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A History of Radio Technology. Demystifying Telecommunications By: Al Klase. What do these Have in Common?. Information-Age Timeline. A Favorite Quote. “Any sufficiently advanced technology is indistinguishable from magic.”
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A History of Radio Technology Demystifying Telecommunications By: Al Klase
A Favorite Quote “Any sufficiently advanced technology is indistinguishable from magic.” Arthur C. Clark, "Profiles of The Future", 1961 (Clarke's third law)English physicist & science fiction author (1917 – 2008) Inventor of the communications-satellite concept.
A Mysterious Force • Start at the beginning • In the Stone Age • Sticks • Stones • Animal Parts
Amber • Naturally polymerized tree resin • Greeks called it elektron
Electric Field Johann Carl Friederich Gauss 1777-1855
The Condenser or Capacitor Stores Energy as electrostatic charge. C = Q / V Q = charge in Coulombs (6.241506×1018 electrons/C ) V = EMF in Volts
Alessandro Volta (1745-1827) Ca. 1774
Yet Another Mysterious Force • Heavy black rock • Lodestone • Proved to be iron ore • Greeks found theirs in Magnesia
Magnetic Field due to Electrical Current 1820 - Hans Christian Ørsted André-Marie Ampère (1775-1836)
Joseph Henry 1797 - 1878 Electro Magnet and Inductor Stores energy as a magnetic field. Taught and did research at Princeton. Ca. 1824
Samuel Morse’sTelegraph1838(Binary Serial Communications!) Speedwell Morristown.
Maxwell Treatise on Electricity and Magnetism (1873) James Clerk Maxwell 1831 - 1879
Hertz Ca. 1888 Heinrich Hertz 1857 - 1894
A Hertzian Experiment From Invention & Innovation in the Radio Industry, W. Rupert MacLaurin, 1949
PHz = petahertz Ehz = exahertz
Short-Wave Broadcast + WiFi, Bluetooth + Satellite TV Cellphones + GPS + + Satellite TV
Propagation ModesDirect-Wave All Frequencies
Propagation ModesGround-Wave ELF-VLF-LF-MF Below 30 HZ – 3 MHz
Propagation ModesSky-Wave MF-HF (VHF) - 300 KHz – 30+ MHz • Can allow global point-to-point communications and broadcasting • Varies with: • Frequency • Time of day • Season • Solar activity (11-year Cycle)
Guglielmo Marconi • Born 1874 • Wealthy Italian father • Wealthy Irish mother (Jamison) • Tech. Institute at Leghorn included telegraphy • Inspired by Hertz’s Obituary in 1894
Marconiat Villa Grifone Photos and drawings from Early Radio by Peter R. Jensen
Marconi Developments • 1896 Moves to Great Britain • Sept. 1896, 2.8Km, Salisbury Plain • Mar. ‘97, 14Km, Bristol Channel • Late 1898, 29Km, Isle of Wright
Patent 7777Application filed 12 April 1900 From The Wonders of Wireless Telegraphy J. A. Fleming, London, 1913
The Fleming Valve John Ambrose Fleming3(1849 - 1945)
From The Wonders of Wireless Telegraphy J. A. Fleming, London, 1913
The Audion Lee Deforest 1906
Armstrong Edwin Howard Armstrong
The Regenerative Circuit “Great amplification obtained at once!”
Regen Prototype Demonstrated to Sarnoff at the Marconi station at Belmar