Ham Radio General Class Test Digital Modes and Data Communications 3

Question 1

What is DMR in the context of amateur radio communication?

Accepted Answer

A Time Division Multiple Access digital voice mode used on VHF and UHF

Answer

DMR (Digital Mobile Radio) uses TDMA technology to allow two simultaneous conversations on a single 12.5 kHz channel and has been widely adopted by amateur operators on VHF/UHF.

Question 2

What is Varicode, as used by PSK31?

Accepted Answer

A variable-length character encoding that assigns shorter codes to more frequently used characters

Answer

Varicode is a variable-length encoding where common characters like 'e' and 't' use fewer bits than rare characters, improving throughput efficiency for typical English text in PSK31.

Question 3

With which digital communication system is D-STAR primarily associated?

Accepted Answer

Digital voice and data linked through repeater networks and the internet

Answer

D-STAR (Digital Smart Technologies for Amateur Radio) is a digital radio system supporting voice, slow-speed data, and high-speed data with worldwide internet linking through repeaters.

Question 4

What is the standard baud rate used for Baudot RTTY on HF amateur radio bands?

Accepted Answer

45.45 baud

Answer

HF RTTY using the Baudot code operates at 45.45 baud, a rate derived from early commercial teleprinter equipment that became the amateur HF RTTY standard.

Question 5

Which of the following best describes the FT4 digital mode?

Accepted Answer

A faster variant of FT8 using 7.5-second cycles designed for contest operation

Answer

FT4 uses 7.5-second transmission cycles — half of FT8's 15 seconds — and was specifically developed to handle higher QSO rates in amateur radio contest environments.

Ham Radio General Class Test Practice Test

Ham Radio General Class Test Practice Test

Ham Radio General Class Test Digital Modes and Data Communications 3