Digital modes: packet, PSK31

Question 1

Which of the following is a digital communications mode?

Answer 1

Packet radio, IEEE 802.11, JT65 (All of these are correct)

Question 2

Which of the following may be included in packet transmissions?

Answer 2

A check sum which permits error detection, A header that contains the call sign of the station to which the information is being sent, Automatic repeat request in case of error, (All of these choices are correct)

Question 3

What is an ARQ transmission system?

Answer 3

A digital scheme whereby the receiving station detects errors and sends a request to the sending station to retransmit the information

Question 4

What does the term “APRS” mean?

Answer 4

Automatic Packet Reporting System

Question 5

Which of the following is an application of APRS (Automatic Packet Reporting System)?

Answer 5

Providing real-time tactical digital communications in conjunction with a map showing the locations of stations

Question 6

Which of the following devices is used to provide data to the transmitter when sending automatic position reports from a mobile amateur radio station?

Answer 6

A global Positioning System receiver

Question 7

What does the abbreviation “PSK” mean?

Answer 7

Phase Shift Keying

Question 8

Which of the following best describes DMR (Digital Mobile Radio)?

Answer 8

A technique for time-multiplexing two digital voice signals on a single 12.5 kHz repeater channel

Question 9

What is a “talk group” on a DMR digital repeater?

Answer 9

A way for groups of users to share a channel at different times without being heard by other users on the channel

Question 10

How can you join a digital repeater’s “talk group”?

Answer 10

Program your radio with the group’s ID or code

Question 11

Which of the following operating activities is supported by digital mode software in the WSJT suite?

Answer 11

Moonbounce or Earth-Moon-Earth, Weak-signal propagation beacons, Meteor scatter, (All of these choices are correct)

Question 12

What is FT8?

Answer 12

A digital mode capable of operating in low signal-to-noise conditions that transmits on 15-second intervals

Question 13

Which of the following best describes Broadband-Hamnet(TM), also referred to as a high-speed multi-media network?

Answer 13

An amateur-radio-based data network using commercial Wi-Fi gear with modified firmware