ADF Flashcards
NDBs operate in which frequency band?
LF and MF
NDBs operate in which frequency spectrum(values)?
200 KHz and 500KHz
The type of antenna a NDB utilise?
Loop aerial
The 5 ADF errors?
- Terrain or mountain effect
- Coastal refraction
- Night effect
- Static interference
- Station interference
Describe terrain or mountain effect:
The error increases with -
Mountains or terrain can reflect the signal and can cause multi path reception. The direct transmission from the NDB is received plus one or more indirect reflections resulting in errors.
Altitude
Describe coastal refraction:
If flying over the ocean, the NDB fix will be towards -
As a radio wave passes from one medium to another its velocity can change and the signal can bend towards the medium with the higher density.
Land(higher density)
Describe Night Effect:
During the day, MF sky waves are normally ineffective due to attenuation in the D layer. At night the D layer disappears and MF waves are reflected by the E layer. Ground and sky waves will mix and phase differences can cause excessive oscillations of the ADF needle.
Describe Static Interference:
Large errors can occur in the vicinity of thunderstorms as a result of static discharge. The ADF needle may even point to the CB.
Describe Station Interference:
Other NDBs and commercial broadcast stations can interfere.
QTE -
TRUE bearing from the station
QDR -
MAGNETIC bearing from the station
QDM -
MAGNETIC track to the station
QUJ -
TRUE track to the station
The actual instrument(one which displays RBs) in the cockpit of an ADF system is called?
An RBI - Relative bearing indicator
a RB is measured -
clockwise from the nose of the aircraft
