Northern Airborne Technology NTX User Manual

SM28

NTX VHF-FM Series

Remote Mount Transceivers

INSTALLATION AND OPERATION MANUAL

REV 4.10 June 1, 2004

Northern Airborne Technology Ltd.

1925 Kirschner Road
Kelowna BC, Canada

V1Y 4N7

Telephone [phone]

Facsimile [phone]

Copyright 2004 by Northern Airborne Technology

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

Performed at factory

Performed at factory

Periodically NAT will release manual amendments. In order to maintain the most
accurate and up to date manual these amendments should be carried out immediately
upon receipt and recorded on the following amendment record.

AMENDMENT RECORD

Amendment

Number

Amendment

Date

Section(s)

Changed

Date

Entered

Entered By

1 Nov 19/04 2

2 Jul 28/05 2

3 Jan 14/08 2

Insert any Amendment Instruction sheets after this page.

Jun 1, 2004 Page ii

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INSTALL_OPS
MANUAL AMENDMENT

Manual:

SM28 NTX VHF-FM Series Remote Mount Transceiver Amendment #: 3

Document # SM28\Install_Ops\809-0003 Amendment Date: Jan 14, 2008

The purpose of this amendment is to update sections 2.3.4, 2.3.5 and 2.3.6.

Amendment Instructions:

1

2-1 and 2-2 Rev. 4.10 Amendment # 1 2-1 and 2-2 Rev. 4.10 Amendment # 3
2-3 and 2-4 Rev. 4.10 2-3 and 2-4 Rev. 4.10 Amendment # 3
2-5 Rev. 4.10 Amendment # 2 2-5 Rev. 4.10 Amendment # 3

Note: Ensure that all drawings are inserted in the order shown on the latest drawing lists.

Remove Pages Replace With Pages

2 Update the Amendment Record sheet at the front of the manual.

3 Insert this page into the manual after the Amendment Record sheet (page ii).

Manual Amendment ends after the following amended pages

Amendment # 3 Jan 14, 2008 Page 1

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INSTALL_OPS
MANUAL AMENDMENT

Manual: SM28 NTX066 Amendment #: 2
Document # SM28\Install_Ops\809-0002 Amendment Date: Jul 28, 2005

The purpose of this amendment is to update Section 2.0 with the Installation Approval
Test Procedure (NTX066\634-0).

Amendment Instructions:

1

2-5 Rev. 4.10 Amendment #1 2-5 Rev. 4.10 Amendment #2

2

NTX066\634-0 Rev. 1.00

Note: Ensure that all drawings are inserted in the order shown on the latest drawing lists.

3 Update the Amendment Record sheet at the front of the manual.

4 Insert this page into the manual after the Amendment Record sheet (page ii).

Manual Amendment ends after the following amended pages

Remove Pages Replace With Pages

Add Drawings (Section 2)

Amendment #2 Jul 28, 2005 Page 1

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INSTALL_OPS MANUAL
AMENDMENT

Manual: SM28 (NTX VHF-FM Transceivers) Amendment #: 1
Document # SM28\Install_Ops\809-0001 Amendment Date: Nov 19, 2004

The purpose of this amendment is to amend the cable and wiring specifications in line
with Transport Canada requirements.

Amendment Instructions:

1 Remove Pages Replace With Pages

2-2 Rev. 4.10 2-1 to 2-2 Rev. 4.10 Amendment 1

2 Update the Amendment Record sheet at the front of the manual.

3 Insert this page into the manual after the Amendment Record sheet (page ii).

Manual Amendment ends after the following amended pages

Amendment # 1 Nov 19, 2004 Page 1

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SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

IMPORTANT INFORMATION

FOR AVIONICS INSTALLATION FACILITIES

The NTX VHF-FM Series Remote Mount 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.

Jun 1, 2004 Page iii

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SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

Table of Contents

Section Title Page

1 Description

1.1 Introduction 1-1

1.2 Purpose of Equipment 1-1

1.3 Features 1-1

1.4 Specifications 1-2

1.4.1 Electrical Specifications 1-2

1.4.2 Receiver 1-3

1.4.3 Transmitter 1-3

1.4.4 Physical Specifications 1-4

1.4.5 Environmental Specifications 1-4

1.5 VHF-FM Radio Spurious Frequencies 1-4

1.6 Unit Nomenclature 1-5

2 Installation

2.1 Introduction 2-1

2.2 Unpacking and Inspection 2-1

2.2.1 Warranty 2-1

2.3 Installation Procedures 2-1

2.3.1 Warnings 2-1

2.3.2 Cautions 2-2

2.3.3 Notes 2-2

2.3.4 Cable and Wiring 2-2

2.3.5 Antennas 2-3

2.3.6 Mechanical Mounting 2-3

2.3.7 Post-Installation Checks 2-4

2.3.8 Post-Installation EMI Test 2-4

2.4 Continued Airworthiness 2-5

2.5 Installation Drawings 2-5

3 Operation

3.1 Introduction 3-1

3.2 General 3-1

3.3 Configuration 3-1

Jun 1, 2004 Page iv

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SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

Section 1 Description

1.1 Introduction

This manual contains information on the NTX VHF-FM Series Remote Mount
Transceivers. All derivative products will be covered by manual supplements, which can
be obtained from NAT as required.

Information in this section consists of purpose of equipment, features and specifications.

1.2 Purpose of Equipment

The NTX VHF-FM Series Remote Mount Transceivers are mounted using a custom 1/4
ATR tray and are operated using an NAT Tac/Com™ control head. The NTX066
models operate over 66 to 88 MHz on the VHF mid-band, and the NTX138 models are
capable of receiving and transmitting over 138 MHz to 174 MHz on the VHF high band.

Primary applications include airborne Search and Rescue, Law Enforcement and
Forestry communications.

1.3 Features

The existing Tac/Com™ series of control heads provide control for the transceivers.

The NTX066 range is 66.0000 to 87.9975 MHz, and the NTX138 VHF-FM models
cover a frequency range of 138.0000-173.9975 MHz, both in 2.5 kHz increments. A
maximum of 200 channels are available depending on the type of control head used.
Depending on the model selected, the channels can include a receive frequency and
CTCSS or DCS tone, transmit frequency and CTCSS or DCS tone, and an
alphanumeric identifier.

Depending on the model selected, the transceiver provides wideband or narrowband
receiver selectivity (selectable by the control head). Wideband operation provides a
bandwidth of 25 kHz and narrowband operation provides a bandwidth of 12.5 kHz.

The NTX138 transceiver can also be selected with an optional guard receiver installed or a
DF compatible output signal. The NTX138-100 provides a DF compatible output signal.

Voice Inversion Scrambling is available as an option, depending on the selected model.

A scan function allows scanning of selected channels. Transmit power of either 1 watt or 10
watts is selectable from the control head. Simplex and semi-duplex operations are available.
DTMF encoding and direct keyboard programming can be added using NAT's DTE12.

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NTX VHF-FM Series Remote Mount Transceivers Manual SM28 Rev. 4. 10

1.4 Specifications

1.4.1 Electrical Specifications

Input power 28 Vdc nominal

Current consumption

NTX066 and NTX138 models 300 mA receive/2.5 A transmit (typical)
500 mA receive/3.0 A transmit (max.)

Sidetone output

NTX066 and NTX138 models 25 mW @ 600 Ω nominal

Microphone

NTX066 and NTX138 models Amplified dynamic or equivalent, 150 Ω
balanced/unbalanced

Scrambling 3.1 kHz Voice Inversion
(Optional on NTX138 and NTX066 models)

Frequency range

NTX066 models 66.0 MHz to 87.9975 MHz

NTX138 models 138.000 MHz to 173.9975 MHz

Tone capability 38 EIA standard CTCSS tones
70 DCS tones

Operating mode F3E simplex or semi-duplex

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SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

1.4.2 Receiver

Channel increments 2.5 kHz

Audio output

NTX066 and NTX138 models 100 mW into 600 Ω, nominal

Sensitivity

NTX066-000 0.50 µV @ 12 dB SINAD

NTX138-050 Main 0.50 µV @ 12 dB SINAD

Guard 0.50 µV @ 12 dB SINAD

NTX138-000 0.35 µV @ 12 dB SINAD

NTX138-100 Main 0.35 µV @ 12 dB SINAD
DF 1.0 µV @ 12 dB SINAD

Selectivity -70 dB min. @ 25 kHz (Wideband)

-60 dB min. @ 12.5 kHz (Narrowband)

Spurious response -70 dB

Intermodulation -70 dB

1.4.3 Transmitter

RF power output 1 W/10 W selectable

RF output impedance 50 Ω nominal

Modulation
Wide band ±5.0 kHz max., limited
Narrow band ±2.5 kHz max., limited

Output spurious -65 dB

Frequency stability ±0.0003 %

FM noise -45 dB

Distortion <5% nominal, 10% max.

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NTX VHF-FM Series Remote Mount Transceivers Manual SM28 Rev. 4. 10

1.4.4 Physical Specifications

Height 2.21" (56.1 mm)

Overall length 11.38"(289.1 mm)

Length without connector 10.67” (271.1 mm)

Width 5.23" (271.2 mm)

Weight 4.0 lbs (1.8 kg)

Mounting Custom NAT ¼ ATR tray mount (NTX-VT1)

Connector type Male filtered 25-pin D-subminiature with Positronics

V5 locking tabs

Antenna connector Bulkhead female BNC

1.4.5 Environmental Specifications

Temperature -30° C to +60° C

Altitude 25,000 feet

Humidity 95 %

Shock 12 g (any axis)

Environmental conformance:

DO-160C Env. Cat. B4-BA[MN]XXXXXXAB[AB]BAUAXXX

1.5 VHF-FM Radio Spurious Frequencies

All VHF-FM radios are subject to the reception of spurious signals. Avoid operation on
these frequencies whenever possible.

The frequencies affected within the NTX066 radio are 66.00 MHz, 72.00 MHz, and

84.00 MHz.

The frequencies affected within the NTX138 radios are 138.000 MHz, 144.000 MHz,

156.000 MHz and 168.000 MHz.

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SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

1.6 Unit Nomenclature

Model Description / Distinction

NTX066-000 66.0 MHz - 88.0 MHz VHF-FM transceiver.

200 channel memory.
38 CTCSS tones

70 DCS tones.

1 W or 10 W selectable.
List, Priority or List+Priority scanning.

Optional Voice Inversion Scrambling

NTX138-000 138 MHz - 174 MHz VHF-FM transceiver.

200 channel memory.
38 CTCSS tones

70 DCS tones.

1 W or 10 W selectable.
List, Priority or List+Priority scanning.

Optional Voice Inversion Scrambling

NTX138-050 138 MHz - 174 MHz VHF-FM transceiver.

200 channel memory.
38 CTCSS tones

70 DCS tones.

1 W or 10 W selectable.
List, Priority or List+Priority scanning.
2 channel crystal controlled USFS guard receiver.

Optional Voice Inversion Scrambling

NTX138-100 138 MHz - 174 MHz VHF-FM transceiver.

200 channel memory.
38 CTCSS tones

70 DCS tones.

1 W or 10 W selectable.
List, Priority or List+Priority scanning.
DF compatible output signal.

Optional Voice Inversion Scrambling

End of section 1.0

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SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

Section 2 Installation

2.1 Introduction

Information in this section consists of: unpacking and inspection procedures, installation
procedures, post-installation checks, and installation drawings.

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. Note that each unit should have the following:

- NTX VHF-FM Series Remote Mount Transceiver

- Warranty Card

- Release certification

Verify that all items are present before proceeding and report any shortage immediately
to your supplier.

2.2.1 Warranty

Complete the warranty card information and send it to NAT when the installation is
complete. If you fail to complete the warranty card, the warranty will be activated on
date of shipment from NAT.

Note: An appropriately rated facility, e.g. Certified Aircraft Repair Station, must install

this equipment in accordance with applicable regulations. NAT Ltd’s warranty is
not valid unless the equipment is installed by an authorized NAT 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 a non-airworthy
installation.

2.3 Installation Procedures

2.3.1 Warnings

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.

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NTX VHF-FM Series Remote Mount Transceivers Manual SM28 Rev. 4.10

2.3.2 Cautions

Severe degradation of audio installations may result from incorrect wiring and shielding.
This could cause much higher cross-talk, hum, and ground-loop interference.

2.3.3 Notes

For maximum resistance to low frequency interference, electrically ground the case of
the transceiver.

2.3.4 Cable and Wiring

All unshielded 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. Wire types should be 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
wiring diagrams in Section 2.5 as required.

To provide easy installation of the hood, allow 3 inches from the end of the wire to the
shield termination. Note: Install the hood after the wiring is complete.

Installation cabling must allow the transceiver to be easily withdrawn for disconnection and
field service adjustments. Ensure an adequate service loop in the routing of the cables.

All wiring should be 22 AWG, except power and ground connections, which must be
18 AWG or larger, as indicated on the installation drawings. Ensure that the ground
connection is clean and well secured. To prevent inadvertent system failure, supply
power to this system from a separate breaker or fuse not connected to any other
device. NAT recommends a 5 A fuse or breaker (28 Vdc Source).

Coaxial cable should be in accordance with MIL-C-17 unless otherwise specified. Do
not use coax with PVC insulation. NAT recommends Teflon dielectric cable at or above
VHF frequencies or where cable runs exceed 8 feet. Note that at VHF frequencies,
cable losses due to long cable runs and tight bends may cut the ERP (Effective
Radiated Power) to less than 50% of specification.

To prevent RF interference between similar systems, NAT recommends that VHF FM
coax runs be widely separated, or be made using triaxial cable. Bond the outer shield to
the airframe at the transceiver end only.

In communication intensive applications, bad cable routing and shielding may drastically
compromise over-all system performance. Symptoms will be spurious squelch opening,
RFI (Radio-Frequency Interference), and garbled reception.

Neatly terminate RF cables (solder or crimp) and test for shorts prior to system check­out (not while connected to the radio!!). Keep cable bends to a minimum at the antenna.

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SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

Avoid sharp bends in the coax cables (minimum 3" radius) to prevent severe reflections.
If sharp bends are required use 90° elbow adapters.

Fabrication and installation of wiring harness should be in accordance with the original
aircraft manufacturer’s maintenance instructions or AC43.13-1B Change 1, chapter 11,
sections 5 to 13, 16 and 17.

Grounding and bonding should be in accordance with the original aircraft manufacturer’s
maintenance instructions or AC43.13-1B Change 1, chapter 11, section 15.

2.3.5 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. Avoid any placement that puts antennas of like
frequencies close together.

Installation of the antenna should be in accordance with the aircraft manufacturer’s
instructions for continued airworthiness or AC43.13-1B 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 ft 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 communication
system wavelengths.

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.

Surround any blade or whip antenna with a ground plane surface (metallic, grounded
material) having a radius equal to or greater than the height of the antenna. Poor
grounding will result in severe reflected power and high levels of RFI throughout the
airframe.

Any antenna will be less prone to interference from rotor modulation and other undesirable
stimuli if installed correctly and surrounded by a large metallic ground plane. Under the
same conditions, it 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.

2.3.6 Mechanical Mounting

Installation of the transceiver should be in accordance with the 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.

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NTX VHF-FM Series Remote Mount Transceivers Manual SM28 Rev. 4.10

The transceiver is tray-mounted and uses a custom 1/4 ATR style tray. Mount (with
countersunk screws) onto a clean, grounded surface having a resistance of less than

0.5 ohms to airframe ground.

The transceiver may be mounted in any attitude, but upright (mounting hook at the
bottom) is preferred for access and condensation drainage.

2.3.7 Post-Installation Checks

2.3.7.1 Voltage/resistance checks

Do not attach the transceiver until the following conditions are met.

Check the following:

a) P101 pins <5> and <6> for +28 Vdc relative to ground.

b) P101 pins <8> and <20> for continuity to ground (below 0.5 Ω).

Ensure that the antenna is disconnected for the following test or erroneous
readings may be obtained.

c) 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.

2.3.7.2 Power On checks

a) Install the transceiver and power up the ship’s systems. Turn on the control head.

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 keying the radio to transmit and amber when receiving.

c) Check the SCAN function.

Note: You may be unable to hear the received audio if the tones do not match

those set in the radio. To avoid any confusion, set the tones 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.

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SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

2.3.8 Post-Installation EMI Test

The purpose of this test is to identify any interference that the transceiver may cause
with existing aircraft systems. The transceiver should be tested in accordance with the
Installation Approval Test Procedure (see section 2.5) and the test results documented
on the record sheets.

2.4 Continued Airworthiness

Maintenance of the NTX VHF-FM Series Remote Mount Transceiver is ‘on condition’
only. Periodic maintenance of these products is not required.

2.5 Installation Drawings

DRAWING REV. DESCRIPTION TYPE

NTX138\403-0 1.22 Remote Mount Radio Interconnect
NTX138\405-0 1.00 Remote Mount Radio Connector Map
NTX138\922-0 1.02 Remote Mount Radio Mechanical
NTX-VT1\922-0 1.00 Vertical Mount Tray Mechanical
NTX138\634-0 1.00 Post-Installation EMI Test Installation Approval Test Procedure
NTX066\634-0 1.00 Post-Installation EMI Test Installation Approval Test Procedure

Section 2 ends after these Drawings

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INSTALLATION APPROVAL

NAT Part #: NTX138 Description: Remote Mount FM Transceivers
Document #: NTX138\634-0 Rev: 1.00

1. Post Installation EMI Test

The purpose of this test is to identify any interference that the NTX138 may cause with
existing aircraft systems.

2. Test Conditions

The NTX138 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

TEST PROCEDURE

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 NTX138 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 NTX138 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 NTX138 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.

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NTX138 Installation Approval Test Procedure

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 NTX138 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 NTX138 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

NTX138 PASS FAIL PASS FAIL

NOTES:

143.180 MHz

143.1825 MHz

157.5000 MHz

157.5425 MHz

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NTX138 Installation Approval Test Procedure

B. Determine if the image frequency for the VHF Comm falls within the range of the

NTX138 unit. If so, select a set of frequencies that will cause the NTX138 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 NTX138 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 NTX138 to

142.8000 MHz.

FREQUENCIES RESULTS

VHF #1 NTX138 PASS FAIL

135.975 138.0000

121.150 157.5000

NOTES:

131.250 157.5000

Image:

FREQUENCIES RESULTS

VHF #2 NTX138 PASS FAIL

135.975 138.0000

121.150 157.5000

131.250 157.5000

Image:

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NTX138 Installation Approval Test Procedure

C. Determine if the image frequency for the VOR/ILS Nav falls within the range of

the NTX138 unit. If so, select two sets of frequencies that will cause the NTX138
to be set as close as possible to the image frequency. Choose one set in the
localizer frequency range, and one in the VOR frequency range. Record these
values in the spaces provided in the following chart. Modulate the NTX138
transmitter on the following frequencies for at least 20 seconds. Listen for any noise or
detected audio signals on the receiver audio; look for any movement of flags or needles
on the navigation display.

FREQUENCIES RESULTS

VOR/ILS #1 NTX138 PASS FAIL

108.000 162.0000

108.100 162.1500

Image:

Image:

NOTES:

FREQUENCIES RESULTS

VOR/ILS #2 NTX138 PASS FAIL

108.000 162.0000

108.100 162.1500

Image:

Image:

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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

NTX138 Installation Approval Test Procedure

D. Modulate the NTX138 transmitter on the following frequencies for at least 20

seconds. Look for any movement of flags or needles on the navigation display.

FREQUENCIES RESULTS

G/S #1 NTX138 PASS FAIL

334.7 (108.1) 167.3500

FREQUENCIES RESULTS

G/S #2 NTX138 PASS FAIL

334.7 (108.1) 167.3500

NOTES:

Note: For the following tests, select frequencies at the top, middle and bottom of the

range of the NTX138.

Frequency #1 ______________ Frequency #2 ______________

Frequency #3 ______________

E. At a safe altitude, engage the autopilot or stability augmentation system.

Modulate the NTX138 transmitter on the above frequencies for at least 20
seconds. Observe any effect on the autopilot or stability augmentation system.

Observations:

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E NG-FORM: 634-0100.DOT

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NTX138 Installation Approval Test Procedure

F. Perform a coupled ILS approach to the aircraft's certified limits. Modulate the

NTX138 transmitter on the above frequencies for at least 20 seconds. Observe
any effect on the autopilot. Repeat for each different system such as ILS #2,
GPS, FMS etc.

Observations:

G. List the power plant, fuel and other electric instruments in the chart provided and

note any anomalies that occur while transmitting. Assess the results.

STEP SYSTEM PASS FAIL NOTES

1 Xponder & Encoder

2 ADF 1 & 2

3 VG

4 Compass

5 Directional Gyro

6 Oil Pressure

7 Fuel Pressure

8 Oil Temp

9 Amps

10 Bus Voltage

11 Fuel %

12 Ng

13 TOT

14 Torque %

15 Annunciators

16 Digital Clock

Page 6 of 7 Aug 31, 2001 Rev. 1.00

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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

NTX138 Installation Approval Test Procedure

STEP SYSTEM PASS FAIL NOTES

NOTES:

End of Installation Approval Test Procedure

Rev. 1.00 Aug 31, 2001 Page 7 of 7

E NG-FORM: 634-0100.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

INSTALLATION APPROVAL TEST

NAT Part #: NTX066 Description: Remote Mount FM Transceivers
Document #: NTX066\634-0 Rev: 1.00

1. Post Installation EMI Test

The purpose of this test is to identify any interference that the NTX066 may
cause with existing aircraft systems.

2. Test Conditions

The NTX066 should be installed and all functions should be tested. The antenna
VSWR should be checked. A forward and reverse power measurement with an
in-line wattmeter installed between the transceiver and antenna should show no
more than 10% reflected power. For the following tests, ensure that the transmit
power is set to HI.

3. Methodology

Most of the EMI tests can be accomplished on the ground. In some cases, in-flight­testing may be required/desired. If the aircraft is approved for IFR operations, it is
mandatory that interference between the NTX066 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 in the
applicable table with the squelch disabled. VOR/ILS/GS receivers should be set to the
frequencies indicated in the applicable table and selected for display. If possible, set
up a VOR/ILS ramp test set on the frequencies indicated in the applicable table 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 NTX066 transmitter on the frequencies indicated in the applicable
table 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 and 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 applicable table
and note any anomalies that occur while transmitting. Assess the results.

If the aircraft is equipped with an autopilot or a stability augmentation system,
test fly the aircraft and verify that the operation of the NTX066 transceiver does

PROCEDURE

Rev. 1.00 Aug 10, 2005 Page 1 of 5

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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

NTX066 Installation Approval Test Procedure

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.

4. Results

If the installed system passes all of the applicable EMI tests, no further action is
required. If interference is observed, 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 NTX066 is transmitting, providing that it recovers properly and promptly.
It is not permissible for an IFR Approach certified GPS to be affected in the same
way. A complete disclosure of all the standards of airworthiness to be applied in
assessing EMI effects is beyond the scope of this document.

5. Procedures

5.1 Operate the NTX066 transmitter on the frequencies listed in Table 1 for at least
20 seconds. Observe the GPS for any degradation in satellite status, or
availability, or flags.

Frequencies GPS #1 GPS #2

NTX066 Pass Fail Pass Fail

68.200 MHz

68.495 MHz

75.020 MHz

81.840 MHz

87.520 MHz

87.525 MHz

Table 1

NOTES:

5.2 If the image frequency for the VHF Comm falls within the range of the NTX066
unit, select a set of frequencies that will cause the NTX066 to be set as close as
possible to the image frequency. Any one of many possible sets can be used.
Record these values in Table 2. Modulate the NTX066 transmitter on the
frequencies listed in Table 1 for at least 20 seconds. Listen for any noise or
detected audio signals on the VHF comm.

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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

NTX066 Installation Approval Test Procedure

Example – Bendix/King KY 196A

The first intermediate frequency (I.F.) is 11.4 MHz. The local oscillator (L.O.)
frequency is above the received frequency (high side injection) therefore, the
image frequency is 22.8 MHz above the selected frequency. The frequency band
for the NTX066 is from 66.000 MHz to 87.9975 MHz therefore, the second
harmonic could cause interference with the VHF Comm. Set the KY 196A to

120.000 MHz and the NTX066 to 71.400 MHz. The image frequency for the KY
196A would then be 120.000 + 22.800 MHz, which equals 142.800 MHz. The
second harmonic of 71.400 MHz is 142.800 MHz.

Frequencies Results

Channel Image NTX066 Pass Fail

VHF #1
VHF #1
VHF #2
VHF #2

NOTES:

5.3 Modulate the NTX066 transmitter on the frequencies listed in Table 3 for at least 20
seconds. Listen for any noise or detected audio signals on the receiver audio and look for
any movement of flags or needles on the navigation displays.

Frequencies Results

Channel VOR/ILS NTX066 Pass Fail

VOR/ILS #1
VOR/ILS #1
VOR/ILS #2
VOR/ILS #2

NOTES:

Table 2

108.000 MHz 66.025 MHz

108.100 MHz 66.025 MHz

108.000 MHz 66.025 MHz

108.100 MHz 66.025 MHz

Table 3

Rev. 1.00 Aug 10, 2005 Page 3 of 5

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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

NTX066 Installation Approval Test Procedure

5.4 Modulate the NTX066 transmitter on the frequencies listed in Table 4 for at least 20
seconds. Look for any movement of flags or needles on the navigation displays.

Frequencies Results

Channel G/S # NTX066 Pass Fail

G/S #1 334.7 (108.100) 66.025 MHz
G/S #1 334.7 (108.100) 77.100 MHz
G/S #1 334.7 (108.100) 87.995 MHz
G/S #2 334.7 (108.100) 66.025 MHz
G/S #2 334.7 (108.100) 77.100 MHz
G/S #2 334.7 (108.100) 87.995 MHz

Table 4

NOTES:

Note: For the following tests, select frequencies at the top, middle and bottom of the

range of the NTX066.

Frequency #1 ______________ Frequency #2 ______________

Frequency #3 ______________

5.5 At a safe altitude, engage the autopilot or stability augmentation system.
Modulate the NTX066 transmitter on frequencies #1, #2 and #3 for at least 20
seconds. Observe any effect on the autopilot or stability augmentation system.

Observations:

5.6 Perform a coupled ILS approach to the aircraft's certified limits. Modulate the
NTX066 transmitter on frequencies #1, #2 and #3 for at least 20 seconds.
Observe any effect on the autopilot. Repeat for each different system such as
ILS #2, GPS, and FMS etc.

Page 4 of 5 Aug 10, 2005 Rev. 1.00

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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

NTX066 Installation Approval Test Procedure

Observations:

5.7 List the power plant, fuel and other electric instruments in Table 5 and note any
anomalies that occur while transmitting. Assess the results.

STEP SYSTEM PASS FAIL NOTES

1 Xponder & Encoder
2 ADF 1 & 2
3 VG
4 Compass
5 Directional Gyro
6 Oil Pressure
7 Fuel Pressure
8 Oil Temp
9 Amps
10 Bus Voltage
11 Fuel %
12 Ng
13 TOT
14 Torque %
15 Annunciators
16 Digital Clock

Table 5

NOTES:

End of installation approval test procedure

Rev. 1.00 Aug 10, 2005 Page 5 of 5

ENG-FORM: 634-0101.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

SM28 Rev. 4.10 NTX VHF-FM Series Remote Mount Transceivers Manual

Section 3 Operation

3.1 Introduction

Information in this section consists of the functional and operational procedures for the
NTX VHF-FM Series Remote Mount Transceivers.

3.2 General

The NTX VHF-FM Series Remote Mount Transceivers are mounted using a custom 1/4
ATR tray and are operated using an NAT Tac/Com™ control head. The NTX138
models are capable of receiving and transmitting over 138-173.9975 MHz on the VHF
high band, and the NTX066 models operate over 66.0 to 88.9975 MHz on the VHF mid­band.

The transceiver is controlled by a Tac/Com™ control head available from NAT Ltd. The
relevant control head operation manual should be consulted for all operational
information.

3.3 Configuration

The NTX VHF-FM Series Remote Mount Transceiver has no normal user
operational aspects. The Tac/Com™ control head provides the user interface. During

installation, or if the unit has been exchanged, it may be a requirement to change
internal level adjustments. This should be done ONLY BY FULLY QUALIFIED
PERSONNEL, as it requires removal of the transceiver’s exterior case and use of test
equipment to measure input and output levels.

End of section 3.0

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CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.