The transmission of electricity at high frequency
takes place at low voltage. Instead of using high tension transmission power,
it uses low tension transmission power. The frequency cuts across a broad band
so that many networks can operate at the same time.
Appliances like radio, television and
telecommunication gadgets operate on these frequencies. The frequencies or
bands include AM, MW,SW and FM bands(this is for the radio frequencies). For
the television band, we have the UHF, VHF and SHF channels.
Principles of
Operation in High Frequency Transmissions.
The basic principle in the transmission of
electricity at high frequency lies in the principle of the tank circuit. It is
the conversion of audio or visual signals into electromagnetic waves, which is
radiated from a sending aerial into space, where the receiving aerial cuts
across it, to be transmitted to the final consumers.
Equipment Used in
Radio Transmission.
(i).Microphone/Camera: This equipment is
used to convert sound and light energy
into electrical signals which are used to modulate the carrier waves.
(ii).Transmitter: The transmitter oscillates the carrier waves between the transmitting aerial and the microphone. It contains a tank circuit which transmits the carrier waves at appropriate frequency.
(iii).Transmitting Aerial: This aerial radiates out the electromagnetic waves received from the transmitter.
(iv).Receiving Aerial: It used to trap the electromagnetic waves from space radiated by the transmitting aerial.
(v).Receiver: The receiver de-modulates (separates) the carrier waves and amplifies the message signals to the loudspeaker.
(vi).Loudspeaker/TV screen: This equipment converts the message signals into sound and electrical energy as images in television signals.eg (Radio Transmission system diagram).
(ii).Transmitter: The transmitter oscillates the carrier waves between the transmitting aerial and the microphone. It contains a tank circuit which transmits the carrier waves at appropriate frequency.
(iii).Transmitting Aerial: This aerial radiates out the electromagnetic waves received from the transmitter.
(iv).Receiving Aerial: It used to trap the electromagnetic waves from space radiated by the transmitting aerial.
(v).Receiver: The receiver de-modulates (separates) the carrier waves and amplifies the message signals to the loudspeaker.
(vi).Loudspeaker/TV screen: This equipment converts the message signals into sound and electrical energy as images in television signals.eg (Radio Transmission system diagram).
Radio Transmission System.
REVIEW QUESTIONS
(i).list the
components used for effective radio communication system.
(ii). explain the functions of the components listed above.(iii). State one difference between the transmission of electricity at high frequency and the transmission of electricity at low frequency.
(ii). explain the functions of the components listed above.(iii). State one difference between the transmission of electricity at high frequency and the transmission of electricity at low frequency.
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