The frequency range from 3 MHz to 30 MHz is commonly referred to as the high frequency (HF) band. This band is also known as the shortwave band and encompasses radio frequencies that propagate via Sky wave propagation, allowing long-range communications beyond line of sight due to reflection from the ionosphere. HF radio waves are used in amateur radio communications, maritime communication, aviation and military applications where reliable long-range communication is essential.
The frequency band between 3 MHz and 30 MHz is in fact the high frequency (HF) band. This designation reflects its position in the radio frequency spectrum, extending from the lower range of the mid-frequency band to the lower edge of the very high frequency (VHF) band. The HF band is characterized by its ability to support long-term communication via ionospheric reflection, making it valuable for global communications networks and emergency communications during disasters when other forms of communication may be disrupted .
The radio frequency band associated with the 30 MHz to 300 MHz range is the very high frequency (VHF) band. VHF ranges from 30 MHz to 300 MHz and is widely used for sight communication due to its ability to effectively penetrate foliage and urban environments. VHF frequencies are used in a variety of applications, including FM radio broadcasting, television broadcasting, air traffic control, land mobile radio systems (such as police and fire departments), and marine communications.
Specifically, the 30 MHz frequency is at the lower end of the VHF band. VHF frequencies range from 30 MHz to 300 MHz, with 30 MHz marking the start of this band. VHF signals are used in many civil and military applications due to their ability to provide reliable communication over moderate distances with relatively simple antenna designs.