Nautel VS2.5 Programming manual

VS2.5 Transmitter
Troubleshooting Manual
Document:NHB-VS2.5-TRB-4.0
Issue: 4.0 2012-12-01
Status: Standard

Nautel Limited
10089 Peggy’s Cove Road
Hackett’s Cove, NS Canada B3Z 3J4
Phone: [phone] or
Toll Free: +1.877.6NAUTEL (6628835) (Canada & USA only)
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. The reader is encouraged to consult the respective
manufacturer's most recent published data for verification.
© Copyright 2012+ NAUTEL. All rights reserved.

VS2.5 Troubleshooting Manual Table of contents
Page v
Contents
Release control record ix
About this manual xi
About safety xv
Safety precautions xvii
Responding to alarms 1-1
Corrective maintenance 1-1
Electrostatic protection 1-3
Identifying an alarm 1-4
Troubleshooting tips 1-25
Operating with defective PAs or cooling fans 1-26
Replacing a suspect PWB, power supply or fan 1-27
PA PWB replacement 1-29
Pre-amp/IPA PWB replacement 1-30
Power Supply Module Replacement 1-33
+48 V Power Supply Replacement 1-34
Cooling fan replacement - fans 3 (B3) through 7 (B7) 1-35
Cooling fan replacement - fans 1 (B1) and 2 (B2) 1-37
Exciter/Control PWB Replacement 1-39
PS Distribution PWB Replacement 1-42
Combiner Interface PWB Replacement 1-43

VS2.5 Troubleshooting Manual Table of contents
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Detailed Circuit Descriptions 2-1
Exciter/control PWB (NAPE87) 2-1
PS distribution PWB (NAPS43A) 2-2
Pre-amp/IPA PWB (NAPA28B) 2-3
Power amplifier PWB (NAPA31B) 2-4
Parts Lists 3-1
Parts information 3-1
Family tree 3-1
How to locate information about a specific part 3-1
Column content 3-2
OEM code to manufacturer’s cross-reference 3-3
Common abbreviations/acronyms 3-4
Wiring/connector lists 4-1
Wiring lists provided 4-1
Wiring lists not provided 4-1
Connector mating information 4-1
Wire colours 4-1
Printed wiring board patterns 4-1
Reading Electrical Schematics 5-1
Component values 5-1
Graphic symbols 5-1
Logic symbols 5-1
Reference designations 5-1
Unique symbols 5-2
Identifying schematic diagrams 5-2
Structure of schematics 5-2
Locating schematic diagram(s) for a functional block 5-3
Locating a part or assembly on a schematic 5-3

VS2.5 Troubleshooting Manual Table of contents
Issue 4.0 2012-12-01 Page vii
Mechanical Drawings 6-1
Identifying mechanical drawings 6-1
Content of mechanical drawings 6-1
Locating a part or assembly on a mechanical drawing 6-1
List of terms 7-1

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VS2.5 Troubleshooting Manual
Issue 4.0 2012-12-01 Page ix
Release control record
Issue Date Reason
4.0 2012-12-01 Release 4 of manual (NARF66C and NARF66C/01).
CE compliant.

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VS2.5 Troubleshooting Manual
Issue 4.0 2012-12-01 Page xi
About this manual
This manual provides troubleshooting information for the VS2.5 transmitter. It is intended for use by
field technicians. This manual allows the troubleshooting technician to diagnose a fault to the system
level, using alarm response procedures, parts lists, wiring lists, and electrical schematics. Electrical
schematics and mechanical drawings are included at the end of the manual.
Performing procedures
When using procedures in this manual, perform each step in sequence.
• If you are asked to see another section of this manual, or another document, refer to that
section or document for additional information, then continue the procedure.
• If you are asked to go to another step within the procedure, jump directly to that step with-
out performing the intervening steps.
• If you are asked to go to another section or document, stop the procedure and perform the
tasks described in the other section or document.
• If you are asked to check a voltage, use a digital voltmeter and test the voltage relative to
ground (unless otherwise instructed).
• If you are asked to check a signal, use an oscilloscope and test the signal relative to ground
(unless otherwise instructed).
Technical support
Nautel offers technical support to customers over the Internet and by telephone. Nautel’s customer
support team will answer your questions and work with you to identify and resolve problems.
For 24-hour technical support, call toll free at 1.877.628.8353 (in USA and Canada only) or call
1.902.823.5100 (international) or find us on the Internet at http://www.nautel.com.
For parts and tools information, see “Parts and tools” on page 9-1 of the VS2.5 Pre-Installation
Manual.

VS2.5 Troubleshooting Manual
Page xii Issue 4.0 2012-12-01
For extended warranty information, see “Pre-installation assistance” on page 10-1 of the
VS2.5 Pre-Installation Manual.
VS2.5 transmitter manuals
The VS2.5 documentation suite includes the following documents:
VS2.5 Pre-installation Manual, VS2.5-PREINST. Provides instructions and reference
information needed when planning and preparing for the installation of a VS2.5 transmitter.
Nautel Site Protection Manual. Provides detailed information about protecting your site from
lightning-related hazards.
VS2.5 Installation Manual, VS2.5-INST. Provides instructions and reference information needed
when installing a VS2.5 transmitter.
VS2.5 Operating and Maintenance Manual, VS2.5-OPS-MAINT. Provides instructions for
operating, maintaining and troubleshooting a VS2.5 transmitter. It also provides reference
information needed when performing diagnostic procedures.
VS2.5 Troubleshooting Manual, VS2.5-TROUBLE. Provides detailed technical information
about the VS2.5 transmitter, including electrical schematics and mechanical drawings.
Nautel website / Online resources
The Nautel website provides useful resources to keep you up to date on your VS2.5.
Nautel User Group (NUG)
The website includes a special section that customers can log into in order to access the Nautel
customer newsletter, product manuals, frequently asked questions (FAQ), information sheets, and
information about field upgrades.
Documentation: online and printed
The website’s NUG section provides online access to all the documentation for your VS2.5.
Documentation is provided in Acrobat (PDF) format. You can use the documentation online or
print the sections that you need.
When using online documents:

VS2.5 Troubleshooting Manual
Issue 4.0 2012-12-01 Page xiii
• Click on blue text (hyperlinks) to jump to a related section, or to get additional information
(e.g., view a term’s definition).
• To search a document to find keywords, use Find in Acrobat Reader’s Edit menu.
• To quickly find a specific section, click the section in the PDF file’s Bookmarks list.
When using printed documents:
• To find a specific term, go to the List of Terms section near the end of the manual.

VS2.5 Troubleshooting Manual
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About safety
All Nautel transmitters are designed to meet the requirements of EN60215, Safety Requirements for
Radio Transmitters.
The philosophy of EN60215 is that the removal of any cover or panel that can only be opened using
a tool is a maintenance activity, and that any person performing a maintenance activity is expected to
be trained for that activity. Under EN60215, it is assumed that trained personnel will be
knowledgeable and will take precautions such as removing all power to the transmitter before
accessing its components.
Electrical hazards
To remove power from the transmitter, switch off and lock out the ac power.
DANGER - HIGH VOLTAGE
Indicates dangerous voltage (in excess of 72 volts), capable of causing a fatal
electrical shock, are present on or near parts bearing this label.
After turning off the ac power, always perform a measurement to confirm that the power is off
before touching anything within the transmitter. If the wrong breaker was opened, the equipment will
be live.
Use only a non-contact voltage probe or a safety voltmeter (available from vendors such as Fluke,
Ideal, and Teagam).
Use a proper lockout procedure to ensure that another worker cannot accidentally reapply power
while you are performing maintenance on any part of the transmitter or site.
WARNING: It is not enough to switch off RF power. The power line is
still connected. Disconnect and lock out the upstream supply before
servicing.
WARNING: Do not use an ordinary multimeter to check for voltage,
since it may have been left inadvertently on the AMP (A) range,
triggering a short and an arc blast that could result in severe burns
and even death.

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Lightning hazards
Before opening the transmitter and touching internal parts, remove and solidly ground the antenna
connection.
RF hazards
A serious RF hazard and very high voltages exist in the vicinity of the antenna and its networks
during normal operations.
Toxic hazards
Some devices used in this equipment contain beryllium oxide ceramic, which is non-hazardous during
normal device operation and under normal device failure conditions. These devices are specifically
identified with “(BeO)” in the Description column of the Troubleshooting Manual’s parts list(s).
Do not cut, crush or grind devices because the resulting dust may be hazardous if inhaled.
Unserviceable devices should be disposed of as harmful waste.
Physical hazards
DANGER - MOVING BLADES
Fan blades can cause injury. Lock out power before removing safety features.
Other hazards
Ensure that appropriate fire alarms and fire extinguishers are available. Extinguishers must be suitable
for use on electrical fires.
Many other site safety risks exist. It is beyond the scope of this manual to identify all the risks and
procedures.
WARNING: It is not enough to ground the antenna terminal with the
antenna still connected. Even a small impedance in the ground strap
will result in lethal voltages during a lightning strike.

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Issue 4.0 2012-12-01 Page xvii
Safety precautions
This section provides very important information about protecting the safety of personnel and
equipment:
• Personal safety - see page xvii
• Site safety - see page xviii
• Equipment safety - see page xx
Personal safety
Training
The training of any personnel who will have physical access to the site or the transmitter is very
important. Personnel must be familiar with the transmitter, so that they can avoid physical danger,
and be aware of hazards to themselves and the equipment.
Nautel offers a number of training courses covering the basic fundamentals of RF systems and
transmitters, and the operation and maintenance of the transmitter. For more information about
available courses and schedules, go to the Nautel website at http://www.nautel.com/Training.aspx,
or ask your Nautel sales representative.
Site orientation
When you give personnel access to the transmitter site (e.g., hiring new personnel, or giving access
keys to personnel), perform a site orientation to ensure that they are familiar with the site, on-site
procedures, and on-site hazards. Cover the following topics:
• Securing the site (locking doors and fences) to prevent unauthorized access
• How and when to call for technical support or emergency assistance
• Areas of the site and pieces of equipment that are off limits

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Voltage awareness
Ensure that all personnel that are able to access areas with high voltage circuits or high field strengths
are aware of the hazards associated with high voltage. Cover the following topics:
• High voltage or high field strength areas where caution is required
• Physical risks of electric shock
• Risks for personnel with pacemakers or other medical implants
• Induced voltages in high field strength areas
• On-site risks during thunderstorms and lightning strikes
• Operation of safety interlocks (if installed)
First aid
Nautel does not offer first aid training, since the hazards associated with high voltage and RF energy
are not specific to the transmitter. However, the customer should provide first aid training to all per-
sonnel who have access to the transmitter site. First aid training should include CPR, care of burns,
artificial respiration, and defibrillation if specific equipment is available on-site.
Site safety
Controlling access
Transmitters and antennas generate and carry dangerous voltages that can be harmful or fatal. It is
very important that you control access to the site and its equipment. To secure your transmitter site,
use:
• Locking steel or security doors to prevent casual access
• A perimeter fence to keep trespassers away from the antenna system and feedline
• “No Trespassing” signs
• An alarm system

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Marking hazards
Place warning signs close to any hazardous areas or systems (e.g., the feedline or the antenna system).
Make the signs large enough that they cannot be missed. Provide signage in all languages used in the
region. These signs are intended not only for authorized personnel, but also for emergency
responders or accidental trespassers.
Qualifying site personnel
Make sure that personnel who have access to the site are qualified to work around electronics and
high voltage systems.
Ac power protection
You should take steps to protect equipment from surges (over-voltage spikes) on the ac power lines.
Surges may occur during thunderstorms, or because of malfunctions in the electrical distribution grid.
Surge suppressors and ac power conditioners can prevent serious damage to your on-site equipment,
including the transmitter.
RF protection
Transmitters and their antenna systems create intense radio frequency fields at the transmitter site,
particularly near the feedline, antenna and tower. At some sites, these fields may cause biological
effects, including the heating of body tissues. Intense fields can also create dangerous high voltages
on ungrounded, conductive surfaces and objects. At certain points where high voltage conductors
come close to grounded conductors (e.g., at feedline junctions or on the tower), dangerous electrical
arcing or flashovers can occur. It is very important that you take the following steps to prevent
damage to equipment or personnel due to RF fields:
• Use safety interlocks to de-energize transmitters if personnel open doors or panels accessing
high field areas
• Place warning signs in any locations where high fields can occur
• Train personnel about the short-term and long-term hazards of RF radiation
• Physically block access to the area around the antenna system, feedline and tower
• Ground all exposed conductive surfaces or objects in high field areas
The RF connection to the transmitter output can be a serious safety hazard. Connect a 50 Ωtest load
during installation and commissioning. It is recommended that a switch be used to automatically
connect the transmitter to the antenna system without human contact with the transmitting
conductors.

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Safety interlocks
The transmitter contains an electrical interlock, which is an external circuit that turns off the RF
output if any of its switches are opened.
Equipment safety
Electrostatic protection
The transmitter’s systems are very rugged and resistant to damage. However, it is possible for damage
to occur because of high voltage electrostatic discharges during servicing. Train all service personnel
to ground themselves to bleed off any static charge before opening the transmitter or touching any
exposed components. Provide a grounding wand or known ground (e.g., a grounded metal table) that
personnel can use to discharge themselves.
Surge protection
Surge protection is recommended for your entire site. However, even if you do not use a surge
protector on the service entrance to the site, you should install a surge protector in the transmitter’s
ac power feed to prevent over-voltage from entering the transmitter.
Lightning protection
The transmitter is designed to resist lightning strike damage. However, intense or repeated strikes
could damage the transmitter. We recommend that you install lightning suppression on the antenna,
tower and feedline to reduce the effect of lightning strikes on the transmitter itself (and to protect the
rest of your site equipment and your personnel). For detailed information about lightning protection,
see the Nautel Site Preparation Manual, available from your Nautel sales agent, or online from the
Nautel website.
Physical protection
Consider physical hazards to equipment at your site, including the transmitter. Ensure that equipment
is protected from weather (e.g., rain or flooding), even during extreme weather events. Place
equipment so that it is not in the path of swinging doors or high-traffic areas. Do not allow wheeled
items like office chairs or tables with wheels in the transmitter room, as these may damage equipment
if accidentally pushed or knocked over. Do not place the transmitter under water pipes, drains, or
sprinklers. Keep any equipment that generates heat, like the transmitter, away from flammable
materials like ceiling panels, cubicle dividers, and curtains.