6.9 how a radio works
Post on 18-Dec-2014
433 Views
Preview:
DESCRIPTION
TRANSCRIPT
6.9 How radio worksApril 10, 2023
What is this image? What other information can
you get from it?
Aims
• Review knowledge of AC• State the difference between AM and FM• Describe how a simple radio works
Sending sounds by radio
RF Oscillator Modulator Amplifier
Microphone
AF signal
RF carrier Modulated RF carrier
Sending sounds by radio
Amplifier demodulator Tuning circuit
Loudspeaker
AF signal Modulated RF carrier
Radio gaga• AF signal: varying voltage• RF oscillator creates high frequency AC, this is the
carrier• AF signals modulate the RF waves• RF wave is then amplified• RF waves then generate a voltage in the aerial• The tuning circuit decides which frequency of RF
carrier to detect• The demodulator then removes the carrier wave
leaving on AF• This is amplified and then converted to sound
AM and FM
• This is amplitude modulation or AM• You can also use frequency modulation (FM)• FM has less noise so this is better
top related