The history
From a set of equations in 1865 to a voice from the sky in almost every Indian home.
In 1865 James Clerk Maxwell predicted waves of electric and magnetic field that no one had seen. Within forty years, Hertz had made them, Jagadish Chandra Bose had sent them through walls in Calcutta, and Marconi had sent them across the Atlantic. Then came voices, tuning and the superhet, and after 1954 the cheap transistor set. In India, radio clubs in the 1920s grew into All India Radio, Akashvani, which now reaches almost everyone and still carries cyclone warnings to boats at sea.
1865
Electromagnetic waves predicted
James Clerk Maxwell, UK
1887
Radio waves made and detected
Heinrich Hertz, Germany
1895
Millimetre waves demonstrated
J. C. Bose, Calcutta
1901
Signal across the Atlantic
Guglielmo Marconi
1918
Superheterodyne receiver
Edwin Armstrong
1923
Broadcasting in India
Radio Club of Bombay
1954
Transistor radio on sale
Regency TR-1, USA
2004
Community radio in India
Anna FM, Chennai
1864 – 1902
Maxwell predicts electromagnetic waves, Hertz makes them, and Bose, Popov and Marconi learn to detect them and send signals.
1865
1864–1865
Maxwell read his paper 'A Dynamical Theory of the Electromagnetic Field' to the Royal Society in December 1864, and it was published in 1865. His equations said that electric and magnetic fields could travel together as a wave, at the speed of light.
Why it mattered. It predicted radio waves, and showed that light is one of them.
1887
1886–1888
Hertz made sparks jump across a gap in a metal dipole and caught the waves with a loop of wire that sparked in reply, across the room. He measured their wavelength and showed they reflect and refract like light.
Why it mattered. Maxwell's invisible waves were real. The unit of frequency, the hertz, is named after him.
1895
1894–1895
At Presidency College, Bose built apparatus for waves only millimetres to centimetres long, far shorter than anyone else used. In a public demonstration in Calcutta, reported as November 1895, his waves passed through walls and a person to ring a bell and fire a small charge some 23 m away.
Why it mattered. It was pioneering millimetre-wave work, now marked as an IEEE Milestone.
1895
7 May 1895
Popov showed a receiver with a coherer, a bell and a long wire antenna that rang when distant sparks or lightning sent out radio waves. Russia still celebrates 7 May as Radio Day.
Why it mattered. Several inventors were closing in on wireless at the same time.
1895
Summer 1895
Marconi found that raising his antenna higher and earthing his transmitter and receiver pushed the range of his spark signals from metres to kilometres, even beyond a hill.
Why it mattered. Tall antennas and an earth connection made long-distance wireless practical.
1899
1899 (patented 1901)
Bose described a detector with a drop of mercury between iron electrodes, listened to with a telephone earpiece, that did not need tapping to reset. Historians still debate how closely it matches the 'Italian Navy coherer' Marconi used in 1901.
Why it mattered. It was an early self-restoring detector, and part of a long argument over credit.
1901
12 December 1901
Using an antenna held up by a kite in Newfoundland, Marconi reported hearing the Morse letter S sent from Poldhu in Cornwall, about 3,500 km away. The waves had followed the curve of the Earth, bent back by the upper air.
Why it mattered. Radio could span oceans. Marconi shared the 1909 Nobel Prize in Physics.
1900 – 1935
Continuous waves carry speech and music, valves amplify them, and the superhet and FM make radios sharp and clear.
1904
Fleming patented a vacuum tube with a hot filament and a plate that let current flow one way only. It could detect radio signals far more reliably than a coherer.
Why it mattered. The valve began electronics; its triode cousin could amplify.
1906
24 December 1906 (reported)
Fessenden had already sent speech by radio in 1900. He later said that on Christmas Eve 1906 he broadcast music and a Bible reading to ships at sea using a high-frequency alternator. Historians question the details, because his account came 26 years later.
Why it mattered. Continuous waves, modulated by sound, turned wireless telegraphy into radio broadcasting.
1906
Pickard patented a silicon crystal touched by a fine wire, the 'cat's whisker', as a radio detector. Bose had used galena crystals to detect waves in the 1890s and patented a crystal detector in 1904. Cheap crystal sets let millions listen with no battery.
Why it mattered. The first semiconductor devices were radio detectors.
1918
Serving in France in the First World War, Armstrong worked out how to mix an incoming signal with a local oscillator to shift it to a fixed, lower frequency, where it could be filtered and amplified easily. Lucien Lévy in France and Walter Schottky in Germany filed related ideas at about the same time.
Why it mattered. Nearly every radio since the 1930s has been a superhet.
1920
2 November 1920
KDKA went on air with the results of the US presidential election, and kept a daily schedule afterwards. It is widely called the first commercial broadcasting station, though others have rival claims.
Why it mattered. Radio became something families listened to at home.
1933
26 December 1933
Armstrong received five patents for frequency modulation with a wide swing, which he showed could beat static far better than AM. He tested it from the Empire State Building in 1934–35.
Why it mattered. FM gave radio its clear, static-free sound.
1921 – 1960
Amateurs and radio clubs start broadcasting, the state takes over, and All India Radio becomes Akashvani, the voice of a new nation.
1921
Gooptu is recorded as India's first licensed amateur radio operator. By the mid-1930s there were only about 20 in the country.
Why it mattered. Hams were India's first radio makers, and later its disaster volunteers.
1927
23 July 1927
A private company opened stations in Bombay on 23 July 1927 and Calcutta on 26 August 1927. It went into liquidation in March 1930, and the government took over as the Indian State Broadcasting Service on 1 April 1930.
Why it mattered. India's first regular stations, and the start of state broadcasting.
1928
Radio owners had to buy a yearly broadcast receiver licence from the post office. In the 1970s and early 80s it cost about ₹15 a year, and inspectors could check homes and shops for it.
Why it mattered. For over fifty years, listening to the radio needed a permit.
1936
8 June 1936
The state service was renamed All India Radio. The same year in Mysore, M. V. Gopalaswamy started a private station at his home and called it Akashvani, 'voice from the sky', a name suggested by the scholar Rallapalli Ananta Krishna Sharma. AIR adopted Akashvani as its on-air name in 1956.
Why it mattered. It gave India its national broadcaster and its best-loved name.
1947
12 November 1947
Unable to travel to the Partition refugee camp at Kurukshetra, Gandhi went to All India Radio and spoke to the refugees over the air, on Diwali. At independence that year AIR had just six stations. India marks 12 November as Public Service Broadcasting Day.
Why it mattered. Radio could reach people when a leader could not.
1952
With film songs scarce on AIR in the early 1950s, Radio Ceylon's shortwave Hindi service drew huge Indian audiences. Ameen Sayani's weekly countdown of film songs, Binaca Geetmala, became a national habit.
Why it mattered. It showed the hunger for film music that Vividh Bharati was built to meet.
1957
3 October 1957
AIR launched Vividh Bharati, a service of film songs and light entertainment, partly to win listeners back from Radio Ceylon. It became one of India's most popular channels.
Why it mattered. Film songs on the national radio shaped decades of Indian popular culture.
1947 – 1990
The transistor shrinks the radio into a cheap battery set, and India drops its radio licence.
1947
December 1947
The point-contact transistor, a small piece of germanium that could amplify, was demonstrated at Bell Labs. Its inventors shared the 1956 Nobel Prize in Physics.
Why it mattered. It made radios small, cheap and battery-powered.
1954
18 October 1954
The Regency TR-1 was announced on 18 October 1954 and went on sale in November for US$49.95. It had four transistors and ran on a 22.5 V battery. Sony's smaller TR-63 followed in 1957 and made pocket radios a worldwide hit.
Why it mattered. Radio left the living room and went everywhere.
1984
1984 or 1985 (sources differ)
India dropped the broadcast receiver licence for radio sets in the mid-1980s. Wikipedia gives 1984; some accounts say 1985. Listening became free for everyone.
Why it mattered. The cheapest mass medium became free to use.
1977 – today
FM, private stations, community radio, ham operators in disasters and digital radio bring new voices to the air.
1977
23 July 1977
India's first FM broadcasts began in Madras, fifty years to the day after the Indian Broadcasting Company opened in Bombay.
Why it mattered. FM brought clearer sound to Indian cities.
2001
3 July 2001
After the government auctioned FM licences, Radio City in Bangalore became the first private FM station on air. Many more followed in later phases. FMClear tells that story.
Why it mattered. Private FM added dozens of new voices in each city.
2004
26 December 2004
A ham radio DXpedition led by Bharathi Prasad was on the air in Port Blair when the earthquake and tsunami struck. With phone links down, the team relayed emergency and welfare messages to the mainland for days.
Why it mattered. Radio that needs no towers works when everything else fails.
2006
December 2006
A new policy let non-profit groups, NGOs and agricultural universities, not only colleges, run community stations of up to 100 watts from masts up to 30 m high, covering about 12 km.
Why it mattered. Villages got their own stations, in their own languages.
2014
3 October 2014
The Prime Minister's radio talk began on AIR and has gone out roughly once a month since, carried across AIR's network and relayed by many other channels.
Why it mattered. A sign of radio's reach in India in the internet age.
By the numbers
From one campus station in 2004, community radio grew slowly, then quickly after the rules were eased.
Did you know?
A medium-wave station at 1,000 kHz sends waves 300 metres long, as tall as a 100-storey tower.
AIR's medium-wave stations sit 9 kHz apart, and India's FM band runs from 88 to 108 MHz.
A crystal set has no battery: every bit of power you hear comes from the radio wave itself.
FM radios use a 10.7 MHz intermediate frequency so that no FM station's 'image' can land inside the band.
India marks 12 November as Public Service Broadcasting Day, for Gandhi's only visit to All India Radio.
The people
1831 – 1879 · Physicist · Scotland
Wrote the equations that predicted radio waves.
1857 – 1894 · Physicist · Germany
First to make and detect radio waves on purpose.
1858 – 1937 · Physicist and biologist · India
Pioneered millimetre waves and crystal detectors, and patented very little of his work.
1874 – 1937 · Inventor and businessman · Italy
Turned wireless into a worldwide business and shared the 1909 Nobel Prize.
1866 – 1932 · Inventor · Canada
Sent the first speech by radio and championed continuous waves.
1890 – 1954 · Engineer · USA
Invented the regenerative circuit, the superhet and wideband FM.
1932 – 2024 · Radio presenter · India
His Binaca Geetmala countdown made him the best-known voice on Indian radio.
active from the 1980s · Ham radio operator (VU2RBI) · India
Led the Andaman DXpedition that became a lifeline after the 2004 tsunami.
Where it happened
Sources
Dates marked “c.” are approximate, and historians sometimes disagree about who was first. If you spot a mistake, tell us.
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