Telecommunication

1.3 – Radio and Television

Radio and TV Receivers

The parts of a radio and TV receiver can be

represented by a block diagram.

Write the name of each part of the radio receiver and the television receiver in the correct block.

In the surrounding space, state the function of each part.

aerial tuner decoder

amplifier

loudspeaker

power supply

picks up ALL signals

(various frequencies)

one signal selected

(one frequency)

decodes signal

signal is made

bigger

provides amplifier with electrical energy

electrical energy

changed to

sound energy.

The Radio Receiver

aerial tuner

decoder (sound)

amplifier (sound) loudspeak

er

power supply

decoder (vision)

amplifier (vision) TV tube

The TV Receiver

Each part has the same function as in the radio receiver.

The sound and vision signals are separate and require to be synchronised.

electrical energy

changed to light energy.

Radio Waves

Radio waves are the signals our aerial receivers pick up.

A radio station transmits a low frequency audio

(sound) wave with a very high frequency carrier wave.

The two waves are combined together either by:

• amplitude modulation

• frequency modulation

Amplitude Modulation (AM)

+

audio wave

(low frequency)

carrier wave

(very high frequency)

amplitude modulated wave

Frequency Modulation (FM)

+

audio wave

(low frequency)

carrier wave

(very high frequency)

frequency modulated wave

Radio Transmission