What type of frequency does an NDB operate on?

An NDB, or Non-Directional Beacon, operates primarily on low or medium radio frequencies. Specifically, NDBs typically transmit signals in the Medium Frequency (MF) band, which ranges from 300 kHz to 3000 kHz. This range is optimal for NDB operations, as it allows for good signal reception over long distances, particularly at low altitudes and in varied weather conditions.

The low or medium radio frequency is crucial because it facilitates the signals traveling through types of atmosphere conducive to their reception, enabling pilots to use these beacons for navigation. NDBs are often used for approach and landing guidance, especially in areas where other navigational aids may not be available.

The other frequency types mentioned do not pertain to NDB operations; high frequency, ultra-high frequency, and very high frequency are associated with different types of communication and navigation systems. For instance, high frequency is used for long-range communication, ultra-high frequency pertains to aviation communications and radar, and very high frequency is primarily used for television and FM radio broadcasting, none of which apply to the functioning of NDBs.