Air Comm Systems, Inc.
Page 6
n
Description
The ACS 300A(SP) Dual Audio Mixer Panel is a compact, lightweight unit which provides full
audio control and ICS support for Pilot and Co-pilot or observer positions in the aircraft. It has
the capability to provide each user with 6 receive audio selections, 6 transmitter selections,
Normal and HOT (Hands Free) ICS, and full headphone audio and ICS volume control. In
addition, an internal expansion slot excepts a plug-in module (optional) which can give the unit
an additional
2
positions of ICS capability.
n
1- Norm - Emer Switch
This switch controls the operation of the audio panel in the event of an audio amplifier failure.
In the “up" position (NORM) the audio panel is in normal operating mode. In the “down" position
(EMER) the unit is in the emergency mode. During Emergency operation,with a receive audio
switch in the "down" position the mic select rotary switch selects the mic, key, and
unamplified audio in the event of an audio amplifier failure. The side in emergency mode will not
have incoming ICS.
n
2 - Receive Audio Select-Mute Switches
Normal operation - In the “up" position the audio selected is summed with any other audios
selected into the headphone amplifier. It also selects or mutes cross sidetone. In the “down"
position the audio selected is muted. Cross sidetone is also muted.
Emergency operation - In the "down" position the mic select rotary switch selects the mic,
key, and unamplified audio in the event of an audio amplifier failure. The side in emergency
mode will not have incoming ICS.
n
3 - Volume Controls
These concentric knobs adjust headphone volume. The larger one adjusts the radio volume
while the smaller one adjusts the intercom (ICS) volume. Clockwise rotation increases the
volume - counter clockwise rotation decreases the volume. To set volume, transmit on the
radio and set the sidetone level slightly on the low side so you will have a tendency to talk up
and have higher modulation. Then set the radio volume for comfortable listening. In the event of
excessive or inadequate receiver volume the pots located on the rear of the unit may be adjusted
for the proper level. (see Figure 2 on page 8)
ACS 300A(SP) Installation and Operations Manual
Front Panel Controls
( See Figure 1 — Page 8 for pictorial )
