HF

High Frequency – 3 to 30 MHz; Amateur HF bands are:

• 80m (3.5 MHz)
• 60m (5.3 MHz)
• 40m (7 MHz)
• 30m (10.1 MHz)
• 20m (14 MHz)
• 17m (18 MHz)
• 15m (21 MHz)
• 12m (24 MHz)
• 10m (28 MHz)

Learn more:
Wikipedia article