The amateur bands
The amateur service holds slices of spectrum from the shortwave bands up to microwaves. Main landmarks (Region 1 — always check the official band plan in force, which is authoritative for the exam):
| Nickname | Approx. frequency | Type |
|---|---|---|
| 80 m | 3.5–3.8 MHz | HF |
| 40 m | 7.0–7.2 MHz | HF |
| 20 m | 14.0–14.35 MHz | HF |
| 15 m | 21 MHz | HF |
| 10 m | 28–29.7 MHz | HF |
| 6 m | 50 MHz | VHF |
| 2 m | 144–146 MHz | VHF |
| 70 cm | 430–440 MHz | UHF |
| 23 cm | 1240–1300 MHz | UHF/SHF |
The nickname ("20 metres") recalls the approximate wavelength — handy for sizing an antenna.
General behaviour: the HF bands (< 30 MHz) allow long-distance contacts via ionospheric reflection; VHF/UHF bands mostly carry "line of sight" but support more bandwidth and digital modes. See Propagation des ondes.
On each band, sub-bands per mode (telegraphy, SSB, digital…) and a primary/secondary status apply — see Réglementation du service amateur. Maximum permitted power depends on licence class and band.
👉 Many of these frequencies are listenable with your SDR: see Bandes intéressantes à explorer.