E2D  Digital Operating: HF digital communications (ie, PacTOR, CLOVER,

AMTOR, PSK31, HF packet); packet clusters; HF digital bulletin boards

 

E2D01 (B)

What is the most common method of transmitting data emissions below 30 MHz?

A.  DTMF tones modulating an FM signal

B.  FSK (frequency-shift keying) of an RF carrier

C.  AFSK (audio frequency-shift keying) of an FM signal

D.  Key-operated on/off switching of an RF carrier

 

E2D02 (A)

What do the letters "FEC" mean as they relate to AMTOR operation?

A.  Forward Error Correction

B.  First Error Correction

C.  Fatal Error Correction

D.  Final Error Correction

 

E2D03 (C)

How is Forward Error Correction implemented?

A.  By transmitting blocks of 3 data characters from the sending station to the receiving station which the receiving station acknowledges

B.  By transmitting a special FEC algorithm which the receiving station uses for data validation

C.  By transmitting each data character twice, since there is no specific acknowledgment of reception

D.  By varying the frequency shift of the transmitted signal according to a predefined algorithm

 

E2D04 (B)

What does "CMD:" mean when it is displayed on the video monitor of a packet station?

A.  The TNC is ready to exit the packet terminal program

B.  The TNC is in command mode, ready to receive instructions from the keyboard

C.  The TNC will exit to the command mode on the next keystroke

D.  The TNC is in KISS mode running TCP/IP, ready for the next command

 

E2D05 (D)

What is the Baudot code?

A.  A code used to transmit data only in modern computer-based data systems using seven data bits

B.  A binary code consisting of eight data bits

C.  An alternate name for Morse code

D.  The "International Telegraph Alphabet Number 2" (ITA2) which uses five data bits

 

E2D06 (A)

If an oscilloscope is connected to a TNC or terminal unit and is displaying two crossed ellipses, one of which suddenly disappears, what would this indicate about the observed signal?

A.  The phenomenon known as "selective fading" has occurred

B.  One of the signal filters has saturated

C.  The receiver should be retuned, as it has probably moved at least 5 kHz from the desired receive frequency

D.  The mark and space signal have been inverted and the receiving equipment has not yet responded to the change

 

E2D07 (D)

Which of the following systems is used to transmit high-quality still images by radio?

A.  AMTOR

B.  Baudot RTTY

C.  AMTEX

D.  Facsimile

 

E2D08 (C)

What special restrictions are imposed on facsimile (fax) transmissions?

A.  None; they are allowed on all amateur frequencies

B.  They are restricted to 7.245 MHz, 14.245 MHz, 21.345, MHz, and 28.945 MHz

C.  They are allowed in phone band segments if their bandwidth is no greater than that of a voice signal of the same modulation type

D.  They are not permitted above 54 MHz

 

E2D09 (D)

What is the name for a bulletin transmission system that includes a special header to allow receiving stations to determine if the bulletin has been previously received?

A.  ARQ mode A

B.  FEC mode B

C.  AMTOR

D.  AMTEX

 

E2D10 (A)

What is a Packet Cluster Bulletin Board?

A.  A packet bulletin board devoted primarily to serving a special interest group

B.  A group of general-purpose packet bulletin boards linked together in a "cluster"

C.  A special interest cluster of packet bulletin boards devoted entirely to packet radio computer communications

D.  A special interest telephone/modem bulletin board devoted to amateur DX operations

 

E2D11 (C)

Which of the following statements comparing HF and 2-meter packet operations is NOT true?

A.  HF packet typically uses an FSK signal with a data rate of 300 bauds; 2-meter packet uses an AFSK signal with a data rate of 1200 bauds

B.  HF packet and 2-meter packet operations use the same code for information exchange

C.  HF packet is limited to Extra class amateur licensees; 2 meter packet is open to all but Novice class amateur licensees

D.  HF packet operations are limited to "CW/Data"-only band segments; 2-meter packet is allowed wherever FM operations are allowed


E1A | E1B | E1C | E1D | E1E | E1F | E1G | E2A | E2B | E2C

E2D | E3A | E3B | E4A | E4B | E4C | E4D | E4E | E5A | E5B

E5C | E5D | E5E | E5F | E5G | E5H | E6A | E6B | E6C | E6D

E6E | E7A | E7B | E7C | E7D | E7E | E7F | E7G | E8A | E8B

E8C | E8D | E8E | E9A | E9B | E9C | E9D | E9E