PS Engineering PAC24 User manual

9800 Martel Road
Lenoir City, TN 37772
www.ps-engineering.com
PAC24
Audio Control Panel and Intercom System
Document P/N 200-240-0010
Revision 13, September 2007
PS Engineering, Inc. 2007 ©
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 Mar-
tel Road, Lenoir City, TN 37772. Phone [phone], email [email protected].
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 -.....................................................................................................................1-2
1.5 SPECIFICATIONS........................................................................................................................1-2
1.6 EQUIPMENT SUPPLIED ............................................................................................................1-3
1.7 EQUIPMENT REQUIRED BUT NOT 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
2.2 UNPACKING AND PRELIMINARY INSPECTION.................................................................................2-1
2.3 EQUIPMENT INSTALLATION PROCEDURES.....................................................................................2-1
2.3.1 COOLING REQUIREMENTS..............................................................................................................2-1
2.3.2 INTERNAL DIP SWITCH CONFIGURATION ......................................................................................2-1
2.3.3 MOUNTING REQUIREMENTS...........................................................................................................2-7
2.3.4 MOUNTING RACK INSTALLATION ..................................................................................................2-7
2.3.5 TRAY AND CONNECTOR ASSEMBLY ..............................................................................................2-7
2.4 CABLE HARNESS WIRING ...............................................................................................................2-7
2.4.1 NOISE ............................................................................................................................................2-7
2.4.2 EXISTING KMA 24H INSTALLATION.............................................................................................2-8
2.4.3 POWER...........................................................................................................................................2-8
2.4.4 COMMUNICATIONS PUSH-TO-TALK (SINGLE PANEL INSTALLATION)..............................................2-8
2.4.5 AUDIO PANEL INTERFACE..............................................................................................................2-8
2.4.6 TRANSMIT INTERLOCK...................................................................................................................2-9
2.4.7 "SWAP" MODE...............................................................................................................................2-9
2.4.8 BACKLIGHTING..............................................................................................................................2-9
2.4.9 UNSWITCHED INPUTS.....................................................................................................................2-9
2.4.10 PA MUTE (J3, PIN 8)...................................................................................................................2-9
2.4.11 PUBLIC ADDRESS (J3, PIN B) ......................................................................................................2-9
2.4.12 INTERCOM WIRING.......................................................................................................................2-9
2.4.13 ENTERTAINMENT INPUT (J3 PIN 7) ............................................................................................2-10
2.4.14 INTERCOM EXPANSION (J3, PINS 22, 23 AND A) ........................................................................2-10
2.4.15 PLAYBACK BUTTON INSTALLATION (PIN 2- OPTION 1 UNITS ONLY)..........................................2-10
2.5 ADJUSTMENTS ...............................................................................................................................2-11
2.6 COMMUNICATIONS ANTENNA INSTALLATION NOTES .................................................................2-11
2.7 WIRELESS TELECOMMUNICATIONS INTERFACE ..........................................................................2-11
2.8 PAC24 PIN ASSIGNMENTS.............................................................................................................2-13
2.9 POST INSTALLATION CHECKOUT..................................................................................................2-14
2.10 UNIT INSTALLATION ...................................................................................................................2-14
2.10.1 OPERATIONAL CHECKOUT.........................................................................................................2-14
2.11 INTERNAL RECORDER CHECKOUT (OPTIONAL UNITS ONLY)....................................................2-15
2.12 FINAL INSPECTION ......................................................................................................................2-15
SECTION III OPERATION ..............................................................................................................3-1
3.1 SCOPE............................................................................................................................................3-1
3.2 PAC24 CONTROLS..........................................................................................................................3-1
3.3 POWER SWITCH (3) (EMG-FAIL SAFE OPERATION).....................................................................3-1
3.3.1 SINGLE PANEL FAIL SAFE OPERATION...........................................................................................3-1
3.3.2 DUAL PANEL FAIL SAFE OPERATION.............................................................................................3-1
3.4 MICROPHONE SELECTOR (2) ..........................................................................................................3-2
3.4.1 TELEPHONE OPERATION ................................................................................................................3-2
3.4.2 STUCK MICROPHONE PROTECTION ................................................................................................3-2

PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010 Page ii Rev. 13, Sept. 2007
3.4.3 SWAP MODE (REMOTE TRANSFER OF COM TRANSCEIVERS) ...........................................................3-2
3.4.4 OBSERVER TRANSMIT SELECTION (PART NUMBER –0400 SERIES)..................................................3-2
3.5 RECEIVE AUDIO SELECTOR (1).......................................................................................................3-3
3.5.1 SPEAKER AMPLIFIER (4) ................................................................................................................3-3
3.5.2 KEY “CLICK”.................................................................................................................................3-3
3.6 SPLIT MODE ....................................................................................................................................3-3
3.6.1 SPLIT MODE, SINGLE PANEL..........................................................................................................3-3
3.6.2 SPLIT MODE, DUAL PANEL............................................................................................................3-4
3.6.3 SPLIT MODE, OBSERVER PANEL (-04XX) .....................................................................................3-4
3.7 INTERCOM OPERATION...................................................................................................................3-4
3.7.1 INTELLIVOX® VOX-SQUELCH.......................................................................................................3-4
3.7.2 VOLUME CONTROL (3) ..................................................................................................................3-5
3.7.3 INTERCOM MODES (5) ...................................................................................................................3-5
3.7.4 ENTERTAINMENT INPUT.................................................................................................................3-5
3.8 TELEPHONE MODE..........................................................................................................................3-6
3.9 INTERNAL RECORDER SYSTEM (OPTION 1 UNITS ONLY) .............................................................3-6
3.9.1 OPERATION....................................................................................................................................3-6
3.9.2 CONCURRENT MESSAGES ..............................................................................................................3-6
SECTION IV- WARRANTY AND SERVICE.................................................................................4-1
4.1 WARRANTY......................................................................................................................................4-1
4.2 FACTORY SERVICE..........................................................................................................................4-1
APPENDIX A – INSTALLATION DRAWING.................................................................................A
APPENDIX B SINGLE INTERCONNECT WIRING ...................................................................... B
APPENDIX B DUAL INTERCONNECT WIRING..........................................................................B
7.1 DUAL PAC24 WIRING WITH OBSERVER CONFIGURATION UNITS...................................................B
7.2 DUAL PAC24 WIRING WITH OBSERVER CONFIGURATION AND EXPANSION UNITS ........................B
APPENDIX C- INSTRUCTIONS FOR FAA FORM 337 AND CONTINUING
AIRWORTHINESS ...................................................................................................................................C
8.1 INSTRUCTIONS FOR FAA FORM 337, AUDIO PANELS......................................................................C
8.2 INSTRUCTIONS FOR CONTINUING AIRWORTHINESS, AUDIO PANELS..............................................C
APPENDIX D – RTCA DO160D (EUROCAE ED-14) ENVIRONMENTAL QUALIFICATION
FORM..........................................................................................................................................................D
Rev Date Change
9 March 2005 Clarified Expansion Grounding, also pin out diagram on 2-11
10 March 2006 Added cross reference tables for DIP switch settings 2.3.2
11 January 2007 Added Vertical Orientation Units

PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010 Page 1-1 Rev. 13, Sept. 2007
Section I GENERAL INFORMATION
1.1 INTRODUCTION
The PAC24 represents the finest in high-performance cockpit audio control and intercommunications. Us-
ing proprietary IntelliVox® design, this unit eliminates the requirements for intercom squelch adjustments.
The unit is designed for outstanding ergonomics and visually defined mode annunciation and selection.
The PAC24 was designed to be a dual audio panel, offering convenience and utility for two-pilot crews, in
installations where a single panel is not practical.
The PAC24 –0500 is available where a vertical orientation would be appropriate.
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 PAC24.
1.2 SCOPE
This manual provides detailed installation and operation instructions for the PS Engineering PAC24-series
of Audio Selector Panel/Intercom Systems. This includes the following units:
Model Description Part Number
PAC24 Standard 050-240-0100
PAC24 Option 1, w/ Recorder 050-240-0200
PAC24 Observer 050-240-0400
PAC24 Observer Configuration with recorder 050-240-0401
PAC24 Standard, Vertical Orientation 050-240-0500
Where the functions are identical to all units, it will be referred to herein as a PAC24. Otherwise, the appli-
cable units will be specified.
1.3 EQUIPMENT DESCRIPTION
The PAC24-series is a state of the art audio isolation amplifier and audio selector that contains an auto-
matic voice activated (VOX) intercom system. It can switch up to five transceivers (Com 1, Com 2 Com 3
Com 4 and Com 5) and 4 receivers (Nav 1, Nav 2, AUX (or ADF in –0500) and MKR).
The Duplex Telephone mode allows the PAC24 to act as an audio interface between aircraft headphone
and microphones and specific aircraft approved (FAA/FCC) cellular telephone equipment.
Warning : Use of non-aviation approved cellular telephone equipment may be prohibited by regulation.
PS Engineering is not responsible for unauthorized airborne use of cellular telephones.
For airborne use, the PAC24 must be interfaced with an approved system.
There are two unswitched inputs, for autopilot disconnect, and/or radar altimeter warning. Push buttons
select the receiver audio source provided to the headphones. A SPR switch allows the user to listen to the
receiver(s) selected on the cabin speaker. Except for the unswitched inputs, all speaker audio is muted dur-
ing transmit.
Push button switches select the communication transceivers in use for the pilot and copilot position, and
allow radio transmission. In "Split Mode" the PAC24 has the ability to allow the pilot and copilot to oper-
ate different transceivers independently. The Com 5/TEL mode (selected at installation) allows the pilot to
use the audio panel for duplex operation, such as with aviation-specific cellular telephones.
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.

PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010 Page 1-2 Rev. 13, Sept. 2007
A voice activated (VOX) intercom is included in the PAC24. This system has PS Engineering’s exclusive
IntelliVox® circuitry that eliminates manual adjustments. The system contains six separate VOX mic cir-
cuits, and only opens the specific microphone channel in use.
The intercom system incorporates pilot isolate and crew modes, a monaural music input with "Soft Mute,"
and LED indicators transmit indications. Intercom control is through front panel-mounted knob and 3 po-
sition mode switch. A single volume controls intercom level for the pilot and copilot. Passenger headphone
volume is factory set, and adjusted in flight with headset-mounted volume controls. Passenger volume con-
trol is further adjustable through screwdriver access in the top of the unit. Intercom squelch is automatic.
The PAC24 is form fit and function compatible with the King Radio KMA24H, part number 066-1055-71,
and may be compatible with 066-1055-70.
1.4 APPROVAL BASIS -
FAA-TSO Approval.
The PAC24 Audio Selector Panels are FAA approved under TSO C50c (Audio Amplifiers). In addition,
the PAC24 is JAA-JTSO approved under LBA.N-O.10.510/003JTSO.
All systems comply with relevant portions of EUROCAE ED-14C/DO-160D (Environmental Conditions and Test
Procedures for Airborne Equipment), ED12B/DO-178B (Software Considerations for Airborne Equipment) and ED-
18/DO-214 (Audio Systems Characteristics and Minimum Operational Performance Standards for Aircraft Audio Sys-
tems).
NOTE: The recorder contained in Option 1 is not TSO-approved, and the installer must determine the relevant ap-
proval basis prior to installation. Contact PS Engineering for information regarding FAA 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 opera-
tion.
1.5 SPECIFICATIONS TSO COMPLIANCE
Audio Selector/Intercom: C50c, Class A
APPLICABLE DOCUMENTS: RTCA/DO-214
RTCA/DO-160D
RTCA/DO-178B
ENVIRONMENTAL Qualifications: B1ZCABSRXXXXXXZBBBATMXXE2XXX
Temperature Range:
Operating:
Storage:
-20ºC to +55ºC with short term operating at +70°C
-55ºC to +85ºC
Altitude: Up to 50,000 feet in a non-pressurized area of the
cockpit.
DIMENSIONS: Height: 1.3 in. (3.3 cm) Width: 6.25 in. (16.9 cm)
Depth: 6.8 in. (17.3 cm) behind panel
WEIGHT (With Rack & Connectors): 1.5 lb. (0.54 kg)

PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010 Page 1-3 Rev. 13, Sept. 2007
Specifications, Continued.
POWER REQUIREMENTS (Including Internal Lighting):
Voltage: 11 to 33 VDC
Maximum Current: 2.5 Amp (Externally protected by a 3 Amp circuit
breaker.)
Typical operating current:
Speaker off:
Speaker on, 28V, full radio volume
350 mA
1.5 A
Audio Selector Specifications
Audio selector panel input impedance: 510 Ω
Input Isolation: -60 dB (min.)
Speaker Muting: -60 dB (min.)
Speaker Output (into 4 Ω) with no clipping
14 VDC:
28 VDC:
3 Watts (min.)
10 Watts (min.)
Receiver Inputs: 10
(Com 1, Com 2, Com 3, Com 4, Com 5, Nav 1,
Nav 2, ADF, DME, MKR)
Unswitched Inputs: 2
(examples: GPS WPT, Value, Autopilot Discon-
nect, Altimeter DH)
Transmitter Selections:5
(Com 1, Com 2, Com 3 Com 4, Com 5)
Speaker Impedance:4 – 8 Ω
Headphone Impedance: 150 – 1000 Ω
Headphone Output: 38 mW each headset, no clipping <1% THD
120 mW each headset with < 10% THD into
150Ω
Microphone Impedance: 150 - 600 Ω
Intercom Specifications
Intercom Positions: Minimum of 5 places (with individual IntelliVox® cir-
cuits)
Music Input: 1 (Monaural)
Music Muting: >-30 dB "Soft Mute" when Com or intercom active.
Distortion: <1% THD @ 38 mW into 150Ω
<10% THD @ 120mW into 150 Ω
Mic Freq. Response, 3 dB: 300 Hz - 6000 Hz
Music Freq. Response, 3 dB: 100 Hz - 18kHz
1.6 EQUIPMENT SUPPLIED
1 ea. of the following units:
Model Description Part Number
PAC24 PAC24 Audio Control Panel with intercom 050-240-0100
PAC24 Option 1 PAC24 Audio Control Panel with intercom and digital recorder, 050-240-0200
PAC24 Observer PAC24 Audio Control Panel for Observer installation 050-240-0400
PAC24 Observer Option 1 PAC24 Audio Control Panel for Observer with recorder 050-240-0401
PAC24 Vertical PAC24 Audio Control Panel with intercom, Vertical Orientation 050-240-0500

PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010 Page 1-4 Rev. 13, Sept. 2007
PAC24 Installation Kit: 250-291-0000
Description Quantity Part
Number
PAC24 installation rack assembly 1 475-240-0040
Molex Connector Shell w/key, 50 pin, key 17/18 1 120-425-5002
Gold Plated Crimp Pins 50 425-001-0002
4 40 X 7/16 screw w/nylon patch 4 475-440-0009
Grounding bar 1 430-007-0001
6-32 X 3/4 pan head Phillips screw 2 475-632-0038
6-32 Nut Flat 2 475-632-0003
6-32 Lock Nut 2 475-632-0004
Cable Clamp 1 625-001-0002
#6-32 x ½” Flat head Phillips screw 6 475-632-0012
#6-32 Clip Nut 6 475-630-0002
Parts identification sheet 1 002-250-0240
1.7 EQUIPMENT REQUIRED BUT NOT SUPPLIED
a) Circuit Breaker: 1 ea. 3 amp
b) Cockpit Speaker, 4 Ωrecommended
c) Cabin or External Speaker 4 Ωrecommended
d) Headphone Jacks (as required)
e) Microphone Jacks (as required)
f) Headphones, 150 Ωas required
g) Microphones, as required
h) Interconnect Wiring
1.8 LICENSE REQUIREMENTS
None

PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010 Page 2-1 Rev. 13, Sept. 2007
Section II - Installation
2.1 GENERAL INFORMATION
2.1.1 SCOPE
This section provides detailed installation and interconnect instructions for the PS Engineering PAC24-
Series Audio Control Panel/Intercom System.
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: The PAC24 requires specialized knowledge and tools for an effective installation. An appropri-
ately 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 au-
thorized PS Engineering, Incorporated dealer. Failure to follow any of the installation instructions, or in-
stallation by a non-certified individual or agency will void the warranty, and may result in an unairworthy
installation.
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 (B). 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 PAC24 is not required. However the unit should be kept away from heat produc-
ing sources (i.e. defrost or heater ducts, dropping resistors, heat producing avionics) without adequate cool-
ing air provided. Outside, ram air cooling of the unit is not permitted, and may result in damage.
2.3.2 Internal DIP Switch Configuration
The tables below describe the various internal switch selections.
The PAC24 can be easily configured for many different applications. This includes dual audio panel
installations. In a single installation, no action is required. In dual installations, place the DIP witches into
the proper position to configure the PAC24 as the pilot, or copilot panel. By designating a pilot or copilot
panel, the aircraft commander, or pilot, will have priority for transmissions and intercom mode selection.
Note:
Bold=Default settings (as shipped from factory)
Units are shipped as single unit configuration, 28V lighting.

PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010 Page 2-2 Rev. 13, Sept. 2007
2.3.2.1 Single/Dual configuration
Switch S5
2 OFF ON ON
3 OFF
Single
PAC24
Installation OFF
Pilot unit –Dual
Installation ON
Copilot
unit –Dual
Installation
Single System/Pilot Copilot Panel
J4 ON (installed) J4 OFF (Removed)
J5 Jumper Pins 1 & 2 J5 Jumper Pins 2 &3
S2
S3
S5
S4
4 3 2 1 4321
4 3 2 1 4321

PS Engineering
PAC24 Series Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-240-0010 Page 2-3 Rev. 13, Sept. 2007
2.3.2.2 Pass 3 / Expansion – J3, pin a configuration
As shipped, the PAC24 is 5-place intercom, and the ability to convert the system from a 5-place intercom
to use an expansion unit that will allow up to 8 places on the intercom per audio panel.
Switch S2
3 ON OFF
4 OFF Pass 3 Mic Input ON Expansion Power
out
2.3.2.3 Pass 1 / Expansion – J3, pin 22 configuration
Switch S3
1 ON OFF
2 OFF Pass 1 mic input ON Expansion audio
input
2.3.2.4 Pass 2 / Expansion - J3, pin 23 configuration
Switch S3
3 ON OFF
4 OFF Pass 2 mic input ON Expansion audio
output
2.3.2.5 CVR / IRS Control – J3, pin 2 configuration
PAC24 units can be equipped with an optional Intercom Recording System (IRS, P/N –0200, -0401),
which will store up to 60 seconds of radio traffic (on the transceiver selected for transmit). The playback
control is a normally open switch connected to ground, which triggers the stored audio.
Internal Recording System units are incompatible with the standard Cockpit Voice Recorder output
J5 J4
Pin 1