Sunday, 10 February 2013

Wireless telegraphy circa 1913

In standard telegraphy,  a complete circuit (two wires) was used.  The first step towards wireless electrical telegraphy was discovered back in 1838, whereby if instead of two wires only one was used, and the other replaced by an earth connection,the effect could be equal to or better than what it was with the metallic circuit.

The second step was, of course, to get rid of the other wire. 


Many scientists made contributions to the practical aspects of wireless technology. Scottish theoretical physicist James Clerk Maxwell predicted the possibility of generating electromagnetic waves that would travel at the speed of light in the 1860s , formulating a classical electromagnetic theory  uniting all previously unrelated observations, experiments, and equations of electricity, magnetism, and optics . (he also made first durable colour photo in 1861).  Twenty years later German physicist Heinrich Hertz demonstrated this when he generated sparks between two metal balls and later experimenters managed to increase the distance across which waves could be transmitted.

In 1879 David Edward 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, and developed his spark-gap transmitter and receiver that could send and receive Morse code signals out to a range limited to 500 yards.  His work was dismissed as induction by some peers (but recognised in 1922 when his devices were recovered 20 years after his death). In 1894 British scientists, Oliver Lodge and Alexander Muirhead , sent Morse-code signals over a distance of half a mile.

David Edward Hughes (1831-1900) and his Telegraph table, source

In 1895 Russian physicist, Aleksandr Stepanovich Popov, built a receiver to detect electromagnetism in the atmosphere. He predicted that it might be used to pick up generated signals, and demonstrated sending and receiving messages between different points the following year.
Radio pioneer Alexander Popov on the 1989 USSR stamp source

In 1898, Nikolas Tesla demonstrated a radio-controlled boat – something he had been working on since 1892.   Tesla changed the boat's direction, with manually operated controls on the command post.  Since this was the first application of radio waves, it made front page news, in America, at that time.  Tesla tried to sell his idea to the U.S. military as a type of radio-controlled torpedo, but they showed little interest,and remote radio control remained a novelty until after WWI.
 Tesla_boat   Tesla_boat1
Tesla’s radio controlled boat, source

Once 20 year old Italian Guglielmo Marconi took several previous inventions and discoveries and brought them together to produce radio in about 1895, it was a short step to produce electric wave telegraphy for communication.  With wireless technology it was possible to contact ships at sea, something which hadn’t been possible previously, so wireless telegraphy was a sure to be a hit. 

Marconi beat everyone to the finish line, applying for a patent and gaining backing in London in 1896.  Marconi founded the The Wireless Telegraph & Signal Company in 1897, and won the support of the Engineer in Chief of the Post office, William Preece,  demonstrating sending Morse signals between two post office buildings.  At first the distance was only 300 yards, but he extended that to 4 miles on Salisbury plains, and then sent messages across the English Chanel in 1899 using large transmitter masts.

Marconi’s first two commercial customers were Lloyd’s of London, who installed radio in a lighthouse off the Irish coast to report the passage of transatlantic ships and the East Goodwin lightship in the English Channel so it could keep in contact with land.  At this stage messages were still in code, but he also managed to transmit the first radio news in 1898 – regatta racing results.  In 1900, Tesla was granted patents for a "system of transmitting electrical energy" and "an electrical transmitter", and when  Marconi made his first 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 favour of Marconi in 1904.
Marconi operating apparatus similar to that used by him to transmit first wireless signal across Atlantic, 1901 source

In 1899 the United States Army established wireless communications with a lightship off Fire Island, New York. Two years later the Navy adopted a wireless system. Up to then, the Navy had been using visual signalling and homing pigeons for communication.
In 1900 Marconi introduced wave tuning, specific wavelengths which radios today still use to send and receive, which meant that more than one transmitter could be used at a time, and also increase the distance the messages could travel.  Oliver Lodge had actually filed for a British patent on his radio tuner in 1898, the same year he applied for a patent for an improved loudspeaker .
Oliver Lodge, with loudspeaker, c. 1913 source

In 1901, radiotelegraph service was instituted between five Hawaiian Islands.  By 1903, a Marconi station located in Wellfleet, Massachusetts, carried an exchange or greetings between President Theodore Roosevelt and King Edward VII, and by then about 50 merchant ships were using wireless telegraph,with 25 shore stations.  The Royal Navy also embraced the technology, which enabled at least 80 naval ships to stay in constant contact with the admiralty – something to affect naval battles during WWI.  In 1905 the naval battle of Port Arthur in the Russo-Japanese war was reported by wireless, and in 1906 the US Weather Bureau experimented with radiotelegraphy to speed notice of weather conditions.

Marconi was also busy.   At the Wardenclyffe plant on Long Island he hoped to demonstrate wireless transmission of electrical energy across the Atlantic, but Marconi ‘s demonstration in 1901 beat him, and Tesla lost his funding.
Tesla's Wardenclyffe plant on Long Island in 1904.

From 1904 when he immigrated to the United States from Luxembourg Hugo Gernsbacher established a radio and electrical supply house called Electro Importing Company and developed a small portable radio transmitter called the Telimco Wireless Telegraph.    He went on to patent 80 inventions. 
telimo wireless telegraph
In 1907 Marconi set up a cheap wireless telegraph service between New York and London, using stations in Ireland and Canada.  In 1909 he shared the Nobel Prize in Physics with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy."
Australia also adopted wireless telegraphy for communications at sea and in lighthouses, and wireless telegraphy gradually replaced the Overland Telegraph (completed 1872) allowing faster communication in remote locations.  Even before Marconi transmitted across the Atlantic,  spark transmitter experiments with radio telegraphy had taken place with 12” and 14” coils, in Australia from the mid 1890s.   In 1902, there was a successful contact from Hobart, Tasmania, with the HMS St. George, which was one of the first ships accompanying the Duke of York (later King George 5th) on his visit to Australia to open the first Federal Parliament in Melbourne.
HMS St George, c. 1902, with telegraph towers, source

The technology quickly came under the control of the newly formed Federal Government through the Wireless Telegraphy Act of 1905.  In the same year Marconi’s company built Australia's first two-way wireless telegraphy station at Queenscliff in Victoria, followed by one in Devonport, Tasmania.  On the opening day for both stations,  July 12 1906, telegraph messages were exchanged between the Australian Prime Minister,   Australian State Governors, and other dignitaries, over the 150 km of water across Bass Strait.

In 1910, the first temporary ship-to-shore station opened in Australia, in Sydney, with the call-sign ATY.  Permanent stations opened in Melbourne (VIM, at the Domain site near Melbourne’s CBD), Perth (VIP), Sydney (VIS), Hobart (VIH), and Brisbane (VIB) in 1912  and in 1913 many other stations started up for ship-to-shore services.  By 1913 there were 19 radio telegraph stations operating from Australia for ships at sea.
1912 - the Domain mast (recolored) source
In October 1911 Mawson purchased from the Australian Wireless Company, on a buy back agreement, two 2-kilowatt long-wave Telefunken wireless sets, costing £650 each (over $65,000 in today’s dollars).  He had decided that the cost was worth it to set up a wireless-telegraph relay station at Macquarie Island to ensure uninterrupted communication between his Australian base at Hobart and his two bases on the Antarctic coast.  This way he was able to take some  uncertainty out of Antarctic exploration and be able to announce his successes and difficulties as they occurred.  Unfortunately sometimes static prevented successful communication.
Hannam and the wireless instruments at Cape Denison during the Mawson expedition.

Although the sinking of the Titanic in 1912 was a terrible disaster, the loss of life may have been total were it not for the ship’s radio operator alerting nearby ships.   Unfortunately other radio operators were not on duty, and so the message was delayed getting through – after 1912 all liners had to have a 24 hour radio watch.

In 1913, Marconi amalgamated with its main competitor, Telefunken, to form Amalgamated Wireless (Australasia) Ltd. (AWA).

rep Tesla-_620x0

During the WWI wireless telegraphy was widely used by wartime ground forces, and most private experiments in wireless technology were stopped for the duration.  Many naval ships were fitted with radios, although when they were used, it did make it easier for enemy submarines to discover where they were, and reconnaissance aircraft that carried wireless sets could also communicate the position of enemy ships and artillery.

In 1943, the 1904 U.S. version of Marconi’s patent,  US patent No. 763,772, was found to be invalid in a US  Supreme Court decision. There are some that claim this decision affirmed Nikolai Tesla as the inventor of radio  and others who claims the high court was trying to nullify a WWI claim against the U.S. government by the Marconi Company by restoring Tesla's prior patent.  What do you  think? I don’t know, I am just happy we have radio!  More on radio and 1913 technology next time.

Deb xx

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