On HF (below 30 MHz), the use of phone (voice) is allowed for Technicians on the 10 meter band only (T1B06), in the 28.300 MHz to 28.500 MHz (T1B01) segment of the band. Also on 10 meters, Technicians may only use single sideband (SSB) for voice communications. Other modes such as FM (frequency modulation) or AM (amplitude modulation) are not allowed on 10 meters for Technicians.
