Radio Theory Flashcards
What speeds do radio waves travel at?
300,000,000 metres per second
What is amplitude?
“The maximum displacement or value attained by the wave from it’s mean value during a cycle”
What is a Hertz?
1 oscillation per cycle
One Gigahertz?
1000 million cycles/sec
(1 Billion)
The frequency of a wave?
Is its rate of oscillation
What use of radio waves is made in the provision of ATC? (5)
- Voice Communication VHF/ UHF
- Navigation VOR /NDB
- Surveillance systems
- Weather radar
- Data transmission
What are the GENERAL ADVANTADGES of FM?
-
Resilience to noise - signal level variations will not affect the audio output.
Easy to apply modulation at a low power
No boosting of the amplitude required.
Use of efficient RF amplifiers
This means that for a given power output, less
battery power is required and this makes the
use of FM more viable for portable two-way
radio applications.
What is FM?
Frequency Modulation
What is AM?
Amplitude Modulation
What are the ADVANTADGES of AM for ATC?
- Stronger stations can override weaker or interfering stations
- Hetrodyne - Talk Over (squeal when two transmitting at once)
What type of radio is used in ATC?
AM
Amplitude Modulation
Why does ATC use AM?
This is because the sounds do not require excellent audio clarity of tone which is required for music and digital broadcasting.
What is Frequency? (F)
The rate of repetition of the cycle in one second
where one cycle per second is known as one Hertz.
How many Hertz in Kilohertz?
1 Kilohertz - 1,000Hz
How many Hertz in Megahertz?
1 Megahertz - 1,000,00Hz
