Radio

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Radio

  1. 1. RADIOHAREEM FATIMAMODERN DEVELOPMENT AND TECHNOLOGYCOURSE NUMBER 632MADAM DR.RIZWANAFASEEL(H.O.D)
  2. 2. Hearing SignalsOut of Thin Air
  3. 3. SOME ONE ISENTERTAININGBY VOICE ANDFEELINGS
  4. 4. The Radio Timeline Project PageThe advance of Science and Technology depends on individuals with a curiosity whostrive to build on the work of others...NO ONE INDIVIDUAL INVENTORINVENTED THE RADIO !List of Inventors / Scientists you may be asked to research includes1. Hans (Christian) Oersted (compass experiment - current makes magnetic field)2. Michael Faraday (magnetic induction - moving magnet/coil makes current)3. James Clerk Maxwell (equations describing Electromagnetic [EM] waves)4. Thomas Edison (harmonic emission leads to design of vacuum tube)5. Heinrich Hertz (spark EM wave transmission experiment)6. Nikola Tesla (awarded radio transmission radio patent posthumously)7. Guglielmo Marconi (famous for many radio transmission experiments)8. John Ambrose Fleming (improved vacuum tube - diode)9. Reginald (Aubrey) Fessenden (first AM radio broadcast)10. Edward Armstrong (wide-band FM radio)
  5. 5. Radio From TelegraphRadio From Telegraph• Radio has its roots inthe Telegraph.• This device was thefirst widely-used formof long-distancecommunication.• In 1836, SamuelMorse invented alanguage of dots anddashes that is still usedtoday.
  6. 6. 1876• In 1876, AlexanderGraham Bell transmittedthe human voice overwires for the first time.
  7. 7. Telephone• Most of thesetelephones were wiredon party lines, whichmeans that many ofyour neighbors couldlisten to your calls.• All the phones on theparty line rang at onetime, and each homehad its own ringpattern.
  8. 8. Radio BroadcastingIn 1883, a dentist named MahlonIn 1883, a dentist named MahlonLoomis received the patent forLoomis received the patent forwireless telegraphy, butwireless telegraphy, butGuglielmo Marconi is commonlyGuglielmo Marconi is commonlycredited as inventing radio in 1895credited as inventing radio in 1895even though there is credibleeven though there is credibleevidence that other inventors wereevidence that other inventors werefirst.first.
  9. 9. Radio BroadcastingOnce Marconi patented hisOnce Marconi patented hisinvention in England, hisinvention in England, hisnext step was to sell it tonext step was to sell it tothe marine industry.the marine industry.Soon, the majority ofSoon, the majority ofoceangoing ships were alloceangoing ships were allequipped with hisequipped with hisequipment - which madeequipment - which madeMarconi a very rich man.Marconi a very rich man.
  10. 10. 1898• In 1898, Danish inventorValdemar Poulsen created thTelegraphone, the firstpractical magnetic soundrecorder using a piano wire athe recording medium.• Soon, wire recorders begin tappear on the Americanmarket.
  11. 11. FIRST RADIO IN HOME• The Congresspassed the RadioAct of 1927, whichcreated the FederalRadio Commission -FRC.• Its purpose was tooversee thelicensing oftransmitters,assigning radiofrequencies, callletters, and powerlimits.
  12. 12. IMPACT ON SOCIETY• Once radio broadcastingwas launched, peoplebegan to realize just howsignificant this newmedium could be.• For example, KDKA,broadcast the 1920Harding-Cox presidentialelection returns well inadvance of the papers.
  13. 13. DEVELOPMENTS IN RADIO
  14. 14. Antennas
  15. 15. RADIO WAVES CATCHING IN AIR1 2 3
  16. 16. AM AND FMRADIO CONSIST OF TWO KINDSOF FREQUENCIES
  17. 17. AM AND FMAM RADIO:It stands foramplitudemodulationFM RADIO:It stands forfrequencymodulation.
  18. 18. TODAY IS FM• FM or frequencymodulated radio and TVwaves act differentlythan AM radio waves.• The FM radio band goesfrom 88 to 108 MHz(megahertz, or millionsof cycles per second).
  19. 19. TODAY RADIO STATIONS
  20. 20. QUESTIONS?THANK YOU…!

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