3.9 KiB
3.9 KiB
G8C – Digital emission modes
- G8C01 (C)
On what band do amateurs share channels with the unlicensed Wi-Fi service? #card
- A. 432 MHz
- B. 902 MHz
- C. 2.4 GHz
- D. 10.7 GHz
- G8C02 (A)
Which digital mode is used as a low-power beacon for assessing HF propagation? #card
- A. WSPR
- B. MFSK16
- C. PSK31
- D. SSB-SC
- G8C03 (C)
What part of a packet radio frame contains the routing and handling information? #card
- A. Directory
- B. Preamble
- C. Header
- D. Trailer
- G8C04 (C)
Which of the following describes Baudot code? #card
- A. A 7-bit code with start, stop, and parity bits
- B. A code using error detection and correction
- C. A 5-bit code with additional start and stop bits
- D. A code using SELCAL and LISTEN
- G8C05 (A)
In an ARQ mode, what is meant by a NAK response to a transmitted packet? #card
- A. Request retransmission of the packet
- B. Packet was received without error
- C. Receiving station connected and ready for transmissions
- D. Entire file received correctly
- G8C06 (B)
What action results from a failure to exchange information due to excessive transmission attempts when using an ARQ mode? #card
- A. The checksum overflows
- B. The connection is dropped
- C. Packets will be routed incorrectly
- D. Encoding reverts to the default character set
- G8C07 (B)
Which of the following narrow-band digital modes can receive signals with very low signal-to-noise ratios? #card
- A. MSK144
- B. FT8
- C. AMTOR
- D. MFSK32
- G8C08 (B)
Which of the following statements is true about PSK31? #card
- A. Upper case letters are sent with more power
- B. Upper case letters use longer Varicode bit sequences and thus slow down transmission
- C. Error correction is used to ensure accurate message reception
- D. Higher power is needed as compared to RTTY for similar error rates
- G8C09 (B)
Which is true of mesh network microwave nodes? #card
- A. Having more nodes increases signal strengths
- B. If one node fails, a packet may still reach its target station via an alternate node
- C. Links between two nodes in a network may have different frequencies and bandwidths
- D. More nodes reduce overall microwave out of band interference
- G8C10 (C)
How does forward error correction (FEC) allow the receiver to correct data errors? #card
- A. By controlling transmitter output power for optimum signal strength
- B. By using the Varicode character set
- C. By transmitting redundant information with the data
- D. By using a parity bit with each character
- G8C11 (D)
How are the two separate frequencies of a Frequency Shift Keyed (FSK) signal identified? #card
- A. Dot and dash
- B. On and off
- C. High and low
- D. Mark and space
- G8C12 (A)
Which type of code is used for sending characters in a PSK31 signal? #card
- A. Varicode
- B. Viterbi
- C. Volumetric
- D. Binary
- G8C13 (D)
What is indicated on a waterfall display by one or more vertical lines on either side of a data mode or RTTY signal? #card
- A. Long path propagation
- B. Backscatter propagation
- C. Insufficient modulation
- D. Overmodulation
- G8C14 (C)
Which of the following describes a waterfall display? #card
- A. Frequency is horizontal, signal strength is vertical, time is intensity
- B. Frequency is vertical, signal strength is intensity, time is horizontal
- C. Frequency is horizontal, signal strength is intensity, time is vertical
- D. Frequency is vertical, signal strength is horizontal, time is intensity
- G8C15 (C)
What does an FT8 signal report of +3 mean? #card
- A. The signal is 3 times the noise level of an equivalent SSB signal
- B. The signal is S3 (weak signals)
- C. The signal-to-noise ratio is equivalent to +3dB in a 2.5 kHz bandwidth
- D. The signal is 3 dB over S9
- G8C16 (D)
Which of the following provide digital voice modes? #card
- A. WSPR, MFSK16, and EasyPAL
- B. FT8, FT4, and FST4
- C. Winlink, PACTOR II, and PACTOR III
- D. DMR, D-STAR, and SystemFusion