Figure 3-2. Marker Beacon Audio Control Panel
3-7. MARKER BEACON AUDIO CONTROL PANEL
Description. The marker beacon audio control
panel, located on the pedestal extension (fig. 2-8) allows the
pilot or copilot to selectively monitor audio signals from the
high frequency (HF), marker beacon (MKR BCN), or ADF
systems. It also has controls for the selection of ADF voice or
Controls and Functions.
HF volume control. Adjusts volume of high-
frequency radio signals received.
MKR BCN HI-LO switch. Selects sensitivity
of marker beacon receiver.
MKR BCN volume control. Adjusts volume
of marker beacon radio signals received.
ADF Filter Switches. Controls selected ADF
FILTER V-OFF switch. Selects filter to
block voice transmissions from ADF ground station.
FILTER R-OFF switch. Selects filter to
block range transmissions from ADF ground station.
3-8. FM/SATCOM AUDIO SELECTOR SWITCH
The FM/SATCOM audio selector switch panel, located
on the pedestal extension (fig. 2-8), provides a means of
selection between SATCOM and the AN/ARC-186 (FM)
radios when position No.2 on the audio control panel (fig. 3-
1) has been selected. The FM/SATCOM audio selector panel
has three pushbutton switch-indicators.
SATCOM/FM selector switch. The center switch,
with illuminated placardeds which read SATCOM or FM,
allows the alternate selection of SATCOM or FM audio.
Depressing the center switch when the SATCOM placard is
illuminated will cause the FM placard to illuminate and the
SATCOM placard to extinguish. Depressing the center
switch again will cause the illuminated placards to reverse. If
the SATCOM system is not operational, the switch should
remain in the FM mode.
Switches. The pilot and copilot are each provided with a
SATCOM/FM monitor control switch, located on the
SATCOM/FM audio selector switch panel (fig. 2-8), on either
side of the SATCOM/FM selector switch. The switches, with
MONITOR OFF, allow the alternate selection of MONITOR
ON or MONITOR OFF. Depressing the switches, when the
MONITOR OFF placard is illuminated, will cause the
MONITOR ON placard to illuminate, and the MONITOR
OFF placard to extinguish. Depressing the switches again
will cause the illuminated placards to reverse. When the
center SATCOM/ FM selector switch has been set to
SATCOM and the pilot's or copilot's SATCOM/FM monitor
switch has been set to MONITOR ON, the pilot or copilot
will receive audio from the FM receiver (the deselected
receiver). When the SATCOM/FM selector switch has been
set to FM, and the pilot's