How many letters does an NDB radio beacon, except compass locators, transmit in a continuous ID using Morse code?

An NDB (Non-Directional Beacon) radio beacon, except for compass locators, transmits a continuous identification signal in Morse code consisting of three letters. This three-letter identification provides a unique identifier for the beacon, helping pilots and air traffic controllers to recognize and differentiate between various beacons in the airspace.

Each of these letters is represented in Morse code and is transmitted in a loop, allowing aircraft equipped with appropriate receiving equipment to determine their location relative to the beacon. The use of three letters ensures a sufficient number of unique identifiers are available, as a single letter would not provide enough unique combinations and four letters would exceed the practical needs for identification. This structured approach to identification is standardized for NDBs to ensure consistent communication and navigation support for aircraft.