The AI signal identifier classifies detected signals into the modes listed below. This reference table describes the modulation characteristics, typical bandwidths, and common uses of each mode recognized by the classifier. For details on how detection and identification work, see Signal Detection and AI Identification.
| Mode | Modulation Type | Tones / Phases | Bandwidth | Modulation Details | Main Use |
|---|---|---|---|---|---|
| CW | On-Off Keying (OOK) | 1 | ~10–20 Hz | Simple carrier on/off (Morse) | Weak signals, contests |
| AM | Amplitude Modulation | — | 6–10 kHz | Analog amplitude variation | Broadcast voice |
| SSB | Single Sideband | — | 2.4–3 kHz | Analog, suppresses carrier & one sideband | Efficient voice |
| FM | Frequency Modulation | — | 5–15 kHz | Analog frequency variation | Local voice, repeaters |
| AFSK | Audio FSK | 2 | 2–3 kHz | Audio tones (usually 1200/2200 Hz) | APRS, packet radio |
| RTTY | Binary FSK / AFSK | 2 | 300–500 Hz | 170 Hz shift, 45.45 baud | Text communication |
| FSK | Frequency Shift Keying | 2 | Variable | Direct frequency shifts | Basic digital |
| MSK | Minimum Shift Keying (CPFSK) | 2 | Moderate | Continuous phase, modulation index = 0.5 | Efficient & constant envelope |
| MFSK | M-ary FSK | M (e.g. 4, 65) | Variable | Multiple discrete frequencies | Weak signal modes |
| WSPR | 4-FSK (MFSK) | 4 | ~6 Hz | Continuous phase, very slow | Propagation monitoring |
| PSK | Phase Shift Keying | 2–8 phases | Narrow | Changes carrier phase | PSK31, digital modes |
| JT65 | 65-FSK (MFSK) | 65 | ~178 Hz | Discrete tones + strong FEC | Weak-signal EME |
| FT8 | 8-GFSK (MFSK) | 8 | ~50 Hz | Gaussian filtered 8-tone FSK | Fast DXing, popular |
| FT4 | 4-GFSK | 4 | ~83 Hz | Gaussian filtered 4-tone FSK | Faster contest QSOs |
| FT2 | 4-GFSK | 4 | ~80–100 Hz | Gaussian filtered, very fast periods | Ultra-fast QSOs (newer mode) |
| Q65 | 65-FSK (MFSK) | 65 | 100–1000+ Hz | Discrete tones, excellent FEC | EME & troposcatter (fading tolerant) |