Amateur allocations are agreed internationally and implemented by the FCC in Part 97. Within the legal edges, band plans are voluntary conventions dividing each band by mode. Following them is what stops a 50 Hz CW signal from landing inside a voice net.
HF — worldwide
| Band | Character |
|---|---|
| 160 m | "Top band". Local by day, continental at night. Needs a big antenna. |
| 80/75 m | Regional nets in the evening and overnight. |
| 60 m | Five fixed channels, USB, limited power. |
| 40 m | The all-rounder: regional by day, intercontinental at night. |
| 30 m | CW and digital only. Quiet and dependable. |
| 20 m | The classic DX band, open worldwide most days. |
| 17 m / 15 m | Excellent DX when solar activity is high. |
| 12 m / 10 m | Spectacular at solar maximum; 10 m also carries local FM and repeaters. |
VHF/UHF — local and line of sight
- 6 m (50 MHz) — the "magic band": mostly local, but sporadic-E openings go continent-wide.
- 2 m (144 MHz) — repeaters, FM simplex, SSB weak-signal work, satellites.
- 1.25 m (222 MHz) — quiet, US-centric, excellent repeater coverage where it exists.
- 70 cm (430 MHz) — repeaters, digital voice, satellites, amateur television.
- 23 cm and up — microwave experimentation, EME, high-speed data.
The shape of every band
CW at the bottom edge, then narrow digital modes, then SSB voice, with FM and repeaters at the top on VHF/UHF. On HF, SSB is lower sideband below 10 MHz and upper sideband above it — a convention, not a rule, but universally followed.
Sub-bands by licence class
Part 97 divides the HF phone segments by class, with Extra having the lowest — and most contested — edges. Keep a current chart at the operating position; the ARRL and NARA both publish one.
Power
The legal maximum is 1,500 watts PEP, but Part 97 requires you to use the minimum power necessary to carry out the communication. On a good 20 m opening that is often five watts.