Embraer EMB145, Operation Manual

Page: 2268 / 2662

NAVIGATION AND
COMMUNICATION
AIRPLANE
OPERATIONS
MANUAL
2-18-11
Page
10
Code
01
REVISION 31
ADF OPERATION
The tuning of ADF frequencies is similar to that performed on the
airplane’s other radio equipment. Pressing the Line Select Button
beside the ADF frequency display will move the yellow cursor box to
surround the ADF frequency in the RMU display. Then, slowly turning
the Frequency Tuning Inner Knob clockwise causes the ADF
frequencies to advance in 0.5 kHz increments, while slowly turning the
outer knob clockwise will cause the frequencies to advance in 10 kHz
increments. ADF tuning through the Frequency Tuning Knobs is
accomplished using proportional rate. If the knobs are turned in slow
deliberate steps, the frequency will follow likewise. However, if the
knob is turned rapidly, the frequency will skip several steps, depending
upon the speed at which the knob is turned. This allows accomplishing
large frequency changes with a very slight rotation of the knob.
The RMU also has the capability of storing an ADF frequency. This is
accomplished by selecting the desired ADF frequency and then
pressing the Memory Storage Button on the RMU Bezel Panel. To
retrieve the stored frequency from memory, the ADF frequency Line
Select Button must be pressed for 2 seconds.
The ADF is provided with a mode control capability. ADF operational
modes can be selected by moving the yellow cursor box to the ADF
modes field in the ADF window and then pressing the Line Select
Button beside the ADF modes field or rotating the Frequency Tuning
Knobs. Repeatedly pressing the Line Select Button will cause the
modes to step in one direction while rotating the Frequency Tuning
Knobs will select the modes either up or down the current location.
The ADF operational modes are the following:
- ANT - The ADF receives signal only.
- ADF - The ADF receives signal and calculates relative bearings to
station.
- BFO - The ADF adds a beat frequency oscillator for reception of
CW signals.
- VOICE - The ADF opens width of IF bandwidth for better aural
reception.
NOTE: Bearing information is available in the ADF and BFO modes
only.