COMMS (Finals) Flashcards
Communication System involves ___ and ___ between aircrafts or aircrafts and ground.
- voice transmission
- Reception
It can be said that safe aircraft operation is dependent to a large extent upon satisfactory performance of
Communication system
What was established in the first world war
Voice communication
In the ___, the first ___ was accomplished. By the end of the decade, use of ___ was explored and included the advent of ___
- 1930s
- all radio-controlled blind-landing
- high frequency radio waves
- high-frequency radar
___ injected urgency into the development of ___. Communication radios, despite their size, were essential on board aircraft. ___ were developed for communication and navigational purposes.
- World War II
- aircraft radio communication and navigation
- Very high frequencies
How does a transformer transfer energy?
By using electromagnetic induction — AC in the primary coil creates a magnetic field that induces voltage in the secondary coil.
How is a transformer similar to radio communication?
Both use electromagnetic fields to transfer energy — a transformer confines it in a core, while radios radiate it through space.
What does the transformer core do?
It directs the magnetic field, ensuring efficient energy transfer.
How is space like a transformer core?
Space acts as the medium for electromagnetic waves to propagate in radio communication.
Why do electromagnetic waves radiate at higher frequencies?
Faster current changes prevent energy from returning to the conductor, causing it to radiate as waves.
What does a transmitting antenna do?
It efficiently leaks electromagnetic waves into space for signal transmission.
The Radio Frequencies are being used in various field, amongst them include :
• AIRCRAFT COMMUNICATIONS
• AIR TRAFFIC CONTROL
• AIR NAVIGATION SYSTEMS (e.g.VOR/DME,ND
The use of the various Radio Frequencies all over the World is allocated by
International Telecommunications Union
The radio frequency portion of the electromagnetic spectrum extends from
30 kHz (kilohertz) to 30,000 MHz (Megahertz)
Why is the spectrum divided into frequency bands
Convenience
may be considered as a generator which changes electrical power into
radio waves.
Transmitter
Functions of transmitters
- Generate RF signal
- Amplify the RF
- Provide a means of placing intelligence on the signal (modulate)
Components of transmitter
- Oscillator
- Amplifier
- Modulator
- circuit to generate RF signal
- circuit to increase the output of the oscillator to the required power level
- to add voice (audio) intelligence to the RF signal.
- Oscillator
- Amplifier
- Modulator
Two ways of modulation
- Frequency Modulation
- Amplitude Modulation
Function of receiver
- Select the desired radio frequency signals
- Amplification
- Demodulation
Demodulator which is used for AM signals is called ___, while the one which is used for FM waves is called ___.
- Detector
- Discriminator
special type of electrical circuit designed to radiate and receive
electromagnetic energy.
Antenna
a ___ is a conductor which radiates EM waves
when a radio frequency is passed through it, while ___ intercepts the EM waves that are present in the air.
- transmitting antenna
- receiving antenna
