PS Engineering
PMA7000M-S Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual for Civil Air Patrol
200-072-0004
Page 3-5
Rev. 4, Sept. 2000
3.6.2 Volume Control
The 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 passengers' 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; therefore, passenger
volume can be adjusted at the headset. If desired, passenger volume level can be adjusted
by a screwdriver adjustment at the top of the tray (see figure 2-1).
3.6.2.1 Mono headsets in Stereo Installation
All passenger headsets are connected in parallel. Therefore, if a monaural headset is
plugged in to a PMA7000M-S Stereo installation, one channel will be shorted. Although
no damage to the unit will occur, all passengers will lose one channel. PS Engineering
modifies headsets to add stereo capability, using high-fidelity speakers. Contact factory
for details.
3.6.3 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 current cockpit situation. The description of the
intercom mode function 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 Entertainment 1, while pas-
sengers 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 Entertainment 1. Pas-
sengers can continue to communicate with themselves without interrupting the Crew and
also may listen to Entertainment 2.
Anytime the PMA7000M-S is in either the C
OM
1/C
OM
2,C
OM
1/C
OM
3, or
C
OM
2/3
("Split Mode"), the pilot and copilot intercom is controlled with the ICS button. The pas-
sengers will maintain intercommunications, but never hear aircraft radios.
