Nautel VX150 Manual

2: OPERATIONS & MAINTENANCE
MANUAL
VX150 TO VX2
TRANSMITTER
Document ID: NHB-VX150-VX2-OPS
Version: 0.2
Issue Date: 2021-01-14
Status: Preliminary
Making Digital Radio Work

VERSION 0.2 2021-01-14 PAGE III
VX-LP OPERATIONS & MAINTENANCE MANUAL
Contact Information
Nautel Limited
10089 Peggy’s Cove Road
Hackett’s Cove, NS Canada B3Z 3J4
Toll Free: +1.877.6NAUTEL (662.8835)
(Canada & USA only) or
Phone: [phone] or
Fax: [phone]
Nautel Inc.
201 Target Industrial Circle
Bangor, Maine USA 04401
Phone: [phone]
Fax: [phone]
Customer Service (24-hour support)
+1.877.628.8353 (Canada & USA only)
+1.902.823.5100 (International)
Email: [email protected]
Web: www.nautel.com
The comparisons and other information provided in this document have
been prepared in good faith based on publicly available information.
For verification of materials, the reader is encouraged to consult the
respective manufacturer's most recent publication on the official
website or through contact with Customer Service.
© Copyright 2020 NAUTEL. All rights reserved.

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL TABLE OF CONTENTS
VERSION 0.2 2021-01-14 PAGE 2.V
CONTENTS
Contact Information 4.1.iii
RELEASE CONTROL RECORD vii
Description 2.1.1
Ac-Dc Power Stage 2.1.1
Control/Excitation Stage 2.1.4
RF Stage 2.1.5
Operating the Transmitter 2.2.1
User Interface Options 2.2.3
Front Panel User Interface (FPUI) 2.2.4
Advanced User Interface (AUI) 2.2.7
Managing and Displaying Widgets 2.2.13
AUI Menu Page 2.2.25
Viewing Transmitter Alarms 2.2.28
Viewing Transmitter Status - using the AUI 2.2.30
Meters 2.2.31
Presets 2.2.32
Preset Scheduler 2.2.50
Audio Player 2.2.53
System Settings 2.2.57
Configuring Remote Inputs and Outputs 2.2.101
Routine Maintenance 2.3.1
Scheduled Maintenance 2.3.1
Replacing an Air Filter 2.3.1
Performing On-Air Checks 2.3.3

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL TABLE OF CONTENTS
PAGE 2.VI VERSION 0.2 2021-01-14
Non-standard maintenance 2.4.1
Upgrading Software 2.4.1
OS Password Recovery 2.4.4
SD Card Replacement 2.4.4
List of terms 2.5.1

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL
VERSION 0.2 2021-01-14 PAGE VII
RELEASE CONTROL RECORD
ISSUE DATE REASON
0.1 2020-12-01 Initial release for VX low power models. Supports hardware
versions:
VX150, VX300, VX600 (NARF81)
VX1 (NARF79)
VX1.5. VX2 (NARF80)
Supports software version VX SW 1.0 and later.
0.2 2021-01-14 Implemented Engineering review changes in sections

VX-LP OPERATIONS & MAINTENANCE MANUAL
PAGE VIII VERSION 0.2 2021-01-14

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
VERSION 0.2 2021-01-14 PAGE 2.1.1
SECTION 2.1: DESCRIPTION
This section provides a high-level description of the transmitter’s key sections. The transmitter circuitry
is subdivided into four basic stages:
Ac-Dc Power Stage
Control/Excitation Stage - see page 2.1.4
RF Stage - see page 2.1.5
Refer to the functional block diagram, Figure 3.1.1 on page 3.1.9.
VX150 to VX2 Electrical Schematics
Some descriptions in this section refer to electrical schematics (SD-#s). These are located in Section 4 of
the VX150 to VX2 Troubleshooting Manual.
Ac-Dc Power Stage
See electrical schematic Figure SD-1. The ac-dc power stage provides power to operate the low voltage
power supply, which generates the +12 dc voltage that is used throughout the transmitter. This supplies
the voltage to operate cooling fans, IPA and power the PWBs. The ac-dc power stage also contains a dc
power supply that provides positive dc voltage (PA volts) for the transmitter's RF power amplifier. The
output voltage range of the dc power supply varies with the model. For VX150 to VX600 transmitters,
the output voltage range is between +18 and 53 V dc. For VX1to VX2 transmitters, the output voltage
range is between +23 and 65 V dc.
For normal operation, VX150 to VX600 transmitters accept a single-phase, 90 - 265 V ac (220 V ac
nominal) ac input voltage.
For normal operation, VX1 to VX2 transmitters accept a single-phase, 185 - 265 V ac (220 V ac nominal)
ac input voltage.
NOTE : VX1 to VX2 transmitters can operate from a 90-185 V ac input, but will have reduced output
power.
The ac-dc power stage consists of Power Supply Interface PWB (A4), low voltage power supply (LVPS)
(U2) and power supply (U3).

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
PAGE 2.1.2 VERSION 0.2 2021-01-14
Power Supply Interface PWB
See electrical schematic Figure SD-1. The Power Supply (PS) Interface PWB (A4):
interfaces between the ac input and the LVPS and the power supply.
distributes LVPS voltage to the RF drive (exciter) stage and the control/monitor stage.
distributes PA voltage to the RF power stage and the control/monitor stage.
controls, with the controller module, the LVPS output voltage.
provides RS485 serial communication between the system interface PWB and the power
supply.
provides status and alarm outputs from the LVPS and power supply, consisting of Module
Present, Power Fail Warning, Rectifier Fault and Overtemp Warning (provided to the Module
Control/Interface PWB over a serial bus).
Low Voltage Power Supply
See electrical schematic Figure SD-1. LVPS module (U2) converts the ac input voltage to the regulated
output (+12 V dc). This voltage is used to power all the PWBs, the cooling fans and the IPA.
Power Supply Modules
See electrical schematic Figure SD-1. Power supply module U3 converts the ac input voltage to a
regulated dc supply (PA volts) for the RF amplifier and provides an output voltage between 18 V and
53 V for the VX150 to VX600, and between 23 and 65 V dc for VX1 to VX2). The modules regulate the
output voltage based on a serial control input from the Power Supply Interface PWB (A4). The supply
also senses out-of-regulation on the ac input and dc output, and applies a Power Fail Warning signal to
the Exciter PWB. Both conditions cause the power supply to shut itself down, thus shutting down the
transmitter's RF output. All power supply module signals are applied to the exciter for system level
monitoring.

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
VERSION 0.2 2021-01-14 PAGE 2.1.3
Control/Excitation Stage
See electrical schematics SD-1 and SD-3. The control/excitation stage performs many critical functions
for the transmitter. The primary components of the control/monitor stage are the Exciter PWB (A1) and
the System Interface PWB (A3).
The display module (U1) uses a rotary button to navigate through the various menus. On the front panel
there is a pushbutton switch (BACK) to allow the user to return to the previous menu. There are two
front panel LEDs that monitor the status (local/remote and RF on/off).
The Exciter PWB (A1) provides a convenient method to remotely control and monitor of the transmitter.
An SD card (A1U63) provides a storage medium that has the operating system (OS) for the transmitter
and stores the presets and calibration data.
Exciter/Controller
The exciter PWB (A1) provides the RF drive source and performs all the necessary control and protection
for the transmitter. It accepts the external audio program information (see the VX150 to VX2
Installation Manual for details on various program input types). The exciter output is applied to the Pre-
Amp/IPA PWB (A6). The exciter PWB’s final stage is a linear gain block with 20 dB gain and a maximum
output of +39 dBm.
Other functions of the Exciter PWB are:
generates RF signal with modulation
accepts analog modulation from analog audio PWB
accepts digital modulation
hosts Ethernet server and remote control I/O
accepts forward power sample from directional coupler
accepts interlock input
accepts SWR shutdown from system interface PWB

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
PAGE 2.1.4 VERSION 0.2 2021-01-14
System Interface
The System Interface PWB (A3) interfaces with the Exciter PWB to perform the following functions:
contains monitoring and protection circuits to prevent transmitter damage under adverse or
fault conditions, including high speed SWR protection and interlock/muting.
monitors the current value of various parameters including cooling fan tachometer outputs,
transmitter output forward and reflected power, heatsink and intake temperature, PA current
levels, and PA power supply status signals.
measures and monitors the output voltage from the power supply modules as well as the low
voltage power supplies.
generates the signals that enable the power supply modules and control their output voltage.
provides the status of any controller fault conditions.
interfaces with the RF and power supply sections of the transmitter to perform control and
monitoring functions.
provides local and remote interfacing for the transmitter. Local interfacing is performed via
the local FPUI on the transmitter and the front panel TFT LCD display (320 x 240 pixels). The
AUI and front panel UI each contain a menu-based series of pages that serve specific
functions. The AUI is available via remote access.

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
VERSION 0.2 2021-01-14 PAGE 2.1.5
RF Stage
See electrical schematics SD-2 and SD-4. The RF power stage accepts the RF drive input and generates
the final RF output. It consists of a Pre-amp/IPA (A6), Power Amplifier (A7), Exciter PWB (A1), a Low
Pass Filter assembly (A9) and a Directional Coupler (A11). The Pre-amp/IPA amplifies the exciter’s RF
output to the proper level required to drive the power amplifier(s).
IPA/RF Power Amplifier
See electrical schematics SD-12 and SD-13. The intermediate RF drive outputs from the RF drive stage
are applied to the RF power amplifier via the system interface PWB (A3). The PA volts inputs from the
associated power supply module controls the RF output of the PA.
Low Pass Filter Assembly
The low pass filter assembly (A9) is applied to the output of the power amplifier to reject harmonics
prior to the directional coupler (A11).
Directional Coupler
See electrical schematic Figure SD-15. The directional coupler (A11) samples the transmitter's forward
and reflected power and generates the Fwd Pwr Sample (A11J2) and Refld Pwr Sample (A11J3) signals
applied to the exciter PWB and system interface PWBs for protection and monitoring. RF monitor
provides -35 dB coupling (1 V at 75 W) at A11J1, which is applied to the panel mount BNC connector
on the rear panel. This can be used with a modulation monitor or spectrum analyzer.

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
PAGE 2.1.6 VERSION 0.2 2021-01-14

VERSION 0.2 2021-01-14 PAGE 2.1.7
Figure 2.1.1: VX150/VX300/VX600 Transmitter Block Diagram
2235-8300-BLK01 Iss. A
ANALOG AUDIO
PWB
MPX/SCA 1
MPX/SCA 2
ANALOG LEFT
ANALOG RIGHT
EXCITER
PWB
AES 1
AES 2
USB 1
USB 2
ETHERNET
XMTR LINK
RDS/SYS CTRL
REMOTE IN
INTERLOCK
EXTERNAL RF SAMPLE
FRONT PANEL
USER INTERFACE
PWB
USB 3
SD CARD
ORBAN AUDIO
PROCESSOR
(OPTIONAL)
SYSTEM INTERFACE
PWB
AMBIENT TEMP
SENSOR
HEATSINK
TEMP SENSOR
FAN 1
FAN 2
DISPLAY
POWER SUPPLY
INTERFACE
PWB
AC IN
+12V
POWER SUPPLY
+53V PA
POWER SUPPLY
IPA
PWB
PA
PWB
LOW PASS FILTER
PWB
DIRECTIONAL
COUPLER
PWB
RF OUT
RF MONITOR
REMOTE OUT
19kHz OUT

VERSION 0.2 2021-01-14 PAGE 2.1.8
Figure 2.1.2: VX1 Transmitter Block Diagram
2235-8100-BLK01 Iss. A
ANALOG AUDIO
PWB
MPX/SCA 1
MPX/SCA 2
ANALOG LEFT
ANALOG RIGHT
EXCITER
PWB
AES 1
AES 2
USB 1
USB 2
ETHERNET
XMTR LINK
RDS/SYS CTRL
REMOTE IN
INTERLOCK
EXTERNAL RF SAMPLE
FRONT PANEL
USER INTERFACE
PWB
USB 3
SD CARD
ORBAN AUDIO
PROCESSOR
(OPTIONAL)
SYSTEM INTERFACE
PWB
AMBIENT TEMP
SENSOR
HEATSINK
TEMP SENSOR
FAN 1
FAN 2
DISPLAY
POWER SUPPLY
INTERFACE
PWB
AC IN
+12V
POWER SUPPLY
+65V PA
POWER SUPPLY
IPA
PWB
PA
PWB
LOW PASS FILTER
PWB
DIRECTIONAL
COUPLER
PWB
RF OUT
RF MONITOR
REMOTE OUT
19kHz OUT

VERSION 0.2 2021-01-14 PAGE 2.1.9
Figure 2.1.3: VX1.5/VX2 Transmitter Block Diagram
2235-8200-BLK01 Iss. A
ANALOG AUDIO
PWB
MPX/SCA 1
MPX/SCA 2
ANALOG LEFT
ANALOG RIGHT
EXCITER
PWB
AES 1
AES 2
USB 1
USB 2
ETHERNET
XMTR LINK
RDS/SYS CTRL
REMOTE IN
INTERLOCK
EXTERNAL RF SAMPLE
FRONT PANEL
USER INTERFACE
PWB
USB 3
SD CARD ORBAN AUDIO
PROCESSOR
(OPTIONAL)
SYSTEM INTERFACE
PWB
AMBIENT TEMP
SENSOR
HEATSINK
TEMP SENSOR
FAN 1
FAN 2
DISPLAY
POWER SUPPLY
INTERFACE
PWB
AC IN
+12V
POWER SUPPLY
+65V PA
POWER SUPPLY
IPA
PWB
PA 1
PWB
LOW PASS FILTER
PWB
COMBINER
PWB
RF OUT
RF MONITOR
REMOTE OUT
19kHz OUT
SPLITTER
PWB
PA 2
PWB
LOW PASS FILTER
PWB
DIRECTIONAL
COUPLER
PWB