CONGRATULATIONS! YOU ARE NOW THE PROUD OWNER OF A FELTED ANTIQUE RADIO
SURPRISE
TURN THE PAGE!
SOME OF YOUR FAVORITE THINGS USE RADIO WAVES!
RADIOS MICROWAVES
CELLPHONES BROADCAST TELEVISION (JUST TO NAME A FEW)
AM
FM
AM
FM
AMPLITUDE MODULATION::::::::::::::::::
FREQUENCY MODULATION:::::::::::::::::::
1906 - INVENTED BY
1933 - INVENTED BY
REGINALD FESSENDEN
EDWIN ARMSTRONG
AM WAVES FLUCTUATE BASED
FM WAVES FLUCTUATE BASED
ON SPECIFIC SIGNAL STRENGH
ON ʻFREQUENCYʼ
(AMPLITUDE); IF THE AMPLITUDE
(HOW MANY TIMES PER
IS NOT STRONG ENOUGH
SECOND THE WAVEʼS CURRENT
WHEN IT REACHES A RECEIVER,
CHANGES DIRECTION.) SINCE
YOU WILL HEAR STATIC.
MOST ENVIRONMENTAL FACTORS THAT DISTORT RADIO
THE RECEIVER DETECTS
WAVES ONLY AFFECT ITS
THE CHANGES IN THE CARRIER
AMPLITUDE AND NOT THE
FREQUENCYʼS AMPLITUDE
FREQUENCY, THIS ALSO MEANS
AND AMPLIFIES IT TO DRIVE
THAT FM SIGNAL QUALITY
A SPEAKER.
DOESNʼT DEGRADE LINEARLY AS YOU GET FURTHER FROM THE
BECAUSE AM WAVES DEPEND
TRANSMITTING STATION.
ON SPECIFIC AMPLITUDES TO GET A SIGNAL, THEY ARE LESS
FMʼS MOST SUBSTANTIAL
RELIABLE AND CAN EASILY BE
BENEFIT IS ITS ABILITY SEND OUT
DISRUPTED BY OBSTACLES SUCH
TWO CHANNELS OF
AS TALL BUILDINGS.
INFORMATION AT THE SAME TIME; THIS ALLOWS THE STATION TO BROADCAST LEFT AND RIGHT AUDIO CHANNELS FOR FULL STEREO SOUND!
TURN IT UP!
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TUNE IT IN . . . . . . . . .
. . . . . . . . . 80 70
10 0
120
104
88
90
60
98
10
2 10
55
96
0
92
94
90
THIRTEEN THOUSAND THREE HUNDRED AND FIVE* *RADIO STATIONS CURRENTLY REGISTERED IN THE UNITED STATES
T
G N I L E V A R
D E E SP
RADIO WAVES TRAVEL AT THE SPEED OF LIGHT
299,792,458 METERS PER SECOND
TI ME
THE MORE YOU
GROW THE MORE YOU LISTEN
MINS
HRS
MINS
YEARS OLD
HRS
YEARS OLD
8 55
EIGHTEEN OR MORE
NINE-ELEVEN
YEARS OLD
SIX-EIGHT
YEARS OLD
7 20
T WELVE-SEVENTEEN
A RECENT STUDY SHOWED THAT CHILDREN AS YOUNG AS SIX LISTEN TO THE RADIO AN AVERAGE OF SEVEN HOURS A WEEK.
14 00 HRS
MINS
22 45 HRS
MINS
R
ANT E WI N
O I T D S A N ESSLY
L E
ANTENNAS USE ELECTRICITY TO MANIPULATE THE ELECTROMAGNETIC FIELD
AFTER CATCHING RADIO WAVES IN THE AIR, THE ANTENNA THEN FILTERS THE ENERGY DOWN INTO A CIRCUIT BOX WHICH CONVERTS THE WAVES BACK INTO SOUND.
B O U N C E
MOONBOUNCE: IN A DAY BEFORE COMMUNICATIONS SATELLITES, HIGH POWERED RADIO WAVES WERE TRANSMITTED FROM ANTENNAS POINTED AT THE MOON.
MOON
THE MOON ACTS AS A GIANT MIRROR, BOUNCING THE RADIO WAVES BACK TO EARTH TO BE RECEIVED BY LISTENERS.
EARTH
THIS WAS THE FIRST METHOD OF LONG DISTANCE RADIO COMMUNICATION WHERE THE EARTH始S IONOSPHERE DID NOT DEGRADE THE SIGNALS BEING SENT.
RADIO IS HARMLESS.
RADIO WAVES ARE NON-IONIZING:
THEY DO NOT CARRY ENOUGH ENERGY TO CHANGE THE STRUCTURE OF ATOMS IN THE HUMAN BODY
EL EC TRO MAG NET IC SPEC TRUM
THE ELECTROMAGNETIC SPECTRUM IS USUALLY DIVIDED INTO SEVEN DIFFERENT FREQUENCIES OF ELECTROMAGNETIC RADIATION:
RADIO MICROWAVE INFRARED VISIBLE ULTRAVIOLET X-RAY GAMMA RAY
100km
10cm 10cm
1mm 1mm
700nm 700nm
400nm 400nm
10nm 10nm
10-2nm 10-2nm
10-6nm
UNDERWATER UNDERWATER
IT始S COMPLICATED.
REMEMBER
RADIO