1-9 .
Which of the following types of
communications channels transmits data
in one direction, pauses, and then receives
data coming in the opposite direction?
1. Simplex
2. Duplex
3. Half duplex
4. Full duplex
1-10.
What device converts digital data signals
to tones and converts tones back to digital
data signals?
1-11.
1-12.
1. Modem
2. Modulator
3. Demodulator
4. Data converter
The modulator of a modem performs
which of the following functions?
1. It converts data to be transmitted into
discrete modifications of the tone or
carrier signal
2. It converts data-carrying tones into
digital data
3. It receives digital data from the
demodulator
4. It receives analog data from the
computer
The operational characteristics of a radio
communications system are determined by
what means?
1. Low frequency
2. High frequency
3. Carrier frequency
4. Radio frequency band
1-13.
1-14.
1-15.
1-16.
1-17.
The tactical digital information links that
the Navy uses generally require which of
the following radio frequency bands?
1 . L F
2 . H F
3. UHF
4. Both 2 and 3 above
The data signals must be
(a)
to the carrier signal at the transmitter and
(b)
from the carrier signal
in the receiver.
1. (a) Modulated (b) modulated
2. (a) Modulated (b) demodulated
3. (a) Demodulated (b) modulated
4. (a) Demodulated (b) demodulated
A radio frequency of 8,090 KHz is in
which of the following frequency bands?
1 . L F
2 . M F
3 . H F
4 . U H F
Which of the following radio frequency
bands is limited to line-of-sight
communications?
1 . L F
2 . M F
3 . H F
4 . U H F
Decibels are the unit of measure of what
function of an amplifier, communications
equipment, or a system?
1 . G a i n
2. Power
3. Output
4. Input
2
