1-37.
1-38.
1-39.
1-40.
1-41.
1-42.
By which of the following
methods can you increase the
maximum number of intelligible
signals transmitted on a single
path?
1.
Modulation
2.
Single audio mixing
3.
Multiplexing
4.
Single signal splitting
Which of the following communi-
cations methods involves
subdividing a channel into
smaller segments of equal size
and placing a signal in each
subchannel?
1.
FDM
2.
TDM
3.
DFM
4.
DTM
Which of the following
requirements does SAS satisfy?
1.
Nonsecure voice
communications
2.
Secure voice communications
3.
Voice signal switching
4.
All of the above
How many crypto and plain
subsystems are used within SAS?
1.
Five
2.
Two
3.
Three
4.
Four
One mode of teletypewriter
operation is the synchronous
mode. What other mode is used
for basic teletypewriter
operation?
1.
Asynchronous
2.
Bisynchronous
3.
Nonsynchronous
4.
Trisynchronous
What is the name of the five-
unit code that includes mark and
space signals and is used in
teletypewriter operation?
1.
Baud
2.
Baudot
3.
ASCII
4.
Morse
4
1-43.
Which of the following problems
is reduced by not using start
and stop signals in the
synchronous teletypewriter mode?
1.
Converted signal
2.
Delayed signal
3.
Distorted signal
4.
Lost signal
1-44.
Which of the following terms
accually pertains only to
modulation rate?
1.
Baud
2.
Words per minute
3.
Bites per second
4.
Words per second
1-45.
In neutral tty operation,
current flow and no current flow
represent the mark and space
conditions. In polar tty
operation what is the condition
of the line current?
1.
It is always absent
2.
It is always positive
3.
It is always negative
4.
It is always present
1-46.
What device is used to change
tty dc pulses into mark and
space signals to modulate the
transmitter carrier wave?
1.
Detector
2.
Keyer
3.
Modulator
4.
Transformer
1-47.
After the tty signal is
received, what device(s) must be
used to change the signal back
to dc pulses?
1.
Convertor
2.
Receiver
3.
Both 1 and 2 above
4.
Keyer
1-48.
The Navy’s two basic RATT
systems are AFTS and RFCS. What
is the RFCS system commonly
called?
1.
ASK
2.
FSK
3.
PSK
4.
RSK
