Nat NPX138N Series User manual

Northern Airborne Technology Ltd.
1925 Kirschner Road
Kelowna, BC, Canada.
V1Y 4N7
Telephone [phone]
Facsimile [phone]
Issued on the authority of Northern Airborne Technology Ltd.
Copyright 2010
Installation and Operation Manual
NPX138N Series
Panel Mount FM Transceiver
SM41
ISSUE 4.01
The document reference is online, please check the correspondence between the online documentation and the printed version.
Published on
August 1, 2012

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Installation and Operation Manual Page ii
ENG-FORM: 820-0116.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
IMPORTANT INFORMATION
FOR AVIONICS INSTALLATION FACILITIES
The NPX138N Series Panel Mount FM Transceivers are supplied without TSO
certification, as no such standard presently exists for airborne VHF-FM radio
transceivers. This equipment provides what is considered as “supplemental”
communications, and can be installed in an aircraft on a “Non interference” basis.
Installation should be performed using standard procedures applicable to aircraft radio
installation, to ensure that the newly installed equipment does not interfere with any other
equipment in the aircraft.
This device complies with Part 15 of the FCC Rules. Operation is subject to the condition
that this device does not cause harmful interference
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Installation and Operation Manual Page iii
ENG-FORM: 820-0116.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
Prepared By: Checked By: Certification: Approved By:
The status of this installation and operation manual is controlled by issue shown on the title page. The
status of each section is controlled by revision shown in the footer of each page. All revisions affecting
sections of this manual have been incorporated into the latest issue.
IMPORTANT NOTICE
Chelton Avionics Inc. doing business as Wulfsburg
Electronics Inc. will be responsible for full distribution and
revisions of ICA’s (Instructions for Continued
Airworthiness).
ISSUE/REVISION RECORD
Manual Issue
Number Section Revision Number Revision Description Issue Date
4.01 Section 1 Rev: 1.00
Section 2 Rev: 1.00
Section 3 Rev: 1.00
Rewritten in latest format Aug 17, 2010
4.00 N/A - Nov 10, 2003
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Installation and Operation Manual Page iv
ENG-FORM: 820-0116.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
Table of Contents
Section Title Page
1. Description
1.1 Introduction 1-1
1.2 Product Description 1-1
1.3 Design Features 1-1
1.4 Specifications 1-2
1.4.1 Electrical Specifications 1-2
1.4.2 Physical Specifications 1-3
1.4.3 Environmental Specifications 1-3
1.5 Unit Nomenclature 1-3
1.5.1 Narrowband Capability 1-4
1.5.2 Lighting Power 1-4
1.5.3 Special Options 1-4
1.5.4 Voice-Inversion Encryption 1-4
2. Installation
2.1 Introduction 2-1
2.2 Unpacking and Inspection 2-1
2.2.1 Warranty 2-1
2.3 Continued Airworthiness 2-1
2.4 Installation Procedures 2-1
2.4.1 Warnings 2-2
2.4.2 Cautions 2-2
2.4.3 Notes 2-2
2.4.4 Cabling and Wiring 2-2
2.4.5 Antennas 2-3
2.4.6 Mechanical Mounting 2-3
2.4.7 Post-Installation Checks 2-4
2.4.8 Post Installation EMI Test 2-5
2.5 Installation Drawings 2-5
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Installation and Operation Manual Page v
ENG-FORM: 820-0116.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
Section Title Page
3. Operation
3.1 Introduction 3-1
3.2 General Information 3-1
3.3 Controls and Indicators 3-1
3.4 Initial Operation 3-2
3.4.1 Power-up Help 3-2
3.4.2 Initial Operating Display 3-2
3.5 Display 3-3
3.6 Function Controls 3-3
3.6.1 Main RX (Receive) Volume Control 3-4
3.6.2 RX/TX Status Indicator 3-4
3.6.3 Scan/Guard TX Switch 3-4
3.6.4 Guard Controls 3-4
3.7 General Controls — Normal Operating Mode 3-5
3.7.1 Channel Switch 3-5
3.7.2 Brightness Switch 3-6
3.7.3 Squelch Pushbutton 3-6
3.8 Channel Display 3-6
3.8.1 ID Display Line 3-6
3.8.2 RX Display Line 3-7
3.8.3 TX Display Line 3-7
3.9 Channel Editing 3-8
3.9.1 SELECT Switch 3-8
3.9.2 NEXT Switch 3-9
3.9.3 EDIT Switch 3-9
3.9.4 HELP Switch 3-9
3.10 Status Editing 3-10
3.10.1 NEXT and SELECT Switch Use 3-10
3.10.2 Status Edit Features 3-11
3.11 Tones 3-12
3.11.1 General 3-12
3.11.2 Tone Display and Selection 3-12
3.11.3 Turning Tones On and Off 3-14
3.12 Scanning 3-14
3.12.1 General 3-14
3.12.2 Scan Operation 3-15
3.12.3 Scan Modes 3-15
3.13 Wideband/Narrowband Operation 3-16
3.13.1 Editing Wideband/Narrowband Flag 3-16
3.14 Configuration Mode 3-17
3.14.1 Using Configuration Mode 3-17
3.14.2 Configuration Option Table 3-18
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Section 1 Rev: 1.00 Issue 4 Page 1-1
ENG-FORM: 800-0116.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
Section 1 Description
1.1 Introduction
Information in this section consists of product description, design features and specifications for the
NPX138N Series Panel Mount FM transceiver, serial number 1238 and above. All derivative product
information will be contained in the applicable manual supplement, which may be obtained from Northern
Airborne Technology Ltd. as required.
Review all notes, warnings and cautions.
1.2 Product Description
The NPX138N Series incorporates Northern Airborne Technology Ltd’s proven user-friendly operating
system with on-line help, making it easy to program and use. The small size makes this radio ideal for
airframes where size and weight are a factor.
The NPX138N Series panel mount FM transceiver is a stand-alone radio designed for the single mission
user. It provides all the features needed to satisfy FM communications within the VHF-FM high band.
1.3 Design Features
The NPX138N Series covers a frequency range of 138.000 MHz to 173.995 MHz in 5.0/6.25 kHz
increments. Each of the 100 available channels can include a receive frequency and CTCSS tone;
transmit frequency and CTCSS tone, and an alpha/numeric identifier.
A SCAN function allows scanning of selected channels. Transmit power of either 1 watt or 10 watts is
selectable from the front of the NPX138N. Simplex and semi-duplex operations are available. An optional
guard receiver is available with some models.
DTMF encoding and direct keyboard entry can be effected by the use of the DTE12, an accessory
available from Northern Airborne Technology Ltd.
Conveniently located beside the display are separate main volume, guard volume and transmit select
switches. Easily identified along the bottom of the front panel are squelch test, channel up/down and
display brightness controls. The aircraft dimmer buss provides control for the panel lighting.
Depending on model selected the NPX138N Series can provide wideband (± 5.0 kHz Rated System
Deviation) and/or narrowband (± 2.5 kHz Rated System Deviation) by channel. Compensation circuitry
ensures that the average receive audio level remains constant when the mode changes.
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Section 1 Rev: 1.00 Issue 4 Page 1-2
ENG-FORM: 800-0116.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
1.4 Specifications
1.4.1 Electrical Specifications
Input power 28 Vdc nominal
Current consumption 0.5 A receive/2.0 A transmit (typical)
0.8 A receive/3.0 A transmit (max.)
Panel lighting 28 Vdc, 14 Vdc or 5 Vdc dependent on model
Sidetone output 25 mW @ 600 Ω, adjustable.
Microphone Amplified Dynamic or equivalent, 150 Ω
balanced/unbalanced
Frequency range 138.000 MHz to 173.995 MHz
Tone capability 38 standard CTCSS tones
Operating mode simplex or semi-duplex
1.4.1.1 Receiver
Channel increments 5 kHz/6.25 kHz
Audio output 100 mW @ 600 ΩBalanced/Unbalanced
Sensitivity
Main 0.5 μV max. @ 12 dB SINAD
Guard 0.5 μV max. @ 12 dB SINAD
Spurious response rejection 70 dB
Adjacent channel rejection
Wideband 70 dB min. @ ±25 kHz
Narrowband 60 dB min. @ ±12.5 kHz
Intermodulation rejection 70 dB
Hum and Noise ratio
Unsquelched >50 dB
Squelched <-80 dBw
Distortion <4% @ rated output
1.4.1.2 Transmitter
RF power output 1 W/10 W Selectable
RF input/output impedance 50 Ωnominal
Rated System Deviation
Wideband ±5.0 kHz max, limited
Narrowband ±2.5 kHz max, limited
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Section 1 Rev: 1.00 Issue 4 Page 1-3
Microphone Audio Sensitivity 100 mVrms into 150 Ω for 60% of rated system deviation
Conducted spurious emissions
High power -64 dBc
Low power -55 dBc
Carrier frequency stability ±0.0003 %
FM hum and noise ratio >40 dB
AM hum and noise ratio >35 dB
Distortion <4 %
1.4.2 Physical Specifications
Height 1.88 inches (47.6 mm)
Overall depth 8.64 inches (219.5 mm)
Depth behind panel 7.66 inches (194.6 mm)
Width 5.75 inches (146.1 mm)
Weight 3.0 lbs. (1.4 kg)
Mounting Standard Dzus mounting (4 fasteners)
Connector type 25 pin D-subminiature male (pins)
Antenna connector BNC female
1.4.3 Environmental Specifications
Operating temperature -30 C to +60 C
Altitude 25,000 feet
Humidity 95%
Vibration DO-160C Cat. M
1.5 Unit Nomenclature
Variants of the NPX138N series radios are identified as follows:
Narrowband Capability
NPX138 N - 000
Special Options
Lighting Power
Encryption
ENG-FORM: 800-0116.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Section 1 Rev: 1.00 Issue 4 Page 1-4
ENG-FORM: 800-0116.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
1.5.1 Narrowband Capability {tc "1.6.1 Narrowband Capability
"}
The letter N after the NPX138 designation indicates the capability for narrowband selection in addition to
wideband. If this part of the name is blank, the unit has wideband capabilities only.
NPX138 N- 000
N = Wideband and Narrowband modulation
Blank = Wideband modulation only
1.5.2 Lighting Power {tc "1.6.2 Options "}
The digit in the first position of the unit suffix indicates the lighting power used.
NPX138 N - 000
0 =28 Vdc Lighting
1 = 14 Vdc Lighting
2 = 28 Vdc NVG NVIS A Compliant
5 = 5 Vdc Lighting
7 = 28 Vdc NVG Compatible Lighting
8 = 14 Vdc NVG Compatible Lighting
9 = 5 Vdc NVG Compatible Lighting
1.5.3 Special Options
The digit in the second position of the unit suffix indicates any special options installed.
NPX138 N - 000
0 =No Special options installed
5 = USFS Standard Guard
6 = Custom Guard - consult factory for details
7 = Synthesized Guard
Other = Special options installed - consult factory for details
1.5.4 Voice-Inversion Encryption
The digit in the third position of the unit suffix indicates whether voice inversion encryption is installed.
NPX138 N - 000
0 =No Encryption
1 = Encryption
Section 1 ends
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Section 2 Rev: 1.00 Issue 4 Page 2-1
ENG-FORM: 805-0121.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
Section 2 Installation
2.1 Introduction
Information in this section consists of unpacking and inspection procedures, installation procedures,
post-installation checks and installation drawings for the NPX138N Series Panel Mount FM Transceiver.
Review all notes, warnings and cautions.
2.2 Unpacking and Inspection
Unpack the equipment carefully and locate the warranty card. Inspect the unit visually for damage due to
shipping and report all such claims immediately to the carrier involved. Check that all items listed below
are present before proceeding and report any shortage immediately to your supplier:
- Warranty Card
- Operators Manual
- Certificate of Conformity or Release Certification
2.2.1 Warranty
All Northern Airborne Technology Ltd. products are warranted for 2 years from date of installation by an
authorized Northern Airborne Technology Ltd. dealer, to be free of defects in workmanship or
performance. This warranty covers all materials and labour, but is exclusive of any transport to deliver the
defective unit to and from Northern Airborne Technology Ltd. or its designated warranty repair center, or
any labour to remove or re-install the defective unit in the aircraft. Contact Northern Airborne Technology
Ltd. for any questions regarding this warranty, its applicability to your units and/or for return authorization.
Northern Airborne Technology Ltd. is the final arbitrator concerning warranty administration. Units which
have been physically damaged, burned, immersed in water or otherwise abused beyond the scope of
normal use will not be considered for warranty. WARRANTY IS VOID UNLESS THE PRODUCT IS
INSTALLED BY AN AUTHORIZED NORTHERN AIRBORNE TECHNOLOGY LTD. DEALER. Product
for which a warranty card is not returned shall be warranted from date of manufacture.
2.3 Continued Airworthiness
Maintenance of the NPX138N Panel Mount FM Transceiver is ‘on condition’ only. Periodic maintenance
of these products is not required.
2.4 Installation Procedures
Installation Notice
This product must be installed in accordance with the installation instructions provided in the latest issue
of this Installation and Operation Manual. Check the Publication Index at www.northernairborne.com for
the issue status of the manual. The latest issue of the manual may be downloaded from the same
website. All risk associated with installation of this product contrary to these instructions shall be the
responsibility of the installing agency.
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Section 2 Rev: 1.00 Issue 4 Page 2-2
ENG-FORM: 805-0121.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
2.4.1 Warnings
WARNING:
High volume settings can cause hearing damage.
Set the headset volume control to the minimum setting prior to
conducting tests, and slowly increase the volume to a comfortable
listening level.
2.4.2 Cautions
CAUTION:
Do not bundle any lines from this unit with transmitter coax lines. Do not
bundle any logic, audio, or DC power lines from this unit with 400 Hz synchro
wiring or AC power lines. Do not position this unit next to any device with a
strong alternating magnetic field such as an inverter or significant interference
to operation will result. In all installations, use shielded cable exactly as
shown and ground as indicated. Significant problems may result if these
guidelines are not followed.
All audio installations can be severely degraded by incorrect wiring and
shielding, and may result in much higher cross-talk, hum, and ground-loop
interference. This should be considered when audio wiring to and from the
radio installation is performed.
2.4.3 Notes
The case of the NPX138N must be electrically grounded for maximum resistance to low frequency
interference. A pin on the connector (Chassis ground) is provided and must be connected by a short wire
to a clean ground, not jumpered to the power ground wire connection.
Refer to the aircraft structural repair manual and maintenance manual for instructions and information
pertinent to this installation.
2.4.4 Cabling and Wiring
All wire shall be selected in accordance with the original aircraft manufacturer's Maintenance Instructions
or AC43.13-1B Change 1, Paragraphs 11-76 through 11-78. Unshielded wire types shall qualify to
MIL-W-22759 as specified in AC43.13-1B Change 1, Paragraphs 11-85, 11-86, and listed in Table 11-11.
For shielded wire applications, use Tefzel MIL-C-27500 shielded wire with solder sleeves (for shield
terminations) to make the most compact and easily terminated interconnect. Follow the interconnect
drawing in Section 2.5 as required.
Coaxial cable shall be selected in accordance with MIL-C-17 unless otherwise specified. Do not use coax
cable with PVC insulation. Teflon dielectric cable is encouraged at or above VHF frequencies or where
cable runs exceed 8 feet. Note that at VHF frequencies, cables losses due to long cable runs and tight
bends may reduce the ERP (Effective Radiated Power) by greater than 50%.
Allow 3" from the end of the shielded wiring to the shield termination to allow the connector hood to be
easily installed. Refer to the interconnect drawing in Section 2.5 for shield termination details. Note that
the hood is a "clamshell" hood, and is installed after the wiring is complete. Aircraft harnessing shall
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Section 2 Rev: 1.00 Issue 4 Page 2-3
ENG-FORM: 805-0121.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
permit the unit to be removed from the panel for easy access to all side adjustments. Do NOT mount the
unit until all adjustments have been performed.
Maintain wire segregation and route wiring in accordance with the original aircraft manufacturers
Maintenance Instructions. Coaxial cables shall be routed separately from existing wire bundles in the
aircraft to minimize electromagnetic coupling effects.
Unless otherwise noted, all wiring shall be a minimum of 22 AWG, except power and ground lines, which
shall be a minimum of 20 AWG. Reference the Interconnect drawing for additional specifications. Check
that the ground connection is clean and well secured, and that it shares no path with any electrically noisy
aircraft accessories such as blowers, turn and bank instruments or similar loads. Power to this unit must
be supplied from a separate circuit breaker or fuse (fast blow), and not attached to any other circuit
breaker without additional protection. Verify that the selected circuit breaker size and wire gauge are
adequate for the installation using the techniques specified in AC43.13-1B Change 1, Paragraphs 11-47
through 11-51 and 11-66 through 11-69.
2.4.5 Antennas
Correct antenna placement and mounting is critical in order to achieve the best possible performance. In
general, keep all antennas as widely separated as possible and clear of any large airframe obstructions.
Installation of the antenna should be in accordance with the original aircraft manufacturer’s instructions
for continued airworthiness or AC 43.13-1B Change 1, chapter 11, section 15 and AC 43.13-2A chapter 3.
If possible, the antenna should be located a minimum of 12 ft from aircraft navigation receiver antennas
and a minimum of 4 feet from aircraft communications and ELT antennas. Be careful not to choose
separations that closely approximate ¼, ½ or whole-number multiples of the navigation or
communications system wavelength.
Note: Avoid any placement that puts antennas of like frequencies close together.
Bottom mounted antennas will perform best in flight, but poorest on the ground during testing. Antennas
may be severely degraded by 'masking' effects of the fuselage or stabilizers, and generally give best
performance when bottom mounted.
To reduce interference from rotor modulation and other undesirable stimuli, any blade or whip antenna
must be surrounded by a ground plane surface (metallic, grounded material) with a radius equal to or
greater than the height of the antenna. Under the same conditions, the antenna is also much less likely to
cause interference to other aircraft systems (e.g. coupling into audio system, fluctuations in instrumentation,
etc.). Poor grounding will result in severe reflected power and high levels of RFI throughout the airframe.
Avoid antenna locations that will become fouled with oil, water, fuel or dirt, as this will degrade
performance. Roof mounts (in close proximity to rotor blades) are permissible.
2.4.6 Mechanical Mounting
Installation of the transceiver should be in accordance with the original aircraft manufacturer’s instructions
for continued airworthiness or AC 43.13-1B Change 1, chapter 7, sections 2 to 7 and AC 43.13-2A, chapter
2. Pr 35 Dzus rail or equivalent may be used.
Mounting the NPX138N requires a Dzus rail assembly with an opening width of 127 mm (5 inches) and a
front clearance width of 146.1 mm (5.75 inches). Height requirement is 47.6 mm (1.875 inches). Refer to
the mounting drawings and unit mechanical specifications to determine proper clearance dimensions. Be
sure that adequate clearance is allowed for the cable connections to each unit.
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Section 2 Rev: 1.00 Issue 4 Page 2-4
ENG-FORM: 805-0121.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
2.4.7 Post-Installation Checks
2.4.7.1 Voltage/resistance checks
Do not attach the NPX138N until the following conditions are met.
Check the following:
a) P101 pins <12> and <13> for +28 Vdc relative to ground.
b) P101 pins <22>, <23>, <24> and <25> for continuity to ground (below 0.5 Ω).
c) Light voltage as listed in the table below.
P101 Pin # Voltage
28 Volt Models 11 28 Vdc
14 Volt Models 10 14 Vdc
5 Volt Models 10 5 Vdc
Light Voltage
Ensure that the antenna is disconnected for the following test or erroneous readings may be
obtained.
d) Radio coax connector for continuity to the antenna coax connector (shield and center conductor),
and for open circuit from the center conductor to ground and open circuit from the center
conductor to the shield.
2.4.7.2 Power On Checks
a) Install the NPX138N and power up the ship’s systems. Turn on the radio. Check the operation of all
front panel controls. Adjust brightness and volume levels as required.
b) Check all transmit and receive functions. Ensure the RX/TX status indicator lights green when
the radio is keyed to transmit and amber when receiving.
c) Check the SCAN function.
Note: It may not be possible to hear the received audio if the tones do not match those set in
the radio. To avoid any confusion, tones should be set to OFF (via the status edit mode)
during scanning so that all channels will be heard.
d) Check the antenna feedline at the R/T with a through-line wattmeter and suitable frequency
elements to ensure correct antenna matching. Reflected power in excess of 25% represents a
serious problem, and should be investigated carefully, or serious RFI and system interference as
well as possible radio damage may result. A VSWR measurement over 3.0:1 represents a
significant loss in signal power to the antenna. Check that forward power is to specifications over
the frequency band of the radio.
Upon satisfactory completion of all performance checks, make all required log book entries, electrical
load, weight and balance amendments and other documentation as required by your local regulatory
agency before releasing the aircraft for service.
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138N Series Panel Mount FM Transceiver
SM41 Installation and Operation Manual
Section 2 Rev: 1.00 Issue 4 Page 2-5
ENG-FORM: 805-0121.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
2.4.8 Post Installation EMI Test
The purpose of this test is to identify any interference that the NPX138N may cause with existing aircraft
systems. The NPX138N should be tested in accordance with the Installation Approval Test Procedure
(see section 2.5), and the test results documented on the record sheets.
2.5 Installation Drawings
DOCUMENT REV. DESCRIPTION TYPE
NPX138\403-0 1.50 Panel Mount Radio Interconnect (2 sheets)
NPX138\405-0 1.20 Panel Mount Radio Connector Map
NPX138\634-0 1.10 Post Installation EMI Test Installation Approval Test Procedure
NPX138\905-0 1.50 Panel Mount Radio Faceplate
NPX138\922-0 1.21 Panel Mount Radio Mechanical Installation
Section 2 ends following the above documents
The document reference is online, please check the correspondence between the online documentation and the printed version.

REVISIONS
REV DESCRIPTION DATE BY
FOR PREVIOUS REVISIONS SEE 403 0 REV 1.40.
1.50
DOCCR01936 - UPDATED TEMPLATE & CHANGED
NOTE 6. ADDED SHEET 2.
OCT 2/07
TAT
J101
NPX138/NPX138N
VHF FM TRANSCEIVER
P1 01
FE MALE 25 PIN DM IN (NOTE 7)
18 AWG or 2 x 20 AWG
~--< +27.5 VDC AVIONICS POWER +28VDC POWER 12
1
+28VDC POWER 13
18 AWG or 2 x 20 AWG
POWER GROU ND 24
1
~
POWER GROUND 25
-
NOTE 1
+28 VDC LIGHTS
+28V LIGHTS 11
NOTE 1
+5V/+14V LIGHTS 10
+5/14 VDC LIGHTS
LIGHTS
GROUND 22
--
/'\ /'\
150/600 OHM NOMINAL
RECEIVE AUDIO Hl 9 1 1 1 1
RECEIVE AUDIO LO 21
"v'
'-___/
MIC KEYLINE ô
fJ
150/600 OHM NOMINAL
!'\ /'\
(CARBON EQUIVALENT)
MIC AUDIO Hl 7 1 1 1 1
MIC AUDIO LO 19 y
'-___/
AUDIO GROUND 18
CHANNEL UR 4 !CHANNEL
URl
CHANNEL DOWN 3
~
NOTE 3
NOTE 4 --
~
SERI AL DATA RX IN 2
/'\ /'\
Tx DATA
!CHANNEL DOWN 1
1 1 1 1
SERI AL DATA TX OUT 1 y
L~
Rx DATA
NOTES'
DIGITAL GROUND 14 DIGITAL GROUND
1. CONNECT ONE LINE ONLY AS REQUIRED TO MATCH
NOTE 2 LIGHTING VOLTAGE STATED
ON ID/MFG LABEL.
RECEIVE ACTIVE 20 2. OPTIONAL CONNECTION TO CC450 COMM
CONTROLLER OR OTHER DEVICE.
SIGNAL STRENGTH 5 }
NOTE
9 3. OPTIONAL
REMOTE CHANNELLING SWITCH.
DETECTOR AUDIO 6 MAY
BE LOCATED ON CYCLIC CONTROL. ETC.
RESERVED 15 NOTE 5 4. OPTIONAL SERIAL COMMUNICATION DEVICE
SUCH AS DATA RAD OR PROGRAMMING PORT.
ALT MIC KEY 16 }
NOTE
5. NO CONNECTION TO THIS PIN. RESERVED FOR
ALT MIC Hl 17
8 OTHER FEATURES, FUTURE UPGRADES.
6. ALL WIRES SHOULD BE 22 AWG UNLESS
OTHERWISE SPECIFIED. ALL UNSHIELDED WIRE SHALL
CHASSIS GROUND 23
BE SELECTED IN ACCORDANCE WITH THE ORIGINAL
m NOTE
10
AIRCRAFT MANUFACTURERS MAINTENANCE
~
INSTRUCTIONS OR AC43.13-1B CHANGE 1,
PARAGRAPHS 11-76 THROUGH 11-78. WIRE TYPES
BNC-MALE
SHOULD BE TO MIL-W-22759 AS SPECIFIED IN
I2
AC43.13-1B CHANGE 1, PARAGRAPHS 11-85,
(\
RG58C/U (\
11-86 AND LISTED IN TABLE 11-11. ALL SHIELDED
ANTENNA RF
'-' '-'
WIRE/CABLE SHOULD BE IN ACCORDANCE WITH
P702
MIL -C-27500.
BNC-MALE
7. INSTALLATION KIT REQUIRm NAT P/N NPX-IKC
(CRIMP PINS) OR NPX-IKS (SOLDER CUPS).
8. PIN 7 IS INTERNALLY CONNECTED TO PIN 17.
PIN 8 IS INTERNALLY CONNECTED TO PIN 16.
THESE PINS INTERFACE TO OPTIONAL DATA PAO/
TONE ENCODER SUCH AS THE DTE12.
9. THESE PINS CONNECT TO OPTIONAL EQUIPMENT.
10. VHF COMMUNICATIONS
ANTENNA. COMANT
P/N Cl 177-13 OR EQUIVALENT.
CONFIDENTIAL AND PROPRIETARY TO NAT L TD.
DESIGNED KEH •
DRAWN KEH
:•:nat NORTHERN
AIRE ORNE TECHNOLOGY LTD.
•
DATE APR 27 95
TITLE PANEL MOUNT
VHF FM TRANSCEIVER
CHECKED
NAT
255
NAT SIZE 1 CAGE CODE 1
PART NO. 1 REV. 1
SHEET
APPROVED
A 3AB01
NPX138/NPX138N
1.50 1/2
131/
FILE 403-0.DWG DWG. TYPE
INTERCONNECT 1 DWG. NO. NPX138\403-0
The document reference is online, please check the correspondence between the online documentation and the printed version.

J101
NPX138/NPX138N
VHF FM TRANSCEIVER P101
FE MALE 25 PIN DMIN (NOTE 6)
18 AWG or 2 x 20 AWG
9-< +27.5 VDC AVIONICS POWER +28VDC POWER 12
1
+28VDC POWER 13
18 AWG or 2 x 20 AWG
POWER GROU ND 24
1
POWER GROUND 25
--
NOTE 1 )
+28 VDC LIGHTS
+28V LIGHTS 11
NOTE 1
+5V/+14V LIGHTS 10
+5/14 VDC LIGHTS
LIGHTS
GROUND 22
-=-
-
NOTE 5
"' "'
150/600 OHM NOMINAL
RECEIVE AUDIO Hl 9 1 1 1 1
RECEIVE AUDIO LO 21
'-..,/
'.__../
MIC KEYLINE 8
fJ
150/600 OHM NOMINAL
/"\
"'
(CARBON EQUIVALENT)
MIC AUDIO Hl 7 1 1 1 1
MIC AUDIO LO 19
'-..,/
'.__../
P/0 J101
AUDIO GROUND 18 DTE12
DTMF/DATA PAO
P/0 ~
AL T MIC Hl 17
("\
r\
8 TONE OUT Hl #1
N~ 7
't_
20 TONE OUT LO #1
AL T MIC KEY 16 7 KEY OUT #1
SERI AL DATA RX IN 2
"' "'
2 TX DATA
1 1 1 1
SERI AL DATA TX OUT 1 y L 1 RX DATA
DIGITAL GROUND 14 14 SERIAL GND
RESERVED 15 NOTE 4
~
RECEIVE ACTIVE 20 NOTE 2
SIGNAL STRENGTH 5 } NOTE 8 NOTES:
DETECTOR AUDIO 6
1. CONNECT ONE LINE ONLY AS REQUIRED TO MATCH
!CHANNEL UPI
LIGHTING VOLTAGE STATED ON ID/MFG LABEL.
2. OPTIONAL CONNECTION TO CC450 COMM
CHANNEL UP 4
NOTE 3
CONTROLLER OR OTHER DEVICE.
CHANNEL DOWN 3 .--------:::L
3. OPTIONAL REMOTE CHANNELLING SWITCH.
-NOTE 9
MAY BE LOCATED ON CYCLIC CONTROL, ETC.
-
4. NO CONNECTION TO THIS PIN. RESERVED FOR
CHASSIS GROUND 23
!CHANNEL DNI
OTHER FEATURES, FUTURE UPGRADES.
~
m 5.
ALL WIRES SHOULD BE 22 AWG UNLESS
OTHERWISE SPECIFIED. ALL UNSHIELDED WIRE SHALL
BE SELECTED IN ACCORDANCE WITH THE ORIGINAL
BNC-MALE
AIRCRAFT MANUFACTURERS MAINTENANCE
I3
r\
RG58C/U
r\
INSTRUCTIONS OR AC4J.1J-1B CHANGE 1,
ANTENNA RF
PARAGRAPHS 11-76 THROUGH 11-78. WIRE TYPES
'-' '-'
SHOULD BE TO MIL-W-22759 AS SPECIFIED IN
P702
AC4J.1J-1B CHANGE 1, PARAGRAPHS 11-85,
BNC-MALE
11-86 AND LISTED IN TABLE 11-11. ALL SHIELDED
WIRE/CABLE SHOULD BE IN ACCORDANCE WITH
MIL-C-27500.
6. INSTALLATION KIT REQUIRED: NAT P/N NPX-IKC
(CRIMP PINS) OR NPX-IKS (SOLDER CUPS).
7. PIN 17 IS INTERNALLY CONNECTED TO PIN 7.
PIN 16 IS INTERNALLY CONNECTED TO PIN 8.
8. THESE PINS CONNECT TO OPTIONAL EQUIPMENT.
9. VHF COMMUNICATIONS ANTENNA. COMANT
P/N Cl 177-13 OR EQUIVALENT.
CONFIDENTIAL AND PROPRIETARY TO NAT L TD.
DESIGNED
KEH
•
DRAWN KEH
:•:nat NORTHERN
AIRBORNE TECHNOLOGY LTD.
•
DATE SEP 17/97
TITLE
PANEL MOUNT VHF FM TRANSCEIVER
CHECKED
NAT
CONNECTING TO A DTE12
255
NAT
SIZE 1CAGE CODE 1
PART NO. 1REV. 1SHEET
APPROVED
13'1_/
A 3AB01
NPX138/NPX138N
1.50 2/2
FILE 403-0.DWG DWG. TYPE
INTERCONNECT
DWG. NO.
NPX138\403-1
The document reference is online, please check the correspondence between the online documentation and the printed version.

REVISIONS
REV DESCRIPTION
DATE BY
1.01
GENERA Tl ON OF -050 DWG'S. SEE ECR #502
APR 30/95
KEH
1.10 ECR #502: ADDED 14V TO PIN 10
JUN 25/96
TGM
1.20
ECR #967: WAS NPX138\050\403-0110.DWG
PINS 5, 6, 16, &: 17 REASSIGNED.
SEP 17/97
KEH
0
0
__J
0 0 z 0 w 0
z z
::J
z 0 > 0 z
-0 z
::J
::J ::J
0
::J 0
f-
__J
::J
>-
0
0 0
0:::
0 ::J
u w
0 -
0:::
0:::
0:::
(.!)
0::: 4:: 4:: 0 I
~
(.!) (.!) (.!)
-
0:::
0
(.!)
Cf)
0
(.!)
w
w w u u >
0:::
0:::
Cf) Cf)
> >
::J
__J
w w
Cf)
f-
--4:: 0
:::2: :::2:
0:::
4::
w w -w
f-
3: 3: 4:: I u u u 0
f- f-
Cf)
(.!)
0 0 I
(.!)
w w
::J
__J __J
w -
()_
()_
u
__J
0::: 0::: :::2: 4:: 4:: 4:: 0::: 0
25124
23 22
21 20
19 18 17 116 115 14
•••0 0 0
o, ., 0 0 o, •
00 00 0
/. 1 1
010 010 010 010
13112
11 110
9 8 7 6 5 4 3 2 1
0::: 0:::
Cf)
Cf) -w -0 I
()_
z z
f-
w w
f-
f-
I z I -
f-
::J
3: -
::J
0
3: 3: I I 0
__J
0
::J
(.!> 0 x 0
0 0 (.!)
(.!)
-
>-
-4:: z
__J
0 0:::
()_ ()_
_J
_J
0 w 0 w w x
::J
~
::J
0:::
z __J 4::
f-
u u > > 4:: 4::
0:::
f-
z w
f-
0 0 u 0
Cf)
4:: z 4:: 4::
> >
IX)
...q-
w u
f-
I z 0
f-
N
..----
>
:::2: u
__J
u 4:: 4::
IX) IX)
+ + w
:::2:
w 4:: I
__J
0
f-
z
N N
""'
u w u 4::
+ +
l{)
w 0
(.!)
-
__J
Cf)
0:::
4::
+
0:::
w -
Cf)
0:::
w
Cf)
• : SOLID CIRCLES DENOTE INTERNALLY CONNECTED GROUND PINS.
VIEW: REAR SIDE OF AIRFRAME CONNECTOR
TYPE: AIRFRAME CONNECTOR IS 25-PIN D-SUBMINIATURE FEMALE (SOCKETS)
1 Confldentlal and Proprletarv to NAT J
~-~-~~-~~_NE_D-+--~~-~---t *~ NORTHERN AIRBORNE TECHNOLOGY LTD.
DATE
CHECKED
APR 27 95 TlTLE
NAT
201
PANEL MOUNT VHF FM TRANSCEIVER
NAT SIZE CAGE CODE IPART NO. IREV. ISHEET
APPROVED
107 A 3AB01
NPX138/NPX138N 1.20 1/1
FILE 405-012'0:15WG DWG. TYPE CONNECTOR MAP DWG. NO. NPX138\405-0
The document reference is online, please check the correspondence between the online documentation and the printed version.

INSTALLATION APPROVAL
TEST PROCEDURE
NAT Part #: NPX138 Description: Panel Mount Radio
Document #: NPX138\634-0 Rev: 1.10
Rev. 1.10 Apr 19, 2004 Page 1 of 7
ENG-FORM: 634-0100.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
1. Post Installation EMI Test
The purpose of this test is to identify any interference that the NPX138 may cause with
existing aircraft systems.
2. Test Conditions
The NPX138 should be installed and function tested. The antenna VSWR should be
checked. A forward/reverse power check with an in-line wattmeter should show no
more than 10% reflected power. For the following tests, insure that the transmit power
is set to HI.
3. Methodology
Most of the EMI tests can be accomplished on the ground. In some cases, flight testing is
required or is easier. If the aircraft is approved for IFR operations, then it is mandatory
that interference between the NPX138 and the approach aids be checked in flight.
The GPS should be operational and navigating with at least the minimum compliment of
satellites. The VHF comm should be set to the frequencies indicated with the squelch open.
VOR/ILS/GS receivers should be set to the frequencies indicated and selected for display. If
possible, set up a VOR/ILS ramp test set on the frequencies indicated and adjust the output
until the flags are out of view. The transponder and encoder should be monitored with ramp
test equipment. If possible set the ADF to a nearby navigation station.
Modulate the NPX138 transmitter on the indicated frequencies for at least 20 seconds.
Observe the GPS for any degradation in satellite status or availability or flags. Listen for
any noise or detected audio signals on the VHF comm(s). Listen for any noise or
detected audio signals on the VOR/LOC receiver audio; look for any movement of flags
or needles on the VOR/LOC/GS navigation display(s).
List the power plant, fuel and other electric instruments in the chart provided and note
any anomalies that occur while transmitting. Assess the results.
If the aircraft is equipped with an autopilot or a stability augmentation system, then test
fly the aircraft and verify that the operation of the NPX138 transceiver does not have
adverse effects on these systems. After checking for gross effects at a safe altitude, fly
an approach with each of the different navigation systems coupled to the autopilot (ILS,
GPS etc.) and look for any anomalies.
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138 Installation Approval Test Procedure
Rev. 1.10 Apr 19, 2004 Page 2 of 7
E NG-FORM: 634-0100.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
4. Results
If the installed system passes all of the applicable EMI tests, then no further action is
required. If interference is observed, then the interference must be assessed against
the appropriate standards of airworthiness for the system in question. For example: it is
permissible for a VFR certified GPS to lose navigation capability while the NPX138 is
transmitting, providing that it recovers properly and promptly, but it is not permissible for
an IFR Approach certified GPS to be affected in the same way. A complete discussion
of all the standards of airworthiness to be applied in assessing EMI effects is beyond
the scope of this document.
5. Procedure
A. Operate the NPX138 transmitter on the following frequencies for at least 20 seconds.
Observe the GPS for any degradation in satellite status, or availability, or flags.
FREQUENCIES GPS #1 GPS #2
NPX138 PASS FAIL PASS FAIL
143.2187 MHz
143.2200 MHz
153.4500 MHz
157.5400 MHz
157.5437 MHz
NOTES:
The document reference is online, please check the correspondence between the online documentation and the printed version.

NPX138 Installation Approval Test Procedure
Rev. 1.10 Apr 19, 2004 Page 3 of 7
E NG-FORM: 634-0100.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
B. Determine if the image frequency for the VHF Comm falls within the range of the
NPX138 unit. If so, select a set of frequencies that will cause the NPX138 to be
set as close as possible to the image frequency. Any one of the many possible
sets will suffice. Record these values in the spaces provided in the following
chart. Modulate the NPX138 transmitter on the following frequencies for at least
20 seconds. Listen for any noise or detected audio signals on the VHF comm.
Example - Bendix/King KY 196A:
The first IF frequency is 11.4 MHz. The L.O. is above the received frequency
(high side injection), therefore the image frequency is 22.8 MHz above the
selected frequency. Set the KY 196A to 120.000 MHz and the NPX138 to
142.8000 MHz.
FREQUENCIES RESULTS
VHF #1 NPX138 PASS FAIL
135.975 138.0000
121.150 157.5000
131.250 157.5000
Image:
FREQUENCIES RESULTS
VHF #2 NPX138 PASS FAIL
135.975 138.0000
121.150 157.5000
131.250 157.5000
Image:
NOTES:
The document reference is online, please check the correspondence between the online documentation and the printed version.