1. RADIO
HAREEM FATIMA
MODERN DEVELOPMENT AND TECHNOLOGY
COURSE NUMBER 632
MADAM DR.RIZWANA
FASEEL(H.O.D)

2. Hearing Signals
Out of Thin Air

3. SOME ONE IS
ENTERTAINING
BY VOICE AND
FEELINGS

6. The Radio Timeline Project Page
The advance of Science and Technology depends on individuals with a curiosity who
strive to build on the work of others...NO ONE INDIVIDUAL INVENTOR
INVENTED THE RADIO !
List of Inventors / Scientists you may be asked to research includes
1. Hans (Christian) Oersted (compass experiment - current makes magnetic field)
2. Michael Faraday (magnetic induction - moving magnet/coil makes current)
3. James Clerk Maxwell (equations describing Electromagnetic [EM] waves)
4. Thomas Edison (harmonic emission leads to design of vacuum tube)
5. Heinrich Hertz ('spark' EM wave transmission experiment)
6. Nikola Tesla (awarded radio transmission radio patent posthumously)
7. Guglielmo Marconi (famous for many radio transmission experiments)
8. John Ambrose Fleming (improved vacuum tube - diode)
9. Reginald (Aubrey) Fessenden (first AM radio broadcast)
10. Edward Armstrong (wide-band FM radio)

7. Radio From TelegraphRadio From Telegraph
• Radio has its roots in
the Telegraph.
• This device was the
first widely-used form
of long-distance
communication.
• In 1836, Samuel
Morse invented a
language of dots and
dashes that is still used
today.

8. 1876
• In 1876, Alexander
Graham Bell transmitted
the human voice over
wires for the first time.

9. Telephone
• Most of these
telephones were wired
on party lines, which
means that many of
your neighbors could
listen to your calls.
• All the phones on the
party line rang at one
time, and each home
had its own ring
pattern.

10. Radio Broadcasting
In 1883, a dentist named MahlonIn 1883, a dentist named Mahlon
Loomis received the patent forLoomis received the patent for
wireless telegraphy, butwireless telegraphy, but
Guglielmo Marconi is commonlyGuglielmo Marconi is commonly
credited as inventing radio in 1895credited as inventing radio in 1895
even though there is credibleeven though there is credible
evidence that other inventors wereevidence that other inventors were
first.first.

12. Radio Broadcasting
Once Marconi patented hisOnce Marconi patented his
invention in England, hisinvention in England, his
next step was to sell it tonext step was to sell it to
the marine industry.the marine industry.
Soon, the majority ofSoon, the majority of
oceangoing ships were alloceangoing ships were all
equipped with hisequipped with his
equipment - which madeequipment - which made
Marconi a very rich man.Marconi a very rich man.

13. 1898
• In 1898, Danish inventor
Valdemar Poulsen created th
Telegraphone, the first
practical magnetic sound
recorder using a piano wire a
the recording medium.
• Soon, wire recorders begin t
appear on the American
market.

14. FIRST RADIO IN HOME
• The Congress
passed the Radio
Act of 1927, which
created the Federal
Radio Commission -
FRC.
• Its purpose was to
oversee the
licensing of
transmitters,
assigning radio
frequencies, call
letters, and power
limits.

15. IMPACT ON SOCIETY
• Once radio broadcasting
was launched, people
began to realize just how
significant this new
medium could be.
• For example, KDKA,
broadcast the 1920
Harding-Cox presidential
election returns well in
advance of the papers.

17. DEVELOPMENTS IN RADIO

18. Antennas

19. RADIO WAVES CATCHING IN AIR
1 2 3

20. AM AND FM
RADIO CONSIST OF TWO KINDS
OF FREQUENCIES

23. AM AND FM
AM RADIO:
It stands for
amplitude
modulation
FM RADIO:
It stands for
frequency
modulation.

24. TODAY IS FM
• FM or frequency
modulated radio and TV
waves act differently
than AM radio waves.
• The FM radio band goes
from 88 to 108 MHz
(megahertz, or millions
of cycles per second).

25. TODAY RADIO STATIONS

27. QUESTIONS?
THANK YOU…!