COMMON HF DIGITAL FREQUENCIES (USA)
| FT8 | Weak-signal 15-second exchange via WSJT-X. Most popular HF digital mode. Full passband (500–3000 Hz above dial). | | RTTY | Radioteletype — the classic digital mode. Widely used in HF contesting. AFSK on USB; audio tones vary by software. |
| FT4 | Faster variant of FT8 with 7.5-second sequences. Primarily used during contest events. Full passband. | | OLIVIA | MFSK weak-signal mode capable of copy under extremely poor conditions. Slower but very robust. Audio center at +1000 Hz. |
| JS8CALL | FT8-based keyboard-to-keyboard messaging with store-and-forward. Good for casual conversations and relay nets. Full passband. | | VARA HF | High-performance modem for Winlink email over radio and peer-to-peer HF connections. Audio center at +1500 Hz. |
| PSK31 | Real-time keyboard-to-keyboard QSO mode. Very narrow bandwidth (<100 Hz), excellent for crowded bands. Tune audio to +1000–1500 Hz above dial. | | | |
All HF digital modes use USB. Values are VFO dial frequencies in MHz. FT8 / FT4 / JS8Call use the full passband (500–3000 Hz above dial); PSK31, Olivia, and VARA HF use a specific audio offset — see legend above.
Common HF digital frequencies| BAND | FT8 USB | FT4 USB | JS8CALL USB | PSK31 USB | RTTY USB | OLIVIA USB | VARA HF USB |
|---|
| 10m | 28.074 | 28.180 | 28.078 | 28.120 | 28.080 | 28.1215 | 28.1385 |
| 12m | 24.915 | 24.919 | 24.922 | 24.920 | 24.920 | — | — |
| 15m | 21.074 | 21.140 | 21.078 | 21.070 | 21.080 | 21.1285 | 21.1035 |
| 17m | 18.100 | 18.104 | 18.104 | 18.100 | 18.100 | 18.106 | 18.106 |
| 20m | 14.074 | 14.080 | 14.078 | 14.070 | 14.080 | 14.1065 | 14.1035 |
| 30m | 10.136 | 10.140 | 10.130 | 10.142 | 10.130 | 10.141 | 10.144 |
| 40m | 7.074 | 7.0475 | 7.078 | 7.070 | 7.080 | 7.0715 | 7.1015 |
| 60m | 5.357 | — | — | — | — | — | — |
| 80m | 3.573 | 3.575 | 3.578 | 3.580 | 3.580 | 3.5625 | 3.601 |
VHF/UHF DIGITAL & PACKET (NATIONAL STANDARDS)
VHF/UHF digital and packet frequencies| MODE | BAND | VFO DIAL | MODULATION | NOTES |
|---|
| FT8 | 6m | 50.313 MHz | USB | Passband 500–3000 Hz · WSJT-X |
| FT8 | 2m | 144.174 MHz | USB | — |
| FT8 | 70cm | 432.174 MHz | USB | — |
| APRS | 2m | 144.390 MHz | FM | US National · 1200 baud AFSK |
| APRS (ISS) | 2m | 145.825 MHz | FM | ISS Digipeater · 1200 baud AFSK |
| Packet / Winlink | 2m | 145.010 MHz | FM | National Packet / BBS |
| Packet / Winlink | 2m | 145.030 MHz | FM | — |
| Packet / Winlink | 2m | 145.050 MHz | FM | — |