Comnav 2

Question 1

COMPONENTS OF A RADIO

Answer 1

TRANSMITTER, RECEIVER, ANTENNA, POWER SUPPLY, CONTROL, AND INTERFACE SYSTEMS

Question 2

responsible for converting audio signals (e.g. speech music) or data into radio-frequency electromagnetic waves.

Answer 2

TRANSMITTER

Question 3

KEY ELEMENTS OF TRANSMITTER

Answer 3

OSCILLATOR, MODULATOR, AMPLIFIER

Question 4

Generates the carrier wave at a specific frequency.

Answer 4

OSCILLATOR

Question 5

Early transmitters used _______, but modern systems rely on _____ for stability.

Answer 5

spark-gap oscillators, crystal-controlled or synthesized oscillators

Question 6

Modifies a carrier wave (a high-frequency signal) by varying its amplitude (AM) frequency (FM) or phase (PM) to encode information. For example AM radio adjusts the amplitude of the carrier wave to match the audio signal while FM alters its frequency.

Answer 6

MODULATOR

Question 7

Boosts the modulated signal’s power for transmission. High-power amplifiers are critical for long-range communication.

Answer 7

AMPLIFIER

Question 8

captures and decodes radio signals

Answer 8

RECEIVER

Question 9

RECEIVER PRIMARY COMPONENTS

Answer 9

ANTENNA, TUNER/FILLER, DEMODULATOR, AMPLIFIER

Question 10

Captures incoming radio waves and converts them into electrical signals.

Answer 10

ANTENNA

Question 11

Selects the desired frequency band while rejecting interference.

Answer 11

TUNER/FILTER

Question 12

Extracts the original modulation signal (e.g. audio) from the carrier wave.

Answer 12

DEMODULATOR

Question 13

AM receivers use ____, while FM systems employ ______

Answer 13

envelope detectors, discriminators

Question 14

Boosts weak signals for audible output.

Answer 14

AMPLIFIER

Question 15

are critical in sensitive applications like radio astronomy

Answer 15

Low-noise amplifiers (LNAs)

Question 16

critical for both transmission and reception.

Answer 16

ANTENNA

Question 17

types of antenna

Answer 17

dipole, yagi-uda, parabolic reflectors

Question 18

Omnidirectional used in FM radios and Wi- Fi routers.

Answer 18

DIPOLE

Question 19

Directional ideal for TV reception and radar.

Answer 19

YAGI-UDA

Question 20

Focus signals into narrow beams used in satellite communication and radio telescopes

Answer 20

PARABOLIC REFLECTORS

Question 21

TYPICAL POWER SOURCES

Answer 21

BATTERY, AMPLIFIER POWER

Question 22

Portable devices use DC power while transmitters often rely on AC mains with rectifiers

Answer 22

BATTERIES

Question 23

High-power transmitters (e.g. broadcasting towers) use specialized power amplifiers and cooling systems.

Answer 23

AMPLIFIER POWER

Question 24

Enable precise tuning across bands (e.g. car radios).

Answer 24

FREQUENCY SYNTHESIZERS

Question 25

Buttons screens or software for adjusting volume frequency and settings.

Answer 25

USER INTERFACE

Question 26

It is the name of the group of frequencies in the VHF radio spectrum allocated for radio communication in civil aviation.

Answer 26

AIRBAND

Question 27

CONTROL AND INTERFACE SYSTEMS

Answer 27

FREQUENCY SYNTHESIZERS, USER INTERFACE

Question 28

The VHF airband uses the frequencies between?

Answer 28

108 AND 137 MHz

Question 29

what is split into 200 narrow-band channels of 50 kHz

Answer 29

lowest 10 MHz of the band 108 to 117.95 MHz

Question 30

These are reserved for navigational aids such as VOR beacons and precision approach systems such as ILS localizers (NAV Channels).

Answer 30

lowest 10 MHz of the band 108 to 117.95 MHz

Question 31

for voice transmissions on frequencies from 118 to 136.975 MHz in steps of 25 kHz (COM Channels).

Answer 31

upper 19 MHz into 760 channels

Question 32

The primary modulation technique used in aviation radios

Answer 32

Amplitude Modulation

Question 33

The primary modulation technique used in aviation radios is Amplitude Modulation (AM) due to its:

Answer 33

simplicity, power-efficiency, compatibility with legacy equipment, not susceptible to “capture effect”

Question 34

TYPES OF RADIOS USED IN AVIATION

Answer 34

HANDHELD, PANEL-MOUNTED, GROUND STATION

Question 35

portable and small enough to be carried. They usually have a shorter range than both panel-mounted or ground station radios and often come with around 6 watts of power.

Answer 35

HANDHELD AIRBAND RADIOS

Question 36

typically found on aircraft and act in much the same way as a radio mounted in a vehicle on the ground. They are more powerful than handheld models most using around 8 watts.

Answer 36

PANEL-MOUNTED

Question 37

Air-to-air communication is much better than ground-to-air because?

Answer 37

VHF works primarily through a line of sight

Question 38

Radios on a desk in an airport and one in a vehicle serving a similar purpose. These radios are sometimes comparable to panel-mounted versions

Answer 38

GROUND STATION

Question 39

AIRCRAFT ANTENNAS:

Answer 39

COMMUNICATION ANTENNAS, UHF ANTENNAS, NAV ANTENNAS, GPS ANTENNAS, MARKER BEACON ANTENNAS, ELT ANTENNAS

Question 40

Each com transmitter has its own antenna mostly for redundancy. They can be mounted on either the top or bottom of the aircraft but each installation is susceptible to shadowing from the fuselage

Answer 40

Communication Antennas

Question 41

is caused by structure such as the vertical stabilizer or landing gear doors in the transmitting path of the antenna

Answer 41

Shadowing

Question 42

commonly used for transponders and DME and they are always found on the bottom of the aircraft.

Answer 42

UHF ANTENNAS

Question 43

almost always mounted on the vertical tail and there are three types: the cat whisker the dual blade and the towel bar.

Answer 43

NAV ANTENNAS

Question 44

what are the three types of NAV ATENNAS

Answer 44

the cat whisker, the dual blade, and the towel bar.

Question 45

transmit less than five watts of power so by the time the signal reaches you it is very very weak.

Answer 45

GPS ANTENNAS

Question 46

Because of this, the GPS antenna has a _____ to boost the signal for the receiver

Answer 46

built-in amplifier

Question 47

the GPS frequency is so high (in the gigahertz band) that the?

Answer 47

signals travel in a line-of-sight manner

Question 48

highly directional which means you have to be almost directly over the transmitting ground station to receive them; therefore these antennas need to be on the bottom of the aircraft.

Answer 48

MARKER BEACON ANTENNAS

Question 49

They are designed to survive an "unscheduled" landing. They are almost always on the upper skin of the empennage and are made of a flexible material.

Answer 49

ELT ANTENNAS