radio history

By khalil.white

  • George Adams

    notices sparks between charged and uncharged conductors when a Leyden jar was discharged nearby.

  • Luigi Galvani

    notices a spark generated nearby causes a convulsion in a frog's leg being touched by a scalpel.[3] In different experiments, he notices contractions in frogs' legs caused by lightning and a luminous discharge from a charged Leyden jar that disappeared over time and was renewed whenever a spark occurred nearby.

  • Hans Christian

    discovers the relationship between electricity and magnetism in a very simple experiment. He demonstrates that a wire carrying a current was able to deflect a magnetized compass needle.

  • Michael Faraday

    begins a series of experiments in which he discovers electromagnetic induction. The relation was mathematically modeled by Faraday's law, which subsequently becomes one of the four Maxwell equations. Faraday proposes that electromagnetic forces extended into the empty space around the conductor, but does not complete his work involving that proposal.

  • Peter Samuel

    observes the permanent increase of the electrical conductivity of a mixture of loose metal filings in a glass tube with two metal plugs in it resulting from the passage of a discharge current of a Leyden jar through it. This is an early example of the coherer effect.

  • Joseph Henry

    publishes his experimental results showing the oscillatory nature of the discharge in leyden jars and describes how a generated spark could magnetize a needle surrounded by a coil up to 220 feet away. He also describes how a lightning strike 8 miles away magnetized a needle surrounded by a coil, an effect that was most probably caused by radio waves. He considered both of these effects to be due to electromagnetic induction at the time

  • first radio signal

    Marconi sent the first radio signal

  • audion tube

    lee de forest created the first audin tube

  • radiostaions

    the first radiostaions

  • 10 min commercial

    weft aired a 10 min commercial

  • FRC

    uncle Charlie was too popular

  • the golden era

    middle of the great depression people needed money