PS Engineering PMA450 Installation Manual
9800 Martel Road
Lenoir City, TN 37772
www.ps-engineering.com
Document P/N 200-450-0000
Revision 3, November 2014
Audio Selector Panel with Marker Beacon Receiver
High-fidelity Stereo Intercom, USB Charging Port
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, 7,391,877
PS Engineering, Inc. 2014 ©
Copyright Notice
Any reproduction or retransmittal of this publication, or any portion thereof, without the expressed written permission of PS
Engineering, Inc. is strictly prohibited. For further information contact the Publications Manager at PS Engineering, Inc., 9800
Martel Road, Lenoir City, TN 37772. Phone (865) 988-9800, email contact@ps-engineering.com.
In certified aircraft, warranty is not valid unless this product is installed by an
Authorized PS Engineering dealer.
P
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A445500
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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
1.4 APPROVAL BASIS......................................................................................................................... 1-2
1.1.1 LIMITATIONS..................................................................................................................... 1-2
1.5 SPECIFICATIONS.......................................................................................................................... 1-2
1.6 EQUIPMENT SUPPLIED............................................................................................................... 1-3
1.7 EQUIPMENT REQUIRED BUTNOT SUPPLIED......................................................................1-4
1.8 LICENSE REQUIREMENTS......................................................................................................... 1-4
Section II - INSTALLATION ........................................2-1
2.1 GENERAL INFORMATION..........................................................................................................2-1
2.1.1 SCOPE.............................................................................................................................. 2-1
2.1.2 CERTIFICATION REQUIREMENTS ...................................................................................... 2-1
2.2 UNPACKING AND PRELIMINARY INSPECTION ..................................................................................2-1
2.3 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
2.4 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........................................................................................................2-5
2.4.9 "SWAP" MODE..................................................................................................................2-5
2.4.10 PUBLIC ADDRESS MODE................................................................................................. 2-6
2.4.11 MISCELLANEOUS LOGIC OUTPUT (J2, PIN 18) ............................................................... 2-6
2.4.12 AUDIO ACTIVE OUTPUT (J1, PIN 24).............................................................................. 2-6
2.5 INTERCOM WIRING............................................................................................................................ 2-6
2.5.1 MUSIC INPUTS................................................................................................................... 2-6
2.5.2 PLAYBACK BUTTON INSTALLATION .................................................................................2-7
2.6 MARKER BEACON INSTALLATION.................................................................................................... 2-7
2.6.1 MARKER ANTENNA INSTALLATION ................................................................................. 2-7
2.6.2 MARKER BEACON HIGH SENSE SELECT (J2, PIN 30)........................................................ 2-7
2.6.3 EXTERNAL MARKER LIGHTS............................................................................................ 2-7
2.6.4 MIDDLE MARKER SENSE ..................................................................................................2-7
2.7 USER ADJUSTMENTS ......................................................................................................................... 2-8
2.7.1 ADJUST SCREEN................................................................................................................ 2-8
2.7.2 RENAME “SWITCHED” INPUTS.......................................................................................... 2-8
2.7.3 BLUETOOTH® MENU ........................................................................................................ 2-9
2.8 COMMUNICATIONS ANTENNA INSTALLATION NOTES ..................................................................... 2-9
2.9 PMA450 PIN ASSIGNMENTS............................................................................................................ 2-10
2.10 WIRING CHECKOUT ...................................................................................................................... 2-11
2.11 UNIT INSTALLATION......................................................................................................................2-11
2.12 OPERATIONAL CHECKOUT ...........................................................................................................2-11
2.12.1 REQUIRED TEST EQUIPMENT........................................................................................ 2-11
2.12.2 AUDIO PANEL TEST...................................................................................................... 2-11
PS Engineering
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page ii Rev. 3, November 2014
2.12.3 MARKER CHECKOUT (050-450-0100, ONLY) ...............................................................2-12
2.12.4 BLUETOOTH CHECKOUT............................................................................................... 2-12
2.12.5 INTERNAL RECORDER CHECKOUT................................................................................2-12
2.13 FINAL INSPECTION ........................................................................................................................2-12
Section III OPERATION............................................3-1
3.1 SCOPE ..............................................................................................................................................3-1
3.2 POWER AND FAIL SAFE (1)................................................................................................................3-1
3.3 MENU SELECTION (6)........................................................................................................................ 3-2
3.4 COMMUNICATIONS TRANSMIT (XMT) SELECTION (2)....................................................................3-2
3.4.1 SPLIT MODE......................................................................................................................3-2
3.5 COM AUDIO SELECTOR (3).............................................................................................................. 3-2
3.5.1 SWAP MODE (SWITCH FROM COM 1 TO 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
3.6 SPEAKER AMPLIFIER (7)................................................................................................................... 3-4
3.6.1 PUBLIC ADDRESS FUNCTION ............................................................................................ 3-4
3.7 MARKER BEACON OPERATION (9) (UNIT PART NUMBER 050-450-0100, ONLY)............................. 3-5
3.8 INTERCOM OPERATION (8)............................................................................................................... 3-6
3.8.1 INTELLIVOX® INTERCOM VOX-SQUELCH........................................................................ 3-6
3.8.2 INTERCOM VOLUME CONTROL (1) ................................................................................... 3-6
3.8.3 INTERCOM MODES (8) ......................................................................................................3-7
3.9 MUSIC AND MUSIC MUTING ............................................................................................................. 3-8
3.9.1 MUSIC MUTING ................................................................................................................ 3-9
3.9.2 MUSIC VOLUME................................................................................................................ 3-9
3.9.3 MUSIC IN PILOT ISO MODE............................................................................................... 3-9
3.10 BLUETOOTH® CONNECTION......................................................................................................... 3-10
3.10.1 PAIRING AND UNPAIRING BLUETOOTH DEVICES .......................................................... 3-10
3.11 BLUETOOTH® TELEPHONEMODE............................................................................................... 3-10
3.11.1 CELLULAR TELEPHONE SIDETONE ................................................................................ 3-11
3.12 INTERNAL RECORDER AND PLAYBACK......................................................................................... 3-11
3.13 USER SETUP MENUS....................................................................................................................... 3-12
3.14 LCD ADJUSTMENT........................................................................................................................ 3-12
3.14.1 DISPLAY TIMEOUT........................................................................................................3-12
3.14.2 RENAME “SWITCHED” INPUTS...................................................................................... 3-13
3.14.3 BLUETOOTH SETUP....................................................................................................... 3-13
3.15 USB CHARGING PORT (10) ........................................................................................................... 3-13
Section IV – Warranty and Service....................................4-1
4.1 WARRANTY........................................................................................................................................ 4-1
4.2 FACTORY SERVICE............................................................................................................................ 4-1
Appendix A – PMA450 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
8.1 INSTRUCTIONS FOR FAA FORM 337, AUDIO PANELS .........................................................................D
8.2 INSTRUCTIONS FOR CONTINUING AIRWORTHINESS,AUDIO SYSTEM ................................................D
Appendix E – RTCA DO160G Environmental Qualification Form.............................E
Rev
Date
Change
0
5/25/2014
New Release of manual
1
July 2014
Revise after TSOA
2
September 2014
Update with no marker version information
3
November 2014
Change Marker High sense operation (S/N E01151 and above)
PS Engineering
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 1-1 Rev. 3, November 2014
Section I – GENERAL INFORMATION
1.1 INTRODUCTION
The PMA450 represents a revolutionary step in cockpit audio control and intercommunications utility.
IntelliAudio®, using the USAF patented technology, provides True Dimensional Sound, helping pilots to
more easily discern from 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 designed 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 PMA450.
1.2 SCOPE
This manual provides detailed installation and operation instructions for the PS Engineering PMA450series of Audio Selector Panel/Intercom Systems. This includes the following units:
Model
Description
Part Number
PMA450
Digital Stereo Audio Selector Panel with Marker Beacon,
USB Charging port
050-450-0100
PMA450
Digital Stereo Audio Selector Panel with USB Charging
port without Marker Beacon
050-450-0200
1.3 EQUIPMENT DESCRIPTION
The PMA450 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 which can be individually labeled, for use with ADF, DME, AUX, etc.).
Warning: Use of non-aviation approved cellular telephone equipment may be prohibited by FCC regulation.
PS Engineering is not responsible for unauthorized airborne use of cellular telephones.
For airborne use, the PMA450 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
allows radio transmission. In "Split Mode" the PMA450 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 PMA450. This system has PS Engineer-
ing’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 vol-
ume control 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 intercom volume. Intercom squelch is automatic.
A, 75 MHz Marker Beacon receiver and 3-light indicator is integrated in the PMA450 (050-450-0100 only). This provides the necessary Marker Beacon lights and audio indications necessary for that portion of an
PS Engineering
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 1-2 Rev. 3, November 2014
Instrument Landing System (ILS) approach. A pushbutton labeled MKR allows the pilot select audio on as
well as test and mute modes. Marker high sensatvoty is also controlled by this button (see § S/N and
above). Below S/N E01151 high sense is switched externally (see §2.6.2 for details.
The front panel USB-type connector is available for charging devices, such as iPad or cell phones. Up to 10
Watts are available. This connector does NOT provide any data interface.
In the PMA450, a Bluetooth® wireless interface is available for wireless telephone and music connection.
1.4 APPROVAL BASIS
FAA TSO Approval
The PMA450-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
Equipment), 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 Systems).
1.1.1 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.
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/DO160G
RTCA/DO-178C, DO-254
ENVIRONMENTAL Qualifications:
A1D1CABSMXXXXXXZBABATBXXE2XXX
Operating Temperature Range:
-15º C to 55ºC
Altitude:
Up to 35,000 feet in an non-pressurized area
DIMENSIONS:
Height: 1.3 in. (3.3 cm) Width: 6.25 in. (16.9 cm)
Depth behind panel 7.15 in. (18.16 cm)
WEIGHT
PMA450 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)
PS Engineering
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 1-3 Rev. 3, November 2014
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, 3 ea. Switched Inputs
available)
Unswitched Inputs:
4
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 (PMA450 -1702 only)
Class 3, FCC ID QOQWT32AE
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
MARKER BEACON RECEIVER (-0100 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
positive when active, max. current 125 mA
MM Sense:
Active high (4.5 ± 1.0VDC)
USB Charging Port
Available Current
10 Watts Maximum output, short circuit and over-current
protected
Voltage
5 VDC
1.6 EQUIPMENT SUPPLIED
1 ea. of the following units:
Model
Description
Part Number
PMA450
PMA450 Digital Audio Panel with Marker, Stereo Intercom, USB
Charging jack, and Bluetooth connectivity
050-450-0100
PMA450
Same as above, without Marker Beacon capability
050-450-0200
PS Engineering
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 1-4 Rev. 3, November 2014
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-
Backshell, connector
2
625-025-2465
Backshell Retainer
2
431-881-0100
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
1.7 EQUIPMENT REQUIRED BUT NOT SUPPLIED
a. Circuit Breaker: 1 ea; 5 amp PULL TYPE REQUIRED for PMA450
b. Isn’t this optional? You’re not required to have speaker are you? Speaker, 4
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) (-0100 Only)
h. Interconnect Wiring
1.8 LICENSE REQUIREMENTS
None
PMA450 Bluetooth™ Radio approval:
FCC ID: QOQWT32AE
Industry Canada ID: 5123A-BGTWT32AE
CE EMC Directive 89/336/EEC as amended by Directives 92/31/EEC and 93/68/EEC
PS Engineering
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 2-1 Rev. 3, November 2014
Section II - INSTALLATION
2.1 GENERAL INFORMATION
2.1.1 SCOPE
This section provides detailed installation and interconnection instructions for the PS Engineering PMA450
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 PMA450 requires specialized knowledge and tools for an effective installation. An appropriately rated
Certified Aircraft Repair Station must install this equipment in accordance with applicable regulations. 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.
2.2 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 components 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 circumstances 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.
2.3 Equipment Installation Procedures
2.3.1 Cooling Requirements
Forced air-cooling of the PMA450 is not required. However, the units should be kept away from heat producing sources (i.e. defrost or heater ducts, dropping resistors, heat producing avionics) without adequate
cooling air provided.
2.3.2 Mounting Requirements
The PMA450 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
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 2-2 Rev. 3, November 2014
2.3.3 Audio Panel Mounting Rack Installation
Remove the unit from the mounting tray by unscrewing the 3/32" hex-head screw that is in the center of the
unit. Use caution to avoid hitting the photo-detector lens. 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 PMA450. 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 and the mounting
block, 431-891-0100. 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
terminations.
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
2.4 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
soldering 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 PMA450 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 PMA450 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 PMA450 was designed in a RFI hardened chassis and has internal Electromagnetic
Interference (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 airframe that are detected by the audio system. Follow the wiring diagram very carefully to help ensure a minimum 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
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 2-3 Rev. 3, November 2014
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
PMA450 units utilize a 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 PMA450. 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 (applies to S/N Exxxx and above). All existing functions of
the GMA340 as afforded by the PMA450 will become instantly available. However, if the previous installation had three COMs, the PMA450 will not support the third COM, the PMA450 handles only two COM
transceivers. The PMA8000C will support three coms.
2.4.2.1 Differences with GMA340 connector
Connector
Pin
GMA340 Function
PMA450 Function
J13COM 3
No Connection
J14COM 3
No Connection
J15COM 3
No Connection
J16COM 3
No Connection
J116MASQ Inhibit
No Connection
J123COM 3 Speaker Load
AUX Audio Input
J124COM 3 Speaker Load
CNX80 Inhibit
J125COM Speaker Load
No Connection
J126COM Speaker Load
No Connection
J127COM Speaker Load
No Connection
J128COM Speaker Load
No Connection
J129No Connection
Unswitched #3
J215High Music Gain Select
Unswitched #4
J2178
Ω Speaker Select
No Connection
J218No Connection
Aux Enable Output
J219Tone Enable
PA Enable
J229Failsafe warn
No Connection
J230Com TX Mute
MKR High Sense control
Table 2-2 GMA340–PMA450 connector differences
Installations where the external marker outputs are connected to a Sandel 3308 Navigation Display will
require additional loading resistors. Refer to the Sandel installation data for more information.
PS Engineering
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 2-4 Rev. 3, November 2014
2.4.3 Power
The PMA450 is compatible with both 14 and 28 Volt DC systems. A five (5) Amp circuit breaker is re-
quired for all installations. Power and ground wires should be #22 connected to J2 Pins 8 and 9. Connect
airframe ground to J2 Pin 10 and 11 only. No dropping resistors are required.
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. There are three typical configurations that can be used. Select the
case that best fits the installation. Only the person who presses their PTT switch will be heard over the ra-
dio. If the pilot and copilot both use the PTT, the only pilot position has access to the radio. The pilot posi-
tion will have PTT control regardless of the mic selector switch or copilot PTT when the PMA450 is in the
OFF/EMG mode.
CASE I: PTT is built into both pilot and copilot yokes.
CASE II: PTT is in pilot yoke only. This configuration requires a modified external PTT switch plugged
into the copilot's microphone jack. (See Appendix A). When the copilot's PTT is pressed, the intercom
switches the microphone audio from pilot to copilot mic.
CASE III: No built in PTT. This requires two built in PTTs to be installed, or modified external PTT
switches to be used. Modify external PTT as required. See Appendix A.
2.4.5 Audio Panel interface
The PMA450 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 conduc-
tor of the twisted-shielded cable.
2.4.5.1 Speaker Load
The PMA450 contains a speaker amplifier. The PMA450 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 PMA450 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) will 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 fully utilize the Split Mode feature,
this function must be disabled. Consult the radio manufacturer's installation manual.
2.4.7 Backlighting
The PMA450 has an automatic dimming of the pushbutton annunciation LEDs and marker lamps con-
trolled by a photocell. Control of the unit nomenclature backlighting is through the aircraft avionics di m-
mer 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
PS Engineering
Installation and Operator’s Manual
PS Engineering
PMA450 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-450-0000 Page 2-5 Rev. 3, November 2014
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
transmitter keying), inputs.
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
No
2NoYes
Yes
No
3NoYes
When SPR Selected
Yes
4NoYes
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.
2.4.9 "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 Cell phone Sidetone
The PMA450 can provide 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 §2.7.
NOTE
Unauthorized use of unapproved cellular telephone devices in aircraft is subject to FCC enforcement action, 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.
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