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.
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.
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.
Other notable milestones in radio transmissions include
- 1899 - Marconi sends a signal over the English Channel
- 1900 - Duddle described and made the first LC tuned circuit
- 1901 - Marconui sends asignal over the Atlantic
- 1902 - Heaviside predicts the existance of "conducting layers" in the atmosphere.
- 1905 - Marconi invents and patents the first horizontal antenna
- 1906 - The first wireless communication of speech
- 1906 - invention of the triode vacuum tube
- 1909 - The first amateur radio club is formed in New York city
- 1910 - "Cats Whisker" detector invented
- 1910 - First Call Book issued
- 1915 - Kellog invents the moving coil loudspeaker
- 1918 - Nicholson invents the rystal controlled oscillator
- 1918 - Armstrong invents the superhetrodyne
- 1923 - SSB invented and patented
- 1926 - Yagi and Uda invent the beam antenna (The Yagi)
- 1933 - the crystal microphone invented
- 1960 - First EME communication
- 1961 - First OSCAR (Orbiting Satellite Carrying Amateur Radio)stallite sent into orbit