Chapter 4, VHF Communications Flashcards
The angle between successive phase changes
of a D8PSK signal is
45°
The method of modulation currently
employed for aircraft VHF voice communication is
DSB AM
The channel spacing currently used in
Europe for aircraft VHF voice communication is
8.33 kHz and 25 kHz
Which one of the following gives the
approximate LOS range for an aircraft at an
altitude of 15,000 feet?
135 nm
The function of the compressor stage in an
aircraft VHF radio is
To increase the average level of modulation
The function of the squelch stage in an
aircraft VHF radio is
To eliminate noise when no signal is received
Large passenger aircraft normally carry
Three VHF radios
The typical bandwidth of a DSB AM voice
signal is
7 kHz
The disadvantage of narrow channel
spacing is
The possibility of adjacent channel interference
The standard for ACARS is defined in
ARINC 724
The frequency band currently used in Europe
for aircraft VHF voice communication is
118 MHz to 137 MHz
The typical output power of an aircraft VHF
radio using voice mode is
25 W
