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History and the Forefathers of Ham Radio

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Barry
History and the Forefathers of Ham Radio

Over the next few weeks, let's talk about the history of Ham Radio and the men and women who were the pioneers of the technology and organization of the hobby called amateur radio.Let's start out this week by talking about the beginning years and how it was determined communication could be accomplished without wires. Who were the prominent figures?

http://ac6v.com/history.htm

http://w2pa.net/HRH/

http://en.wikipedia.org/wiki/Alessandro_Volta

http://en.wikipedia.org/wiki/Hans_Christian_%C3%98rsted

http://en.wikipedia.org/wiki/Andr%C3%A9-Marie_Amp%C3%A8re

http://en.wikipedia.org/wiki/Michael_Faraday

http://en.wikipedia.org/wiki/Joseph_Henry

http://en.wikipedia.org/wiki/Guglielmo_Marconi

http://en.wikipedia.org/wiki/Nikola_Tesla

http://en.wikipedia.org/wiki/James_Clerk_Maxwell

More Detailed info:

Hans Christian Ørsted  14 August 1777 – 9 March 1851) was a Danish physicist and chemist who discovered that electric currents create magnetic fields, an important aspect of electromagnetism.

 

On 21 April 1820, during a lecture, Ørsted noticed a compass needle deflected from magnetic north when an electric current from a battery was switched on and off, confirming a direct relationship between electricity and magnetism. His initial interpretation was that magnetic effects radiate from all sides of a wire carrying an electric current, as do light and heat. Three months later he began more intensive investigations and soon thereafter published his findings, showing that an electric current produces a circular magnetic field as it flows through a wire. This discovery was not due to mere chance, since Ørsted had been looking for a relation between electricity and magnetism for several years. The special symmetry of the phenomenon was possibly one of the difficulties that retarded the discovery.

 

André-Marie Ampère (20 January 1775 – 10 June 1836) was a French physicist and mathematician who is generally regarded as one of the main founders of the science of classical electromagnetism, which he referred to as "electrodynamics". The SI unit of measurement of electric current, the ampere, is named after him.

 

In September 1820, Ampère’s friend and eventual eulogist François Arago showed the members of the French Academy of Sciences the surprising discovery of Danish physicist Hans Christian Ørsted that a magnetic needle is deflected by an adjacent electric current. Ampère began developing a mathematical and physical theory to understand the relationship between electricity and magnetism. Furthering Ørsted’s experimental work, Ampère showed that two parallel wires carrying electric currents attract or repel each other, depending on whether the currents flow in the same or opposite directions, respectively - this laid the foundation of electrodynamics. He also applied mathematics in generalizing physical laws from these experimental results. The most important of these was the principle that came to be called Ampère’s law, which states that the mutual action of two lengths of current-carrying wire is proportional to their lengths and to the intensities of their currents. Ampère also applied this same principle to magnetism, showing the harmony between his law and French physicist Charles Augustin de Coulomb’s law of magnetic action. Ampère’s devotion to, and skill with, experimental techniques anchored his science within the emerging fields of experimental physics.

Ampère also provided a physical understanding of the electromagnetic relationship, theorizing the existence of an “electrodynamic molecule” (the forerunner of the idea of the electron) that served as the component element of both electricity and magnetism. Using this physical explanation of electromagnetic motion, Ampère developed a physical account of electromagnetic phenomena that was both empirically demonstrable and mathematically predictive.

 

Michael Faraday, FRS (22 September 1791 – 25 August 1867) was an English scientist who contributed to the fields of electromagnetism and electrochemistry. His main discoveries include those of electromagnetic induction, diamagnetism and electrolysis.

Although Faraday received little formal education he was one of the most influential scientists in history.[1] It was by his research on the magnetic field around a conductor carrying a direct current that Faraday established the basis for the concept of the electromagnetic field in physics. Faraday also established that magnetism could affect rays of light and that there was an underlying relationship between the two phenomena.[2][3] He similarly discovered the principle of electromagnetic induction, diamagnetism, and the laws of electrolysis. His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts that electricity became practical for use in technology.

 

Albert Einstein kept a picture of Faraday on his study wall, alongside pictures of Isaac Newton and James Clerk Maxwell. Physicist Ernest Rutherford stated; "When we consider the magnitude and extent of his discoveries and their influence on the progress of science and of industry, there is no honour too great to pay to the memory of Faraday, one of the greatest scientific discoverers of all time".

 

Faraday's breakthrough came when he wrapped two insulated coils of wire around an iron ring, and found that, upon passing a current through one coil, a momentary current was induced in the other coil. This phenomenon is now known as mutual induction. The iron ring-coil apparatus is still on display at the Royal Institution. In subsequent experiments, he found that, if he moved a magnet through a loop of wire, an electric current flowed in that wire. The current also flowed if the loop was moved over a stationary magnet. His demonstrations established that a changing magnetic field produces an electric field; this relation was modelled mathematically by James Clerk Maxwell as Faraday's law, which subsequently became one of the four Maxwell equations, and which have in turn evolved into the generalization known today as field theory. Faraday would later use the principles he had discovered to construct the electric dynamo, the ancestor of modern power generators and the electric motor.

In 1839, he completed a series of experiments aimed at investigating the fundamental nature of electricity; Faraday used "static", batteries, and "animal electricity" to produce the phenomena of electrostatic attraction, electrolysis, magnetism, etc. He concluded that, contrary to the scientific opinion of the time, the divisions between the various "kinds" of electricity were illusory. Faraday instead proposed that only a single "electricity" exists, and the changing values of quantity and intensity (current and voltage) would produce different groups of phenomena.

Near the end of his career, Faraday proposed that electromagnetic forces extended into the empty space around the conductor. This idea was rejected by his fellow scientists, and Faraday did not live to see the eventual acceptance of his proposition by the scientific community. Faraday's concept of lines of flux emanating from charged bodies and magnets provided a way to visualize electric and magnetic fields; that conceptual model was crucial for the successful development of the electromechanical devices that dominated engineering and industry for the remainder of the 19th century.

 

Joseph Henry (December 17, 1797 – May 13, 1878) was an American scientist who served as the first Secretary of the Smithsonian Institution, as well as a founding member of the National Institute for the Promotion of Science, a precursor of the Smithsonian Institution. He was highly regarded during his lifetime. While building electromagnets, Henry discovered the electromagnetic phenomenon of self-inductance. He also discovered mutual inductance independently of Michael Faraday, (1791-1867), though Faraday was the first to publish his results. Henry developed the electromagnet into a practical device. He invented a precursor to the electric doorbell (specifically a bell that could be rung at a distance via an electric wire, 1831) and electric relay (1835). The SI unit of inductance, the henry, is named in his honor. Henry's work on the electromagnetic relay was the basis of the practical electrical telegraph, invented by Samuel F. B. Morse, (1791-1872),

 

Alessandro Giuseppe Antonio Anastasio Volta (18 February 1745 – 5 March 1827) was an Italian physicist known for the invention of the battery in the 1800s.

 

Luigi Galvani discovered something he named "animal electricity" when two different metals were connected in series with the frog's leg and to one another. Volta realized that the frog's leg served as both a conductor of electricity (what we would now call an electrolyte) and as a detector of electricity. He replaced the frog's leg with brine-soaked paper, and detected the flow of electricity by other means familiar to him from his previous studies. In this way he discovered the electrochemical series, and the law that the electromotive force (emf) of a galvanic cell, consisting of a pair of metal electrodes separated by electrolyte, is the difference between their two electrode potentials (thus, two identical electrodes and a common electrolyte give zero net emf). This may be called Volta's Law of the electrochemical series.

In 1800 as the result of a professional disagreement over the galvanic response advocated by Galvani, he invented the voltaic pile, an early electric battery, which produced a steady electric current. Volta had determined that the most effective pair of dissimilar metals to produce electricity was zinc and silver. Initially he experimented with individual cells in series, each cell being a wine goblet filled with brine into which the two dissimilar electrodes were dipped. The voltaic pile replaced the goblets with cardboard soaked in brine.

 

Guglielmo Marconi, 1st Marquis of Marconi (Italian: [ɡuʎˈʎɛːlmo maɾˈkoːni]; 25 April 1874 – 20 July 1937) was an Italian inventor and electrical engineer, known for his pioneering work on long distance radio transmission and for his development of Marconi's law and a radio telegraph system. Marconi is often credited as the inventor of radio, and he shared the 1909 Nobel Prize in Physics with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy".

 

During his early years, Marconi had an interest in science and electricity. One of the scientific developments during this era came from Heinrich Hertz, who, beginning in 1888, demonstrated that one could produce and detect electromagnetic radiation—now generally known as radio waves, at the time more commonly called "Hertzian waves" or "aetheric waves". Hertz's death in 1894 brought published reviews of his earlier discoveries, and a renewed interest on the part of Marconi.

 

His goal was to use radio waves to create a practical system of "wireless telegraphy"—i.e. the transmission of telegraph messages without connecting wires as used by the electric telegraph. This was not a new idea—numerous investigators had been exploring wireless telegraph technologies for over 50 years, but none had proven technically and commercially successful. Marconi's system had the following components:

 


  • A relatively simple oscillator, or spark-producing radio transmitter.
  • A wire or capacity area placed at a height above the ground;
  • A coherer receiver, which was a modification of Edouard Branly's original device, with refinements to increase sensitivity and reliability;
  • A telegraph key to operate the transmitter to send short and long pulses, corresponding to the dots-and-dashes of Morse code; and
  • A telegraph register, activated by the coherer, which recorded the received Morse code dots and dashes onto a roll of paper tape.

Similar configurations using spark-gap transmitters plus coherer-receivers had been tried by others, but many were unable to achieve transmission ranges of more than a few hundred metres.

 

Nikola Tesla (Serbian  10 July 1856 – 7 January 1943) was a Serbian American inventor, electrical engineer, mechanical engineer, physicist, and futurist best known for his contributions to the design of the modern alternating current (AC) electricity supply system.

 

Tesla's radio wave experiments in 1896 were conducted in Gerlach Hotel (later renamed The Radio Wave building), where he resided.

In 1898, Tesla demonstrated a radio-controlled boat—which he dubbed "teleautomaton"—to the public during an electrical exhibition at Madison Square Garden. The crowd that witnessed the demonstration made outrageous claims about the workings of the boat: everything from magic to telepathy to being piloted by a trained monkey hidden inside. Tesla tried to sell his idea to the U.S. military as a type of radio-controlled torpedo, but they showed little interest.[98] Remote radio control remained a novelty until World War I and afterward, when a number of countries used it in military programs.[99] Tesla took the opportunity to further demonstrate "Teleautomatics" in an address to a meeting of the Commercial Club in Chicago, whilst he was travelling to Colorado Springs, on 13 May 1899.

In 1900, Tesla was granted patents for a "system of transmitting electrical energy" and "an electrical transmitter". When Guglielmo Marconi made his famous first ever transatlantic radio transmission in 1901, Tesla quipped that it was done with 17 Tesla patents. This was the beginning of years of patent battles over radio with Tesla's patents being upheld in 1903, followed by a reverse decision in favor of Marconi in 1904. In 1943, a Supreme Court of the United States decision restored the prior patents of Tesla, Oliver Lodge, and John Stone.[100] The court declared that their decision had no bearing on Marconi's claim as the first to achieve radio transmission, just that since Marconi's claim to certain patents were questionable, he could not claim infringement on those same patents (there are claims the high court was trying to nullify a World War I claim against the U.S. government by the Marconi Company via simply restoring Tesla's prior patent).

 

James Clerk Maxwell FRS FRSE (13 June 1831 – 5 November 1879) was a Scottish mathematical physicist. His most prominent achievement was to formulate a set of equations that describe electricity, magnetism, and optics as manifestations of the same phenomenon, namely the electromagnetic field. Maxwell's achievements concerning electromagnetism have been called the "second great unification in physics", after the first one realized by Isaac Newton.

With the publication of A Dynamical Theory of the Electromagnetic Field in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving at the speed of light. Maxwell proposed that light is in fact undulations in the same medium that is the cause of electric and magnetic phenomena. The unification of light and electrical phenomena led to the prediction of the existence of radio waves.

 

Heinrich Rudolf Hertz ( 22 February 1857 – 1 January 1894) was a German physicist who clarified and expanded James Clerk Maxwell's electromagnetic theory of light, which was first demonstrated by David Edward Hughes.

 

 Hertz is distinguished from Maxwell and Hughes because he was the first to conclusively prove the existence of electromagnetic waves by engineering instruments to transmit and receive radio pulses using experimental procedures that ruled out all other known wireless phenomena. The scientific unit of frequency – cycles per second – was named the "hertz" in his honor.

 

In 1886, Hertz developed the Hertz antenna receiver. This is a set of terminals which is not electrically grounded for its operation. He also developed a transmitting type of dipole antenna, which was a center-fed driven element for transmitting UHF radio waves. These antennas are the simplest practical antennas from a theoretical point of view.

 

Through experimentation, he proved that transverse free space electromagnetic waves can travel over some distance. This had been predicted by James Clerk Maxwell and Michael Faraday. With his apparatus configuration, the electric and magnetic fields would radiate away from the wires as transverse waves. Hertz had positioned the oscillator about 12 meters from a zinc reflecting plate to produce standing waves. Each wave was about 4 meters. Using the ring detector, he recorded how the magnitude and wave's component direction varied. Hertz measured Maxwell's waves and demonstrated that the velocity of radio waves was equal to the velocity of light. The electric field intensity and polarity was also measured by Hertz.

 

David Edward Hughes (16 May 1831 – 22 January 1900), was a Welsh-American scientist and musician. Hughes was co-inventor of the microphone and teleprinter, inventor of the spark-gap transmitter and inventor of the crystal radio.

 

In 1879, Hughes discovered that sparks would generate a radio signal that could be detected by listening to a telephone receiver connected to his new microphone design. He developed his spark-gap transmitter and receiver into a working communication system using trial and error experiments, until eventually he could demonstrate the ability to send and receive Morse code signals out to a range limited to 500 yards

 

Notably, the radio receiver technology of David E. Hughes surpassed the simplistic spark-gap device that would first be studied by later radio researchers. He discovered that his microphone design exhibited unusual properties in the presence of radio signals. He experimented with the discovery, and described his creation of both the device classically known as a "coherer", and an improved semiconductor carbon and steel point-contact rectifying diode, which he also called a "coherer". The point-contact diode version of the device is now known as a crystal radio detector, and was the key component of his sensitive crystal radio receiver.

 

Amos Emerson Dolbear (November 10, 1837 – February 23, 1910) was an American physicist and inventor. His patents interfered with Guglielmo Marconi's planned activities in the U.S. Dolbear researched electrical spark conversion into sound waves and electrical impulses. He was a professor at University of Kentucky in Lexington from 1868 until 1874.

 

Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932), was a Canadian inventor, born in Quebec, Canada, who performed pioneering experiments in radio, including the use of continuous waves and the early—and possibly the first—radio transmissions of voice and music. In his later career he received hundreds of patents for devices in fields such as high-powered transmitting, sonar, and television.

 

Fessenden worked with Edison and after being laid off was offered the chair at the University of Pittsburg by George Westinghouse in 1908. Fessenden began experimenting with wireless telephones in 1898; by 1899 he had a wireless communication system functioning between Pittsburgh and Allegheny City.

 

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