TM 1-1520-238-10
Change 4
3-33
Table 3-10.
AN/ARN-149(V)3 ADF Control Panel Control Functions
Control
Function
Mode selector
switch
OFF
Removes power from the ADF.
ANT
Provides for operation as an AM receiver.
ADF
Provides both ADF and AM receiver operations.
TAKE CMD switch
Not used.
VOL control
Controls the audio volume in 12 discrete steps.
TEST-TONE switch
Selects the submode of operation. If TEST is selected, the HSI No. 2 bearing pointer and
RMI pointer momentarily move 90 degrees as a self-test. If TONE is selected, the normal
audio is replaced by a 1 kHz tone for tuning to a (cw) station.
Frequency switches
and indicators
Control and indicate the selected operating frequency when the MAN-2182-500 switch is in
the MAN position. 2182 kHz and 500 kHz are international distress frequencies.
NOTE
2182 kHz and 500 kHz are international distress frequencies.
MAN-2182-500
switch
MAN
Enables the frequency switches for manual frequency selection.
2182
2182 kHz is the operating frequency.
500
500 kHz is the operating frequency.
3.13.3 Modes of Operation.
The AN/ARN-149 ADF
system has two functional modes and a submode as fol-
lows:
a. ADF Mode.
In this mode, the system functions
as an ADF that provides a relative bearing-to-
station to the HSI No. 2 bearing pointer and the
RMI pointer.
b. ANT Mode.
In this mode, the system functions
as an audio receiver, providing only an audio
output of the received signal.
c. Tone Submode.
This submode may be cho-
sen in either ADF or ANT mode of operation. In
the tone submode, the system provides a 1 kHz
audio output tone when a signal is being re-
ceived to identify keyed cw signals. This sub-
mode can be used when normal audio reception
is insufficient to identify the station; the cw
coded signal can be used to identify the station.
