PS Engineering 050-450-0801 User manual

9800 Martel Road
Lenoir City, TN 37772
www.ps-engineering.com
PMA450C
Document P/N 200-450-0800
July 2022
Audio Selector Panel with Marker Beacon Receiver
High-fidelity Stereo Intercom, USB Charging Port
with Bluetooth® Connectivity
System Installation and Operation Manual
FAA- TSO C139a, C35d, C71
Patented under one or more of the following;
No. 4,941,187; 5,903,227; 6,160,496 and 6,493,450,
PS Engineering, Inc. 2022 ©
Copyright Notice
Any reproduction or retransmittal of this publication, or any portion thereof, without the expressed written permission of PS En-
gineering, Inc. is strictly prohibited. For further information, contact the Publications Manager at PS Engineering, Inc., 9800
Martel Road, Lenoir City, TN 37772. Phone [phone], email [e-mail].
In certified aircraft, warranty is not valid unless this product is installed by an
Authorized PS Engineering dealer.

Table of Contents
Section I –GENERAL INFORMATION................................................................1-1
1.1 INTRODUCTION .............................................................................................................................................................................................1-1
1.2 SCOPE................................................................................................................................................................................................................1-1
1.3 EQUIPMENT DESCRIPTION.........................................................................................................................................................................1-1
APPROVAL BASIS...........................................................................................................................................................................................1-2
1.4.1 LIMITATIONS.....................................................................................................................1-2
1.5 SPECIFICATIONS ...........................................................................................................................................................................................1-3
1.6 EQUIPMENT SUPPLIED ................................................................................................................................................................................1-4
1.8 LICENSE REQUIREMENTS...........................................................................................................................................................................1-4
Section II - INSTALLATION 2-1
GENERAL INFORMATION............................................................................................................................................................................2-1
2.1.1 SCOPE..............................................................................................................................2-1
2.1.2 CERTIFICATION REQUIREMENTS ......................................................................................2-1
UNPACKING AND PRELIMINARY INSPECTION......................................................................................................................................................2-1
EQUIPMENT INSTALLATION PROCEDURES ..........................................................................................................................................................2-1
2.3.1 COOLING REQUIREMENTS ................................................................................................2-1
2.3.2 MOUNTING REQUIREMENTS.............................................................................................2-1
2.3.3 AUDIO PANEL MOUNTING RACK INSTALLATION.............................................................2-2
2.3.4 AUDIO PANEL TRAY AND CONNECTOR ASSEMBLY .........................................................2-2
CABLE HARNESS WIRING....................................................................................................................................................................................2-2
2.4.1 ELECTRICAL NOISE...........................................................................................................2-2
2.4.2 EXISTING GMA340 AND PMA8000 INSTALLATIONS ......................................................2-3
2.4.3 POWER ..............................................................................................................................2-4
2.4.4 COMMUNICATIONS PUSH-TO-TALK..................................................................................2-4
2.4.5 AUDIO PANEL INTERFACE ................................................................................................ 2-4
2.4.6 TRANSMIT INTERLOCK .....................................................................................................2-4
2.4.7 BACKLIGHTING.................................................................................................................2-4
2.4.8 UNSWITCHED INPUTS........................................................................................................2-4
2.4.9 "SWAP"MODE ..................................................................................................................2-5
2.4.10 PUBLIC ADDRESS MODE.................................................................................................2-5
2.4.11 WIRED TELEPHONE/SATELLITE COMMUNICATION INPUT..............................................2-5
2.4.12 MUSIC INPUTS.................................................................................................................2-6
2.4.13 PLAYBACK BUTTON INSTALLATION (J2 PIN 22).............................................................2-6
MARKER BEACON INSTALLATION (050-450-0801, ONLY) ..................................................................................................................................2-6
2.5.1 MARKER ANTENNA INSTALLATION .................................................................................2-6
2.5.2 EXTERNAL MARKER LIGHTS............................................................................................2-7
2.5.3 MIDDLE MARKER SENSE.................................................................................................. 2-7
USER SETUP ADJUSTMENTS.................................................................................................................................................................................2-7
2.6.1 ADJUST SCREEN................................................................................................................2-7
2.6.2 RENAME “SWITCHED”INPUTS.......................................................................................... 2-8
2.6.3 VOLUME SETUP ................................................................................................................2-9
2.6.4 BLUETOOTH®MENU ........................................................................................................2-9
2.6.5 BLUETOOTH #2(P/N 050-450-0801 &-0901 ONLY) ......................................................2-10
COMMUNICATIONS ANTENNA INSTALLATION NOTES .......................................................................................................................................2-10
PMA450C PIN ASSIGNMENTS ...........................................................................................................................................................................2-11
WIRING CHECKOUT ..........................................................................................................................................................................................2-12
UNIT INSTALLATION..........................................................................................................................................................................................2-12
OPERATIONAL CHECKOUT................................................................................................................................................................................2-12
2.11.1 REQUIRED TEST EQUIPMENT........................................................................................2-12
2.11.2 AUDIO PANEL TEST ......................................................................................................2-12
2.11.3 MARKER CHECKOUT (050-450--0801 ONLY)...............................................................2-13
2.11.4 BLUETOOTH CHECKOUT...............................................................................................2-13
2.11.5 INTERNAL RECORDER CHECKOUT................................................................................2-13
FINAL INSPECTION ............................................................................................................................................................................................2-13
Section III OPERATION 3-1
SCOPE................................................................................................................................................................................................................3-1
POWER AND FAIL SAFE (1)..................................................................................................................................................................................3-1
DISPLAY MENU SELECTION (6)...........................................................................................................................................................................3-1
COMMUNICATIONS TRANSMIT (XMT) SELECTION (2) .......................................................................................................................................3-2

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page ii July 2022
3.4.1 SPLIT MODE......................................................................................................................3-2
COM AUDIO SELECTOR (3)................................................................................................................................................................................3-2
3.5.1 SWAP MODE (SWITCH FROM COM 1TO COM 2REMOTELY)............................................ 3-3
3.5.2 INTELLIAUDIO®DIMENSIONAL AUDIO ...........................................................................3-3
3.5.3 COM MONITOR MODE ......................................................................................................3-3
3.5.4 NAVAID SELECTION (4)....................................................................................................3-3
SPEAKER AMPLIFIER (7) .....................................................................................................................................................................................3-4
3.6.1 PUBLIC ADDRESS FUNCTION............................................................................................3-4
MARKER BEACON OPERATION (9) (PART NUMBER 050-450-0801, -0901 ONLY).................................................................................................3-5
3.7.1 MARKER BEACON SENSITIVITY........................................................................................3-5
INTERCOM OPERATION (8)..................................................................................................................................................................................3-5
3.8.1 INTELLIVOX®INTERCOM VOX-SQUELCH........................................................................3-5
3.8.2 INTERCOM VOLUME CONTROL (1)...................................................................................3-6
3.8.3 INTERCOM MODES (8) ......................................................................................................3-6
MUSIC CONTROL,DISTRIBUTION AND MUTING..................................................................................................................................................3-8
3.9.1 MUSIC MUTING ................................................................................................................3-9
3.9.2 MUSIC VOLUME..............................................................................................................3-10
3.9.3 MUSIC IN PILOT ISO MODE.............................................................................................3-10
BLUETOOTH®CONNECTION..............................................................................................................................................................................3-10
3.10.1 PAIRING AND UN-PAIRING BLUETOOTH DEVICES.........................................................3-10
BLUETOOTH®TELEPHONE MODE....................................................................................................................................................................3-11
3.11.1 BLUETOOTH RESET.......................................................................................................3-11
3.11.2 BLUETOOTH PIN...........................................................................................................3-12
3.11.3 BLUETOOTH CELLULAR TELEPHONE SIDETONE ...........................................................3-12
WIRED SATCOM/CELL PHONE INPUT................................................................................................................................................................3-13
INTERNAL RECORDER AND PLAYBACK..............................................................................................................................................................3-13
USER SETUP MENUS.............................................................................................................................................................................................3-1
3.14.1 ADJUST SCREEN (OLED ADJUSTMENT).........................................................................3-1
3.14.2 RENAME “SWITCHED”INPUTS........................................................................................ 3-2
3.14.3 OPTIONS..........................................................................................................................3-3
BLUETOOTH SETUP .............................................................................................................................................................................................3-3
3.15.1 UNPAIR ALL (BLUETOOTH RESET).................................................................................3-3
3.15.2 PIN: ................................................................................................................................3-3
3.15.3 BLUETOOTH 1(BT1), BLUETOOTH 2(BT2) ...................................................................3-3
3.15.4 BT1 CONFIGURATION.....................................................................................................3-4
3.15.5 BT2 CONFIGURATION.....................................................................................................3-4
3.15.6 VOLUME SETUP ..............................................................................................................3-5
USB CHARGING PORT (10) .................................................................................................................................................................................3-5
Section IV –Warranty and Service 4-1
WARRANTY .........................................................................................................................................................................................................4-1
FACTORY SERVICE..............................................................................................................................................................................................4-1
Appendix A –PMA450C Installation Drawings........................................................A
Appendix B –J1 Connector Interconnect ..................................................................B
Appendix C –J2 Connector Interconnect..................................................................C
Appendix D –Instructions for FAA Form 337 and continuing airworthiness .......D
INSTRUCTIONS FOR FAA FORM 337, AUDIO PANELS............................................................................................................................................ D
INSTRUCTIONS FOR CONTINUING AIRWORTHINESS,AUDIO SYSTEM.................................................................................................................... D
Appendix E –RTCA DO160G Environmental Qualification Form........................E
Rev
Date
Change
New
July 2022
Release of manual for PMA450C

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 1-1 July 2022
Section I – GENERAL INFORMATION
1.1 INTRODUCTION
The PMA450C represents a revolutionary step in cockpit audio control and intercommunications utility. In-
telliAudio®, using the USAF patented technology, provides True Dimensional Sound, which helps pilots to
easily discern simultaneous radio receptions. Our patented IntelliVox® design, front panel USB power jack,
and pilot programmable configurations, marks this panel as the next level of audio control. The unit is de-
signed for outstanding ergonomics and visually defined mode annunciation and selection.
Before installing and/or using this product, please read this manual completely. This will ensure that you will
take full advantage of all the advanced features in the PMA450C.
1.2 SCOPE
This manual provides detailed installation and operation instructions for the PS Engineering PMA450C-
series of Audio Selector Panel/Intercom Systems. This includes the following units:
Model
Part Number
Marker Receiver
PMA450C
050-450-0801
YES
PMA450C
050-450-0901
NO
1.3 EQUIPMENT DESCRIPTION
The PMA450C is a state-of-the-art audio isolation amplifier and audio selector that contains an automatic
voice activated (VOX) intercom system and integral marker beacon receiver. It can switch two transceivers
(Com 1, Com 2) and six receivers (Nav 1, Nav 2, MKR, and three additional inputs that can be individually
labeled, for use with ADF, DME AUX, etc.).
Warning: Use ofnon-aviation approvedcellular telephone equipmentmaybe prohibited by FCC regulation.
PS Engineering is not responsible for unauthorized airborne use of cellular telephones.
For airborne use, the PMA450C must be interfaced with an approved system.
There are four unswitched inputs, available for traffic or EGPWS, autopilot disconnect, and/or radar altimeter
warning.
Pushbuttons select the receiver audio source provided to the headphones. A SPR button allows the user to
listen to the receiver(s) selected on the cabin speaker. Except for the unswitched inputs, all speaker audio is
muted during transmit. Unswitched inputs 1& 2 are always presented to the aircraft speaker. Unswitched
input 3 & 4 will be presented to the speaker when the front panel SPR push button has been selected.
Pushbutton switches select one of the communication transceivers for the pilot and copilot position, and allow
radio transmission. In "Split Mode”, the PMA450C has the ability to allow the pilot to transmit on Com 1
while the copilot can transmit on Com 2. A fail-safe mode connects the pilot headphone and microphone to
COM 1 if power is removed for any reason, or if the power switch is placed in the Off (Fail-safe) position.
Unswitched input #1 is also provided to the pilot headphone (left side headset ear cup) in fail-safe
A six-station voice activated (VOX) intercom is included in the PMA450C. This system has PS Engineering’s
patented IntelliVox® circuitry that eliminates manual adjustments. The intercom system incorporates pilot
isolate, all and crew modes, two independent stereo music inputs with "SoftMute™". Intercom volume con-
trol is through two concentric front panel knobs and a pushbutton intercom mode switch. The small volume
knob controls the intercom level for the pilot and copilot, while the large knob controls the passenger inter-
com volume. Intercom squelch is automatic.
PMA450C part number 050-450-0801 contains a 75 MHz Marker Beacon receiver and 3-light indicator. This
provides the necessary Marker Beacon lights and audio indications necessary for that portion of an Instrument

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 1-2 July 2022
Landing System (ILS) approach. A pushbutton labeled MKR allows the pilot select audio on as well as test
and mute modes. Marker high sensitivity is also controlled by this button.
The front panel USB-type connector is available for charging devices, such as iPad or cell phones. Up to 15
Watts and 3.5 Amps are available. This connector does NOT provide any data interface.
In the PMA450C, a Bluetooth® wireless interface is available for wireless telephone and music connection.
APPROVAL BASIS
FAA TSO Approval
The PMA450C-series Audio Selector Panels are FAA approved under TSO C139A (Audio Amplifiers) TSO
C35d (Marker Beacon Receivers) and C71 (DC Power Supplies)
All systems comply with relevant portions of EUROCAE RTCA MPS WG No. 7/70, DO-143 and (Marker
Beacon Receivers), ED-14C/DO-160G (Environmental Conditions and Test Procedures for Airborne Equip-
ment), ED12B/DO-178B, Level D (Software Considerations for Airborne Equipment) and ED- 18/DO-214A
(Audio Systems Characteristics and Minimum Operational Performance Standards for Aircraft Audio Sys-
tems).
1.4.1 Limitations
This article meets the minimum performance and quality control standards required by a technical standard
order (TSO). Installation of this article requires separate approval.
Refer to Advisory Circular 20-41A for information on TSO installation approval.
Operation is subject to the following conditions:
This device may not cause harmful interference.
This device must accept any interference received, including interference that may cause undesired operation.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 1-3 July 2022
1.5 SPECIFICATIONS
TSO COMPLIANCE
Marker Beacon:
FAA TSO C35d, Class A
Audio Selector/Intercom:
FAA TSO C139a, Class 1a
DC Charging Jack
FAA TSO C71
APPLICABLE DOCUMENTS:
RTCA/DO-214A RTCA/DO-143 RTCA/DO-160G
RTCA/DO-178C, DO-254
ENVIRONMENTAL Qualifications:
A1D1CABSMXXXXXXZBABATBXXE2XXX
Operating Temperature Range:
-15º C to 55ºC
Altitude:
Up to 35,000 feet in a non-pressurized area
DIMENSIONS:
Height: 1.3 in. (3.3 cm) Width: 6.25 in. (15.9 cm)
Depth behind panel 7.15 in. (18.16 cm)
WEIGHT
PMA450C Unit
Rack with connectors
1.34 lb. (0.61 kg)
0.51 lb. (0.24 kg)
POWER REQUIREMENTS (Including Internal Lighting):
Voltage:
11 to 33 VDC
Maximum Current:
3.5 Amp (Externally protected by a 5A pull-type breaker)
Audio Selector Specifications
Audio selector panel input impedance:
510 
Input Isolation:
-60 dB (min.)
Speaker Muting:
-60 dB (min.)
Speaker Output (into 4 ) with no clipping
14 VDC:
28 VDC:
3 Watts (min.)
10 Watts (min.)
Receiver Inputs:
7 (Com 1, Com 2, Nav 1, Nav 2, 2 ea. Additional switched
inputs available for ADF, DME, etc.)
Unswitched Inputs:
4 (Two switched inputs can be converted to unswitched, if
desired, during installation.)
Transmitter Selections:
3 (Com 1, Com 2, Com1/2)
Speaker Impedance:
4 
Headphone Impedance:
150 –1000 
Headphone Output:
30 mW each headset, no clipping <.5% THD typical
Microphone Impedance:
150 - 600 
Bluetooth® Radio
Class 3, FCC ID QOQWT32AE or QOQWT32I
Intercom Specifications
Intercom Positions:
6 places (with individual IntelliVox® circuits)
Music Inputs:
2, (Independent, Stereo)
Music Muting:
>-30 dB "Soft Mute" when Com or intercom active.
Distortion:
<1% THD @ 30 mW into 150
Mic Freq. Response, 3 dB:
300 Hz - 6000 Hz
Music Freq. Response, 3 dB:
10 Hz –26 kHz

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 1-4 July 2022
MARKER BEACON RECEIVER (-0801 only)
Frequency:
75 MHz Crystal Controlled
Sensitivity:
Low:
High:
Capable of: (preset at factory for field application)
1000 Volts (Hard) (360 to 570 V soft)
200 Volts (Hard) (130 to 200 V soft)
Selectivity:
-6 dB at ±10 kHz
-40 dB at ±120 kHz
External Lamp Output:
7.5 (±4 VDC unloaded, at maximum brightness) VDC posi-
tive when active, max. current 125 mA
MM Sense:
Active high (4.5 ± 1.0VDC)
USB Charging Port
Available Current
3.5A (15W Maximum) output, short circuit and over-current
protected
Voltage
5 VDC
1.6 EQUIPMENT SUPPLIED
One each of the following units:
Model
Description
Part Number
PMA450C
Digital Stereo Audio Selector Panel with Marker Beacon, IntelliAu-
dio® and USB Charging port
050-450-0801
PMA450C
Digital Stereo Audio Selector Panel, with USB Charging port, and In-
telliAudio®, without Marker Beacon
050-450-0901
PMA450 Installation Kit: 250-890-0000
Description
Quantity
Part
Number
Installation rack assembly
1
430-890-0040
Rack back plate
1
430-890-0050
44-pin connector kit
2
120-891-2045-
Back shell, bottom
2
625-025-1131
Back shell cover
2
625-025-1132
2-56 X 3/16 screw for connector shell
4
475-256-0516
4 40 X 7/16 screw w/nylon patch
4
475-440-0007
4 40 X 3/8 screw w/nylon patch
4
475-440-1038
4-40 x ¼” screw with lock washer
2
475-440-0001
Solder Lug
2
475-009-0001
Cable Clamp
1
625-001-0002
#6-32 x ½” Flat head Philips screw
6
475-632-0012
#6-32 Clip Nut
6
475-630-0002
EQUIPMENT REQUIRED BUT NOT SUPPLIED
a. Circuit Breaker: 1 ea.; 5 amp PULL TYPE REQUIRED for PMA450C
b. Speaker, 4 as desired
c. Headphone Jacks (Stereo, as Required)
d. Microphone Jacks (as Required)
e. Headphones, 150 (Stereo), up to 6 as required
f. Microphones, up to 6 as required
g. Marker Antenna (75 MHz, VSWR <1:1.5, and appropriate for the airspeed) (-08010801, Only)
h. Interconnect Wiring
1.8 LICENSE REQUIREMENTS
None
PMA450C Bluetooth™ Radio approval:

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 1-5 July 2022
•FCC ID: QOQWT32AE or QOQWT32I
•Industry Canada ID: 5123A-BGTWT32AE, or 5123-BGTWT32I
•CE EMC Directive 89/336/EEC as amended by Directives 92/31/EEC and 93/68/EEC
NOTE
Unauthorized use of unapproved cellular telephone devices in aircraft is subject to FCC enforcement ac-
tion, which may include a $10,000 fine per incident.
FCC Regulation 47 CFR § 22.925 Prohibition on airborne operation of cellular telephones.
Cellular telephones installed in or carried aboard airplanes, balloons or any other type of aircraft must not
be operated while such aircraft are airborne (not touching the ground). When any aircraft leaves the ground,
all cellular telephones on board that aircraft must be turned off.
PS Engineering, Inc. does not endorse using unapproved cellular telephone equipment in flight, and takes
no responsibility for the user’s action.
PS Engineering does not guarantee compatibility with personal cellular telephones.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 2-1 July 2022
Section II - INSTALLATION
GENERAL INFORMATION
2.1.1 SCOPE
This section provides detailed installation and interconnection instructions for the PS Engineering PMA450C
Audio Selector Panel/Intercom/ with internal Marker Beacon.
Please read this manual carefully before beginning any installation to prevent damage and post-installation
problems.
Installation of this equipment requires special tools, test equipment (refer to §2.12.1) and installer knowledge
as required by 14 CFR 65.81 (b).
2.1.2 Certification Requirements NOTE
The PMA450C requires specialized knowledge and tools for an effective installation. An appropriately
rated Certified Aircraft Repair Station must install this equipment in accordance with applicable regula-
tions. PS Engineering, Incorporated warranty is not valid unless the equipment is installed by an authorized
PS Engineering, Incorporated dealer.
Failure to follow any of the installation instructions, or installation by a non-certified individual or agency
will void the warranty, and may result in an unairworthy installation.
This article meets the minimum performance and quality control standards required by a technical standard
order (TSO). Installation of this article requires separate approval. Refer to AC 20-41A for information
regarding Substitute TSO Aircraft Equipment.
Unpacking and Preliminary Inspection
Use care when unpacking the equipment. Inspect the units and parts supplied for visible signs of shipping
damage. Examine the unit for loose or broken buttons, bent knobs, etc. Verify the correct quantity of com-
ponents supplied with the list in §1.6. If any claim is to be made, save the shipping material and contact the
freight carrier. Do NOT return units damaged in shipping to PS Engineering. If the unit or accessories show
any sign of external shipping damage, contact PS Engineering to arrange for a replacement. Under no cir-
cumstances attempt to install a damaged unit in an aircraft. Equipment returned to PS Engineering for any
other reason should be shipped in the original PS Engineering packaging, or other UPS approved packaging.
Equipment Installation Procedures
2.3.1 Cooling Requirements
Forced air-cooling of the PMA450C is not required. However, the units should be kept away from heat pro-
ducing sources (i.e. defrost or heater ducts, dropping resistors, heat producing avionics) without adequate
cooling air provided.
2.3.2 Mounting Requirements
The PMA450C must be rigidly mounted to the instrument panel of the aircraft structure, within view and
reach of the pilot position(s). Installation must comply with FAA Advisory Circular AC 43.13-2B, or other
FAA-approved aircraft technical data. The unit may be mounted in any area where adequate clearance for
the unit and associated wiring bundle exist.
To prevent noise, avoid installing the unit close to high current devices or systems with high-voltage pulse
type outputs, such as DME or transponders. Avoid running the interconnecting bundles near any high current
wires.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 2-2 July 2022
2.3.3 Audio Panel Mounting Rack Installation
Carefully slide the unit free of the tray. Set the unit aside in a safe location until needed. Install the tray using
six clip nuts (475-630-0002), and six FHP 6-32 x ½" screws (475-632-0012). The audio selector panel must
be supported at front and rear of the mounting tray.
2.3.4 Audio Panel Tray and Connector Assembly
The rack connectors mate with two 44-pin connectors in the PMA450C. The connectors are a sub-miniature
crimp-type, and require the use a hand crimp tool, from table below (or equiv.). The connectors are mounted
to the tray back plate with #4-40 screws (475-440-1038), from the inside of the tray. The connector back
shell is two pieces, (625-025-1131 and cover 625-025-1132) held together by 4 #2-56 screws (475-256-0516).
This allows the back shell to be installed after the connector is populated.
Ensure that proper strain relief and chafing precautions are made during wiring and installation, using the
cable clamp (625-001-0002).
Two grounding lugs are provided, which may be attached to the rear mounting plate with 2 ea. #4-40 x ¼”
screws with captivated lock washers. These provide a convenient location to connect the shield ground ter-
minations.
Manufacturer
Crimping Tool
Positioner
Extraction tool
AMP
601966-1
601966-6
91067-1
Daniels
AFM8
K42
M24308-1
ITT-Cannon
995-0001-584
995-0001-739
91067-1
Table 2-1 Connector Pin crimping tools
Cable Harness Wiring
Referring to the appropriate Appendix, assemble a wiring harness as required for the installation. All wires
must be MIL-SPEC in accordance with current regulations. Two- and three-conductor shielded wire must be
used where indicated and be MIL-C-27500 or equivalent specification. Proper stripping, shielding and sol-
dering technique must be used at all times. It is imperative that correct wire be used.
Refer to FAA Advisory Circular 43.13-2B for more information. Failure to use correct techniques may result
in improper operation, electrical noise or unit failure. Damage caused by improper installation will void the
PS Engineering warranty.
2.4.1 Electrical Noise
Due to the variety and the high power of radio equipment often found in today's general aviation aircraft,
there is a potential for both radiated and conducted noise interference.
The PMA450C power supply is specifically designed to reduce conducted electrical noise on the aircraft
power bus by at least 50dB. Although this is a large amount of attenuation, it may not eliminate all noise,
particularly if the amplitude of noise is very high. There must be at least 13.8 VDC present at the connector,
J2 pins 8 & 9, of the PMA450C for the power supply to work in its designed regulation. Otherwise, it cannot
adequately attenuate power line noise. Shielding can reduce or prevent radiated noise (i.e., beacon, electric
gyros, switching power supplies, etc.) However, installation combinations can occur where interference is
possible. The PMA450C was designed in an RFI hardened chassis and has internal Electromagnetic Inter-
ference (EMI) filters on all inputs and outputs.
Ground loop noise occurs when there are two or more ground paths for the same signal (i.e., airframe and
ground return wire). Large cyclic loads such as strobes, inverters, etc., can inject noise signals onto the air-
frame that are detected by the audio system. Follow the wiring diagram very carefully to help ensure a min-
imum of ground loop potential. Use only Mil Spec shielded wires (MIL-C-275000, or better). Under no
circumstances combine a microphone and headphone wiring into the same shielded bundle. Always use a 2-
or 3-conductor, shield wire as shown on the installation-wiring diagram.
The shields can be daisy-chained together, and then connected to the ground lugs mounted on the back plate
shown in Appendix B.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 2-3 July 2022
Radiated signals can be a factor when low-level microphone signals are "bundled" with current carrying
power wires. Keep these cables physically separated. It is very important that you use insulated washers to
isolate the ground return path from the airframe to all headphone and microphone jacks.
2.4.1.1 Music Inputs and Noise
PMA450C units utilize a wired differential input to help prevent noise from entering the music system. This
feature is usually transparent to the installer; however, it is important that the appropriate music signal and
ground connections are made directly to the dedicated music signal and ground inputs on the PMA450C. The
power for IFE and audio panel should be a common bus.
If a music jack instead of a music source is installed for Music 1 or 2, we recommend grounding the jack to
airframe ground.
NOISE NOTE
Adding a high-performance audio control system, particularly in conjunction with high-performance active
noise canceling headsets, cannot improve on older avionics that were designed for cabin-speaker use. PS
Engineering makes no claim that the audio panel will provide a noise-free audio quality under all installation
conditions, particularly with older avionics.
2.4.2 Existing GMA340 and PMA8000 Installations
If the installation replaces a GMA340 or any of the PMA8000 series, no changes are necessary as long as the
existing installation meets the requirements. All existing functions of the GMA340 as afforded by the
PMA450C will become instantly available. However, if the previous installation had three COMs, the
PMA450C will not support the third COM; the PMA450C handles only two COM transceivers. The
PMA8000C, P/N 050-890-0303 will support three COMs, call your local PS Engineering dealer for more
information.
2.4.2.1 Differences with GMA340 connector
Connector
Pin
GMA340 Function
PMA450C Function
J1
3
COM 3
TEL Audio Hi
J1
4
COM 3
TEL Lo
J1
5
COM 3
TEL Mic Audio Hi
J1
6
COM 3
No Connection
J1
16
MASQ Inhibit
No Connection
J1
23
COM 3 Speaker Load
AUX Audio Input
J1
24
COM 3 Speaker Load
No Connection
J1
25
COM Speaker Load
No Connection
J1
26
COM Speaker Load
No Connection
J1
27
COM Speaker Load
No Connection
J1
28
COM Speaker Load
No Connection
J1
29
No Connection
Unswitched #3
J2
15
High Music Gain Select
Unswitched #4
J2
17
8Ω Speaker Select
No Connection
J2
18
No Connection
Aux Enable Output
J2
19
Tone Enable
PA Enable
J2
29
Failsafe warn
No Connection
J2
30
Com TX Mute
No Connection
Table 2-2 GMA340–PMA450C connector differences
Installations where the external marker outputs are connected to a Sandel 3308 Navigation Display will re-
quire additional loading resistors. Refer to the Sandel installation data for more information.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 2-4 July 2022
2.4.3 Power
The PMA450C is compatible with both 14- and 28-Volt DC systems. A five (5) Amp circuit breaker is
required for all installations. Power and ground wires should be #22AWG connect power to J2 Pins 8 and 9.
Connect airframe ground to J2 Pin 10 and 11 only.
2.4.4 Communications Push-to-Talk
An important part of the installation is the PTT (Push-To-Talk) switches that allow the use of your aircraft
communications radio for transmissions. Only the person who presses their PTT switch will be heard over
the radio. If the pilot and copilot both use the PTT, the only pilot position has access to the radio. The pilot
position will have PTT control regardless of the mic selector switch or copilot PTT when the PMA450C is
in the OFF/EMG mode.
2.4.5 Audio Panel interface
The PMA450C is designed to interface with standard aircraft avionics, and presents a 510 receiver imped-
ance. For best results, a twisted-shielded cable is recommended from the avionics audio source to the audio
panel, with the shield grounded at the audio panel end.
Some avionics do not provide a separate audio low, and may introduce additional electrical noise into the
system. For best results, connect the audio low from the audio panel to the radio ground, using one conductor
of the twisted-shielded cable.
2.4.5.1 Speaker Load
The PMA450C contains a speaker amplifier. The PMA450C does not contain any resistive speaker loads.
Some older aviation radios units with internal speaker amplifiers, require a resistive load if their speaker
amplifier is not used. If needed, connect the radio speaker output from the transceiver to a 16, 3W resistor
in the harness.
2.4.5.2 Installation with Monaural Headsets
Not recommended, because the benefit of IntelliAudio is lost. However, if desired, the PMA450C can be
installed monaurally by using the LEFT audio connections only (left side contains Fail-Safe audio). Do NOT
short left and right together.
NOTE: Mono headsets that short the tip and ring (i.e. older models) may introduce audio distortion
when used. Modern, stereo headsets are recommended in all positions.
2.4.6 Transmit Interlock
Some communications transceivers use a transmit-interlock system. To utilize the Split Mode feature, this
function must be disabled. Consult the radio manufacturer's installation manual.
2.4.7 Backlighting
The PMA450C has an automatic dimming of the pushbutton annunciation LEDs and marker lamps controlled
by a photocell. Control of the unit nomenclature backlighting is through the aircraft avionics dimmer. For 14
V aircraft, connect J2 Pins 6 and 7 to the aircraft dimmer bus, and pin 5 to ground. For 28-volt systems,
connect pin 7 to the aircraft dimmer, and pins 5 and 6 to ground.
If an external dimmer control is not used, a constant back light illumination can be established for nighttime
viewing. Pin 6 or 7 (depending on system voltage) must be tied to power (J2, pin 8 or 9) for the back lighting
system to work. The photocell mounted in the unit face will automatically adjust the intensity of the push-
button annunciator LEDs.
2.4.8 Unswitched inputs
J1, pins 31 (Unsw 1), 44 (Unsw 2) 29 (Unsw 3) and J2 pin 15 (Unsw 4) are unswitched, unmuted (by trans-
mitter keying), inputs.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 2-5 July 2022
These inputs are presented to the pilot and copilot regardless of the audio configuration, and will always mute
the crew entertainment inputs. These 510Ω inputs can be used for altimeter DH audio, GPS waypoint audio,
autopilot disconnect tones, or any other critical audio signal.
Unswitched #1 is always presented to the speaker, plus to the crew headphones, and is available to the pilot
in fail-safe (off) mode.
Unswitched 1 & 2 are always presented to the speaker, plus to the crew headphones.
*Unswitched 3 and 4 inputs are always presented to the crew headphones but presented to the aircraft speaker
only when the speaker is selected.
Unswitched
Input
Hear in
Fail Safe
Hear in
Crew Headset
Hear in SPR
Adjustable at installation
1
Yes
Yes
Yes
Yes
2
No
Yes
Yes
Yes
3
No
Yes
When SPR Selected
Yes
4
No
Yes
When SPR Selected
Yes
Table 2-3 Unswitched inputs
The audio low for unswitched #4 (J2, pin 15) should be connected to a convenient audio low. However, this
should NOT be connected to Music Low. NOTE
Inputs 1 and 2 are fixed (1:1), and any audio level adjustments must be made at the input source. Unswitched
#3 and #4 can be adjusted at installation. Refer to Adjustments §2.7.
2.4.8.1 Additional unswitched inputs
If necessary, unused switched inputs (ADF, DME, etc.) can be converted to unswitched inputs. Contact PS
Engineering for more information.
2.4.9 "Swap" Mode
When a momentary, normally open, push-button switch is connected between pin 20 on the J2 connector and
aircraft ground, the user can switch between Com 1 and 2 by depressing this switch without having to turn
the mic selector switch. This yoke-mounted switch eliminates the need to remove your hands from the yoke
to change transceivers. The transfer of TX indication from Com 1 to Com 2 shows that the swap has been
initiated; there is no dedicated swap indicator.
2.4.9.1 Remote ICS mode control
A long press of the remote SWAP switch (>1 second) will change the intercom mode, in order
All/CREW/ISO/All, as shown on the intercom mode indicator on the PMA450C.
2.4.10 Public Address Mode
By holding the N1 pushbutton for more than one (1) seconds, the PMA450C will be placed into public ad-
dress (PA) mode. In this mode, the pilot will be talking over the cockpit speaker when he presses his PTT
switch. Copilot will continue on the selected COM radio. The C1 & C2 Transmit indicates will go off in PA.
The display will include PA & SPR on the right side, and change to PUBLIC ADDRESS when the pilot’s
PTT is pressed.
2.4.10.1 PA Mute (J2, Pin 12)
Pin 12 of J2 is a TTL logic output that is pulled low during PTT operation. This is used to control external
public address or external entertainment systems and prevent feedback during radio transmission.
2.4.11 Wired Telephone/Satellite Communication input
The PMA450C can accommodate a wired cell phone interface on J1 Pins 3, 4 and 5.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
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200-450-0800 Page 2-6 July 2022
Whenever the wired telephone/satellite is active, the telephone configuration will appear on the OLED screen
for dynamic adjustments to volume and sidetone as needed.
Both Bluetooth and wired Telephone and be accommodated, however, only ONE can be active at a time.
See Appendix C and D for intercom connection configurations. It is critical to the proper operation of this
system to have this connector wiring made in accordance with these diagrams. Use 2- and 3-conductor, MIL-
spec cable as shown. Connect the shields at the audio panel end only, and tie to the audio low inputs as shown.
2.4.12 Music Inputs
The PMA450C has four available music inputs. Music input number 1 is J2 pins 23 (left channel) and 24
(right channel), with respect to pin 25, and Music number 2 is connected to 26 (left channel), 27 (right chan-
nel), with respect to 28, plus Bluetooth® modules to stream music from a paired device.
NOTE
Use the low-level output of any additional Music device to connect to the audio panel.
Maximum signal level is 3 VAC p-p. DO NOT use a speaker-level output; this will
cause internal damage in the audio panel.
CAUTION
Local oscillators and internal signals from Music equipment can cause undesired interference with other
aircraft systems. Before takeoff, operate the entertainment devices to determine if there is any adverse effect
within the aircraft systems. If any unusual operation is noted in flight, immediately switch off the entertain-
ment devices.
All additional entertainment devices must be switched off for both takeoff and landing.
2.4.12.1 Passenger Mute (J2 Pin 13 & 14)
Connecting J2 pin 13 to pin 14 (or ground) through a SPST switch places the Passenger music source into
the Karaoke Mode. In this mode, incoming music and intercom conversation will not mute the music for the
passengers’ intercom net. This is useful for passenger-area control of the music muting, and overrides the
PMA450C Music Mute menu-controlled setting.
2.4.13 Playback button Installation (J2 Pin 22)
The pilot and copilot can hear the aircraft radio playback.
The Internal Recorder System can be played back from the front panel by pressing the RCV button of the
radio selected for transmission.
Alternatively, a remote, momentary, normally open (NO) push button switch may be installed if desired to
activate the Recording System playback. This switch can be located anywhere in cockpit convenient to the
pilot's reach. The NO switch should be connected to pin 22 of J2 of the PMA450C, and ground. When in-
stalled, this button will act as in §3.13.
2.4.13.1 Cell phone Sidetone
The PMA450C provides cellular telephone sidetone (the user’s voice fed back to the headset). Some cell
phones provide sidetone and may have poor audio quality if both sources are combined. The cell phone
sidetone is adjustable in the Bluetooth® operation screen See §2.6.
Marker Beacon Installation (050-450-0801, Only)
2.5.1 Marker Antenna Installation
A marker beacon antenna, appropriate to the type and speed of the aircraft, is required (not included). Refer
to aircraft and antenna manufacturer's installation instructions, as well as AC43.13-2B (or later revision),
Chapter 3, for information on proper antenna installation techniques. The marker beacon antenna must be
mounted on the bottom of the aircraft.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 2-7 July 2022
2.5.2 External Marker Lights
For installations that require external marker beacon lights, there are three outputs that can drive 12-Volt
lamps only. The external output lamps are driven high (typically +7.0 VDC 4.0 VDC unloaded, at MAX
brightness) when active. Maximum source current per lamp is 125 mA. Voltage varies with photocell dim-
ming.
2.5.3 Middle Marker Sense
A Middle Marker Sense output signal is available from the PMA450C to certain flight control systems. This
function will not operate during the test mode. This output will go to +4.5 VDC (1.0 VDC) when a valid
Middle Marker signal is received. This output is J1, pin 39.
User Setup Adjustments
**DO NOT MAKE ADJUSTMENTS IN FLIGHT**
Cycling power will remove the audio panel from the user setup menus and back to normal audio panel oper-
ation.
To access the user setup adjustment menus, turn the PMA450C off and then back on. While the version
screen is displayed, push and hold the bottom line-select button (there is an indicator bar in the display indi-
cating that a menu is available).
This places the unit into the “User Configurable Mode – home screen”. This allows adjustment for:
•OLED Screen Adjustment
•Rename Switched Inputs
•Bluetooth menus
•Mute mode recall
Note: in this mode, the audio panel functions will be inoperative
2.6.1 Adjust Screen
The first items are adjustments to the OLED, allowing the installer or user to tailor the backlight intensity to
suit the cockpit conditions, and set the time period before the menus revert to the “home” screen.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
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200-450-0800 Page 2-8 July 2022
2.6.1.1 Brightness
Adjusting the Brightness level requires se-
lecting either of the two line select buttons
and then turning the inner knob. Counter-
clockwise to lower the number (level of
Brightness) and clockwise to increase the
number (level of Brightness).
To change the display:
Press the line select for the desired item.
Turn the small, inner knob to change the
brightness as desired.
OLED will change in real time while adjustments are made.
It will stay in this screen until the menu times out and returns to the adjustment home screen.
2.6.1.2 Display Timeout
This is a feature that allows the end user to adjust how quickly the screen menu timeout (revert to main
menu), factory setting is 8 seconds.
NOTE: A long press (> 1 second) will also back up one menu level.
This allows adjustment of the timeout screen and can be configured from 1 second to 30 seconds when turning
the inner knob.
For a user that is unfamiliar with the product, this will give them enough time to learn the system. After being
familiar then the user can speed up the timeout screen as needed.
It will stay in this screen until the menu times out and returns to the adjustment home screen.
To exit the home screen and return to normal operation, turn the PMA450C off, and back on again.
2.6.2 Rename “Switched” Inputs
The system is factory set to default as ADF, & DME as shown.
The three inputs are from top to bottom:
1. Switched input #1 J1, Pin 7 wrt Pin 8 (Default ADF)
2. Switched input #2 J1, Pin 21 wrt Pin 22 (Default DME)
3. NOTE: In PMA450C --0901 (No Marker) Switched #1, or #2 can be renamed to MKR for a re-
mote audio input.
The customer will have access to rename. Maximum 9 letters per line and A thru a and 0 thru 9 will be
available.
•Press the line select for desired input.
•Turn the large outer knob to select the letter to change. A cursor appears under the active letter po-
sition.
•Turn the small, inner knob to increment or decrement the letter.
•You can select 9 alphanumeric digits.
•To add a blank space:
oBlank spaces can’t be added to the end of a string, but you can add a temporary character
and go back and change it to a space:
oADFA1
oChange extra “A” to space ADF 1
It will stay in this screen until the menu times out and returns to the adjustment home screen.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
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200-450-0800 Page 2-9 July 2022
Cycle PMA450C power to exit the setup screen.
2.6.3 Volume Setup
The volume level of the marker beacon receiver, cockpit speaker, and switched inputs can be adjusted at the
setup menu.
From the Setup menu, press More → More→ Marker, or Speaker, → More, Switched Inputs and
turn the small knob to adjust the volume of the marker beacon, cockpit speaker, and switched (ADF/DME)
volumes. The green volume bar and numerical readout will indicate the receiver volume in this menu. NOTE:
volume cannot be turned completely off. Units without marker receiver will not have a MKR Volume menu.
2.6.4 Bluetooth® menu
The Bluetooth menu allows the user to:
•Reset (remove) all paired devices
•Set or disable a pairing pass code (factory set for “disable”)
•Change the PMA450C’s device ID name.
2.6.4.1 Un-pair All (Resets Bluetooth)
Pressing the line select next to Un-pair All removes all Bluetooth devices. This is used when the pairing of
devices becomes unreliable.
2.6.4.2 PIN Disable
Some phones will not pair if a Personal Identification Number (PIN) is required. To remove the PIN require-
ment:
•Enter configuration menu, select Bluetooth.
•Select PIN code for editing. Press PIN button one more time.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
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200-450-0800 Page 2-10 July 2022
•“Bluetooth Reset” will appear on screen. When the menu returns, the PIN code will report “Disa-
bled”.
•To re- enable the PIN code for a different device, press the PIN button.
“Bluetooth Reset” will appear on screen. When the menu returns, the last stored PIN code will be shown.
2.6.4.3 ID:
This allows the user to set the name of the audio panel as it will appear on devices searching for the
PMA450C. Seven alphanumeric digits are available. Factory default is BT1, but you could set “N1245,” or
“Skyhawk,” as an example.
2.6.5 Bluetooth #2(P/N 050-450-0801 & -0901 Only)
Certain PMA450C’s have an additional Bluetooth Module that can be used as an audio input (useful for EFB
such as ForeFlight or music & entertainment).
As shipped, the BT2 module is configured as a music input. It can be reconfigured in the User Setup as an
audio output. See §3.15.
Communications Antenna Installation Notes
For best results while in Split Mode, it is recommended that the one VHF communications antenna is located
on top of the aircraft while the other communications antenna is installed on the bottom. Any antenna relo-
cation must be accomplished in accordance with AC 43.13-2B, aircraft manufacturers’ recommendations and
FAA-approved technical data.
WARNING
It is probable that radio interference will occur in the split mode when the frequencies of the two air-
craft radios are adjacent, and/or the antennas are physically close together. PS Engineering makes no
expressed or implied warranties regarding the suitability of the PMA450C in Split Mode.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 2-11 July 2022
PMA450C Pin assignments
J1
Function
J2
Function
1
Marker Antenna
1
Pilot Phones Lo
2
Marker Ant Lo
2
Copilot Phones Lo
3
TEL Audio Hi
3
Copilot Phones (L)
4
TEL Audio Lo
4
Copilot Phones (R)
5
TEL Mic Audio
5
Lights lo
6
No Connect
6
14/28 V Lights
7
SW#1 (ADF Audio) In
7
14/28 V Lights
8
SW#1 (ADF Audio) Lo
8
Aircraft Power
9
Com 1 Audio
9
Aircraft Power
10
Com 1 Audio Lo
10
Aircraft Ground
11
Com 1 Mic
11
Aircraft Ground
12
Com 1 Mic Key
12
PA Mute
13
Com 2 Audio
13
Mute Inhibit
14
Com 2 Audio Lo
14
Mute Inhibit Lo
15
Com 2 Mic
15
Unswitched #4
16
No Connect
16
Pilot Phones (L)
17
Nav 1 Audio
17
No Connect
18
Nav 1 Audio Lo
18
AUX output
19
Nav 2 Audio
19
No Connect
20
Nav 2 Audio Lo
20
Swap/Remote ICS
21
SW#2 (DME) Audio
21
Swap Lo
22
SW#2 (DME) Audio Lo
22
IRS Playback
23
(Aux) Audio*
23
Music 1 (L)
24
No Connect
24
Music 1 (R)
25
No Connect
25
Music 1 Lo
26
No Connect
26
Music 2 (L)
27
No Connect
27
Music 2 (R)
28
No Connect
28
Music 2 Lo
29
Unswitched #3
29
No Connect
30
Com 2 Mic Key
30
No Connect
31
Unswitched Audio 1
31
Pilot Phones (Rt)
32
Unswitched Lo
32
Copilot Mic Audio
33
Pilot Mic Audio
33
Copilot Mic PTT
34
Pilot Mic PTT
34
Copilot Mic Lo
35
Pilot Mic Lo
35
Pass 1 Mic Audio
36
Ext IM MKR
36
Pass 1 Mic Audio Lo
37
Ext OM MKR
37
Pass 2 Mic Audio
38
Ext MM MKR
38
Pass 2 Mic Audio Lo
39
MM Sense
39
Pass 3 Mic Audio
40
Pass HP (L)
40
Pass 3 Mic Audio Lo
41
Pass HP (R)
41
Pass 4 Mic Audio
42
Pass HP Lo
42
Pass 4 Mic Audio Lo
43
Unswitched 2 Lo
43
Speaker Lo
44
Unswitched 2 Audio
44
Speaker Output
*AUX will be present when SW2 (21) is on
Table 2-4: PMA450C Pin Assignments.

PS Engineering
PMA450C Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0800 Page 2-12 July 2022
Wiring Checkout
After wiring is complete, verify power is ONLY on pins 8 and 9 of the J2 and airframe ground on connector
pins 10 and 11. Failure to do so will cause serious internal damage and void PS Engineering's warranty.
Unit Installation
To install the PMA450C, gently slide the unit into the mounting rack until the hold-down screw is engaged.
While applying gentle pressure to the face of the unit, tighten the 3/32" hex-head in the center of the unit
until it is secure. DO NOT OVER TIGHTEN. CAUTION
Apply steady pressure to the bezel while screwing the unit into the tray to ensure even seating of the unit and
connectors. WARNING Do not over-tighten the lock down screw while installing the unit in tray. Internal
damage will result.
Operational Checkout
2.11.1 Required Test Equipment
In order to return an aircraft to service after installation of the PMA450C, the installer must have access to a
Marker Beacon signal generator:
a. IFR NAV401L, NAV402AP, IFR4000
b. TIC T-30D, T-36C
Equivalent test equipment is acceptable as long as the testing requirements can be met.
2.11.2 Audio Panel Test NOTE
The IntelliVox® is designed for ambient noise levels of 80 dB or above. Therefore, some clipping may occur
in a quiet cabin, such as without the engine running, in a hangar. This is normal.
Use of a Stereo headset is required to obtain full effect of IntelliAudio processing in the crew positions.
1. Apply power to the aircraft and avionics.
2. Plug stereo headsets into the pilot, copilot, and occupied passenger positions.
3. Verify fail-safe operation by receiving and transmitting on com 1 from the pilot position, with the audio
panel power off. The Com audio will be present in one ear cup only.
4. Switch on the unit by pressing the volume (VOL) knob.
5. Check intercom operation.
6. Push the C1 Xmt select button (lower row).
7. Verify that both of the C1 indicators light. Verify that transmit button LED (Light Emitting Diode) near
the mic selector is not blinking. If the LED is blinking, stop testing and troubleshoot the microphone
PTT installation.
8. Verify proper transmit and receive operation from the copilot position, noting that the copilot PTT switch
allows proper transmission on the selected transceiver. Verify that the C1 Xmt button blinks when trans-
mitting.
9. Verify that pushing the C2 button causes the button to illuminate, and the Com 2 receiver to be heard.
Verify operation on Com 1 from the pilot position.
10. Repeat for Com 2
11. Press and hold the C1 Xmt button. While holding the C1 button, press the C2 Xmt button. This places
the unit in “Split Mode;” Verify that the pilot can transmit and receive on Com 1, while the copilot
transmits and receives on Com 2.
12. Verify proper operation of all receiver sources by selecting them using the appropriate button or menu.
13. Activate the cockpit speaker by holding the lower line select for 1 second SPR should appear on the
OLED display. Verify that all selected audio is heard in the cockpit speaker. Verify that the audio mutes
when the mic is keyed.
14. Verify that the appropriate LED in the lower button row blinks when either push to talk is keyed.