This page is created for my students who took up Electronics as their major in TLE. This page will serve as their online-classroom so that learning experiences will be enjoyable, interactive and make the lesson available at all times.
History of radio
The early history of radio is the history of technology that produced radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy".Later radio history increasingly involves matters of programming and content. James Clerk Maxwell showed mathematically that electromagnetic waves could propagate through free space. Heinrich Rudolf Hertz and many others demonstrated radio wave propagation on a laboratory scale. Transmission and radiation of radio frequency energy was a feature exhibited in the experiments by Nikola Tesla, that he proposed in 1892 and 1893 might be used for the telecommunication of information.The Tesla method was described in New York in 1897. In 1897, Tesla applied for two key United States radio patents, US 645576, first radio system patent, and US 649621. Tesla also used sensitive electromagnetic receivers, that were unlike the less responsive coherers later used by Marconi and other early experimenters. Shortly thereafter, he began to develop wireless remote control devices. In 1895, Marconi built a wireless system capable of transmitting signals at long distances (1.5 mi./ 2.4 km). From Marconi's experiments, the phenomenon that transmission range is proportional to the square of antenna height is known as "Marconi's law". This formula represents a physical law that radio devices use. The term wireless telegraphy is a historical term used today to apply to early radio telegraph communications techniques and practices, particularly those used during the first three decades of radio (1887 to 1920) before the term radio came into use. Guglielmo Marconi demonstrated application of radio in commercial, military and marine communications and started a company for the development and propagation of radio communication services and equipment. The field of radio development attracted many researchers, and bitter arguments over the true "inventor of radio" persist to this day.
