UBS Axcera 6U4AD 5000-Watt UHF Digital Transmitter User Manual Instruction manual

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Instruction Manual
6X Series,
Liquid-Cooled
Transmitter
Axcera, LLC
103 Freedom Drive, P.O. Box 525 Lawrence, PA 15055-0525 USA
PHONE: 1-724-873-8100 • FAX 1-724-873-8105
www.axcera.com • info@axcera.com
RESTRICTIONS ON USE, DUPLICATION OR DISCLOSURE
OF PROPRIETARY INFORMATION
This document contains information proprietary to Axcera, to its affiliates or to a third party to which Axcera
may have a legal obligation to protect such information from unauthorized disclosure, use or duplication. Any
disclosure, use or duplication of this document or any of the information herein for other than the specific
purpose for which it was disclosed by Axcera is expressly prohibited, except as Axcera may otherwise agree in
writing. Recipient by accepting this document agrees to the above stated conditional use of this document and
this information disclosed herein.
Copyright © 2009, Axcera
6X Series Liquid-Cooled Transmitter
Table of Contents
Table of Contents
Instruction Manual, Rev. 0
October 14, 2009
6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction
CHAPTER 1 ........................................................................................................ 3
1.1
1.2
1.3
1.4
1.5
1.6
Manual Overview ..........................................................................................3
Assembly Designators ...................................................................................3
Safety .........................................................................................................3
Contact Information ......................................................................................4
Material Return Procedure..............................................................................5
Limited One-Year Warranty for Axcera Products................................................5
CHAPTER 2 ........................................................................................................ 1
2.1:
2.2:
2.3:
2.4:
2.5:
2.6:
2.7:
2.8:
2.9:
Digital Modulator .........................................................................................1
Exciter, Upconverter, Driver Tray...................................................................3
Power Amplifiers..........................................................................................4
Combiners ..................................................................................................4
Liquid Cooling System ..................................................................................4
Protection Circuits........................................................................................5
GUI and Problem Identification System ..........................................................5
Local Control & Monitoring ............................................................................6
Remote Control & Monitoring ........................................................................6
CHAPTER 3 ........................................................................................................ 1
3.1: Unpacking and Installation of the Cabinets......................................................2
3.2: Unpacking and Installation of the RF System and Cooling System ......................2
3.2.1: Ethylene Glycol/Distilled Water Cooling System ..........................................4
3.2.1.1: Initial Filling the Water Cooled System ................................................4
3.3: Main AC Connections....................................................................................5
3.4: Main AC Power Up and Verification.................................................................5
3.5: Initial Turn-On Procedures ............................................................................6
3.6: Setup and Operation Procedures....................................................................6
3.6.1: Axciter Set Up Overview ..........................................................................6
3.6.2: Transmitter Set Up Procedures .................................................................7
3.6.2.1: Initial Test Set Up.............................................................................7
3.6.2.2: Setting Up the Output Power of the Transmitter ...................................7
3.6.2.3: Setting up of AGC 1 ..........................................................................7
3.6.2.4: Setting up of AGC 2 ..........................................................................8
3.6.2.5: Setting up of Overdrive Threshold ......................................................8
3.6.2.6: Axciter Pre and Post Filter Sample Values ............................................8
3.6.2.7: Exciter Driver Adjustment..................................................................8
3.7: Problem Identification ..................................................................................9
3.7.1: Pump Rack Cabinet Assembly...................................................................9
3.8: 6X PLC pump rack control software .............................................................. 10
3.8.1: Functions............................................................................................. 10
CHAPTER 4 ........................................................................................................ 1
4.1 Exciter, Upconverter, Driver Tray Boards .........................................................1
4.1.1 Frequency Agile Upconverter Board (1309695) ............................................1
4.1.2 Downconverter Board (1311103) ...............................................................1
4.1.3 Button Board (1311306) ...........................................................................2
4.1.4 Pre-Driver Amplifier Board, Exciter, 6X (1313190) .......................................2
4.2 Power Controller/AC Distribution Assembly, Boards ...........................................3
4.2.1 Button Board (1311306) ...........................................................................3
4.2.2 Power Supply Line Monitoring Board (1311312) ...........................................3
4.2.3 Power Supply Control Board (1312059) ......................................................3
4.3: Power Amplifier Tray, Boards ........................................................................3
4.3.1 (A1) Fan Power Supply Board (1312004) ....................................................3
Instruction Manual, Rev. 0
1-1
6X Series Liquid-Cooled Transmitter
4.3.2
4.3.1
4.3.2
4.3.3
4.3.4
4.3.5
4.3.6
4.3.7
4.3.8
Chapter 1, Introduction
Front Panel Smart Button Board (1310349).................................................4
(A2) Phase/Gain Board (1312011) .............................................................4
(A8) Interface Board (1312562) ................................................................6
(A5) 4 Way Splitter Board, Top (1312033) ..................................................6
(A6) 4 Way Splitter Board, Bottom (1310448) .............................................6
(A7 & A9-A16) 878 Amplifier Pallets, Digital Bias (1310321) .........................7
(A17) 4 Way Combiner Board, Top (1310305) .............................................8
(A18) 4 Way Combiner Board, Bottom (1310308) ........................................8
(A19) Power Combiner (1312281)..............................................................9
CHAPTER 5: ....................................................................................................... 1
5.1: Maintenance ...............................................................................................1
5.1.1: Exciter/Amplifier Assembly ......................................................................1
5.1.2: Ethylene Glycol/Distilled Water Cooling System ..........................................1
5.1.2.1: Flushing and cleaning of the strainers .................................................1
5.1.2.2: Checking the glycol concentration level and PH value ............................2
5.1.2.3: Checking and cleaning the Heat Exchanger and back up Pump ...............3
5.2: 6X Transmitter Normal Inspection and Maintenance Schedule ...........................3
APPENDIX A ...................................................................................................... 6
6X DRAWINGS................................................................................................... 6
APPENDIX B ...................................................................................................... 6
TRANSMITTER SPECIFICATIONS ....................................................................... 6
Instruction Manual, Rev. 0
1-2
6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction
Chapter 1
Introduction
1.1 Manual Overview
This instruction manual is divided into five chapters and supporting appendices. Chapter
1, Introduction, contains information on safety, material return procedures, and
warranties. Chapter 2, System Description, contains the system and assembly
descriptions. Chapter 3, Installation and Set Up Procedures, describes the installation
procedure, set up procedure and the operation of the transmitter. Chapter 4, Circuit
Descriptions, contains the detailed circuit descriptions of the boards and subassemblies
that are contained in the transmitter. Chapter 5, Maintenance, describes the periodic
maintenance procedures for the transmitter. Appendix A contains the System,
Assemblies, Subassemblies and Boards drawings and parts lists.
1.2 Assembly Designators
Axcera has assigned assembly numbers, Ax designations, where x=1,2,3 etc, example A1,
to all assemblies, modules, and boards in the system. These designations are referenced
in the text of this manual and shown on the block diagrams and interconnect drawings
provided in the appendices. The Block Diagrams, Interconnects, Schematics, Assembly
Drawings and Parts Lists are arranged in increasing numerical order in the appendices.
Section titles in the text for assembly or module descriptions or alignment procedures
contain the associated part number(s) and the relevant appendix that contains the
drawings for that item.
The cables that connect between the boards within a tray or assembly and that connect
between the trays, racks and cabinets are labeled using markers. Figure 1-1 is an
example of a marked cable. There may be as few as two or as many as four Markers on
any one cable. These markers are read starting farthest from the connector. If there
are four Markers, the marker farthest from the connector is the system number such as
system 1 or translator 2. The next or the farthest Marker is the rack or cabinet “A”
number on an interconnect cable or the board “A” number when the cable is within a
tray. The next number on an interconnect cable is the Tray location or Board “A”
number. The marker closest to the connector is the jack or connector “J” number on an
interconnect cable or the jack or connector “J” number on the board when the cable is
within a tray.
Figure 1-1: Marker Identification
1.3 Safety
It is important that any user of this equipment read all of the instructions, especially the
safety information in this chapter, before operating the transmitter. Products
manufactured by Axcera are designed to be easy to use and repair while providing
protection from electrical and mechanical hazards. Listed throughout the manual are
notes, cautions, and warnings concerning possible safety hazards that may be
encountered while operating or servicing the product. Please review these warnings and
Instruction Manual, Rev. 0
1-3
6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction
familiarize yourself with the operation and servicing procedures before working on the
product.
Hazardous Accessibility – Axcera has made attempts to provide appropriate
connectors, wiring and shields to minimize hazardous accessibility.
Circuit Breakers and Wiring – All circuit breakers and wire are UL and CE certified and
are rated for maximum operating conditions.
Single Point Breaker or Disconnect - The customer should provide a single point
breaker or disconnect at the breaker box for the main AC input connection to the
transmitter.
Transmitter Ratings - The transmitter ratings are provided in the text of this manual
along with voltage and current values for the equipment.
Protective Earthing Terminal – A main protective earthing terminal is provided for
equipment required to have protective earthing.
Read All Instructions – All of the operating and safety instructions should be read and
understood before operating this equipment.
Retain Manuals – The manuals for the equipment should be retained at the site in which
the equipment is operating for future reference. We provide two manuals for this purpose;
one manual can be left at the office while the other manual can be kept at the site.
Heed all Notes, Warnings, and Cautions – All of the notes, warnings, and cautions
listed in this safety section and throughout the manual must be followed.
Follow Instructions – All of the operating and use instructions for the product should be
followed.
Cleaning – Unplug or otherwise disconnect all power from the equipment before cleaning.
Do not use liquid or aerosol cleaners. Use a damp cloth for cleaning.
Ventilation – Openings in the cabinet and module front panels are provided for
ventilation. To ensure the reliable operation of the transmitter, and to protect the unit
from overheating, these openings must not be blocked.
Servicing – Do not attempt to service this product yourself until becoming familiar with
the equipment. If in doubt, refer all servicing questions to qualified Axcera service
personnel.
Replacement Parts – When replacement parts are needed, be sure that the parts have
the same functional and performance characteristics as the original part. Unauthorized
substitutions may result in fire, electric shock, or other hazards. Please contact the
Axcera Technical Service Department if you have any questions regarding service or
replacement parts.
1.4 Contact Information
The Axcera Field Service Department can be contacted by phone at 1-724-873-8100 or
by fax at 1-724-873-8105.
Instruction Manual, Rev. 0
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6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction
Before calling Axcera, please be prepared to supply the Axcera technician with answers to
the following questions. This will save time and help insure the most direct resolution to
the problem.
1.
2.
3.
4.
What are the Customers’ Name and call letters?
What are the model number and type of transmitter?
Is the transmitter digital or analog?
How long has the transmitter been on the air? (Approximately, when was the
transmitter installed?)
5. What are the symptoms being exhibited by the transmitter? Include the current LCD
and/or touch screen readings. Also the status of LEDs on the front panels of the
trays or modules. If possible, include the LED, LCD and/or touch screen readings
before the problem occurred.
1.5 Material Return Procedure
To insure the efficient handling of equipment or components that have been returned for
repair, Axcera requests that each returned item be accompanied by a Return Material
Authorization Number (RMA#). The RMA# can be obtained from any Axcera Service
Engineer by contacting the Axcera Technical Service Department by Phone at 724-8738100 or by Fax at 724-873-8105. This procedure applies to all items sent to the
Technical Service Department regardless of whether the item was originally
manufactured by Axcera.
When equipment is sent to the field on loan, the RMA# is included with the unit. The
RMA# is intended to be used when the unit is returned to Axcera. In addition, all shipping
material should be retained for the return of the unit to Axcera. Replacement assemblies
are also sent with the RMA# to allow for the proper routing of the exchanged hardware.
Failure to close out this type of RMA# will normally result in the customer being invoiced
for the value of the loaner item or the exchange assembly.
When shipping an item to Axcera, please include the RMA# on the packing list and on the
Axcera-provided shipping container. The packing slip should also include contact
information and a brief description of why the unit is being returned.
Please forward all RMA items to:
Axcera
Customer Service Department
103 Freedom Drive
P.O. Box 525
Lawrence, PA 15055-0525 USA
For more information, concerning this procedure, call the Axcera Customer Service
Department.
Axcera can also be contacted through e-mail at service@axcera.com and on the Web at
www.axcera.com.
1.6 Limited One-Year Warranty for Axcera Products
Axcera warrants each new product that it has manufactured and sold against defects in
material and workmanship under normal use and service for a period of one (1) year
from the date of shipment from Axcera's plant, when operated in accordance with
Instruction Manual, Rev. 0
1-5
6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction
Axcera's operating instructions. This warranty shall not apply to tubes, fuses, batteries,
or bulbs.
Warranties are valid only when and if (a) Axcera receives prompt written notice of
breach within the period of warranty, (b) the defective product is properly packed and
returned by the buyer (transportation and insurance prepaid), and (c) Axcera
determines, in its sole judgment, that the product is defective and not subject to any
misuse, neglect, improper installation, negligence, accident, or (unless authorized in
writing by Axcera) repair or alteration. Axcera's exclusive liability for any personal
and/or property damage (including direct, consequential, or incidental) caused by the
breach of any or all warranties, shall be limited to the following: (a) repairing or
replacing (in Axcera's sole discretion) any defective parts free of charge (F.O.B. Axcera’s
plant) and/or (b) crediting (in Axcera's sole discretion) all or a portion of the purchase
price to the buyer.
Equipment furnished by Axcera, but not bearing its trade name, shall bear no warranties
other than the special hours-of-use or other warranties extended by or enforceable
against the manufacturer at the time of delivery to the buyer.
NO WARRANTIES, WHETHER STATUTORY, EXPRESSED, OR IMPLIED, AND NO
WARRANTIES OF MERCHANTABILITY, FITNESS FOR ANY PARTICULAR
PURPOSE, OR FREEDOM FROM INFRINGEMENT, OR THE LIKE, OTHER THAN AS
SPECIFIED IN PATENT LIABILITY ARTICLES, AND IN THIS ARTICLE, SHALL
APPLY TO THE EQUIPMENT FURNISHED HEREUNDER.
Instruction Manual, Rev. 0
1-6
6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction

 WARNING!!!
 HIGH VOLTAGE 
DO NOT ATTEMPT TO REPAIR OR TROUBLESHOOT THIS EQUIPMENT UNLESS
YOU ARE FAMILIAR WITH ITS OPERATION AND EXPERIENCED IN
SERVICING HIGH VOLTAGE EQUIPMENT. LETHAL VOLTAGES ARE PRESENT
WHEN POWER IS APPLIED TO THIS SYSTEM. IF POSSIBLE, TURN OFF
POWER BEFORE MAKING ADJUSTMENTS TO THE SYSTEM.
 RADIO FREQUENCY RADIATION HAZARD 
MICROWAVE, RF AMPLIFIERS AND TUBES GENERATE HAZARDOUS RF
RADIATION THAT CAN CAUSE SEVERE INJURY INCLUDING CATARACTS,
WHICH CAN RESULT IN BLINDNESS. SOME CARDIAC PACEMAKERS MAY BE
AFFECTED BY THE RF ENERGY EMITTED BY RF AND MICROWAVE
AMPLIFIERS. NEVER OPERATE THE TRANSMITTER SYSTEM WITHOUT A
PROPERLY MATCHED RF ENERGY ABSORBING LOAD ATTACHED.
KEEP
PERSONNEL AWAY FROM OPEN WAVEGUIDES AND ANTENNAS. NEVER
LOOK INTO AN OPEN WAVEGUIDE OR ANTENNA. MONITOR ALL PARTS OF
THE RF SYSTEM FOR RADIATION LEAKAGE AT REGULAR INTERVALS.
Instruction Manual, Rev. 0
1-7
6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction
EMERGENCY FIRST AID INSTRUCTIONS
Personnel engaged in the installation, operation, or maintenance of this equipment are urged to become
familiar with the following rules both in theory and practice. It is the duty of all operating personnel to be
prepared to give adequate Emergency First Aid and thereby prevent avoidable loss of life.
RESCUE BREATHING
1. Find out if the person is
breathing.
You must find out if the person
has stopped breathing. If you
think he is not breathing, place
him flat on his back. Put your ear
close to his mouth and look at his
chest. If he is breathing you can
feel the air on your cheek. You
can see his chest move up and
down. If you do not feel the air
or see the chest move, he is not
breathing.
2. If he is not breathing, open
the airway by tilting his head
backwards.
Lift up his neck with one hand
and push down on his forehead
with the other. This opens the
airway. Sometimes doing this will
let the person breathe again by
himself.
3. If he is still not breathing,
begin rescue breathing.
-Keep his head tilted backward.
Pinch nose shut.
-Put your mouth tightly over his
mouth.
-Blow into his mouth once every
five seconds
-DO NOT STOP rescue breathing
until help arrives.
LOOSEN
WARM
CLOTHING
KEEP
Do this when the victim is
breathing by himself or help is
available. Keep him as quiet as
possible and from becoming
chilled. Otherwise treat him for
shock.
BURNS
SKIN REDDENED: Apply ice cold water to burned
area to prevent burn from going deeper into skin
tissue. Cover area with a clean sheet or cloth to
keep away air. Consult a physician.
SKIN BLISTERED OR FLESH CHARRED: Apply
ice cold water to burned area to prevent burn from
going deeper into skin tissue.
Instruction Manual, Rev. 0
Cover area with clean sheet or cloth to keep away
air. Treat victim for shock and take to hospital.
EXTENSIVE BURN - SKIN BROKEN: Cover area
with clean sheet or cloth to keep away air. Treat
victim for shock and take to hospital.
1-8
6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction
dBm, dBw, dBmV, dBµ
µV, & VOLTAGE
EXPRESSED IN WATTS
50 Ohm System
WATTS
1,000,000,000,000
100,000,000,000
10,000,000,000
1,000,000,000
100,000,000
10,000,000
1,000,000
100,000
10,000
1,000
100
50
20
10
0.1
0.01
0.001
0.0001
0.00001
0.000001
0.0000001
0.00000001
0.000000001
0.0000000001
0.00000000001
0.000000000001
PREFIX
1 TERAWATT
100 GIGAWATTS
10 GIGAWATTS
1 GIGAWATT
100 MEGAWATTS
10 MEGAWATTS
1 MEGAWATT
100 KILOWATTS
10 KILOWATTS
1 KILOWATT
1 HECTROWATT
1 DECAWATT
1 WATT
1 DECIWATT
1 CENTIWATT
1 MILLIWATT
100 MICROWATTS
10 MICROWATTS
1 MICROWATT
100 NANOWATTS
10 NANOWATTS
1 NANOWATT
100 PICOWATTS
10 PICOWATTS
1 PICOWATT
dBm
+150
+140
+130
+120
+110
+100
+ 90
+ 80
+ 70
+ 60
+ 50
+ 47
+ 43
+ 40
+ 30
+ 20
+ 10
- 10
- 20
- 30
- 40
- 50
- 60
- 70
- 80
- 90
dBw
+120
+110
+100
+ 99
+ 80
+ 70
+ 60
+ 50
+ 40
+ 30
+ 20
+ 17
+ 13
+ 10
- 10
- 20
- 30
- 40
- 50
- 60
- 70
- 80
- 90
-100
-110
-120
dBmV
dBµV
VOLTAGE
+137
+127
+117
+107
7.07V
2.24V
0.707V
224mV
TEMPERATURE CONVERSION
°F = 32 + [(9/5) °C]
°C = [(5/9) (°°F - 32)]
Instruction Manual, Rev. 0
1-9
77
67
57
47
6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction
USEFUL CONVERSION FACTORS
To Convert From
To
Multiply By
mile (US statute)
kilometer (km)
inch (in)
millimeter (mm)
inch (in)
centimeter (cm)
inch (in)
meter (m)
foot (ft)
meter (m)
yard (yd)
meter (m)
mile per hour (mph)
kilometer per hour(km/hr)
mile per hour (mph)
meter per second (m/s)
pound (lb)
kilogram (kg)
gallon (gal)
liter
U.S. liquid
(One U.S. gallon equals 0.8327 Canadian gallon)
fluid ounce (fl oz)
milliliters (ml)
British Thermal Unit
watt (W)
horsepower (hp)
watt (W)
1.609347
25.4
2.54
0.0254
0.3048
0.9144
1.60934
0.44704
0.4535924
3.7854118
29.57353
0.2930711
per hour (Btu/hr)
746
NOMENCLATURE OF FREQUENCY BANDS
Frequency Range
Designation
3 to 30 kHz
30 to 300 kHz
300 to 3000 kHz
3 to 30 MHz
30 to 300 MHz
300 to 3000 MHz
3 to 30 GHz
30 to 300 GHz
VLF
LF
MF
HF
VHF
UHF
SHF
EHF
Very Low Frequency
Low Frequency
Medium Frequency
High Frequency
Very High Frequency
Ultra High Frequency
Super High Frequency
Extremely High Frequency
LETTER DESIGNATIONS FOR UPPER FREQUENCY BANDS
Letter
Freq. Band
Ku
Ka
Instruction Manual, Rev. 0
1000 - 2000 MHz
2000 - 4000 MHz
4000 - 8000 MHz
8000 - 12000 MHz
12 - 18 GHz
18 - 27 GHz
27 - 40 GHz
40 - 75 GHz
75 - 110 GHz
1-10
6X Series Liquid-Cooled Transmitter
Chapter 1, Introduction
ABBREVIATIONS/ACRONYMS
AC
Alternating Current
FCC
Federal Communications
Commission
AFC
Automatic Frequency
Control
FEC
Forward Error Correction
AGC
Automatic Gain Control
FM
Frequency modulation
ALC
Automatic Level Control
FPGA
Field Programmable Gate
Array
AM
Amplitude modulation
HXB
High Power Transmitter, B-line
ASI
Asynchronous Digital Interface
Hz
Hertz
ATSC
Advanced Television
Systems Committee (Digital)
ICPM
Incidental Carrier Phase
Modulation
I/P
Input
IF
Intermediate Frequency
LED
Light emitting diode
LSB
Lower Sideband
AWG
American wire gauge
BER
Bit Error Rate
BW
Bandwidth
CE
Product has met EU consumer
safety, health or environmental
requirements.
COFDM Coded Orthogonal Frequency
Division Multiplexing modulation
scheme
DC
Direct Current
D/A
Digital to analog
DSP
Digital Signal Processing
DTV
Digital Television
DVB
Digital Video Broadcasting
dB
Decibel
dBm
Decibel referenced to
1 milliwatt
dBmV
Decibel referenced to
1 millivolt
dBw
Decibel referenced to 1 watt
Instruction Manual, Rev. 0
LDMOS Lateral Diffused Metal Oxide
Semiconductor Field Effect
Transistor
MPEG
Motion Pictures Expert
Group
NTSC
National Television
Systems Committee (Analog)
O/P
Output
PLL
Phase Locked Loop
PCB
Printed circuit board
QAM
Quadrature Amplitude
Modulation
SMPTE Society of Motion Picture
and Television Engineers
SNMP
Simple Network Management
Protocol
VSB
Vestigial Side Band
1-11
6X Series Liquid-Cooled Transmitter
Chapter 2, System Description
Chapter 2
System Description
The 6X Series Liquid-Cooled Transmitter is made up of a frequency agile exciter and
a multi tray power amplifier system. The 6X Series is a state-of-the-art liquid cooled
transmitter which uses our frequency agile exciter and the latest LDMOS devices for
broadband operation across the entire UHF band. The power amplifier system
operates at the highest power density available, reducing floor space requirements.
The 6X Series transmitter is available in power levels up to 40kW ATSC in a very
small footprint.
The very compact and completely modular design uses parallel amplifier and power
supply modules which can be removed and replaced while the transmitter is on the
air. This allows users to minimize spare parts stock and also enables simple and
inexpensive channel changes. Additionally, the modular construction provides a
clear upgrade path, allowing broadcasters to begin with a low power transmitter and
add modules and combiners to achieve any power level desired.
2.1: Digital Modulator
The Axciter adaptive digital television modulator utilizes a patented VSB modulation
technique, which makes it possible to generate a virtually perfect 8VSB IF signal.
Since the Axciter is a completely reprogrammable digital television exciter, it can be
easily upgraded in the field with new software versions through the convenient front
panel USB port. Critical parameters can be set and queried directly on the color LCD
screen or through an interface to a personal computer.
The DSP circuitry also handles frequency offsets allowing an unlimited number of
user selectable offsets. In addition, asynchronous resampling techniques
Instruction Manual, Rev. 0
2-1
6X Series Liquid-Cooled Transmitter
Chapter 2, System Description
compensate for errors in the SMPTE-310M input sample rate, ensuring the best
possible signal generation.
Non-volatile operation is achieved through flash-RAM (random access memory),
which instantaneously stores all digital settings for the entire exciter-modulator
system. This ensures that in case of power loss, the system will return to the
previously selected settings when power is restored, saving time by eliminating the
need to re-enter operating parameters.
Standard with all Axciters, Axcera Adaptive Correction Technology (AXACT™)
provides dynamic digital pre-correction that automatically tracks and corrects for
distortions, both linear and non-linear, in the complete transmitter system. All
adaptive operations are performed in the high-speed processor, which is capable of
equalizing a complete transmitter system in just sixty seconds, and completing a full
system optimization in about two minutes.
To obtain the necessary data, AXACT continuously samples the transmitter system
output, both before and after the mask filter, this is done through a down converter
located in the upconverter/driver tray. The modulator processes the data and the
necessary digital pre-correction is applied to the modulator output signal, resulting in
consistent transmitter system performance, independent of environmental changes.
The Axciter also performs over fifteen safety tests upon each adaptive correction run
to confirm that the new correction values are appropriate before applying them to
the on-air signal. This ensures that the signal will not be negatively affected by a
failure of an RF component in the sample path, such as an RF coupler, connector,
relay or cable.
DTVision Digital Signal Analysis and Test System is available as an option to the
Axciter. This system samples the transmitter output and measures critical
transmitter performance parameters. The information is then displayed in highresolution graphical format on the modulator's front panel display. Available
performance parameters include, digital SNR, error vector magnitude (EVM), eye
diagram, graphs of adaptive equalizer performance and RF spectrum, constellation
diagram, and more.
The Axciter employs dual processors to ensure on-air reliability. The low-level
control computer is a simple, highly reliable processor that is dedicated to running
the modulator hardware, thereby generating the ATSC signal. This processor uses a
highly reliable real-time operating system based on uC/OS for the mission critical
8VSB signal generation.
A second computer is dedicated to providing the adaptive processing, user interface,
diagnostics and graphics, using the very stable and reliable Linux operating system.
This high performance computer handles the processor intensive functions of
performing all adaptive correction and processing the data for the optional DTVision
signal analysis measurement and display, all without negatively affecting the critical
on-air signal path. In the unlikely event of a failure of this computer, the Axciter
remains on the air with a fully corrected ATSC signal. The Linux computer may even
be rebooted with no interruption of the on-air signal, and the Axciter is capable of a
cold start without the Linux computer.
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6X Series Liquid-Cooled Transmitter
Chapter 2, System Description
All ATSC Axciters are field upgradeable to new operating modes, such as ATSC M/H
Mobile DTV, DTx slave, Watermark, or other yet to be adopted ATSC enhancements.
A dual exciter system is an option for the 6X transmitter.
2.2: Exciter, Upconverter, Driver Tray
The exciter, upconverter, driver tray accepts the digital IF from the Axciter
modulator tray and converts it to any UHF channel using a very low phase noise
dual-conversion synthesized oscillator that is fully compliant with ATSC
recommendations. The output channel is easily selected through the front panel of
the system controller for a truly frequency agile exciter/driver chassis.
The Exciter, Upconverter, Driver Tray (1312871) contains a Frequency Agile
Upconverter Board (1309695), an Exciter Controller Board (1312413), a
Downconverter Board (1311103), Pre-Driver Exciter Assembly, 6X (1313190), and a
Button Board (1311306).
The 44 MHz digital IF input to the exciter, upconverter, driver tray connects through
the IF input jack located on the rear panel to the Frequency Agile Upconverter board.
The IF is converted to a second IF of 1044 MHz by an image rejection mixer mounted
on the Frequency Agile Upconverter board. A filter selects the appropriate
conversion product, which is then amplified to a level of approximately –8 dBm. The
1 GHz local oscillator (LO) frequency is generated on the board and is applied to a
high pass and low pass filter designed to eliminate any other interfering signals that
might be coupled into the 1 GHz LO. The LO is connected to an ALC circuit that
maintains the LO level to each mixer of +13 dBm over a wide range of 1 GHz LO
input levels. The LO sample is also sent to the Downconverter board.
This second IF signal is then applied to a second mixer mounted on the Frequency
Agile Upconverter board that downconverts it to a broadcast channel (2-69) by a LO
that operates in 1.0 MHz steps between 1.1-1.9 GHz depending on the channel
selected. The LO frequency equals the Channel center frequency plus 1044 MHz.
(As an example CH: 14: Center Frequency is 473.00 MHz therefore the LO2 is 473 +
1044, which equals 1517.00 MHz.)
The output of the mixer is connected to a 900 MHz Low pass filter to remove
unwanted conversion products. The resulting signal is amplified and wired to a Pin
Diode Attenuator which adjusts the gain of the tray that is controlled by an
Automatic Gain Control circuit, which maintains a constant power out of the
upconverter, and also the transmitter. The gain controlled output of the pin diode
circuit is connected to the output of the Tray.
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6X Series Liquid-Cooled Transmitter
Chapter 2, System Description
2.3: Power Amplifiers
The Axcera 6X Series transmitter is comprised of highly reliable broadband amplifier
modules operating in a parallel configuration. Each module uses the latest LDMOS
transistors, providing very efficient and linear operation and the highest power
density available today. For convenience, each amplifier module operates
independently, allowing easy removal and replacement while the transmitter is on
the air. All power amplifier modules are interchangeable. The extensive correction
capability of Axcera's digital exciter allows all stages of the final amplifiers to operate
in the very efficient class AB mode, minimizing system power consumption.
The broadband amplifier design allows all modules to operate over the entire
operating band without any retuning, helping to minimize spare parts stock for
multiple station operators. This also provides for simplified channel changes,
requiring only replacement of channelized filters.
The fan power supply board and the amplifier pallets operate using +42 VDC from
the buss bar assembly through 30 Amp fuses. Two spare 30 Amp fuses are mounted
on the Fan Power Supply Board.
2.4: Combiners
Each Axcera 6X transmitter employs progressive combiners, to combine the power
amplifier modules. This design is very low loss, for optimal overall system efficiency,
and utilizes liquid-cooled reject loads to minimize size. The progressive combiner
design is very modular, allowing for systems to be configured for lower power levels
and easily upgraded with additional sections for future migration to higher power.
The combiner system is mounted in the rear of the amplifier cabinet, immediately
behind the amplifier modules and adjacent to the cooling plenum, minimizing
required cabling.
2.5: Liquid Cooling System
The liquid cooling system is made up of three primary systems:
1)
PA Cabinet Distribution – Cooling liquid is distributed equally to all power
amplifiers and power supplies within the power amplifier cabinet through a water
manifold located in the rear of the cabinet. Each amplifier module and power
supply plugs directly into the manifold through two drip-less blind-mate
connectors, one input and one output. This minimizes the plumbing required
within each power amplifier cabinet.
2)
Control and Pump Rack – This rack houses the cooling system controller, dual
pump system (n+1 configuration optional), cooling liquid reservoir, bleeder
valves, and debris filters. The control system monitors temperature in various
places throughout the transmitter system and maintains consistent
temperatures, independent of ambient temperature changes, in order to reduce
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6X Series Liquid-Cooled Transmitter
Chapter 2, System Description
stress on system components, maximizing component life. The control and
pump rack is typically mounted indoors, but is also available in an outdoor
version, if required.
3)
Fan and Heat Exchanger System – The heat exchanger is a very compact, highefficiency unit, manufactured by Gunter USA.
These primary cooling systems are interconnected using Gates Premo-Flex Hose, or
equivalent, and barbed hose fittings, providing high reliability while simplifying
installation and maintenance.
2.6: Protection Circuits
To ensure that the 6X Series transmitter will provide reliable service in challenging
environments, a high degree of protection is provided in each amplifier chassis,
including overdrive, VSWR and overtemperature protection.
Axcera's Intelligent VSWR Protection™ (IVP) is designed to recognize the cause of
VSWR and react appropriately in order to protect the entire transmission system
while ensuring minimal loss of signal coverage. IVP determines whether the high
VSWR is caused by a catastrophic problem like a transmission line arc, or if it is a
temporary problem such as antenna icing. In the catastrophic case a typical
transmitter may continue to produce power, resulting in expensive antenna,
transmission line or RF system repairs. But IVP is designed to quickly remove drive
to the final amplifier, avoiding further damage to the system components. For a
temporary VSWR condition like antenna icing, the system is designed to remain on
the air at a reduced power level until the VSWR returns to a normal level, ensuring
minimal coverage loss during the VSWR condition.
AGC around the system ensures that the transmitter output remains stable. An
output bandpass and trap filter is included to provide out of band rejection. This RF
network also adds lightning protection through the DC short circuit of the band pass
filter.
2.7: GUI and Problem Identification System
The GUI has a pre-set group of graphical screens that can be navigated by the
standard touch screen included in the system. These are somewhat auto-configuring
depending on what hardware is found in the system at any given point in time. The
GUI system allows the reading of all significant parameters of the transmitter. It
also enables and disables the transmitter, controls different modes the transmitter
can be placed, and enables or disables the remote control.
Most major components of the transmitter system have a button on the front panel.
This is a pushbutton with a three color LED mounted in it, Red, Blue and Green. The
standard operation of this button is that it stays blue whenever the system is
operating normally, which is all parameters are within acceptable limits. If a
problem occurs, the color changes to RED. When the button is pressed, that
subsystem is brought to the foreground on the controller touch screen, and if the
button was red when pushed, indicating a problem in that module, the touch screen
will show the details of the problem. Pushing these buttons will have no effect on
any operating mode of the transmitter, you can push them anytime and nothing will
change other than what parameters the GUI displays.
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6X Series Liquid-Cooled Transmitter
Chapter 2, System Description
The GUI also contains operation and help screens for the transmitter. Any touch
area on the screen that can affect the on-air operation of the transmitter is colored
RED, no matter what the function. You can touch anything, anywhere on the touch
screen without worry of its effect on the transmitter EXCEPT those that are Red.
Touching any Red function on the touch screen may have an effect on the on-air
status and performance of the transmitter.
2.8: Local Control & Monitoring
6X System Controller Tray
The 6X controller tray provides manual push buttons for Operate and Standby
control of the Transmitter. All local transmitter control and monitoring functions are
available through the front panel touch screen VGA display, mounted under the 6X
System Controller Tray. The LCD display provides a detailed look into the operation
of the transmitter system. Parameters such as forward and reflected power,
transistor currents, power supply voltages, module temperatures, system mode, and
much more can be viewed directly on the LCD display.
2.9: Remote Control & Monitoring
Systems can be remotely monitored and controlled through a Web browser or
available SNMP client. An Ethernet connection jack is provided on the front panel of
the 6X system controller tray.
The Web browser option allows real-time remote control of the transmitter system
from any Internet connection and a standard PC with a Web browser, such as
Microsoft Explorer.
Systems are available with a SNMP client, which have the ability to communicate
with higher-level network management systems that support simple network
management protocol, SNMP.
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6X Series Liquid-Cooled Transmitter
Chapter 3, Installation, Set Up and
Problem Identification Procedures
Chapter 3
Installation and Setup Procedures
As part of the installation of the 6X transmitter, it will be necessary to plan for mechanical,
electrical, and plumbing issues. It is a good idea to spend the time to review the site
drawing, the RF system requirements, the racking plan of the transmitter cabinets, the
plumbing diagram which includes the pump package, and the heat exchanger, before
installing this equipment. Site drawings should have been generated for the particular
transmitter and the site that it is to be installed that will help in the positioning of the
equipment.
6X Typical System Floor Plan
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Chapter 3, Installation, Set Up and
Problem Identification Procedures
3.1: Unpacking and Installation of the Cabinets
Locate the driver/amplifier cabinet, which contains the Axciter, exciter/driver, amplifier,
controller and power supply trays, the pump cabinet assembly and the heat exchanger.
Remove the driver/amplifier cabinet, the pump cabinet assembly, the heat exchanger and
any installation material from the crates and boxes. Remove the straps that hold the
cabinets to the shipping skids and slide the cabinets from the skids. Remove the plastic
wrap and foam protection from around the cabinets. Do not remove any labeling or tags
from any hoses, cables or connectors; these are identification markers that make
assembly of the transmitter system much easier. Open the rear door and carefully
remove any packing material. The Axciter, exciter/driver, controller and power supply
trays are mounted in the cabinet using Chassis Trak cabinet slides. Slowly slide each tray
in and out to verify that they do not rub against each other and have no restrictions to
free movement. Adjustments may be necessary. The adjustments are accomplished by
loosening the cabinet slide mounting bolts that hold the front of the slide to the mounting
frame of the cabinet and moving the tray up or down as needed. Inspect the trays for any
loose hardware or connectors, tightening where required. Open the rear door to the
cabinet and inspect the interior for packing material and carefully remove any material
that is found. The cabinet should be positioned with consideration for adequate ventilation
and access to the front of the exciter/amplifier cabinet for the installation and removal of
the trays and the opening of the rear door. Locate the pump cabinet assembly and the
heat exchanger and position according to the Site drawing. Refer to the 6X Typical
System Floor Plan drawing for an idea as to the installation of the transmitter.
3.2: Unpacking and Installation of the RF System and Cooling System
The RF System for your transmitter will vary in size and configuration, depending on the
frequency and manufacturer of the RF system. The RF System may be dropped shipped
directly to the site or included with the transmitter material. Locate and inventory the RF
System checking that all items are accounted for. The preparation and the actual
installation of the RF system may take a full week to complete, so allow time for the
installation. Install the RF System according to the floor plan drawings for your site.
The Cooling System for the transmitter will vary in size and configuration, depending on
the power rating of the transmitter and location of the heat exchanger and pump cabinet
assembly. The Exciter/Amplifier cabinet and heat exchanger each have two Hose Barb
Connectors, one for the input and one for the output of the water, to which the 1-1/4”
hoses connect. The pump rack has four Hose Barb connections, one to and one from the
heat exchanger and one to and one from the Transmitter. Refer to the 6X Water Cooling
System Block Diagram, the Pump Rack drawing, and heat exchanger drawing for the
connection locations. Connect the 1-1/4” hoses to the barb connectors and fix each
connection in place with a hose clamp.
NOTE: Use Gates Premo-Flex Hose or equivalent only. NOTE: Refer to the detailed
system drawings for the site into which the transmitter is to be installed for the exact
location of the exciter/amplifier cabinet, pump rack assembly, and heat exchanger.
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Chapter 3, Installation, Set Up and
Problem Identification Procedures
Water Input
Water Output
Water Input
Water Output
Water Input
Water Output
Block Diagram 6X Water System
Pump Rack
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Chapter 3, Installation, Set Up and
Problem Identification Procedures
6X Typical Cooling System Block Diagram
3.2.1: Ethylene Glycol/Distilled Water Cooling System
3.2.1.1: Initial Filling the Water Cooled System
A positive displacement pull must be used to fill and charge the coolant system.
During the filling process, check for leaks through-out the system.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Check and tighten all fittings.
Open all air vent valves
Locate the pressure gauge on the pump
Locate the fill port (GHT) and install hose.
Open the fill valve.
Operate the fill pump to a pre-charge of 30psi.
Turn off the fill pump and close the fill valve.
Apply main AC power to the pump rack.
Move the PLC mode switch to RUN.
Locate the Auto/Man switch and place in Man, the pumps will start.
Run the system for 3 to 5 minutes.
Place the Auto/Man switch to Auto, the pumps will turn off.
Repeat Steps 5 through 12 until the pressure gauge maintains 30psi.
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Chapter 3, Installation, Set Up and
Problem Identification Procedures
6X Typical Electrical System
3.3: Main AC Connections
The Electrician should install the Main AC and the control & monitoring conduit for
the transmitter site to meet all NEC regulations and also according to the electrical
system transmitter site drawing. Use conduit, in the size needed for running the
wires, as called out on the Electrical drawing for your site and as required by NEC
regulations.
NOTE: Site grounding is required as recommended by Axcera on the typical
electrical system drawing.
The AC feeds for a typical exciter/amplifier cabinet consist of two 50 Amp 480 VAC 3
wire three phase feeds that are connected to terminal blocks mounted in the cabinet.
Connect the 480 VAC 3 phase inputs to the exciter/amplifier cabinet. The pump
cabinet assembly requires a 20 Amp 480 VAC 3 phase feed. Connect the 480 VAC 3phase inputs to the terminal block mounted in the pump cabinet assembly.
3.4: Main AC Power Up and Verification
The Electrician must power up the 480 VAC 3 phase Distribution Panel circuit
breakers, the primary site power and also verify the operation of the surge
suppressor and voltage regulator, if present.
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Chapter 3, Installation, Set Up and
Problem Identification Procedures
3.5: Initial Turn-On Procedures
After the cabinets and the transmission lines have been connected, the system should
first be swept and fine matched through to the Station Load. Then the system should
be turned on using the following procedure. During the initial turn-on procedure the
system should be tested into a system test load and not the antenna. The transmitter
should be operated in this mode until initial testing is completed. After the initial turnon procedure is completed, the output of the transmitter can be connected to the
antenna for normal operation.
NOTE: Check that all installation has been completed before proceeding with the
initial turn-on of the transmitter.
Caution: Check that all circuit breakers on the exciter/amplifier, pump
cabinet assembly and heat exchanger have been turned off.
Check that the combined RF output of the RF system is terminated into a dummy load
with a rating of at least the rated output of the transmitter. Check that all hoses are
connected to the exciter/amplifier, pump cabinet assembly and heat exchanger.
Switch on the Main AC circuit to the system. Switch On the circuit breakers on the
exciter/amplifier, pump cabinet assembly and heat exchanger. Push the Operate
button on exciter/amplifier cabinet, which will indicate Amber until all systems are
operating normally. The automatic controls will purge the water system and check for
proper water flow throughout the system. When all systems are operating properly,
the Operate button will turn Green. Push the Green button to place the transmitter in
Operate. Warning: Do not operate the exciter/amplifier cabinet assembly with no
water flow through the system.
Connect a Digital test signal to the Input jack on the rear panel of the Axciter
Modulator Tray.
Slowly adjust the gain pot on the front panel of the Axciter to attain 100% output
power on the LCD display on the exciter/amplifier cabinet.
3.6: Setup and Operation Procedures
The exciter/driver was set up at the factory for normal operation and only
minor adjustments may be required.
3.6.1: Axciter Set Up Overview
It is one of the features of the Axciter that it has no internal adjustments that are
made on its circuitry. There is not even an adjustable pot, capacitor, or coil
anywhere on the boards. This is made possible through the use of almost entirely
digital electronics that are under software control. Even component aging should not
put the unit out of normal operation.
Several system parameters are adjusted through the user interface screens, such as
power output, AGC levels, etc. Mostly this is through commands sent from the
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Chapter 3, Installation, Set Up and
Problem Identification Procedures
Axciter to the upconverter. Proper setting of these parameters is system dependent,
and other systems manuals should be referenced for information on their setting.
3.6.2: Transmitter Set Up Procedures
3.6.2.1: Initial Test Set Up
This Exciter Digital transmitter was aligned at the factory and should not require
additional adjustments to achieve normal operation.
This section describes the set up of the Axciter Modulator system. The Axciter
Modulator takes the SMPTE 310 or optional ASI digital stream input and converts it to
a 44MHz intermediate frequency (IF). This IF then feeds the upconverter which
converts the signal to the desired On Channel RF Output. The signal then drives the
power amplifier section of the transmitter, which produces the system’s output power
level.
Check that the RF output at the DTV Mask Filter is terminated into a dummy load of at
least the rated output of the system or connected to the antenna for your system.
While performing the alignment, refer to the Test Data Sheet for the transmitter and
compare the final readings from the factory with the readings on each of the modules.
The readings should be very similar. If a reading is substantially different from the
factory reading, it is likely that there is a problem in that module that should be
rectified before proceeding with the transmitter setup.
Switch On the main AC for the system and the individual circuit breakers on the
cabinets and assemblies. Check that AC is present to all systems.
This transmitter operates using a SMPTE 310M or optional ASI input that connects to
J27 located on the rear panel of the Axciter Modulator Tray. Check that the input is
present. If an (Optional) external 10 MHz reference input from a GPS is used, check
that it is connected to J9 on the Axciter Modulator.
The check of and the setup of the drive levels are completed using the front panel
adjustments located on the Axciter Modulator Tray. The level of the RF output which
includes adjustment of the drive level of the Intermediate Power Amplifier and the
adjustment of the linearity and phase pre-distortion to compensate for any nonlinear
response of the Power Amplifiers are controlled within the Axciter Modulator Tray.
3.6.2.2: Setting Up the Output Power of the Transmitter
The following adjustments are completed using the LCD screen located on the front
panel of the Axciter Modulator Tray. On the Axciter Main Screen, push the button
next to the Upconverter tab on the right side of the screen. This will open the
Upconverter Main Screen. Set the AGC to Manual by selecting 3 on the keyboard
entry. The screen will now indicate AGC Manual. Set the transmitter to full power
using the front panel screen of the Axciter.
3.6.2.3: Setting up of AGC 1
To set up the AGC, first the AGC must be activated. Locate the 8 position DIP switch
SW1 mounted on the Control Board in the Exciter Driver Tray. The Upconverter DIP
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Chapter 3, Installation, Set Up and
Problem Identification Procedures
Switch Position 6 must be switched ON (0) which allows the user to modify the AGC
1 and AGC 2 gain through the Axciter Modulator.
On the Axciter Upconverter Screen, set AGC 1 to 1.5 Volts, by selecting 4 on the key
board entry. This will cause a detail screen to appear prompting you to enter a
number value. Monitor the AGC 1 Gain Value on the screen and increase or decrease
the value of the number entered until the monitored reading is 1.5 Volts.
3.6.2.4: Setting up of AGC 2
On the Axciter Upconverter Screen, set AGC 2 to 1.7 Volts, by selecting 5 on the
keyboard entry. This will cause a detail screen to appear prompting you to enter a
number value. Monitor the AGC 2 Gain Value on the screen and increase or decrease
the value of the number entered until the monitored reading is 1.7 Volts.
After the setting up of the AGC, the AGC must be de-activated to prevent accidental
changes. The Upconverter DIP Switch SW1 Position 6 must be switched OFF (1)
which locks the AGC 1 and AGC 2 gain.
3.6.2.5: Setting up of Overdrive Threshold
On the Axciter Upconverter Screen set the Overdrive Threshold to 1.6 Volts, by
selecting 7 on the keyboard entry. This will cause a detail screen to appear.
Increase or decrease the voltage as needed until the monitored reading is 1.6 Volts.
Place the Transmitter into AGC by pushing the 3 of the keyboard entry on the Axciter
Upconverter Screen. This will place the Transmitter AGC into Auto.
3.6.2.6: Axciter Pre and Post Filter Sample Values
Pre and Post RF samples are connected to the rear panel of the Exciter Driver tray.
These levels should be measured with a power meter before connecting them. Your
installation may require RF attenuators to be placed in line with the samples to get
them within the desired range.
J17 on the Exciter Driver Tray is the connection to the Forward power sample of
the coupler before the mask filter, Pre-Filter Sample.
The Level into the Relay at J1 or the Upconverter Tray at J17 should be 0 dBm to
–10 dBm, –5 dBm typical.
J16 on the Exciter Driver Tray is the connection to the Forward power sample
after the mask filter, Post-Filter Sample.
The Level into the Relay at J2 or the Upconverter Tray at J16 should be 0 dBm to –
10 dBm. –5 dBm typical, but within .5 dB of the Pre-Filter sample.
3.6.2.7: Exciter Driver Adjustment
On the Axciter Modulator, activate the Upconverter Main screen by selecting
Upconverter using the button next to it on the right side of the Axciter Main Screen.
Activate the Downconverter Output Gain by pushing 2 on the key board entry.
Monitor the DTVision Linear Display by pushing the button next to the DTVision
Linear display on the right side of the Axciter Main Screen. At the bottom of the
DTVision linear screen, locate the reading next to RMS. If this reading is between –
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6X Series Liquid-Cooled Transmitter
Chapter 3, Installation, Set Up and
Problem Identification Procedures
10 dBm & 0 dBm no adjustment is needed. If it is not, adjust the “Downconverter
Gain”, then view the RMS value until it is within the –10 dBm to 0 dBm range.
This completes the set up and adjustment of the transmitter using the Axciter
Modulator.
If a problem occurred during set up, contact Axcera field service at 1-724-873-8100.
3.7: Problem Identification
3.7.1: Pump Rack Cabinet Assembly
The Programmable Logic Controller, PLC, makes decisions based on inputs from the
transmitter and the various sensors throughout the pump rank and outside heat
exchanger. To turn the pumps ON the PLC is expecting a high signal from the
transmitter controller. Pump 1 will turn ON, after a 20 second delay pump 2 will turn
ON. Pump 3 will only turn ON if there is a fault in either pump 1 or 2. If 2 pumps
fault the PLC will send an alarm signal to the transmitter controller. The PLC also
controls the heat exchanger fan by monitoring the coolant return temperature from
the transmitter, optional load and optional filter. When the Coolant reaches 50°C the
PLC energizes the fan motor contactor. The PLC issues a warning signal or alarm to
the transmitter system controller when one of the following conditions occurs (See
Warnings/Alarms Table). The transmitter WILL NOT shut down when issued a
warning. The transmitter WILL shut down when an alarm is issued.
Condition
Temperature
Warning
50°C<(T1) < 55°C
Heat Exchanger Fan
Failure
(T1)>50°C and (X7)low
Pump Failure
(X4) or (X5) or (X6)
Clogged Upper Filter
Clogged Lower Filter
P1 >high
P4 >high 24> F1<28
Blown Hose
Transmitter
Blown Hose
Transmitter
Blown Hose
Exchanger
Blown Hose
Exchanger
to
(X4) and (X5) or (X4) and
(X6) or (X5) and (X6)
05
from
P5=0
to Heat
055°C
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6X Series Liquid-Cooled Transmitter
Chapter 3, Installation, Set Up and
Problem Identification Procedures
Coolant System Schematic
3.8: 6X PLC pump rack control software
3.8.1: Functions
Turn pumps on as required
Turn pump on at startup request
Delay start of second pump
Monitor Contactor Overload Relay
If pump 1 or 2 fails start pump 3 on 3 pump system
If 2 pumps fail shut down
Monitor and display Flow Meter in integer gallons per minute
Monitor temperature sensors
Display all temperature readings
Display delta temperature (T2-T1)
Display outside ambient temperature
Calculate and display Heat Exchanger efficiency (T3-T4)
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Chapter 3, Installation, Set Up and
Problem Identification Procedures
Monitor pressure sensors
Display all pressure sensor readings
Monitor pressure sensors to issue alarms (see Warning / Alarm table)
Monitor request to start from transmitter controller
Must be normally high signal (Low means shut down or lost cable to pump rack)
Control Heat Exchanger
High signal from contactor overload relay
Low signal from fan motor temperature switch
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Chapter 3, Installation, Set Up and
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Chapter 4, Circuit Descriptions
Chapter 4
Circuit Descriptions
4.1 Exciter, Upconverter, Driver Tray Boards
4.1.1 Frequency Agile Upconverter Board (1309695)
The board takes a 44 MHz or 36 MHz IF signal and converts it to a TV channel in the
range of 54-860 MHz. The 44 MHz or 36 MHz IF input signal, (≈-8dBm level), is
connected to J6 on the board. The IF first passes through a frequency response precorrector, consisting of R145, C188, R 146 and C189. The pre-corrector circuit
compensates for any response variation in the ceramic filter used to pick the
appropriate conversion sideband. The pre-corrected signal is then converted to a
second IF centered at 1044 MHz using the mixer U16, the 1.044 GHz filter U18 and
associated components. The mixer IC U16 has a 1 GHz LO1 connected to the LO
input. The 1.044 GHz signal is next applied to a second mixer, U15, where it is
mixed with the LO2 signal and converted to the final RF channel frequency. The RF
output is then sent to a low pass filter that removes unwanted conversion products
above 1 GHz, amplified by U21 then passed to another low pass filter. The filtered
output is amplified by U20 and connected to J7 the RF output jack for the board at
≈-3dBm level.
The upconverter has two local oscillators, LO1 and LO2. The LO1 oscillator consists
of U1, U2, U5, U6 and amplifiers U3 and U4. The LO1 oscillator operates at 1 GHz
for 44 MHz IF inputs and is used to convert the signal to 1044 MHz. In 36 MHz IF
systems, this oscillator circuit operates at 1.008 GHz which also converts the signal
to 1044 MHz. The Red LED DS4 will light if the PLL for the LO1 oscillator is not
locked.
The second LO, LO2, consists of two VCOs, U26 and U31, that are used to generate
the LO2 signal. One VCO operates from 1.1-1.5 GHz, for the VHF frequency band,
and the second from 1.5-1.9 GHz, for the UHF band. The Red LED DS2 will light if
the PLL for the LO2 oscillator is not locked.
Both of the LOs, LO1 and LO2, are locked to an on board 10 MHz VCXO reference
signal. The 10 MHz VCXO circuit consists of U36, U39, the VCTCXO Y1 and
associated components. When an external 10 MHz reference signal is applied to J10
on the board, the internal VCXO is locked to the external 10 MHz. Otherwise, the
internal VCXO is free-running. The Red LED DS6 will light if an External 10 MHz
reference is present. The Red LED DS3 will light if the PLL for the 10 MHz oscillator
is not locked.
4.1.2 Downconverter Board (1311103)
A sample of the transmitter’s RF output is applied to J6 on the downconverter board
at an input level of –10 to +10 dBm. The signal is fed through a matching network
and connected to the pin diode attenuator circuit consisting of DS1, DS2 and
associated circuitry which allows the operator to adjust the gain of the
downconversion path using R1. The RF is then amplified by U2 and converted to the
first conversion IF of 1044 MHz by the mixer U4 and the filter IC U5. Also connected
to the U4 mixer is the variable LO, 1.5 to 1.9 GHz for UHF, which is generated on the
external frequency agile upconverter board that mixes with the output RF frequency
to produce the 1044 MHz first conversion IF output at J9, typically -25 dBm.
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Chapter 4, Circuit Descriptions
A 1 GHz LO1 signal, typically -15 dBm, which is generated externally on the Frequency
Agile Upconverter Board is connected to the downconverter board at J12. The 1 GHz
LO is amplified by U9 and applied to a high pass filter, amplified by J10 and connected
to a low pass filter. The filters are designed to eliminate any other interfering signals
that might be coupled into the 1 GHz LO. The LO1 is split with one part connected to
the LO input on the U11 mixer. The other part of the LO1 signal is connected to the
LO1 sample jack J13. Also connected to the U11 mixer is the first conversion IF of
1044 MHz. The output of the U11 mixer is the 44 MHz second IF signal. This 44 MHz
second IF signal is then applied to a low pass filter to remove any out of band energy,
amplified by U12 and U15 and connected to a frequency response correction circuit
intended to compensate for any linear distortions in the downconversion path.
Adjustments R50-R52 and C79-C81 are used to control the frequency response of the
downconverter. The resulting signal is then amplified by U14 and applied to a
cascaded high pass low pass filter, which removes any out of band products that are
generated in the demodulation process. The filtered output is connected through U16
a coupler to J15 the IF output jack of the board. Typical level is -6 dBm. The coupler
provides a sample that is split. One sample output, -20 dBm, is connected to J16 the
output sample Jack of the board. The other sample output connects to a detector IC
U17 that provides a detected output level that is used in the Mute circuitry of the tray.
4.1.3 Button Board (1311306)
The Button Board provides the front panel accessed push button switch which is
illuminated by multicolored LEDs. The switch lit Blue indicates normal operation.
When the switch is lit Red, it indicates a malfunction has occurred. Pushing the
button will cause the front panel LCD on the system controller tray to display the
operating parameters of the selected power controller and/or the malfunction which
has occurred.
4.1.4 Pre-Driver Amplifier Board, Exciter, 6X (1313190)
The Pre-Driver Amplifier Board provides up to 22 dB of gain. The RF output of the
upconverter board, ≈-3dBm in level, connects to J1 the RF input jack on the predriver board. The RF is connected to DS1 and DS2 and associated components
which make up a pin diode attenuator circuit that controls the output level of the
board. A gain adjust voltage, from the Exciter Controller Board, connects though L3
to the pin diodes and increases or decreases the level through the circuit and
therefore the output drive level of the exciter, upconverter, driver tray. The output
of the pin diode level control circuit is amplified by U3 and connected to the IC U2
which is a 1 Watt driver amplifier with approximately 17 dB of gain. The amplified
output of U2 is connected through a directional coupler IC U5 to the RF output jack
J2 of the board. The RF output, ≈19 dBm maximum, is cabled to the RF output jack,
J2, mounted on the rear panel of the exciter, upconverter, driver tray. A sample of
the RF from the coupler connects to U6 that generates a DC output level based on
the RF level, which is amplified by the IC U1B and fed, output level, to the Exciter
Controller Board, for metering and level control.
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Chapter 4, Circuit Descriptions
4.2 Power Controller/AC Distribution Assembly, Boards
4.2.1 Button Board (1311306)
The Button Board provides the front panel accessed push button switch which is
illuminated by multicolored LEDs. The switch lit Blue indicates normal operation.
When lit Red, indicates a malfunction has occurred. Pushing the button will cause
the front panel LCD on the system controller tray to display the operating
parameters of the selected power controller and/or the malfunction which has
occurred.
4.2.2 Power Supply Line Monitoring Board (1311312)
The power supply line monitor board monitors the voltage and current on each of the
incoming three phase AC lines from the input power connection. The measured
values are connected the power supply control board. The power supply line
monitoring board also has a 600V solid state relay mounted on it that drives the coil
of the power contactors.
4.2.3 Power Supply Control Board (1312059)
The power supply control board is mounted behind the front panel of the power
controller/AC distribution assembly. The power supply control board monitors
signals that deal with the transmitter’s power circuitry. The three incoming AC lines
voltage and current are monitored along with signals that pertain to the power
supplies. The power contactors are controlled from this board. The board contains a
local 5 VDC power supply that powers the logic contained on the board.
4.3: Power Amplifier Tray, Boards
4.3.1 (A1) Fan Power Supply Board (1312004)
The Fan Power Supply Board contains three power supplies, two identical +12 VDC
fan power supplies and a +32 VDC pre driver power supply. All three of the power
supplies are current mode flyback topology DC-DC type. The power supplies are all
short circuit protected. The fan power supply board is connected to the main +42V
Buss rail through a 3 Amp fuse. This fuse protected +42 VDC is also wired to the
Phase/Gain Board. There are clips containing two "spare" 30 Amp fuses located on
the Fan Power Supply Board which can be used to replace the fuses to the amplifier
pallets, if needed.
+5 VDC from the phase/gain board connects to the fan power supply board at J9-2.
The +5 VDC is connected to a 3.3V regulator IC U11 that takes the +5V input and
generates the regulated +3.3VDC labeled +3.3V that connects to rest of the board.
The Green LED DS1 is lit if the +3.3VDC is present on the board. The +5 VDC is
split on the board and connected out of the board at J6-3, which is cabled to the
bottom combiner board, at J5-3, which is cabled to the front panel button board, and
at J7-3, which is cabled to the bottom splitter board.
The board contains two PIC microprocessors, PIC 1, U7, for Fan 1 and temperature
and PIC 2, U9, for Fan 2 and the +32 VDC pre driver power supply, which monitor
the power supplies and communicate with the tray on Serial Data Line connections at
J5-2, J6-2, J7-2 and J9-1. The system controller for the transmitter monitors these
samples and determines if a power supply needs to be shut down. J8 is a
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Chapter 4, Circuit Descriptions
programming port which is initially used to program the U7 microcontroller and is not
used by the customer. J10 is the programming port which is initially used to
program the U9 microcontroller and is not used by the customer.
The fan power supply that uses the T1 transformer takes the +42 VDC input and
produces the +12 VDC output, which connects to the (A20) F1 Fan through Jack J1-2
& 1. The Fan 1 voltage, current and spin rate (Tach) are sampled and connected to
the PIC 1 microcontroller.
The fan power supply using the T2 transformer takes the +42 VDC input and
produces the +12 VDC output, that connects to the (A21) F2 Fan through Jack J3-2
& 1. The Fan 2 voltage, current and spin rate (Tach) are sampled and connected to
the PIC 2 microcontroller.
The pre driver power supply, that uses the T3 transformer, takes the +42 VDC and
produces the +32VDC needed to power the pre driver (Q6) that is located on the
Phase/Gain Board. The +32 VDC pre driver power supply voltage is sampled and
connected to the PIC 2 microcontroller.
R108 is a thermistor mounted on the fan power supply board, which generates a
voltage reference of the temperature of the board that is connected to the PIC 1 U7
microcontroller. The microcontroller takes this input and the Fan 1 information and
supplies a serial data output that is buffered by U8 before it is wired to the Serial
Data Line connections at J5-2, J6-2, J7-2 and J9-1.
4.3.2 Front Panel Smart Button Board (1310349)
The Button Board provides the front panel accessed push button switch which is
illuminated by multicolored LEDs. The switch lit Blue indicates normal operation.
When lit Red, indicates a malfunction has occurred. Pushing the button will cause
the front panel LCD on the system controller tray to display the operating
parameters of the selected power controller and/or the malfunction which has
occurred. J3 is the programming port which is used to initially program the
microcontroller and is not used by the customer.
4.3.3 (A2) Phase/Gain Board (1312011)
This board performs a variety of functions. It amplifies the incoming RF signal to the
amplifier tray, ≈15mW ATSC, to the level at the output of the board, ≈.6W ATSC,
which can drive the output stage of the tray to full power. It adjusts the phase shift
through the board so that parallel amplifiers combine correctly. The board also
contains protection circuitry to quickly mute RF drive in the event of an overdrive or
reflected power fault. It contains circuitry that controls and monitors the amplifier
tray. Finally, it contains DC/DC converters that generate various needed power
supply voltages for the board.
The RF input to the board at J3-A1, RF_RFIN, ≈15mW ATSC, is connected to the
directional coupler U20 which provides a sample of the signal. This sample is used to
drive the log amp detector U39 which measures the input level to the board. The
main RF signal, RF_U6, is then applied to a PIN diode attenuator consisting of CR9,
CR10, CR40, CR41 and U6. This attenuator is used to set the overall output level of
the tray. Increasing the voltage at TP2 will increase the gain of the tray.
The output of the PIN attenuator drives a high speed PIN switch consisting of CR7,
CR8 and associated components. This switch is used to remove RF drive quickly in
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Chapter 4, Circuit Descriptions
the event of a fault. The switch can be controlled by three separate sources, the
overdrive protection circuitry, the reflected power protection circuitry, and the Rabbit
microcontroller that is controlling and monitoring the amplifier tray. The overdrive
protection and reflected power protection circuitry are extremely fast, and will
remove the RF drive in a few hundred nanoseconds. Removing the RF drive will also
remove the faults, so the output of the comparators U25 and U26 that generate
these faults drive a flip flop U41, which latches the faults so the Rabbit
microcontroller is able to see them. Once the faults are recorded the Flip Flops are
reset and the drive is re-applied.
The output of the PIN switch drives three cascaded phase shifters consisting of U21,
U22 and U23 and their associated components. These three phase shifters each
have a range of about 135°, giving an overall adjustment range in excess of 360°,
allowing the amplifier to adjust the output phase of the tray to any required value.
The output of the phase shifters, RF_A, is applied to a MMIC U4 that amplifies the RF
signal to overcome any loss which occurred in the previous stages. The output of
the MMIC drives an LDMOS amplifier, Q6, which amplifies the RF output signal to an
approximate level of 1W average power for ATSC that is applied to the Directional
Coupler U31. +32 VDC needed to operate Q6 is generated by the Fan Power Supply
Board. The coupler provides a signal to the detector IC U44 which measures the
instantaneous output power of the signal. This detected level is used to drive the
overdrive detector, U25. This signal, ODVR_LVL, is not filtered so that the protection
circuitry can react quickly. The detected level is also applied to a low pass filter
consisting of R175 and C145 whose output is used for metering, RF OUT LVL.
The board has mounting, RB1, for a daughter board that contains a Rabbit
microcontroller. This microcontroller communicates with the outside world via an
Ethernet connection, and also communicates with the other microcontrollers located
in the amplifier tray using a one wire serial bus.
The various analog parameters of the board are sampled via U45 which feeds the
detected levels of each of its inputs back to the Rabbit. U45 also controls an
external multiplexer U54, which extends the number of inputs that can be sampled.
The Rabbit also controls the settings of the digital potentiometers U33-U35. These
potentiometers generate voltages used to set the Phase, U33, the Gain, U34, and the
Overdrive Fault, U35, thresholds for the amplifier tray. There is a fourth digital pot
U36 which is not used in this configuration. The U63 microcontroller, U64 buffer
amplifier and the J5 programming port are not used in this configuration.
+32 VDC and +42 VDC needed to operate the board is supplied from the Fan Power
Supply Board. The +32 VDC connects through J3-2 and the +42 VDC connects
through J3-3. There are three power supplies on the board which are current mode
flyback topology DC-DC types that use the +42 VDC as the input voltage. The power
supply using the T1 transformer produces the +5VDC labeled +5VR for use by the
rest of the board. The power supply using the T2 transformer produces the +12VDC
labeled +12V for the rest of the board. The power supply using the T3 transformer
produces the +5VDC labeled +5V to the rest of the board. There is also a 3.3V
regulator IC U52 that takes the +5V input and generates the regulated +3.3VDC
labeled +3.3V that connects to rest of the board. The Green LED DS2 is lit if the
+3.3VDC is present on the board. A sample of the +5VDC generated on the board
connects out of the board at J3-4 and is cabled to the fan power supply board for use
on that board.
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4.3.4 (A8) Interface Board (1312562)
The RF output of the phase/gain board connects to the SMB connector J1 on the
interface board. The RF is fed though solder track to J4 the output pad on the board.
A wire jumper is soldered from the J4 pad to the J1 input pad, (≈.6Watts ATSC), on
the driver pallet assembly. A wire jumper is soldered from the J3 pad to the J3 Data
pad on the driver pallet assembly. A wire jumper is soldered from the J5 pad to the
J5 Slot location pad on the driver pallet assembly.
Refer to section 4.3.7 for the description of the (A7) 878 Driver Amplifier Pallet.
4.3.5 (A5) 4 Way Splitter Board, Top (1312033)
The Top 4 way splitter board takes the RF from the 878 Amplifier Pallet driver at J1
(≈45Watts ATSC) on the board and connects it to a coupler U2. One output of the
coupler is fed to a two way splitter. The other output of the coupler is wired to a Log
Amplifier IC U5 which produces a voltage reference of the RF input level to the top
splitter board, which connects to the U4 microcontroller. R15 is a thermistor
mounted on the heat sink for the splitter, which generates a voltage reference of the
temperature of the heat sink that is connected to the U4 microcontroller. The
microcontroller takes the inputs and supplies a serial data output that is buffered by
U3 before it is wired to the Serial Data Line connections at J6-2 and J7-2. Serial
Data is also connected to the amplifier pallets through Jacks J9 to amplifier pallet 1,
J10 to amplifier pallet 2, J11 to amplifier pallet 3, and J12 to amplifier pallet 4. J15
is the programming port which is initially used to program the U4 microcontroller and
is not used by the customer.
One output of the two way splitter connects to the output jack J8 which is cabled to
the input of the bottom 4 Way splitter. The other output of the two way splitter is
connected to a four way splitter. The four equal outputs (≈4.5 Watts) connect at J2
to amplifier pallet 1, J3 to amplifier pallet 2, J4 to amplifier pallet 3, and J5 to
amplifier pallet 4.
The final amplifier Pallet Slot location identification is achieved using the resistor,
each one a different value, connected to J16 for pallet 1, J17 for pallet 2, J18 for
pallet 3, and J19 for pallet 4.
+5 VDC is supplied to the top splitter board thru J6-3 & 1 from the bottom splitter
board. The +5 VDC connects to U5 on the board and to the 3.3V regulator IC U6.
The regulator IC takes the +5 VDC input and generates the regulated +3.3VDC that
is used by the ICs U3 and U4. The Green LED DS1 is lit if the +3.3VDC is present on
the board.
4.3.6 (A6) 4 Way Splitter Board, Bottom (1310448)
The Bottom 4 way splitter board takes the RF from the top 4 way splitter board at J1
(≈45Watts ATSC) on the board and connects it to a four way splitter. The four equal
outputs (≈4.5 Watts) of the splitter connect at J2 to amplifier pallet 5, J3 to amplifier
pallet 6, J4 to amplifier pallet 7, and J5 to amplifier pallet 8.
R15 is a thermistor mounted on the heat sink for the splitter, which generates a
voltage reference of the temperature of the heat sink that is connected to the U4
microcontroller. The microcontroller takes this input and supplies a serial data
output that is buffered by U3 before it is wired to the Serial Data Line connections at
J6-2 and J7-2. Serial Data is also connected to the amplifier pallets through Jacks J9
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Chapter 4, Circuit Descriptions
to amplifier pallet 5, J10 to amplifier pallet 6, J11 to amplifier pallet 7, and J12 to
amplifier pallet 8. J15 is the programming port which is initially used to program the
U4 microcontroller and is not used by the customer.
The final amplifier Pallet Slot location identification is achieved using the resistor,
each one a different value, connected to J16 for the amplifier pallet 5, J17 for the
amplifier pallet 6, J18 for the amplifier pallet 7, and J19 for the amplifier pallet 8.
+5 VDC is supplied to the bottom splitter board thru J7-3 & 1 from the Fan Power
Supply Board. The +5 VDC connects through rectifier diodes CR2 and CR3 which
drop the voltage to +3.3 VDC whose output level is maintained by C7. The +3.3VDC
is used by the ICs U3 and U4. The Green LED DS1 is lit if the +3.3VDC is present on
the board.
4.3.7 (A7 & A9-A16) 878 Amplifier Pallets, Digital Bias (1310321)
There are nine 878 Amplifier Pallets mounted in the amplifier tray. One is used as a
driver (A7) and eight are final amplifier pallets (A9-A16). Each of the 878 pallets has
approximately +17dB of gain for the UHF frequency range of 470 to 860 MHz. The
pallets have dual parallel amplifier circuits, each using a BLF878 LDMOS RF power
transistor, which operate Class AB. The driver pallet normally operates with an RF
input of .6 Watts ATSC typically produces 30 Watts ATSC output. With an RF input
of 4.5 Watts ATSC the output of the final amplifier pallet should be 225 Watts ATSC.
The paralleling network is achieved using an input hybrid splitter and an output
hybrid combiner. The RF input is applied to the hybrid splitter that produces two
outputs, one at 0° and one at -90°. Each output connects to identical amplifier
circuits. Each signal is applied to a Balun assembly that produces two 180° out of
phase outputs. The two outputs connect to a dual LDMOS transistor, configured in a
push pull arrangement, with approximately 17 dB of gain. The amplified outputs of
the transistors connect to a Balun assembly that combines the two 180° out of phase
signals into a single output. The output connects to one input of a hybrid combiner
circuit. The 0° and the -90° signals from the amplifier circuits are combined by the
hybrid combiner circuit and connected to J2 the RF output jack on the board (≈+55
dBm).
U2 and U7 are digital to analog converter ICs that generate the bias voltage for each
transistor. U1 and U5 are current sense ICs that monitor the current at the output of
the Q1 and Q2 amplifiers and provide a sample to the U6 microcontroller. R24 is a
thermistor mounted to the board, which generates a voltage reference of the
temperature of the board that is connected to the U6 microcontroller. The
microcontroller takes the parameter sample inputs and supplies a serial data output
that is buffered by U8 before it is wired to the Serial Data Line connection at J3.
The final amplifier Pallet Slot location identification for the individual amplifier pallets
is achieved by connecting the voltage at J5 to one of the resistors, each one a
different value located on the top splitter board and the bottom splitter board. Four
of the resistors are located on the top splitter board and four are located on the
bottom splitter board.
The +42 VDC needed to operate the individual pallets is supplied from the Buss Bar
Assembly thru 30 Amp fuses to the pallet at FC1. Filtering of the +42VDC is provided
by the capacitor network consisting of C24, C30, C64, C75 and C76. There are clips
containing two "spare" 30 Amp fuses located on the Fan Power Supply Board. The
fuse protected and filtered +42 VDC is applied through the .002Ω resistors R32 and
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Chapter 4, Circuit Descriptions
R33 and the output Balun assemblies to the drains of Q1 and Q2. The +42 VDC is also
connected through the 12V Zener diode CR1 to the regulator IC U4 that supplies +3.3
VDC, which is used by the U2, U6 and U7 ICs on the pallet.
4.3.6 (A17) 4 Way Combiner Board, Top (1310305)
The Top 4 way combiner board takes the four RF Inputs at J4, J5, J6 & J7
(≈225Watts ATSC) on the board and combines them into a single output
(≈750Watts) at J2 on the board which is cabled to one input of the Power Combiner.
The microcontroller, U2 takes the parameter sample inputs and supplies a serial data
output that is buffered by U1 before it is wired to the Serial Data Line connections at
J11-2 and J19-2. The Serial Data Line connects to the system controller for the
transmitter. U5 is not used in this configuration. R10 is a thermistor mounted to the
board, which generates a voltage reference of the temperature of the board that is
connected to the U2 microcontroller. The microcontroller generates a bit stream
sample of the reflected threshold level system setting that connects to the digital to
analog converter IC. The DAC IC generates a DC level that sets the reflected
threshold, which connects to the reflected fault comparator IC U10. J8 is a
programming port which is initially used to program the U2 microcontroller and is not
used by the customer. J12 is a programming port which is initially used to program
the U5 microcontroller and is not used by the customer.
The power detector portion of the board provides forward and reflected samples to the
U2 microcontroller. A Forward Output Power Sample connects to the board at J15.
The sample is split with one output connected to J8, the Forward Power Sample Jack,
located on the front panel and the other output filtered and split again. One output of
the splitter is connected to the detector IC U8, which produces an average forward
power DC level that connects to the microcontroller U2. The other output of the
splitter is connected to the detector IC U6, which produces an output that is fed to U7A
and U7B and associated circuitry. This circuit generates a peak forward power DC
level that connects to the microcontroller U2.
A Reflected Output Power Sample connects to the board at J17. The sample is filtered
and connected to the detector IC U9, which produces a reflected power DC level that
connects to the microcontroller U2. Another output of U9 is fed to a comparator IC
U10 that generates a reflected fault output if the input reflected level exceeds the
Fault threshold setting for the tray. The reflected fault output is wired to J18 that is
cabled to the phase/gain board where it connects to the fault protection circuitry.
Four 50Ω/120W terminations are mounted on the top combiner board for amplifier
pallets 1-4. The termination R34 connects at J14 to pallet 1, R15 at J9 to pallet 2, R23
at J10 to pallet 3 and R27 at J13 to pallet 4. The rest of the circuitry after the
terminations on the schematic is not used in this configuration.
+5 VDC is supplied to the top combiner board thru J11-3 & 1 from the bottom
combiner board. The regulator IC, U11, takes the +5 VDC input and generates the
regulated +3.3VDC that is used by the ICs on the board. The Green LED DS1 is lit if
the +3.3VDC is present on the board.
4.3.7 (A18) 4 Way Combiner Board, Bottom (1310308)
The Bottom 4 way combiner board takes the four RF Inputs at J4 from pallet 5, J5
from pallet 6, J6 from pallet 7 and J7 from pallet 8 (≈225Watts ATSC) on the board
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Chapter 4, Circuit Descriptions
and combines them into a single output (≈750Watts) at J2 on the board which is
cabled to one input of the Power Combiner.
The microcontroller, U5 takes the parameter sample inputs and supplies a serial data
output that is buffered by U4 before it is wired to the Serial Data Line connections at
J11-2 and J15-2. The Serial Data Line connects to the system controller for the
transmitter. R36 is a thermistor mounted to the board, which generates a voltage
reference of the temperature of the board that is connected to the U5
microcontroller.
Four 50Ω/120W terminations are mounted on the bottom combiner board for amplifier
pallets 5-8. The termination R27 connects at J13 to pallet 5, R23 at J10 to pallet 6,
R15 at J9 to pallet 7 and R34 at J14 to pallet 8. The rest of the circuitry after the
terminations on the schematic is not used in this configuration.
+5 VDC is supplied to the bottom combiner board thru J11-3 & 1 from the fan power
supply board. The +5 VDC is split and one part connected to the top combiner board
thru J15-2 & 1. The other +5 VDC connects through rectifier diodes CR5 and CR6
which drop the voltage to +3.3 VDC whose output level is maintained by C14. The
+3.3VDC is used by the ICs U4 and U5. The Green LED DS1 is lit if the +3.3VDC is
present on the board.
4.3.8 (A19) Power Combiner (1312281)
The Power Combiner takes the outputs of the top (≈750Watts ATSC) and bottom
(≈750Watts ATSC) combiners and combines them to a single output (≈1.5 kW
ATSC) which is the output of the power amplifier tray.
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6X Series Liquid-Cooled Transmitter
Chapter 5, Maintenance
Chapter 5:
Maintenance
5.1: Maintenance
The 6X Series Transmitter is designed with components that require little periodic
maintenance except for the routine cleaning of the filters and the fans in the amplifier
cabinets and trays. For maintenance procedures on vendor items, such as the blower,
heat exchanger, motor, contactor, starter, sensor or flow meter, refer to the
manufacturers’ manuals, included with the item or with the installation material.
The amount of time between cleanings depends on the conditions within the transmitter
room. While the electronics have been designed to function even if covered with dust, a
heavy buildup of dust, dirt, or insects will affect the cooling of the components. This could
lead to a thermal shutdown or a premature failure of the affected tray.
Axcera recommends that the operating parameters of the transmitter be recorded from
the touch screen weekly. It is suggested that this data be retained in a rugged folder or
envelope.
5.1.1: Exciter/Amplifier Assembly
The individual trays in the exciter/amplifier must also be cleaned. If the front panels
become covered with dust, the top covers should be taken off and any foreign material
that has accumulated should be removed. A vacuum cleaner, utilizing a small, wand-type
attachment, is an excellent way to suction out the dirt. Alcohol and other cleaning agents
should not be used unless you are certain that the solvents will not damage any
components or the silk-screened markings on the trays and boards. If water-based
cleaners are used, be careful that the components do not become saturated. The fans and
heat sinks should be cleaned of all dust or dirt to permit the free flow of air for cooling
purposes.
5.1.2: Ethylene Glycol/Distilled Water Cooling System
5.1.2.1: Flushing and cleaning of the strainers
The strainers can be cleaned by flushing them out. Begin the flushing process by
placing a bucket under the drain and opening the drain valve to the strainer. See Figure
5-1.
Strainer
Assembly
1.5” Nut
Drain
Valve
Figure 5-1: Strainer
Instruction Manual, Rev. 0
5-1
6X Series Liquid-Cooled Transmitter
Chapter 5, Maintenance
Output
Valves
Input
Valves
Figure 5-2: Input and Output Valves
Let the water run for approximately 3 seconds. This should clean the strainer. Repeat
for the strainer in the other line. Periodically, the strainers should be removed and
cleaned. This is accomplished by first isolating the desired pump and strainer by turning
off the input and output valves to the pump. See Figure 5-2. Place a bucket under the
drain and open the drain valve. Remove the 1.5” nut from the bottom of the strainer
assembly and remove the strainer, noting the orientation of the strainer. Clean the
strainer, may need to use a metal brush, and return it to the strainer assembly in the
same position as removed. Tighten the 1.5” nut. Repeat for the strainer in the other
line. Turn on the input and output valves to the pump. Also, check and clean the single
strainer located in the input line to the reservoir tank in the same manner as described
for the output strainers.
If you are doing the initial installation flushing, connect the water lines to the 6X and the
Test Load.
5.1.2.2: Checking the glycol concentration level and PH value
It is recommended to use Dow Chemicals’ Dowtherm SR-1 at a 50/50 mix with distilled
water for cooling the 6X transmitter.
The concentration and condition of the mixture should be checked monthly. This can be
done with a hydrometer, if the temperature of the mixture is known. However, a
refractometer will indicate the concentration regardless of the temperature of the
mixture. To test the coolant mixture for pH and concentration, Axcera recommends the
use of a pH-meter supplied by Misco and a refractometer supplied by Misco (7084 VP+
[oF] or 7064 VP+ [oC]). The pH value of the mixture is important. The glycol mixture
must be monitored at monthly intervals for the pH value. The desired range of the
value is between 8 and 10. If this value falls below 8 and is ignored, the mixture will
rapidly become acidic and could damage the 6X amplifier trays. When the pH value of
the mixture falls below 8, the entire mixture must be replaced or a small, 50% diluted
quantity of sodium hydroxide (very caustic) or potassium hydroxide (less caustic) should
be added to the system. This will bring the pH back into the required range. The use of
sodium hydroxide or potassium hydroxide can only be repeated three times, after which
the whole mixture should be replaced.
If, when the coolant is inspected, the color of the glycol mixture has changed to gray or
black, or there is an oily layer, a burnt odor, or any sludge in the mixture, this will
indicate a need for the replacement of the entire mixture.
Instruction Manual, Rev. 0
5-2
6X Series Liquid-Cooled Transmitter
Chapter 5, Maintenance
NOTE: Dowtherm SR-1 in the undiluted state should not be stored outside
during the summer, because it begins to decompose at temperatures above
100°° F. In addition, undiluted SR-1 will freeze at a few degrees under 32°° F, but
it will recover.
5.1.2.3: Checking and cleaning the Heat Exchanger and back up Pump
The heat exchanger should be checked for weeds, leaves, debris or any other obstructions
around the sides of the unit and the heat rejection coils and fins. The coils and fins can be
cleaned with compressed air or a commercial coil cleaner, being careful not to distort the
fins. During the winter months, be sure to remove any snow accumulation around the
sides and top of the system or on the fan blades. Also check for leaks or excessive
vibrations in the plumbing and fan. If your system has a back up pump for your cooling
system, it will need to be cycled on approximately every 3 months to prevent it from
seizing up.
5.2: 6X Transmitter Normal Inspection and Maintenance Schedule
Refer to the chart Table 5-1 that follows for the 6X recommended maintenance schedule.
Instruction Manual, Rev. 0
5-3
X
Instruction Manual, Rev. 0
5-4
Visual check of all Fans, Blowers and Pumps in the system for
normal operation and any signs of wear or overheating
Verify proper operation of all Interlock and Ready Status Switches
Visual check of Power Amplifiers condition, including voltage cable
forms, resistors and capacitors and miscellaneous hardware
Visual check of sub-systems power supplies
Inspection of Heat Exchangers Fans and Lubrication.
Inspection of Heat Exchangers for Leaks, Corrosion etc.
Inspection of High Voltage lines
Ethylene Glycol/Distilled Water Mixture PH Level Check
Ethylene Glycol/Distilled Water Mixture Concentration Check
Check Cooling Fluid Level
Check Cooling System for Leaks
Check and Clean or Change Filters
Verify Local and Remote Metering Calibration.
Half Year
Data Recording or Inspection Interval
Daily Weekly
Monthly
Quarterly
Yearly
Chapter 5, Maintenance
Check and correct all appropriate protection trip circuits
Check and Correct Parameters and Settings of the Output Amplifiers.
Analysis and Correction of Transmitter Upper and Lower Sideband
Response.
Power Measurement and Correction.
Carrier Frequency Measurement and Correction
Check performance for FCC Compliance.
Record a full set of Operating Readings.
Type of Record or Inspection Check
6X Transmitter
Normal Record, Inspection and Maintenance Schedule
Table 5-1: 6X Transmitter normal record, inspection and maintenance schedule
6X Series Liquid-Cooled Transmitter
Instruction Manual, Rev. 0
Clean the Exciter/Power Amplifier Cabinet
Check & Clean the Strainers in the Pump Assembly & Reservoir
Lubricate the Pumps, both Primary and Back Up Pumps
Cycling of the Dual Pumps, Back Up Pump
Type of Maintenance
5-5
Maintenance Interval
Daily Weekly
Monthly
6X Transmitter
Normal Record, Inspection and Maintenance Schedule
6X Series Liquid-Cooled Transmitter
Quarterly
Half Year
Yearly
Chapter 5, Maintenance
Appendix A
6X Drawings
6X Series Liquid-Cooled Transmitter
Appendix A, Drawing List
6X Series Liquid-Cooled Transmitter
6X Series Transmitter System Block Diagram ........................................ 1312362
6X Series Transmitter System Block Diagram Water Cooling System........ 1311561
6X Series Transmitter System Rack Interconnect ................................... 1311569
6X Series Transmitter System Rack Interconnect ................................... 1313729
6X Series Transmitter Typical Racking Plan............................................ 1313501
Amplifier Cabinet Assembly, 6X
Interconnect .................................................................................... 1312832
Dual RF Power Detector Assembly, 6X
Dual RF Power Detector Board
Schematic ..................................................................................... 1313067
871 Driver Amplifier Assembly, 6X
871 Driver Amplifier Board, 6X
Schematic ..................................................................................... 1312846
Controller Rack Assembly, 6X
Controller Rack Assembly Board, 6X
Schematic ..................................................................................... 1312856
Axciter Modulator Tray
Block Diagram ................................................................................. 1305844
Interconnect Drawing ....................................................................... 1310628
Electrical Overlay Schematic .............................................................. 1305409
VSB Modulator Board, Axciter
Schematic ..................................................................................... 1305067
Exciter/Upconverter/Driver Tray
Interconnect Drawing ....................................................................... 1313395
Frequency Agile Upconverter Board
Schematic.......................................................................................... 1309696
Downconverter Board
Schematic.......................................................................................... 1311104
Button Board
Schematic.......................................................................................... 1311307
Exciter Controller Board
Schematic.......................................................................................... 1312414
Exciter Pre-Driver Assembly
Schematic.......................................................................................... 1313191
Instruction Manual, Rev. 0
A-1
6X Series Liquid-Cooled Transmitter
Appendix A, Drawing List
System Controller Tray, 6X
Block Diagram ................................................................................. 1312829
Interconnect .................................................................................... 1313638
System Controller Button Board
Schematic.......................................................................................... 1312056
Power Controller/AC Distribution Assembly, 6X
Block Diagram ................................................................................. 1312834
Interconnect .................................................................................... 1312772
Button Board
Schematic.......................................................................................... 1311307
Power Supply Line Monitoring Board
Schematic.......................................................................................... 1311313
Power Supply Control Board
Schematic.......................................................................................... 1312060
Amplifier Tray, Water Cooled, 6X
Block Diagram .................................................................................... 1313406
Interconnect ...................................................................................... 1312691
6kW Gain Block Amplifier Tray, RF Block Diagram .................................. 1311567
4 Way Combiner Board, Top
Schematic.......................................................................................... 1310306
4 Way Combiner Board, Bottom
Schematic.......................................................................................... 1310309
878 Pallet, Digital Bias
Schematic.......................................................................................... 1310322
F.P. Smart Button Board
Schematic.......................................................................................... 1310350
Splitter Board, Bottom, 6X
Schematic.......................................................................................... 1310449
Fan Power Supply Board, 6X
Schematic.......................................................................................... 1312005
Phase Gain Board, UHF, 6X
Schematic.......................................................................................... 1312012
Splitter Board, Top, 6X
Schematic.......................................................................................... 1312034
Coolant Monitor
Coolant Monitor Interconnect ............................................................... 1313676
Instruction Manual, Rev. 0
A-2
6X Series Liquid-Cooled Transmitter
Appendix A, Drawing List
Power Supply Assembly, 6X
Pioneer Magnetics Information
Pump Rack Assembly, 6X
Grainger Pump Information
Block Diagram Electrical Water Cooling System...................................... 1312836
Instruction Manual, Rev. 0
A-3
6X Series Liquid-Cooled Transmitter
Appendix A, Drawing List
Appendix B
Transmitter Specifications
Instruction Manual, Rev. 0
A-4
6X SERIES
Liquid-Cooled Solid State ATSC Transmitter
With over twenty five years of experience in the design and
manufacture of solid state transmitters, Axcera continues to
provide the latest technology, enabling our customers to focus on
the future. Axcera’s 6X Series liquid-cooled solid state transmitters
are available in power levels up to 40 kW ATSC.
These advanced solid state transmitters were designed specifically
to meet the needs of today’s broadcaster, offering high levels of
reliability, efficiency and performance. The modular construction
provides a clear upgrade path, allowing broadcasters to begin
with a low power transmitter and easily add modules to achieve
any power level desired. With its parallel amplifier design,
Axcera’s 6X Series transmitters are perfect for long-term,
unattended operation. State-of-the-art design and components
achieve industry leading power density resulting in the smallest
transmitter footprint available.
DIGITAL
6X SERIES
DIGITAL
Liquid-Cooled Solid State ATSC Transmitter
Performance
Frequency Range
General
470 to 862 MHz
Standard
ATSC
Frequency Stability
w/GPS
0.2 ppm (max 30 day variation)
0.001 ppm
Operational Temperature Range
Indoor
Outdoor
Regulation of RF Output Power
3%
Out of Band Emissions
Compliant with FCC Mask
Signal to Noise (SNR)
30dB or better (typical), 27dB min.
Data Interface
Input Rate
Input Interface
Cable Equalization
Impedance
Level
19.39 Mbps, 6 MHz channel
SMPTE 310M (ASI optional) 		
Automatic			
75Ω, BNC			
800mV±10%
0ºC to +50°C, derate 2°C/1000 ft.
-20ºC to +50ºC
Maximum Altitude1
8500 feet (2600m) AMSL
Operational Humidity Range
0% to 95% non-condensing
Output Impedance
50 Ω
Line Voltage
358-528 VAC, 3 Phase, 50/60 Hz,
Delta or WYE
Options
DTVision Signal Analysis System					
Bandwidth Enhancement Technology					
Dual Exciter with Automatic Switch
N+1 Power Supply
AC Surge Protector
Spare Parts Kit
GPS Receiver
N+1 Water Pump
SNMP Client
Other Frequencies, Altitudes & Voltages - Consult Factory
Measured after output mask filter.
Typical power consumption
Model Specific Specifications
Model Numbers
6U2AD
6U3AD
6U4AD
6U5AD
6U6AD
6U7AD
6U8AD
6U12AD
6U16AD
6U24AD
Power Output
2.5kW
3.7kW
5kW
6kW
7.5kW
8.5kW
10kW
15kW
19kW
29kW
Power Consumption
13kW
19kW
25kW
32kW
38kW
42kW
50kW
76kW
99kW
150kW
No. of Final PA Modules
12
16
24
Dimensions (H x W x D)
Inches
79 x 24 x 50
Centimeters
Weight (lbs/kg)
79 x 48 x 50
200 x 60 x 127
660/300
Output Connector
715/324
940/426
1000/454
1060/480
1 5/8” EIA
79 x 72 x 50
200 x 120 x 127
1120/509
1200/544
2100/952
200 x 180 x 127
2350/1065
3 1/8”EIA
3500/1590
4 1/16” EIA
Specifications published here are current as of the date of publication of this document. Because we are continuously improving our products, Axcera reserves the right to change specifications without prior notice.
At any time, you may verify product specifications by contacting our office. Axcera views it’s patent portfolio as an important corporate asset and vigorously enforces its patents. Products or features contained
herein may be covered by one or more U.S. or foreign patents.
0906R2
© 2009 AXCERA
All Rights Reserved
103 Freedom Drive, PO Box 525, Lawrence, PA 15055, USA
An Equal Opportunity Employer
t:+1 724-873-8100
f:+1 724-873-8105
www.axcera.com		
Axcera 6X Series ATSC Tx

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