Practical takeaway
Image modes, CW, packet, PSK, APRS, error detection/correction, networking, DMR, WSJT modes, and Broadband-Hamnet.
T8D · 12 pool questions
Digital & Non-Voice Communications
Image modes, CW, packet, PSK, APRS, error detection/correction, networking, DMR, WSJT modes, and Broadband-Hamnet.
Technician exam focus
This group contains 12 questions in the current pool. The teaching below keeps the important tested terms visible while explaining what they mean in normal Amateur Radio use.
1. Digital means information is encoded as data
Packet radio, FT8, PSK, many forms of amateur networking, and IEEE 802.11-based systems all convey digitally encoded information. FT8 is specifically designed for low signal-to-noise operation and uses short, tightly timed transmissions.
2. Different digital modes solve different problems
Packet radio sends data in packets. PSK31 is a narrow keyboard-to-keyboard mode. APRS is widely used for position reports and other real-time local information. DMR carries digital voice/data through time-slotted channels and talkgroups.
3. Error checking keeps bad data from looking good
Digital protocols use methods such as checksums/CRC and sometimes forward error correction to detect or correct errors. The goal is not merely to make a signal sound clean; it is to tell whether the received bits are trustworthy.
4. Not every non-voice mode is the same thing
CW sends information by keying a carrier on and off. Slow-scan television sends images. Amateur high-speed networking can use microwave/Wi-Fi-derived equipment such as Broadband-Hamnet. Each has different bandwidth and equipment needs.
T8D checklist
- Packet, FT8, PSK, and IEEE 802.11 are digital communication methods.
- FT8 is designed for low signal-to-noise operation.
- PSK31 is narrow keyboard-to-keyboard digital communication.
- APRS commonly carries position and local data.
- Error-detection/correction techniques help identify or repair corrupted data.
- CW is carrier on/off keying; SSTV carries images.
- Broadband amateur networking can use Wi-Fi-derived microwave equipment.
Exam scope: NCVEC 2026–2030 Technician Class (Element 2), effective July 1, 2026 through June 30, 2030, with February 19, 2026 errata. The current NCVEC pool is the exam authority; explanatory prose here is SPARKA teaching material. NCVEC pool