greater area they will cover.
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NOW, BACK TO OUR STORY…
So, how could this medium hold families around their radios night after night, and
hold women around their radios every weekday afternoon with soap operas?
For one thing, radio in the Golden Age wasn’t just designed to appeal to specific musical
and philosophical tastes as it is today.It was a family medium.
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NOW, BACK TO OUR STORY…
Families sat around the radio and listened to shows like “The Shadow,” “Gunsmoke,”
“Ellery Queen,” “Dick Tracy,” “Buck Rogers,” and a host of others.
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THE FOUNDATIONS OF RADIO
Today’s listeners, who use radio largely as a background to do other things, might
wonder how radio could hold a listener’s interest for several hours at a time.
There’s a one-word answer:
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Imagination
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THE FOUNDATIONS OF RADIO
Not being “troubled” by the spelled out details in pictures, the people of that era could –and did– imagine what the people
and situations looked like.
For this reason, radio was personally involving.