FREE HAM Radio Extra Class Test Advanced Digital Modes Questions and Answers

Question 1

Which advanced digital mode is specifically designed for reliable, low-power communication over noisy channels, often utilizing Forward Error Correction (FEC) and very narrow bandwidths?

Accepted Answer

FT8

Answer

PSK31

Answer

RTTY

Answer

Contestia

Question 2

An Extra Class licensee is attempting to establish a long-distance (DX) contact under extremely poor band conditions with high QRM and QRN. Which of the following digital modes would offer the best chance of decoding a weak signal through the noise?

Accepted Answer

Olivia

Answer

JS8Call

Answer

SSTV

Answer

FT4

Question 3

What is a primary advantage of using VarAC over modes like FT8 for keyboard-to-keyboard ragchewing, especially when conditions allow for higher data rates?

Accepted Answer

It supports adaptive data rates and robust ARQ (Automatic Repeat reQuest) for reliable text exchange.

Answer

It uses a fixed 8-tone FSK modulation for maximum robustness.

Answer

It has a significantly narrower bandwidth than FT8, allowing more stations per kilohertz.

Answer

It is designed exclusively for satellite communication.

Question 4

Which characteristic differentiates a 'robust' digital mode like Olivia or Contestia from a 'fast' mode like FT8 or FT4?

Accepted Answer

Robust modes prioritize reliable decoding under poor conditions, often at the expense of speed or bandwidth efficiency.

Answer

Robust modes typically use fewer tones but higher symbol rates.

Answer

Fast modes always incorporate ARQ for guaranteed message delivery.

Answer

Fast modes are exclusively used for emergency communications.

Question 5

An amateur radio operator is setting up a digital voice (DV) hotspot for D-STAR, DMR, and Fusion. Which open-source software project is commonly used on a Raspberry Pi to bridge these different digital voice protocols to the internet?

Accepted Answer

MMDVMHost / Pi-Star

Answer

WSJT-X

Answer

fldigi

Answer

Winlink Express

Question 6

Which of the following digital modes is best suited for unattended, automated messaging and file transfer over HF, especially in emergency or tactical communications where guaranteed delivery is paramount?

Accepted Answer

Winlink (e.g., using ARDOP or PACTOR)

Answer

PSK31

Answer

JT65

Answer

RTTY