Although this lection focuses on VHF radio, which is the standard for aviation communication, it is worth understanding how VHF differs from UHF (Ultra High Frequency) systems, which are used in other applications.

VHF frequencies range from 30 MHz to 300 MHz. Aviation uses the 117.975–137 MHz portion of this band. VHF propagation is quasi-optical, meaning it travels in relatively straight lines and follows the curvature of the Earth. VHF range is dependent on antenna height and line-of-sight distance.

UHF frequencies range from 300 MHz to 3,000 MHz. UHF is used for television broadcasting, some military communications, and cellular systems. UHF also propagates quasi-optically, but because the wavelengths are shorter, UHF signals are more susceptible to obstruction by buildings, trees, and terrain. UHF antennas are typically smaller and more efficient at high frequencies.

In European airspace, VHF is the sole standard for aviation radiotelephony in the controlled airspace where most pilots operate. You will not encounter UHF frequencies on a standard civilian aircraft operating under VFR in continental Europe. Some military aircraft use UHF, but this is outside the scope of VFR pilot training.

The key point to remember: VHF (aviation band 118–137 MHz) is the standard. Understand it thoroughly, and you have the foundation for all radiotelephony training.