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Radio. *Warning* Heavy Science Content Ahead. Baghdad battery – 250 BCE. Electricity was a heavy duty toy for decades, including Ben Franklin and his kite, people rubbing cat skins on glass or amber rods, spinning sulfur balls, and sparking everything and everyone in sight.

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Radio

Radio


Warning heavy science content ahead

*Warning*Heavy Science Content Ahead


Baghdad battery 250 bce

Baghdad battery – 250 BCE


Radio

  • Electricity was a heavy duty toy for decades, including Ben Franklin and his kite, people rubbing cat skins on glass or amber rods, spinning sulfur balls, and sparking everything and everyone in sight


Luigi galvani 1786

Luigi Galvani - 1786

  • Believed everything contained electricity

  • Looked for “animal magnetism”

  • Touched different metals to frogs’ legs which twitched


Alessandro volta 1796

Alessandro Volta - 1796


Alessandro volta 17961

Alessandro Volta - 1796

  • Volta took Galvani’s experiment and showed that it was the current produced by the different metals that caused the twitch

  • Built a pile of alternating sandwiches of zinc and copper in an acid and created electicity


Hans christian oersted 1820

Hans Christian Oersted - 1820


Oersted s experiment 1820

Oersted’s experiment - 1820

  • In a lecture in Copenhagen he performed an experiment to demonstrate there was no connection between electricity and magnetism by showing that an electric current passing through a wire wouldn’t affect a nearby compass needle


Radio

  • Imagine his surprise when the needle swung the moment he turned on the current

  • He demonstrated that electricity created a magnetic field


William sturgeon 1825

William Sturgeon - 1825

  • Created the first electromagnet by wrapping wire around a soft iron bar and sending a current through the wire

  • Electricity can create magnetism


Michael faraday 1826

Michael Faraday - 1826

  • Reversed Sturgeon’s experiment

  • Showed that magnetism could create an electric current


Samuel f b morse 1838

Samuel F. B. Morse - 1838


Radio

  • Used a an on-off switch – the telegraph key – to turn an electric current on and off, sending pulses of current through a wire to an electromagnet that would click in time to the pulses


Johannes mueller 1840

Johannes Mueller - 1840


Radio

  • Examined physical sensations

    • Can you feel colors

    • Can you hear shapes

    • Can you smell sounds

  • Discovered that each sense detects different things

  • We think this is obvious, but no one had proven it before. Remember “common sense”?


Herman hemholtz 1857

Herman Hemholtz - 1857


Radio

  • Meuller’s pupil

  • Investigated hearing

  • Noticed sound produced vibrations


Radio

  • Did the vibrations operate at different frequencies?

    • They did

    • Thus, sound traveled at different frequencies

  • Used an electromagnet to attract the arms of a tuning fork, causing it to vibrate and produce sound


Leon scott de martinville phonautograph 1857

Leon Scott de Martinville - phonautograph - 1857

  • Attached a bristle to a membrane at the end of a cone, set the bristle to touch a piece of smoked glass

  • Spoke into the cone

  • membrane vibrated to the sound and the bristle etched a wavy line onto the smoked glass


The telephone 1876

The Telephone - 1876

  • Scott’s membrane, Faraday’s electromagnet, Oersted’s and Sturgeon’s electromagnet, Morse’s wire and electrical current, Heimholtz’s vibration, Scott’s membrane


Bell and gray

Bell and Gray


Samuel morse

Samuel Morse


Heinrich hertz 1886

Heinrich Hertz - 1886


Radio

  • Hemholtz’s pupil

  • Investigated whether electricity traveled in frequencies the way sound did


Spark gap generator

Spark gap generator


Hertz spark gap experiment

Hertz’ spark gap experiment


Radio

Demonstrated that electricity traveled through air at specific frequencies, just like it did through wires


Guglielmo marconi 1894

Guglielmo Marconi - 1894


Marconi radio

Marconi radio


Morse key

Morse key


Marconi and his radio

Marconi and his radio


Nikola tesla

Nikola Tesla


Tesla coil 1891

Tesla coil - 1891

  • Developed the first amplifier coil, the Tesla coil

  • Raised the voltage of an electrical current high enough to allow the air to conduct the current

  • Key to wireless transmission of radio waves


Reginald fessenden

Reginald Fessenden


Radio

  • Felt that the variation in electrical amplitude created by a voice, just like on a telephone, could be carried by electrical wave of a radio signal

  • Did the first voice broadcast in 1900

    • Short range

    • Poor quality

  • Needed far more power


Ernst alexanderson

Ernst Alexanderson


Radio

  • Developed the Alexanderson Alternator, a machine capable of generating the power, up to 100,000 hertz, that Fessenden needed to piggyback voice onto radio waves

  • In Dec. 1906, Fessenden did the first good voice and music broadcast, going hundreds of miles

    • Poetry and a Bible reading

    • A woman singing opera

    • A violin playing a Christmas carol


Lee de forest

Lee de Forest


Radio

  • The audion tube is actually a Fleming valve (British term for tube) invented in England

  • de Forest simply added the bent wire


De forest s audion tube 1904

De Forest’s audion tube - 1904


Radio

  • Audion tube amplified the radio signal the way the Alexanderson generator increased the electrical power

  • de Forest didn’t know how the audion worked

  • Another man did


Edwin howard armstrong

Edwin Howard Armstrong


Radio

  • Investigated the audion tube, figured out how it worked, and improved it

  • Developed “regeneration”

    • The signal was fed back into the tube over and over again, up to 20,000 times a second

    • Vastly increased the power of the tube to output the signal – it was an amplifier

    • Raise the level enough and the tube becomes a transmitter

    • Armstrong invented the ability to broadcast sound


Radio

  • It combined high frequency waves with low frequency waves, then fed them back into the system to amplify the signal and increase its sensitivity

  • Resulted in the creation of the home, and the portable, radio


Armstrong s superheterodyne

Armstrong’s superheterodyne

  • Armstrong’s next invention was the superheterodyne


Crystal radio

Crystal Radio


David sarnoff

David Sarnoff


Radio

  • Enamored of radio

  • Saw the possibilities

  • Wrote the “Radio Music Box Memo” that outlined the commercial possibilities of radio


Rca radio corporation of america

RCA (Radio Corporation of America)

  • After World War I

  • Four companies merged their patents to create RCA

    • American Marconi

    • General Electric

    • American Telephone & Telegraph

    • Westinghouse

  • Sarnoff named as commercial manager


Radio

  • Used Armstrong’s inventions, building superheterodyne radios to build RCA, the Radio Corporation of America, into one of the biggest companies in the world


Radio stations soon opened all over the u s

Radio stations soon opened all over the U.S.

Including KWSC (now KWSU) in 1922, one of the first radio stations in the country


Https skylight wsu edu student

https://skylight.wsu.edu/student


Examples of programming

Operas

Concerts

Sports

News

Dramas

Comedies

Variety shows

Soap operas

Pretty much everything we get on TV today

Examples of programming


Fibber mcgee and molly

Fibber McGee and Molly


Burns and allen

Burns and Allen


Fred allen

Fred Allen


Abbott and costello

Abbott and Costello


Orson welles 1938

Orson Welles - 1938


Hindenburg disaster 1937

Hindenburg disaster - 1937


Edward r murrow

Edward R. Murrow


The advent of television

The Advent of Television


Radio

  • It was assumed that radio would be dead

    • Audiences would watch TV instead of listening to the radio

    • TV took over so many of the radio programs

      • Soap operas

      • Dramas

      • Sitcoms

      • Sports

      • news


Radio had a great advantage over tv portability

Radio had a great advantage over TV –Portability


Take it anywhere

Take it anywhere


Even in the car

Even in the car


New kinds of programming

New kinds of programming

  • Music

    • Top 40

    • Country

    • Rock

    • Easy listening

    • Golden oldies

  • Talk shows


Howard stern

Howard Stern


On the right rush limbaugh michael savage glenn beck

On the RightRush Limbaugh Michael Savage Glenn Beck


On the left ed schultz stephanie miller

On the LeftEd Schultz Stephanie Miller


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