1. WELCOME TO
RADIO
COMMUNICATION

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Jagadish Chandra Bose
Guglielmo Marconi
Alexander Stepanovich Popov
Nikola Tesla
Ernest Rutherford
Alexander Popov
German troops erecting a wireless field
telegraph station during World War I
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Classic radio receiver dial
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6. Guglielmo Marconi
• Guglielmo Marconi was an electrical engineer and Nobel laureate
known for the development of a practical wireless telegraphy
system.
• In 1896, Guglielmo Marconi was awarded a patent for radio with
British Patent 12039, Improvements in Transmitting Electrical
Impulses and Signals and in Apparatus There-for. This was the
initial patent for the radio, though it used various earlier
techniques of various other experimenters (primarily Tesla) and
resembled the instrument demonstrated by others (including
Popov). During this time spark-gap wireless telegraphy was
widely researched.
• In 1896, Bose went to London on a lecture tour and met Marconi,
who was conducting wireless experiments for the British post
office. In 1897, Marconi established the radio station at
Niton, Isle of Wight, England. In 1897, Tesla applied for two key
radio patents in the USA. Those two patents were issued in early
1900. In 1898, Marconi opened a radio factory in Hall Street,
Chelmsford, England, employing around 50 people. In 1899,
Bose announced his invention of the "iron-mercury-iron coherer
with telephone detector" in a paper presented at Royal Society,
London.

7. Jagdish Chandra Bose
In November 1894, the Indian physicist, Jagdish Chandra Bose
, demonstrated publicly the use of radio waves in Calcutta, but
he was not interested in patenting his work.[10] Bose ignited
gunpowder and rang a bell at a distance using electromagnetic
waves, proving that communication signals can be sent without
using wires. He was thus the first to send and receive radio
waves over a significant distance but did not commercially
exploit this achievement.
The 1895 public demonstration by Bose in Calcutta was before
Marconi's wireless signalling experiment on Salisbury Plain in
England in May 1897.[11][12] In 1896, the Daily Chronicle of
England reported on his UHF experiments: "The inventor (J.C.
Bose) has transmitted signals to a distance of nearly a mile and
herein lies the first and obvious and exceedingly valuable
application of this new theoretical marvel."

8. Nikola Tesla

Nikola Tesla developed means to reliably produce radio frequencies,
publicly demonstrated the principles of radio, and transmitted long distant
signals. He holds the US patent for the invention of the radio, as defined
as "wireless transmission of data".This box: view • talkNikola Tesla
 In 1891 Tesla began his research into radio. He later published an article,
"The True Wireless", concerning this research.[4] In 1892 he gave a
lecture called "
Experiments with Alternate Currents of High Potential and High Frequency
", in London (Available at Project Gutenberg).[5] In 1893, at
St. Louis, Missouri, Tesla gave a public demonstration of "wireless" radio
communication. Addressing the Franklin Institute in Philadelphia and the
National Electric Light Association, he described in detail the principles of
radio communication.[6]
 The apparatus that Tesla used contained all the elements that were
incorporated into radio systems before the development of the "oscillation
valve", the early vacuum tube. Tesla initially used sensitive
electromagnetic receivers,[7] that were unlike the less responsive
coherers later used by Marconi and other early experimenters.
 Afterward, the principle of radio communication (sending signals through
space to receivers) was publicized widely from Tesla's experiments and
demonstrations. Various scientists, inventors, and experimenters began
to investigate wireless methods. For more information see
Tesla's wireless work

9. Oliver Lodge
• Oliver Lodge transmitted radio signals on August 14, 1894 (one
year after Tesla, five years after Heinrich Hertz and one year
before Marconi) at a meeting of the
British Association for the Advancement of Science at
Oxford University.[8] (In 1995, the Royal Society recognized this
scientific breakthrough at a special ceremony at Oxford
University. For more information, see Past Years: An
Autobiography, New York: Charles Scribner's Sons, p231.)
• On 19 August 1894 Lodge demonstrated the reception of
Morse code signalling via radio waves using a "coherer". He
improved Edouard Branly's coherer radio wave detector by
adding a "trembler" which dislodged clumped filings, thus
restoring the device's sensitivity. [9] In August 1898 he got
U.S. Patent 609,154, "Electric Telegraphy", that made wireless
signals using Ruhmkorff coils or Tesla coils for the transmitter
and a Branly coherer for the detector. This was key to the "
syntonic" tuning concept. In 1912 Lodge sold the patent to
Marconi.

10. Alexander Popov
 Popov was the first man to demonstrate the practical applications of radio waves.
 In 1895, the Russian physicist Alexander Popov built a coherer. On May 7, 1895,
Popov performed a public demonstration of transmission and reception of radio
waves used for communication at the Russian Physical and Chemical Society,
using his coherer:[13] this day has since been celebrated in Russia as "
Radio Day". He did not apply for a patent for this invention. Popov's early
experiments were transmissions of only 600 yards (550 m). Popov was the first to
develop a practical communication system based on the coherer, and is usually
considered by the Russians to have been the inventor of radio.[14][15]
 Around March 1896 Popov demonstrated in public the transmission of radio
waves, between different campus buildings, to the Saint Petersburg Physical
Society. (This was before the public demonstration of the Marconi system around
September 1896). Per other accounts, however, Popov achieved these results
only in December, 1897; that is, after publication of Marconi's patent.[16] In 1898
his signal was received 6 miles (9.7 km) away, and in 1899 30 miles away. In
1900, Popov stated at the Congress of Russian Electrical Engineers that,
 "the emission and reception of signals by Marconi by means of electric
oscillations was nothing new, as in America Nikola Tesla did the same
experiments in 1893."[17][18]
 Later Popov experimented with ship-to-shore communication. Popov died in 1905
and his claim was not pressed by the Russian government until 1945.
 Around 1895: 3-way near photofinish for first use of radio
 In March 1895, Popov transmitted radio waves between campus buildings in
Saint Petersburg, but did not apply for a patent.

11. Ernest Rutherford
• The New Zealander Ernest Rutherford, 1st Baron Rutherford of Nelson
was instrumental in the development of radio. In 1895 he was awarded an
Exhibition of 1851 Science Research Scholarship to Cambridge. He
arrived in England with a reputation as an innovator and inventor, and
distinguished himself in several fields, initially by working out the
electrical properties of solids and then using wireless waves as a method of
signalling. Rutherford was encouraged in his work by Sir Robert Ball, who
had been scientific adviser to the body maintaining lighthouses on the Irish
coast; he wished to solve the difficult problem of a ship’s inability to detect
a lighthouse in fog. Sensing fame and fortune, Rutherford increased the
sensitivity of his apparatus until he could detect electromagnetic waves
over a distance of several hundred meters. The commercial development,
though, of wireless technology was left for others, as Rutherford continued
purely scientific research. Thomson quickly realised that Rutherford was a
researcher of exceptional ability and invited him to join in a study of the
electrical conduction of gases.

12. Telephone Herald in Donald Manson working as an employee
Budapest, Hungary (1901).of the Marconi Company (England, 1906)

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A Fisher 500 AM/FM hi-fi
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American girl listens to radio
during the Great Depression.

14. Pure One Classic- DAB Amateur radio station with
Digital Radio from 2008 multiple receivers and
transceivers

15. Bush House, home
of the BBC World
Service.

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I FM MHz103.8 (Hunasgiriya)Upcountry & Islandwide (Mt Oliphant, Colombo
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SIRASA 88.8 MHz101.7 Central Sri Lanka (Mt Oliphant, Nuwara Eliya 4 PO Box 25
FM MHz106.2 kW)Rajarata, Northern & Eastern Sri Lanka Araliya Uyana
MHz106.2 (Gammaduwa)Kandy (Hunasgiriya, 2 kW)Southern Pannipitiya
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MHz106.5 MHz kW)Uva (Nayabedda)
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MHz101.3 MHz (Nayabedda) Colombo 2