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1.6.2
Intercom Volume Control
The intercom volume control is the smaller concentric knob on the left side of the
unit. This volume control knob adjusts the loudness of the intercom for the pilot and
copilot only. It has no effect on selected radio levels, music input levels or passen-
gers' volume level.
Adjust the radios and intercom volume for a comfortable listening level for the
pilot. Most general aviation headsets today have built-in volume controls; there-
fore, passenger volume can be adjusted at the headset. If desired, passenger vol-
ume level can be adjusted by a screwdriver adjustment at the top of the tray.
1.6.2.1 Mono headsets in Stereo Installation
All passenger headsets are connected in parallel. Therefore, if a monaural headset
is plugged in to an Apollo SL15-CD Stereo installation, one channel will be
shorted. Although no damage to the unit will occur, all passengers will lose one
channel, unless they switch to the “MONO” mode on the headset. PS Engineer-
ing modifies headsets to add stereo capability, using high-fidelity speakers. Con-
tact factory for details.
1.6.3
Intercom Modes
The lower switch on the left side is a 3-position mode switch that
allows the pilot to tailor the intercom function to best meet the cur-
rent cockpit situation. The description of the intercom mode func-
tion is valid only when the unit is not in the "Split" mode. Then,
the pilot and copilot intercom is controlled with the ICS button.
I
SO
:
(Up Position): The pilot is isolated from the intercom and is connected only
to the aircraft radio system. He will hear the aircraft radio reception (and sidetone
during radio transmissions). Copilot will hear passengers’ intercom and Enter-
tainment 1, while passengers will hear copilot intercom and Entertainment 2.
Neither will hear aircraft radio receptions or pilot transmissions.
A
LL
:
(Middle Position): All parties will hear the aircraft radio and intercom. Crew
will hear Entertainment 1, passengers will hear Entertainment 2. During any radio
or intercom communications, the music volume automatically decreases. The
music volume increases gradually back to the original level after communications
have been completed.
C
REW
(Down Position): Pilot and copilot are connected on one intercom channel
and have exclusive access to the aircraft radios. They may also listen to Enter-
tainment 1. Passengers can continue to communicate with themselves without
interrupting the Crew and also may listen to Entertainment 2.
Anytime the SL15-CD is in either the C
OM
1/C
OM
2, C
OM
2/C
OM
1 ("Split
Mode"), the pilot and copilot intercom is controlled with the ICS button. The pas-
sengers will maintain intercommunications, but never hear aircraft radios.
