What is Radio?Wireless communication, which is the order of the day has only been possible with the discovery of the radio over eight decades ago. Radio technology is all about the use of radio waves to transmit information, particularly through sound by the systematic modulation of electromagnetic energy waves that are transmitted over space like frequency, amplitude, pulse width or phase. As the radio waves hit the electrical conductor, the alternating current induce oscillating fields in the latter. The information carried by the waves are extractable and may be transformed into the original form.
How does Radio work?
Any radio system requires a transmitter to change some properties of the produced energy to impress signals on it, by way of angle modulation or amplitude modulation. An antenna is also required for conversion of electrical currents into radio waves and vice versa. The antenna is usable both for receiving and transmitting and the tuned circuit electrical resonance of a radios allows for selection of individual stations. The tuned receiver antenna intercepts the electromagnetic wave while the radio’s receiver catches the input given by the antenna, converting it into an usable form for the end user by way of pictures, sound, measurement values, digital data and navigational positions. The usual range of radio frequency is from 3 kHz to 300 GHz.
Advent of the radio
Radio was and still is used more frequently by seafarers. Early maritime users sent telegraphic messages by using the Morse code from their ships. It was as early as 1905 when the Japanese Navy scouted the Russian fleet in the Battle of Tsushima. Another notable use of radio took place in 1912 when the RMS Titanic was sinking to send out SOSs to vessels nearby as also to shore stations for relief.
Radio’s use and importance was further underscored for military communications during World War I. Germany resorted to radio communications to transmit coded secret messages on discovering that the British had intercepted its submarine cables.
Official radio broadcasting in the United States started in 1909 from San Jose in California and became commercially feasible in the Twenties as radio receivers were placed in a plethora of European countries as also the United States. It was, however, in the Thirties that point-to-point broadcasting, telephonic messages and radio program relays for entertainment became popular. A notable development during this time was radar to detect and locate ships and aircraft.
Radio’s Golden Age was before television’s advent. Commercial broadcasts included news, music, plays, variety shows and comedies and these kept listeners glued to their radio sets till the mid-1950s before television slipped in.
Radio’s portability increased by leaps and bounds with the discovery and development of the miniature transistor which the Japanese popularized worldwide. The erstwhile heavy valve sets that needed to be warmed up before they could emit sound gave way to much smaller, portable transistors that were not only battery operated but emitted sound at the mere touch of a switch.
It also became possible to tune into any major radio station worldwide through Short Waves 1 and 2 and the Sixties often saw transistor advertisements with families picnicking in parks or beaches with a transistor by their side, its antenna up and trembling in the wind.
With the advent of cable TV and other forms of digital entertainment, however, the popularity of radio may have decreased. However, its utility value as a communication tool has not gone down, particularly in the global shipping industry. On numerous occasions, it has been seen that during widespread natural calamities, HAM Radio has come to the rescue of those affected where other modes of communication have failed. This in itself underscores the importance of radio which may have been down but is certainly not out.