Module 6: Basic Radio Fundamentals and Radio Communication Flashcards
an electronic device which produces radio waves with an antenna
transmitter
The purpose of most _____________ is radio communication of information over a distance.
transmitters
The information is provided to the transmitter in the form of an ____________
electronic signal
Examples of an electronic signal
- audio (sound) signal from a microphone
- video (TV) signal from a video camera
- digital signal from a
computer.
Simple Block Diagram of a Transmitter
- Acoustic Components - microphone, handset, boom headset
- Transducer - Analog/Digital
- Electronic Processor
- Transmitter
Classifications of radio transmission system
- radio-telephony transmitter
- radio-telegraphy transmitter
- TV transmitter
- code transmitter
for transmission of music and speech
radio-telephony transmitter
for transmission of signals
radio-telegraphy transmitter
for transmission of moving picture
TV transmitter
the transmission of codes
code transmitter
an electronic device that receives radio waves and converts the information carried by them to a usable form
receiver
The information produced by the receiver may be in the form of ______, _________, or ________.
sound, moving images (television), digital data
characteristics of a receiver
- receiver’s sensitivity
- receiver’s selectivity
defined as its ability to drive the output transducer to an acceptable level
receiver’s sensitivity
defined as the extent to which a receiver of differentiating between the desired signal and disturbances at other frequency
receiver’s selectivity
Receiver Block Diagram
- Antenna
- Ground
- Tuner
- Mixer
- Local Oscillator
- IF Amplifier
- Detector
- AF Amplifier
- Speaker or Earphone
the way radio signals are transmitted from one point to another inside the Earth’s atmosphere or free space
radio propagation
Modes of Propagation
- Ground Wave
- Sky Wave
- Space Wave
- Satellite Communication
a radio wave that travels along Earth’s surface
ground wave
also called SURFACE WAVE
ground wave
have a strong effect on ground waves
changes in terrain
Ground wave propagation is much better over ______ than ______ terrain.
water, desert
used for long distance transmission
sky wave
It has the ability to strike the ionosphere, be refracted from it to ground, strike the ground, be reflected back toward the ionosphere.
sky wave
The propagated wave is direct from transmitting to receiving antenna and does not travel along the ground.
space wave
also called line-of-sight transmission disturbances
space wave
A communication satellite is placed into synchronous orbit, which means its position remains fixed with respect to the earth’s rotation.
satellite communication
radio frequencies
- VLF (3-30 kHz)
- LF (30-300 kHz)
- MF (300-3000 kHz)
- HF (3-30 MHz)
- VHF (30-300 MHz)
- UHF (300-3000 MHz)
- SHF (3-30 GHz)
- EHF (30-300 GHz)
Where are aircraft antennas located?
outer skin of the aircraft
Where are acoustic equipment located?
cockpit
controls the channel and volume of transmission/reception
audio control panel (ACP)
How many Audio Control Panels are located next to an RMP?
3
How many Audio Control Panels are located on the center pedestal? On the overhead panel
2, 1
give the capability of tuning all communication radios
radio management panels (RMPs)
The frequencies are tuned by using the _ concentric knobs.
2
How many Radio Management Panels are located on the center pedestal? On the overhead panel?
2, 1
How to establish communication on radio?
- Tune the frequency using knob and select what type of frequency key using RMP
- To transmit and receive the voice signals, on the ACP, press the designated frequency and its corresponding knob.
____ operates at 118-135 MHz frequency range.
VHF (transceiver)
____ provides much clearer reception and is much less affected by atmospheric conditions but the electromagnetic waves in the _____ band are limited to line of sight.
VHF
____ has designated VHF as the standard radio communication system for ____ purposes.
ICAO, ATC
usually used by the flight crew for voice communications
VHF 1 and VHF 2
used for Aircraft Communication Addressing and Reporting System (ACARS) functions and as back-up voice communications if there is a failure of other systems
VHF 3
a digital data link system for the transmission of messages between aircraft and ground stations, which has been in use since 1978
Aircraft Communication Addressing and Reporting System (ACARS)
Types of ACARS messages
- Air Traffic Control (ATC)
- Aeronautical Operational Control (AOC)
- Airline Administrative Control (AAC)
serves for all long-distance voice communications between different aircraft in flight or on the ground, or between the aircraft and one or several ground stations
HF system (transceiver)
records the conversation of pilots and ambiance sound on flight deck every 30 mins
cockpit voice recorder (CVR)
records the last 2 hours of the flight crew conversations and communications and aural warnings
Solid State Cockpit Voice Recorder (SSCVR)
records automatically in flight and on ground when at least 1 engine is running and for 5 minutes after the last engine is shut down
Solid State Cockpit Voice Recorder (SSCVR)
avoid static electricity discharging noise and ensure a good quality of radio transmission, without interference
static dischargers
Purpose of static dischargers
- To discharge the static electricity accumulated by the aircraft during its flight
- To supply better intelligibility on the HF and VHF system (avoid static electricity discharge noise)
Where are static dischargers located?
- wing tip and aileron
- horizontal stabilizer tip zone
- fin and rudder
- flap track fairing
How many static dischargers are in the wing tip and aileron?
9 per wing (2 may be missing from each wing)
How many static dischargers are in the horizontal stabilizer tip zone?
5 per side (1 may be missing from each side)
How many static dischargers are in the fin and rudder?
5 (1 may be missing)
How many static dischargers are in the flap track fairing?
3 per wing (1 may be missing from each wing
Kinds of static dischargers and retainers
- One with a straight mounting installed at the trailing edges
- One with a a 30 degree angle mounting installed at the tips
- A flat retainer at the trailing edges
- An angular retainer at the tips