NAVEDTRA 14189A, Ch. 3 Flashcards
What provides the capability to transfer remote control station functions and signals to transmitters?
Transmitter transfer switchboard
What is the most widely used code in manual telegraphy?
Morse code
The interval between words is equal to how many dots in morse code?
Seven
The five-unit (five-level) code has been the most commonly used in modern printing telegraphy and is universally used in teletypewriter operation. This is also known as what code?
Baudot
What are the two basic modes of teletypewriter operation?
Asynchronous and Synchronous
What is the most common mode used in teletypewriter operation?What is the most common mode used in teletypewriter operation?
Start-stop
What is the reciprocal of the time in seconds of the shortest signal element?
Baud rate
How many words per minute is the defense communications system standard speed for teletypewriter operation?
100
Which type of circuits make use of the presence or absence of current flow to convey information?
Neutral
Under which condition does the teletypewriter appear to be running because the machine is decoding the constant space as the Baudot character blank and the type hammer continually strikes the type box but there is no printing or type box movement across the page?
Running open
Which two basic radio teletypewriter (ratt) systems does the Navy use?
Tone modulated and Carrier Frequency Shift
Which colors are used on patch panels to identify whether that panel is used for passing secure or non-
secure information?
Red and Black
Which type of equipment is used to encrypt and decrypt tty messages that require security handling?
Cryptographic
What takes the rf signal passed on by the antenna filter and translates it to an audio signal?
Radio Receiver
What is a combined, simultaneous display of the amplitude and phase relationships of two input signals?
Lissajous pattern
Which type of communications circuit permits two-way communications between stations?
Half-duplex
What is the simultaneous transmission of a number of intelligible signals (messages) in either or both directions called using only a single rf carrier?
Multiplexing
Which two methods of multiplexing can be used?
Time-Division and Frequency-division
What is the normal voice speaking frequency range?
100 to 3,500 hertz
By multiplexing tty circuits, up to how many circuits may be carried in any one of the 3,000 hertz multiplexed channels?
16
Which transmission method is used for transmitting still images over an electrical communications system?
Facsimile
What are compromising emanations (ce) generally referred to as?
Tempest
What includes all measures designed to protect transmission from interception, traffic analysis, and imitative deception?
Transmission security
What occurs when a person comes into contact with a source of rf voltage in a manner that allows rf current to flow through the area of contact?
RF burn
Which device changes dc pulses to mark and space modulation for teletypewriter transmissions?
Keyer
What changes an audio signal back to dc pulses during teletypewriter reception?
Converter
Which device stores a teletypewriter message on a paper tape by punching Baudot coded messages into it?
Perforator
What stores an incoming tty signal on paper tape?
Reperforator
What is the reference color of equipment that passes classified information?
Red
