The automatic direction finder, also called radio compass, refers to the on-board receiver. It consists of ground and aircraft equipment.
There are two types of equipment depending on where this equipment is installed.
If it's near an Aerodrome, we talk about a locator. The locator is intended for IFR approach. It is usually identified by two letters.
If it's in the field, we talk about the NDB. The NDB (Non Directional Beacon) is identified by three letters.
Consists of an antenna placed under the aircraft, a receiver to select the frequency and operating mode, and an indicator to read the bearing.
The ground beacon emits an omni-directional signal which is received by the antenna. The display then shows a bearing, which is the angle between the Heading and the direction of the beacon.
The radio compass is sensitive to atmospheric disturbances. In stormy weather, the needle will tend to indicate thunderstorms.
In addition, during twilight, the information is unreliable as the wave reflects off the upper layers of the Earth's atmosphere.
Status:: #wiki/notes/germinating
Plantations:: Avionic - 20230221094041
References:: Le Manuel de Pilotage d'Avion