PS Engineering PA50 User manual

9800 Martel Road
Lenoir City, TN 37772
www.ps-engineering.com
P
PA A5 50 0
4-Channel Audio Summing Amplifier
Installation and Operation Manual
Document P/N 200-150-0100
October 2006
PS Engineering, Inc. 2006 ©
Copyright Notice
Any reproduction or retransmittal of this publication, or any portion thereof, without the expressed written permission of PS Engi-
neering, Inc. is strictly prohibited. For further information contact the Publications Manager at PS Engineering, Inc., 9800 Martel
Road, Lenoir City, TN 37772. Phone [phone].
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
1.4 APPROVAL BASIS -...................................................................................................... 1-1
1.5 SPECIFICATIONS......................................................................................................... 1-2
1.6 EQUIPMENT SUPPLIED ............................................................................................. 1-2
1.7 EQUIPMENT REQUIRED BUT NOT SUPPLIED .................................................... 1-3
1.8 LICENSE REQUIREMENTS ....................................................................................... 1-3
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 CONNECTOR ASSEMBLY ................................................................................................ 2-2
2.4 CABLE HARNESS WIRING ............................................................................................... 2-2
2.4.1 NOISE ............................................................................................................................. 2-2
2.4.2 POWER (PIN 25).............................................................................................................. 2-2
2.4.3 UNSWITCHED INPUTS (PINS 3, 4, 15, AND 16) ............................................................... 2-2
2.4.4 OUTPUT WIRING ............................................................................................................. 2-2
2.5 ADJUSTMENTS.................................................................................................................. 2-2
2.6 POST INSTALLATION CHECKOUT ................................................................................... 2-3
2.6.1 OPERATIONAL CHECKOUT ............................................................................................. 2-3
2.7 FINAL INSPECTION........................................................................................................... 2-3
SECTION III OPERATION .............................................................................................. 3-1
SECTION IV- WARRANTY AND SERVICE.................................................................. 4-1
4.1 WARRANTY ...................................................................................................................... 4-1
4.2 FACTORY SERVICE .......................................................................................................... 4-1
APPENDIX B – INSTALLATION DRAWING ........................................................... B
APPENDIX C CONNECTOR INTERCONNECT ......................................................C
Record of revisions:
Revision Date Reason
New Release October 2006 New Release

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Page 1-1 October 2006
Section I - GENERAL INFORMATION
1.1 INTRODUCTION
The PA50 is an accessory device designed to accept four audio inputs and present a single summed output.
This accommodates the proliferation of unswitched priority audio signals in aviation, and the limited avail-
ability of unswitched audio inputs to the aircraft system.
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 PA50.
1.2 SCOPE
This manual provides detailed installation and operation instructions for the PS Engineering PA50-series of
Audio Selector Panel/Intercom Systems. This includes the following units:
Model Description Part Number
PA50 Audio Summing Amplifier 14100
1.3 EQUIPMENT DESCRIPTION
The unit provides audio summing for up to four unswitched inputs, into a single headphone level output.
1.4 APPROVAL BASIS - None
FAA Approval. None
NOTE: The installer must determine the relevant approval basis prior to installation.
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 opera-
tion.

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Page 1-2 October 2006
1.5 SPECIFICATIONS
Specifications
ENVIRONMENTAL CONDITIONS:
Temperature Range:
Operating:
Storage:
-15º C to 55º C
-40º C to 85º C
Altitude: Up to 50,000 feet in an unpressurized area of the
aircraft.
DIMENSIONS: Height: 1.25 in. Length: 5.5 in
Width: 4.0 in . (w/ mounting flanges)
WEIGHT (With Connector): 8.5 Oz. (0.34 kg)
POWER REQUIREMENTS
Voltage: 11 to 33 VDC
Maximum Current: Mot more than 100 mA (Externally protected by a
0.5 Amp circuit breaker.)
Audio Specifications
Audio selector panel input impedance: 510 Ω
Input Isolation: -60 dB (min.)
Unswitched Audio: 4 inputs
Audio Output: 38 mW, no clipping into 150Ω
Distortion: <1% THD @ 38 mW into 150Ω
Audio Freq. Response, 3 dB: 300 Hz - 6000 Hz
1.6 EQUIPMENT SUPPLIED
1 ea. of the following units:
Model Part Number
PA50 14100

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Page 1-3 October 2006
PA50 Installation Kit:
Part Number Description Quantity
425-025-0006 DB25 Female 1
200-150-0100 Operator's and Installation Manual 1
1.7 EQUIPMENT REQUIRED BUT NOT SUPPLIED
Circuit Breaker: 1 ea. 1 amp.
Input signal source, (in ex TAWS alert signal)
Aircraft audio system to accept the summed signals
Interconnect Wiring
1.8 LICENSE REQUIREMENTS
None

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Page 2-1 October 2006
Section II - Installation
2.1 GENERAL INFORMATION
2.1.1 SCOPE
This section provides detailed installation and interconnect instructions for the PS Engineering PA50
Please read this manual carefully before beginning any installation to prevent damage and post-installation
problems. Installation of this equipment requires special tools and knowledge.
NOTE: 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.
2.1.2 Certification Requirements
When the PA50 system is installed in a certified aircraft, certification basis is the installer’s responsibility.
Due to the variety and options available for interface, PS Engineering, will only provide manufacturers
data for our equipment interface. Contact PS Engineering for more details.
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 com-
ponents supplied with the list in Section 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 ac-
cessories shows any sign of external shipping damage, contact PS Engineering to arrange for a replace-
ment. 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 PA50 is not required. However the unit 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 PA50 must be rigidly mounted to the aircraft structure. Installation must comply with FAA Advisory
Circular AC 43.13-2A. The unit may be mounted in any area where adequate clearance for the unit and
associated wiring bundle exist. The unit may be mounted in any position or orientation.
Avoid installing the PA50 close to high current devices or systems with high-voltage pulse type outputs,
such as DME or transponders.
To install the PA50, select a location convenient to the warning panel providing the output, and the audio
panel. The unit may be installed in any position, on a surface that will allow for installation in accordance
with AC43-13.

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Page 2-2 October 2006
2.3.3 Connector Assembly
The rear of the PA50 contains a male DB25 connector. In the parts kit is a female shell with qty. 12 crimp
type pins. The appropriate crimper is Paladin PA1440. Ensure that proper strain relief and chafing precau-
tions are made during wiring and installation.
2.4 Cable Harness Wiring
Referring to the 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 solder-
ing technique must be used at all times. It is imperative that correct wire be used.
Refer to FAA Advisory Circular 43.13-2A (or later revision) 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 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.
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).
Radiated signals can be a factor when low level audio signals are "bundled" with current carrying power
wires. Keep these cables physically separated.
2.4.2 Power (Pin 25)
The PA50-Series are compatible with both 14 and 28 Volt DC systems. A one (1) Amp circuit breaker is
required. Power and ground wires must be a twisted minimum #20 AWG pair. Connect airframe power
ground to Pin 13 only.
2.4.3 Unswitched Inputs (Pins 3, 4, 15, and 16)
Four 510Ωunswitched inputs are provided for audio summing on pins 3, 4, 15, and 16 with respect to
(WRT) pin 18. These can be used to add audio capability such as TAWS, autopilot audio, etc, to an audio
panel that only has two inputs. The output is on Pin 14.
2.4.4 Output wiring
The output on Pin 14 (WRT Pin 18) of the PA50 is usually presented to the unswitched audio panel or in-
tercom input. It is critical to the proper operation of this system to have this connector wiring made in ac-
cordance with these diagrams. Use 2- and 3-conductor, MIL-spec cable as shown. Connect the shields at
one end only, and tie to the audio low inputs as shown.
2.5 Adjustments
The PA50 is factory adjusted to accommodate the typical requirements for most aircraft configurations.
The output volume can be adjusted by turning “VOL ADJ” clockwise to increase the volume or counter-
clockwise to decrease. The gain adjust affects all four inputs. See Appendix B for locations

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Page 2-3 October 2006
2.6 Post Installation Checkout
After wiring is complete, verify power is ONLY on pin 25 of the J1 connector, and airframe ground on pin
13. Failure to do so will cause serious internal damage and void PS Engineering's warranty.
2.6.1 Operational Checkout
Apply power to the aircraft and avionics. Verify that the audio signal connected to the PA50 are provided
to the aircraft’s audio system. Verify that the unit is fully functional and in condition for safe operation.
2.7 Final Inspection
Verify that the wiring is bundled away from all controls and no part of the installation interferes with air-
craft control operation. Move all controls through their full range while examining the installation to see
that no mechanical interference exists. Verify that the cables are secured to the aircraft structure in accor-
dance with good practices, with adequate strain relief. Ensure that there are no kinks or sharp bends in the
cables and coaxial cables. Verify that the cables are not exposed to any sharp edges or rough surfaces, and
that all contact points are protected from abrasion.
Complete logbook entry, and any other documentation such as FAA Form 337, weight and balance compu-
tation if required. Sample text for FAA Form 337, and instructions for continuing airworthiness can be
found in Appendix F.
Return completed warranty registration application to PS Engineering.

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Page 3-1 October 2006
Section III OPERATION
GENERAL INFORMATION
There are no external operational controls on the PA50, only one internal volume control that affects all
four audio inputs.

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Page 4-1 October 2006
Section IV- Warranty and Service
4.1 Warranty
In order for the factory warranty to be valid, the installations in a certified aircraft must be accomplished by
an FAA-certified avionics shop and authorized PS Engineering dealer. If the unit is being installed by a
non-certified individual in an experimental aircraft, a factory-made harness must be used for the warranty
to be valid.
PS Engineering, Inc. warrants this product to be free from defect in material and workmanship for a period
of one (1) year from the date of installation as recorded in aircraft logbook and/or on FAA Form 337. Dur-
ing the twelve (12) months of the warranty period, PS Engineering, Inc., at its option, will send a replace-
ment unit at our expense if the unit should be determined to be defective after consultation with a factory
technician.
All transportation charges for returning the defective units are the responsibility of the purchaser. All do-
mestic transportation charges for returning the exchange or repaired unit to the purchaser will be borne by
PS Engineering, Inc. The risk of loss or damage to the product is borne by the party making the shipment,
unless the purchaser requests a specific method of shipment. In this case, the purchaser assumes the risk of
loss.
This warranty is not transferable. Any implied warranties expire at the expiration date of this warranty. PS
Engineering SHALL NOT BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES. This
warranty does not cover a defect that has resulted from improper handling, storage or preservation, or un-
reasonable use or maintenance as determined by us. This warranty is void if there is any attempt to dissem-
ble this product without factory authorization. This warranty gives you specific legal rights, and you may
also have other rights, which may vary from state to state. Some states do not allow the exclusion of limita-
tion of incidental or consequential damages, so the above limitation or exclusions may not apply to you.
All items repaired or replaced under this warranty are warranted for the remainder of the original warranty
period. PS Engineering, Inc. reserves the rights to make modifications or improvements to the product
without obligation to perform like modifications or improvements to previously manufactured products.
4.2 Factory Service
The unit is covered by a one-year limited warranty. See warranty information. Call PS Engineering, Inc. at
[phone] before you return the unit. This will allow the service technician to provide any other sug-
gestions for identifying the problem and recommend possible solutions.
After discussing the problem with the technician and you obtain a Return Authorization Number, ship
product to:
[Note: PS Engineering will not be responsible for items shipped in US Mail.]
PS Engineering, Inc.
Attn: Service Department
9800 Martel Rd
Lenoir City, TN 37772
[phone] FAX [phone]

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Appendix C October 2006
Appendix B – Installation Drawing
4.725
AA
A
5.480
4.000 3.500
Ø0.136
AUDIO ADJUST
Not to scale
Appendix C Connector Interconnect
PowerGnd
11-33VDCPower
N/C
N/C
N/C
N/C
N/C
AudioLo
N/C
N/C
Aux1AudioIn
Aux3AudioIn
Aux2AudioIn
AudioOutput
Aux4In
13
25
12 11
24 23
10
22 21 20 19
9876
18 17 16 15 14
54321
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
Connector Map, viewed from front of connector
VOL ADJ

PS Engineering
PA50 Four-channel Audio Summing Amplifier
Installation and Operator’s Manual
200-150-0100 Appendix C October 2006
1A
11-33 VDC
25
13
PA50 Sub-D DB-25 Male
14
Power In
Ground
Audio Output Hi
16
Aux 1 Input Hi
4
ToUnswitchedAudioSources
NOTES:1.AllwiremustconformtoMIL-22759
or27500.Minumum24gageshieldedwire.
2.Use2--conductorwithshield
asindicated.
4.Connectshieldsatoneendonly
REV
DATE: SHEET 1 OF 1
TITLE:
DOCUMENT NUMBER:
SIZE
PA50 WIRING DIAGRAM
120-150-0000 New
10/05/06
9800 MARTEL ROAD, LENOIR CITY TN 37772
Aux 2 Input Hi
Aux 3 Input Hi Aux 3
Audio Output
Aux 2
Audio Output
Aux 1
Audio Output
3
18
Audio Lo
Aux 4 Input Hi Aux 4
Audio Output
15
Audio Panel
Unsw. Input