Air Comm Systems ACS 300A-100 User manual

Dual Audio Mixer Panel
Installation and Operations Manual
ACS 300A-100 Revision 1.5
Air Comm Systems, Inc
37610 Sky Canyon Dr., Hangar 51
Murrieta, CA 92563
Ph: 951-677-0101 ~ Fx: 951-677-0701
[email protected] ~ www.AirCommSystems.com
VHF1 VHF2 FM1 FM2 AUXFM VHF1 VHF2FM1 FM2 AUXFM
OFF OFF
EMER AUX AUX EMER
XMIT XMIT
NORM NORM
ICS
MIC SEL VOL ICS VOL ICS MIC SEL
VHF2
VHF1
VHF2
VHF1
ON
OFF
HOT
Air Comm
ACS 300A-100
FM1 FM2FM1 FM2
AUXFM
AUX
AUXFM
AUX

Air Comm Systems, Inc. Page 2
nInstallation
Physical and Operating Specifications Page 3
Physical Dimensions Page 4
Interface Schematic Page 5
nOperation
Front Panel Controls Page 6-7
Front Panel Controls Pictorial Page 8
Rear Panel Adjustment Pictorial Page 8
nInstructions for Continued Airworthiness
Instruction for Continued Airworthiness Page 9
nWarranty Information
Warranty Information Page 10
ACS 300A-100 Installation and Operations Manual
Table of Contents

Air Comm Systems, Inc. Page 3
nPhysical Specifications
nOperating Specifications
SIZE: 6.31 in.(16.03 cm) W WEIGHT: 2.90 lb
2.62 in.( 6.65 cm) H
6.78 in.(17.22 cm) D w/ connector MOUNTING: Dzus rail mount
CONTROLS: Panel mounted - transmit = rotary switch, audio inputs = toggle switch
volume control = dual potentiometer
ILLUMINATION: Edge lit front panel per MIL-P-7738E, type 3. Capable of connection to
dimmer bus for adjustment. Transmit light indicates when unit is in transmit mode.
INPUTS: 6 receive audio inputs per position. 6 transmit selections per position.
DUTY CYCLE: Continuous POWER REQUIREMENTS: 28V DC +/- 10%
MAXIMUM OPERATING ALTITUDE: 16,500 ft.(5029 m)
OPERATING TEMPERATURE RANGE: -40 C to +85 C (operating)
-65 C to +125 C (storage)
CURRENT DRAIN: 50 mA at 28V (standby) - 1.5 A at 28V (max. signal)
AUDIO OUTPUT: Minimum 250 mW into 600 ohms
FREQUENCY RESPONSE: Within 6 db - 300-3000Hz
ICS INPUT IMPEDANCE: 600 ohms
RECEIVER INPUT IMPEDANCE: 600 ohms - matched to receiver
INPUT ISOLATION: Not less than 45 db between inputs
AUDIO MUTING: Not less than 45 db during transmit/ICS (optional)
MIC SENSITIVITY: 300 mV for rated output
DISTORTION: Less than 10% at 1000 Hz for maximum output
ACS 300A-100 Installation and Operations Manual
Physical and Operating Specifications

Air Comm Systems, Inc. Page 4
nPhysical Dimension Outline
ACS 300A-100 Installation and Operations Manual
Physical Dimensions
Physical Installation
The ACS 300A-100 is designed to be Dzus mounted and should be installed in the aircraft using the
Installation Kit that was included with the unit. The above outline drawing of the unit with dimensions
will facilitate the installation. The Installation Kit consists of the following:
-One (1) 37 pin AMP D-Subminiature female mating connector complete with crimp pins, hood, and slide
lock.
-One (1) 25 pin AMP D-Subminiature female mating connector complete with crimp pins, hood, and slide
lock.
The connector pin configuration of the ACS 300A-100 rear connector and the recommended wire size
for the aircraft cable harness is shown on the following page.
VHF1 VHF2FM1 FM2 AUXFM VHF1 VHF2FM1 FM2 AUXFM
OFF OFF
EMER AUX AUX EMER
XMIT XMIT
NORM NORM
ICS
MIC SEL VOL ICS VOL ICS MIC SEL
VHF2
VHF1
VHF2
VHF1
ON
OFF
HOT
Air Comm
ACS 300A-100
FM1 FM2 FM1 FM2
AUXFM
AUX
AUXFM
AUX

Air Comm Systems, Inc. Page 5
The ACS 300A wiring harness should be constructed of Tefzel aircraft wire (M22759/16 grade). Power
and ground wires should be 18 or 20 AWG, and all other wires may be 22 AWG. Shielded wires should
be used where noted. Adequate protection against wear and chafing should be taken by using a braided
cable sleeving or jacket. Before completing installation, verify that all cable connector pins are seated
properly and that the connector is securely mounted to the unit mating connector.
Pre-fabricated cable harnesses are available from Air Comm to expedite installation — consult our sales
department for details.
NOTE: Pins noted NC = No Connection.
nConnector Pin-out
ACS 300A-100 Installation and Operations Manual
Interface Schematic
37
28VDC POWER IN
LEFT MICROPHONE HI
LEFT TRANSMIT KEY
LEFT ICS KEY
LEFT HEADPHONE AUDIO
RIGHT MICROPHONE HI
RIGHT TRANSMIT KEY
RIGHT ICS KEY
RIGHT HEADPHONE AUDIO
INPUT 1 MIC HI COM1
INPUT 1 KEY
INPUT 1 AUDIO
INPUT 2 MIC HI FM1
INPUT 2 KEY
INPUT 2 AUDIO
INPUT 3 MIC HI FM2
INPUT 3 KEY
INPUT 3 AUDIO
INPUT 4 MIC HI HT1
INPUT 4 KEY
INPUT 4 AUDIO
PA MIC HI
PA KEY
SHIELDED GROUND
LEFT PASSENGER MIC
SPARE AUDIO IN
RIGHT PASSENGER MIC
CENTER PASSENGER MIC
LEFT PASSENGER KEY
RIGHT PASSENGER KEY
CENTER PASSENGER KEY
LEFT PASSENGER HEADPHONE AUDIO
RIGHT PASSENGER HEADPHONE AUDIO
CENTER PASSENGER HEADPHONE AUDIO
ICS BUSS
LIGHT DIM
POWER GROUND
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
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9
8
7
6
5
4
3
2
1
ACS 300A
AUDIO PANEL
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
NC
NC
RIGHT AFT PASS KEY
LEFT AFT PASS KEY
NC
NC
CENTER AFT PASS HEADPHONE AUDIO
RIGHT AFT PASS HEADPHONE AUDIO
LEFT AFT PASS HEADPHONE AUDIO
INPUT 8 AUDIO HI
INPUT 7 AUDIO HI
INPUT 6 AUDIO HI
SHIELDED GROUND
NC
LEFT AFT PASS ICS KEY
RIGHT AFT PASS ICS KEY
CENTER AFT PASS ICS KEY
NC
LEFT AFT PASS MIC HI
RIGHT AFT PASS MIC HI
CENTER AFT PASS MIC HI
INPUT 5 MIC HI
INPUT 5 KEY
INPUT 5 AUDIO HI
ONLY USED WITH SIX (6) PASSENGER ICS
OPTION (INTERNAL MODULE)
NOT USED

Air Comm Systems, Inc. Page 6
ACS 300A-100 Installation and Operations Manual Front
Panel Controls
( See Figure 1 — Page 8 for pictorial )
nDescription
The ACS 300A -100 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 accepts a plug-in module
(optional) which can give the unit an additional 6 positions of ICS capability, 2 of which
also have TX capability.
n1- 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.
n2 - 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 side tone.
In the “down” position the audio selected is muted. Cross side tone 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.
n3 - 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 side tone 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).

Air Comm Systems, Inc. Page 7
n4 - Lighting
The audio panel is lit by two 28V lamps which provide night time visibility for all panel
legends. They can be connected to a dimmer bus for adjustment. The lamps can be
changed from the front panel by unscrewing the light filter cap. The lamp part number is 327,
and is readily available from the factory and most electronic component suppliers.
n5 - Mic Selector
This rotary switch performs three functions simultaneously. It (a) connects the mic to the
selected transmitter (b) selects the associated keyline, and (c) selects the associated audio
(if not already selected using the audio select-mute switch). The audio selected also allows
for cross side tone if the other mic select switch has selected the same transmitter.
n6 - Transmit Indicator
When the transmit key is activated this indicator lights up show that the audio panel is in the
transmit mode.
n7 - ICS Switch
This switch selects the ICS mode. In the “up” position (ICS) each side of the audio panel is
connected to the common ICS bus. This enables each side to communicate with the other
side when their respective ICS PTT switches are keyed.
In the “center” position (OFF), the ICS bus is disconnected and both sides are isolated.
The ICS switch also provides for “Hands Free” operation. In the “down” position (HOT ICS) ,
both headphone mics are active and signals are fed into the ICS bus without having to key the
respective ICS PTT switches.
ACS 300A-100 Installation and Operations Manual
Front Panel Controls
( See Figure 1 — Page 8 for pictorial )

Air Comm Systems, Inc. Page 8
nFigure 1 - Front Panel Controls
nFigure 2 - Rear Panel Adjustment
ACS 300A-100 Installation and Operations Manual
Front and Rear Panel Controls
VHF1 VHF2 FM1 FM2 AUXFM AUX
VHF1 VHF2FM1 FM2 AUXFM VHF1 VHF2FM1 FM2 AUXFM
OFF OFF
EMER AUX AUX EMER
XMIT XMIT
NORM NORM
ICS
MIC SEL VOL ICS VOL ICS MIC SEL
VHF2
VHF1
VHF2
VHF1
ON
OFF
HOT
Air Comm
ACS 300A-100
FM1 FM2 FM1 FM2
AUXFM
AUX
AUXFM
AUX

Air Comm Systems, Inc. Page 9
ACS 300A-100 Installation and Operations Manual
Instruction for Continued Airworthines
nGENERAL DESCRIPTION:
The Audio Mixer Panel consists of a Dzus mounting located in the cockpit or cabin area which
provides access to multiple radios for transmitting and receiving. It also provides intercom, and
keyed between other audio mixer panels or slave units located elsewhere in the aircraft.
nPURPOSE:
To provide instructions for the maintenance and inspection of the Air Comm Systems, Inc. Model
ACS-300 Series Audio Mixer Panels.
This Manual provides instructions supplementing the aircraft maintenance manual. These
instructions only supersede the aircraft manual in the indicated areas.
nOPERATIONAL CHECK:
nMAINTENANCE:
nOn Condition.
Check security and condition of Dzus mounted panel(s), check associated wiring harness at
periodic inspections such as annual/100 hour IAW FAR43 Appendix D(i).
The Audio Mixer Panel should be checked prior to first flight each day per current operations
manual.
Send Audio Mixer Panel(s) to qualified repair facility for any repairs. Contact Air Comm
Systems, Inc. Phone [phone] or FAX [phone] for more information.

Air Comm Systems, Inc. Page 10
ACS 300A-100 Installation and Operations Manual
Warranty Information
■Limited Warranty Information
Air Comm Systems, Inc. warrants each new product to be free from defective
material and workmanship and agrees to remedy any defect or to furnish a new
part in exchange for any defective unit provided an examination discloses such
defect occurred under normal use and service, and provided the defective unit is
delivered to us, with transportation charges prepaid, within 1 year from the date
of acceptance of equipment by the owner. Each unit required and claimed
defective must be returned to:
Air Comm Systems, Inc.
37610 Sky Canyon Dr., Hangar 51
Murrieta, CA 92563
Ph: 951-677-0101
Fx: 951-677-0701
[email protected]
This warranty does not extend to any products which have been subjected to
misuse, neglect, accident, or in violation of instructions furnished, nor does it
extend to units which have been repaired or altered outside of our factory except
where such repairs are specifically authorized in writing by us.
This warranty is in lieu of all other warranties expressed or implied, and no
representative or person is authorized to assume for us any other liability in
connection with the sale of our products.
■