Technician T8D: Digital modes
These are the 12 official questions in group T8D of the 2026–2030 Technician question pool, with the correct answer marked and a plain-English explanation of why it's right. The real exam asks one question from this group.
- T8D01Question 1
Which of the following is a digital communications mode?
- APacket radio
- BIEEE 802.11
- CFT8
- DAll these choices are correct Correct
Why: Packet, PSK, FT8 and DMR are all digital modes.
- T8D02Question 2
What is FT8?
- AA wideband FM voice mode
- BA digital mode capable of low signal-to-noise operation Correct
- CAn eight-channel multiplex mode for FM repeaters
- DA digital slow-scan TV mode with forward error correction and automatic color compensation
Why: FT8 is a digital mode that works even at very low signal-to-noise ratios.
- T8D03Question 3
What kind of data can be transmitted by APRS?
- AGPS position data
- BText messages
- CWeather data
- DAll these choices are correct Correct
Why: APRS can send position, weather data and text messages. All the choices are correct.
- T8D04Question 4
What is meant by the term "NTSC?"
- AA digital transmission standard for encrypting data
- BA special mode for satellite uplink
- CAn analog fast-scan color TV signal Correct
- DA frame compression scheme for TV signals
Why: NTSC is the analog fast-scan color TV standard.
- T8D05Question 5
Which of the following is an application of APRS?
- AProviding real-time tactical digital communications in conjunction with a map showing the locations of stations Correct
- BAutomatically showing the number of packets transmitted via PACTOR during a specific time interval
- CProviding voice over internet connection between repeaters
- DProviding information on the number of stations signed into a repeater
Why: APRS provides real-time tactical messaging with station locations on a map.
- T8D06Question 6
What does the abbreviation "PSK" mean?
- APulse Shift Keying
- BPhase Shift Keying Correct
- CPacket Sampled Keying
- DPower Sampled Keying
Why: PSK stands for Phase Shift Keying.
- T8D07Question 7
Which of the following describes DMR?
- AA technique for time-multiplexing two digital voice signals on a single 12.5 kHz repeater channel Correct
- BAn automatic position tracking mode for FM mobiles communicating through repeaters
- CAn automatic computer logging technique for hands-off logging when communicating while operating a vehicle
- DA digital technique for transmitting on two repeater inputs simultaneously for automatic error correction
Why: DMR fits two digital voice signals in time slots on one 12.5 kHz channel.
- T8D08Question 8
Which of the following is included in packet radio transmissions?
- AA checksum that permits error detection
- BA header that contains the call sign of the station to which the information is being sent
- CAutomatic repeat request in case of error
- DAll these choices are correct Correct
Why: Packet transmissions include a header, the data and error checking. All the choices are correct.
- T8D09Question 9
What is CW?
- AA type of electromagnetic propagation
- BA digital mode used primarily on 2-meter FM
- CError correction for digital transmission using code words
- DAnother name for a Morse code transmission Correct
Why: CW is another name for Morse code.
- T8D10Question 10
Which of the following operating activities is supported by digital mode software in the WSJT-X software suite?
- AEarth-Moon-Earth
- BWeak signal propagation beacons
- CMeteor scatter
- DAll these choices are correct Correct
Why: WSJT-X supports FT8, meteor scatter, moonbounce and more. All the choices are correct.
- T8D11Question 11
What is the role of ARQ in a transmission system?
- AA special transmission format limited to video signals
- BA system used to encrypt command signals to an amateur radio satellite
- CAn error correction method in which the receiving station detects errors and sends a request for retransmission Correct
- DA method of compressing data using autonomous reiterative Q codes prior to final encoding
Why: ARQ: the receiver detects errors and asks for the data to be sent again.
- T8D12Question 12
Which of the following best describes an amateur radio mesh network?
- AAn amateur-radio data network using commercial Wi-Fi equipment with modified firmware Correct
- BA wide-bandwidth digital voice mode employing DMR protocols
- CAn amateur-radio satellite communications network using modified commercial satellite TV hardware
- DAn internet linking protocol allowing communication through repeaters around the world
Why: A ham mesh network uses commercial Wi-Fi gear with modified firmware.