History

Communication before Radio

The history of radio communication is really a part of the history of communication, with particular reference to the electromagnetic spectrum. It is argued by some historians that the first recoded transmission in the electromagnetic spectrum is in Homer's Iliad (about 1200BC) where communication through a series of fires is described.

There are also reports of mirrors being used by the Persian army in about 500BC.

Essential Discoveries

Most of the fundamental electrical knowledge that lead to the development of radio was discoveres in the 1500's to the 1800's. Scientists of note include Alessandro Volta, Georg Ohm, Andre-Marie Ampere andCharles Wheatstone.

In 1610, sunspots were discovered by Galileo but their influence on communication was not recognised for many years.

The telegraph was invented in 1823 by Sir Francis Reynolds, and after initially being ignored, was developed throughout the middle 1800's to become a successful communication medium. The communication "language" used was Morse Code, invented by Samuel Morse. It is still used today by radio amateurs in CW.

During the 1800's a number of scientists contributed greatly to the understanding of Electromagnetism, perhaps the most influential of them being James Clerk Maxwell who in 1861 predicted the existance of electomagnetica waves. There existance was not confirmed or demonstrated until Heinrich Hertz did so in 1888. A flurry of activity in the late 1880's included successful communication over 2 miles in 1896 by Marconi.

Ham radio can be thought to have started in 1898 when Leslie Miller encouraged experimenters to work on the then new field of wireless.

Notable dates

• 1899 - Marconi sends a signal across the English Channel
• 1900 - Duddle described and made the first LC tuned circuit
• 1901 - Marconi sends a signal across the Atlantic
• 1902 - Heaviside predicts the existence of "conducting layers" in the atmosphere.
• 1905 - Marconi invents and patents first horizontal antenna
• 1906 - First wireless communication of speech
• 1906 - Triode vacuum tube invented
• 1909 - First amateur radio club is formed in New York City
• 1910 - "Cat Whisker" detector invented
• 1910 - First amateur "callbook" issued
• 1912 - Radio Act of 1912 restricts private stations to wavelengths of 200 meters or less
• 1915 - Kellogg invents the moving-coil loudspeaker
• 1918 - Nicholson invents the crystal-controlled oscillator
• 1918 - Armstrong invents the superheterodyne receiver
• 1923 - Single Sideband (SSB) invented
• 1926 - Yagi and Uda invent the beam antenna now known as the Yagi
• 1927 - First International Radiotelegraph Conference establishes 80, 40, 20 and 10 metre bands, and amateur callsigns
• 1933 - Crystal microphone invented
• 1947 - Heathkit introduces its first electronic kit
• 1960 - First Earth-Moon-Earth communication
• 1961 - First OSCAR (Orbiting Satellite Carrying Amateur Radio) satellite sent into orbit
• 1979 - WARC bands created (12, 17, and 30 metres)

Local Histories

• Ham Radio History - Australia
• Ham Radio History - Canada
• Ham Radio History - New Zealand
• Ham Radio History - United Kingdom
• Ham Radio History - USA

History of amateur radio
Local histories:	Australia * United Kingdom