Thursday, June 3, 2010

Philip Old Transistor Radio

This old radio was never tested so I do not know whether it is working or not. But it is very nice for your home decorative or display items.


Radio Info

Radio is the transmission of signals by modulation of electromagnetic waves with frequencies below those of visible light.Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space. Information is carried by systematically changing (modulating) some property of the radiated waves, such as amplitude, frequency, phase, or pulse width. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can be detected and transformed into sound or other signals that carry information.

Originally, radio or radiotelegraphy was called "wireless telegraphy", which was shortened to "wireless" by the British. The prefix radio- in the sense of wireless transmission, was first recorded in the word radioconductor, coined by the French physicist Édouard Branly in 1897 and based on the verb to radiate (in Latin "radius" means "spoke of a wheel, beam of light, ray"). "Radio" as a noun is said to have been coined by the advertising expert Waldo Warren (White 1944). This word also appears in a 1907 article by Lee De Forest, was adopted by the United States Navy in 1912 and became common by the time of the first commercial broadcasts in the United States in the 1920s. (The noun "broadcasting" itself came from an agricultural term, meaning "scattering seeds widely".) The term was then adopted by other languages in Europe and Asia. British Commonwealth countries continued to mainly use the term "wireless" until the mid 20th century, though the magazine of the BBC in the UK has been called Radio Times ever since it was first published in the early 1920s.

In recent years the term "wireless" has gained renewed popularity through the rapid growth of short-range computer networking, e.g., Wireless Local Area Network (WLAN), WiFi, and Bluetooth, as well as mobile telephony, e.g., GSM and UMTS. Today, the term "radio" often refers to the actual transceiver device or chip, whereas "wireless" refers to the system and/or method used for radio communication, hence one talks about radio transceivers and Radio Frequency Identification (RFID), but about wireless devices and wireless sensor networks.

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.[1] Radio development began as "wireless telegraphy".[1] Later radio history increasingly involves matters of programming and content.

Who invented the radio?
In the history of radio and development of "wireless telegraphy", several people are claimed to have "invented the radio" leading to a great radio controversy. The most commonly accepted claims are:

Jagadish Chandra Bose
Guglielmo Marconi, who equipped ships with life-saving wireless communications, conducted a reported transatlantic radio communications experiments in 1901 and established the first commercial transatlantic radio service in 1907.
Alexander Stepanovich Popov
Nikola Tesla, who developed means to produce radio frequency currents, publicly demonstrated the principles of radio, and transmitted long distance signals.
Radio technology is a product of many different discoveries and developments.

Various scientists proposed that electricity and magnetism, both capable of causing attraction and repulsion of objects, were linked. In 1802 Gian Domenico Romagnosi suggested the relationship between electric current and magnetism, but his reports went unnoticed. In 1820 Hans Christian Ørsted performed a widely known experiment on man-made electric current and magnetism. He demonstrated that a wire carrying a current could deflect a magnetized compass needle. Ørsted's experiments discovered the relationship between electricity and magnetism in a very simple experiment. Ørsted's work influenced André-Marie Ampère to produce a theory of electromagnetism. During its early development and long after wide use of the technology, disputes persisted as to who could claim sole credit for this obvious boon to mankind. Closely related, radio was developed along with two other key inventions, the telegraph and the telephone.

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