UBS Axcera LU500ATD 500-Watt UHF Digital Transmitter User Manual TITLE PAGE
UBS-Axcera 500-Watt UHF Digital Transmitter TITLE PAGE
Contents
- 1. Driver Operating Manual
- 2. Amplifier Operating Manual
- 3. Chapter 5 Block Diagrams
Driver Operating Manual
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| Date Submitted | 2007-04-16 00:00:00 |
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Instruction Manual
Innovator,
LX Series
Digital UHF
Driver/Transmitter
AXCERA, LLC
103 FREEDOM DRIVE, P.O. Box 525 LAWRENCE, PA 15055-0525 USA
(724) 873-8100 • FAX (724) 873-8105
www.axcera.com • info@axcera.com
Digital UHF Driver/Transmitter
Table of Contents
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION
SECTION
PAGE
1.1 Manual Overview ...................................................................................1-1
1.2 Assembly Designation Numbers ..............................................................1-1
1.3 Safety ..................................................................................................1-2
1.4 Contact Information ......................................................................... 1-2
1.5 Material Return Procedure ......................................................................1-2
1.6 Limited One Year Warranty for Axcera Products ........................................1-3
CHAPTER 2 SYSTEM DESCRIPTION & REMOTE CONTROL CONNECTIONS
2.0 System Overview .................................................................................2-1
2.1 (Optional) Exciter Switcher Tray..............................................................2-2
2.2 Exciter Amplifier Chassis Assembly..........................................................2-3
2.2.1 DM8 Modulator Assembly ..............................................................2-3
2.2.2 IF Processor Module .....................................................................2-4
2.2.3 VHF/UHF Upconverter Module........................................................2-6
2.2.4 Control & Monitoring/Power Supply Module .....................................2-7
2.2.5 Power Amplifier Module (In 5-50W Transmitters).............................2-8
2.2.6 Or Driver Amplifier Module (In High Power Transmitters)................ 2-10
2.3 RF Output Assemblies .......................................................................... 2-12
2.4 Control and Status............................................................................... 2-12
2.4.1 Front Panel LCD Display Screen ................................................... 2-12
2.5 System Operation................................................................................ 2-12
2.5.1 Principles of Operation ................................................................ 2-12
2.6 Maintenance ....................................................................................... 2-14
2.7 Customer Remote Connections ....................................................... 2-14
CHAPTER 3 SITE CONSIDERATIONS, INSTALLATION AND SETUP PROCEDURES
3.1
3.2
3.3
3.4
3.5
Site Considerations................................................................................3-1
Unpacking the Chassis w/Modules ...........................................................3-5
Installing the Chassis w/Modules.............................................................3-5
AC Input...............................................................................................3-7
Setup and Operation..............................................................................3-8
3.5.1 Input Connections ........................................................................3-8
3.5.2 Initial Turn On .............................................................................3-9
3.5.2.1 DM8 Digital Modulator Module LEDs on Front Panel.................3-9
3.5.2.2 IF Processor Module LEDs on Front Panel...............................3-9
3.5.2.3 VHF/UHF Upconverter Module LEDs on Front Panel .................3-9
3.5.2.4 Controller Module LEDs on Front Panel ................................ 3-10
3.5.2.5 Power Amplifier or Driver Module LEDs on Front Panel .......... 3-10
3.5.3 Front Panel Screens for the Exciter/Amplifier Chassis Assembly....... 3-10
3.5.4 Operational Procedure ................................................................ 3-19
CHAPTER 4 CIRCUIT DESCRIPTIONS
4.0 (Optional) Exciter Switcher Tray..............................................................4-1
4.0.1 Exciter Switcher Control Board.......................................................4-1
4.1 DM8 Digital Modulator Module.................................................................4-1
4.1.1 Digital Modulator, DT1D Board.......................................................4-1
4.1.1.1 SMPTE-310 Input ................................................................4-1
LX Series, Digital, Rev. 4
March 8, 2007
Digital UHF Driver/Transmitter
Table of Contents
TABLE OF CONTENTS - (Continued)
SECTION
PAGE
4.1.1.2 Channel Coder ....................................................................4-1
4.1.1.3 Analog Output Section .........................................................4-2
4.1.1.4 Pilot Frequency Generation...................................................4-2
4.1.1.5 Voltage Requirements .........................................................4-2
4.1.2 VSB Front Panel Board ..................................................................4-3
4.2 IF Processor Module...............................................................................4-3
4.2.1 IF Processor Board .......................................................................4-3
4.2.1.1 DM8 Modulator Selected ......................................................4-3
4.2.1.2 External Modulated IF Selected.............................................4-3
4.2.1.3 Main IF Signal Path (Part 1 of 3) ...........................................4-3
4.2.1.4 Input Level Detector Circuit..................................................4-4
4.2.1.5 Pin Diode Attenuator Circuit .................................................4-5
4.2.1.6 Main IF Signal Path (Part 2 of 3) ...........................................4-5
4.2.1.7 Amplitude and Phase Pre Correction Circuits ..........................4-6
4.2.1.8 Main IF Signal Path (Part 3 of 3) ...........................................4-7
4.2.1.9 ALC Circuit .........................................................................4-7
4.2.1.10 Fault Command.................................................................4-8
4.2.1.11 ±12 VDC Needed to Operate the Board ...............................4-8
4.3 VHF/UHF Upconverter Module .................................................................4-8
4.3.1 Downconverter Board ...................................................................4-9
4.3.2 L-Band PLL Board.........................................................................4-9
4.3.3 First Conversion Board ..................................................................4-9
4.3.4 Upconverter Control Board .......................................................... 4-10
4.4 Control Monitoring/Power Supply Module ............................................... 4-10
4.4.1 Power Protection Board ............................................................... 4-11
4.4.2 Control Board ............................................................................ 4-12
4.4.2.1 Schematic Page 1.............................................................. 4-12
4.4.2.2 Schematic Page 2.............................................................. 4-12
4.4.2.3 Schematic Page 3.............................................................. 4-13
4.4.2.4 Schematic Page 4.............................................................. 4-13
4.4.2.5 Schematic Page 5.............................................................. 4-13
4.4.3 Switch Board ............................................................................. 4-14
4.4.4 Switching Power Supply Assembly................................................ 4-14
4.5 Power Amplifier Module Assembly (In 5-50W Transmitters) ..................... 4-14
4.5.1 1-Watt Amplifier Module Assembly ............................................... 4-14
4.5.2 1-Watt UHF Amplifier Board ........................................................ 4-15
4.5.3 40 Watt UHF Amplifier Assembly.................................................. 4-15
4.5.4 UHF Module Assembly, RF Module Pallet ....................................... 4-16
4.5.5 Coupler Board Assembly ............................................................. 4-16
4.5.6 Amplifier Control Board ............................................................... 4-16
4.5.6.1 Schematic Page 1.............................................................. 4-17
4.5.6.2 Schematic Page 2.............................................................. 4-17
4.5.6.3 Schematic Page 3.............................................................. 4-18
4.6 Or Driver Amplifier Module Assembly (In high power Transmitters)........... 4-19
4.6.1 1-Watt Amplifier Module Assembly ............................................... 4-19
4.6.2 1-Watt UHF Amplifier Board ........................................................ 4-19
4.6.3 40 Watt UHF Amplifier Assembly.................................................. 4-20
4.6.3.1 250 Watt UHF Amplifier Assembly ....................................... 4-20
4.6.4 Coupler Board Assembly ............................................................. 4-21
4.6.5 Amplifier Control Board ............................................................... 4-21
4.6.5.1 Schematic Page 1.............................................................. 4-21
LX Series, Digital, Rev. 4
ii
March 8, 2007
Digital UHF Driver/Transmitter
Table of Contents
TABLE OF CONTENTS - (Continued)
SECTION
PAGE
4.6.5.2 Schematic Page 2.............................................................. 4-22
4.6.5.3 Schematic Page 3.............................................................. 4-23
4.7 Dual Peak Detector Board..................................................................... 4-23
CHAPTER 5 DETAILED ALIGNMENT PROCEDURES
5.1 System Preparation ...............................................................................5-1
5.1.1 Module Replacement.....................................................................5-1
5.1.2 Initial Test Set Up ........................................................................5-1
5.2 LX Series Exciter/Amplifier Chassis Assembly ...........................................5-1
5.2.1 IF Processor Module Assembly .......................................................5-2
5.3 Setting up the drive level of the transmitter up to 50 Watt.........................5-2
5.3.1 Setting up the Manual AGC............................................................5-2
5.3.2 Setting up the Auto AGC ...............................................................5-2
5.4 Changing the transmitter channel procedure ............................................5-3
5.5 Calibration of Output & Reflected Power for transmitters up to 50W ............5-4
5.5.1 Calibration of Output Power for transmitters up to 50W....................5-5
5.5.2 Calibration of Reflected Power for transmitters up to 50W ................5-5
5.6 Setting ALC Gain, AGC1, AGC2 and AGC Cutback is Xmitrs above 50W .......5-5
5.7 Calibration of Output & Reflected Power for transmitters above 50W...........5-6
5.7.1 Calibration of Forward Power for transmitters above 50W .................5-6
5.7.2 Calibration of Reflected Power for transmitters above 50W ...............5-6
5.8 Linearity Correction Adjustment ..............................................................5-7
5.9 Frequency Response Delay Equalization Adjustment..................................5-8
APPENDICES
APPENDIX A INNOVATOR LX SERIES SPECIFICATIONS
APPENDIX B DRAWINGS AND PARTS LISTS
APPENDIX C TRANSMITTER LOG SHEET
LX Series, Digital, Rev. 4
iii
March 8, 2007
Digital UHF Driver/Transmitter
Table of Contents
LIST OF FIGURES
FIGURE
1-1
PAGE
Brady Marker Identification Drawing.................................................1-1
2-1
2-2
2-3
Digital LX Series Front View Trays and Assemblies .............................2-1
Example of switching and displayed count with two faulted exciters.....2-2
Rear View LX Series Chassis Assembly............................................ 2-15
3-1
3-2
3-3
3-4
3-5
3-6
1 kW Minimum Ventilation Configuration...........................................3-4
Tray Slide Cabinet Mounting Diagram ...............................................3-6
Front and Rear View Reconnection Drawing.......................................3-6
Cabinet Front and Rear View Reconnection Drawing...........................3-7
AC Input Box Assembly...................................................................3-7
Rear View of Exciter Driver..............................................................3-8
4-1
4-2
4-3
4-4
40 Watt UHF Amplifier Module ....................................................... 4-15
250 Watt UHF Amplifier Module ..................................................... 4-16
40 Watt UHF Amplifier Module ....................................................... 4-19
250 Watt UHF Amplifier Module ..................................................... 4-20
5-1
Typical Digital Spectrum .................................................................5-8
LX Series, Digital, Rev. 4
iv
Digital UHF Driver/Transmitter
Table of Contents
LIST OF TABLES
TABLE
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
2-18
2-19
2-20
2-21
2-22
2-23
PAGE
Digital LX Series Assemblies and Tray...............................................2-1
Digital Modulator Status Indicators...................................................2-4
Digital Modulator Sample ................................................................2-4
Digital Modulator Alignment Port ......................................................2-4
IF Processor Front Panel Switch .......................................................2-5
IF Processor Front Panel Status Indicators ........................................2-5
IF Processor Front Panel Control Adjustments....................................2-5
IF Processor Front Panel Sample ......................................................2-6
VHF/UHF Upconverter Front Panel Switch..........................................2-6
VHF/UHF Upconverter Front Panel Status Indicators...........................2-7
VHF/UHF Upconverter Front Panel Control Adjustments......................2-7
VHF/UHF Upconverter Front Panel Samples .......................................2-7
Controller/Power Supply Front Panel Display .....................................2-8
Controller/Power Supply Front Panel Status Indicators .......................2-8
Controller/Power Supply Front Panel Control Adjustments...................2-8
Power Amplifier Front Panel Status Indicators....................................2-9
Power Amplifier Front Panel Control Adjustments............................. 2-10
Power Amplifier Front Panel Sample ............................................... 2-10
Driver Amplifier Front Panel Status Indicators.................................. 2-11
Driver Amplifier Front Panel Control Adjustments............................. 2-11
Driver Amplifier Front Panel Sample ............................................... 2-11
LX Series Exciter Driver Customer Remote Connections.......... 2-15
(Optional) Exciter Switcher Customer Remote Connections .... 2-17
3-1
LX Series Digital Transmitters AC Input and Current Requirements......3-1
3-2
Rear Chassis Connections for LX Series Digital Exciter/Driver ..............3-8
(Optional) Exciter Switcher Tray Menu Screens ............................................... 3-10
3-3
Exciter Switcher Menu 01 Splash Screen #1.................................... 3-11
3-4
Menu 02 Splash Screen #2............................................................ 3-11
3-5
Menu 03 Exciter Switcher Control Screen, Automatic Operation......... 3-11
3-6
Menu 04 Exciter Switcher Control Screen, Manual Operation ............. 3-11
3-7
Menu 05 Exciter Switcher Control Screen, Amps On Line .................. 3-11
3-8
Menu 06 Exciter Switcher Control Screen, Cancel Auto Back up......... 3-12
3-9
Menu 07 Exciter Switcher Control Screen, B Back up to A ................. 3-12
3-10
Menu 08 Exciter Switcher Control Screen, back up Changeover ......... 3-12
3-11
Menu 09 Exciter Switcher Control Screen, Ext Amp Status................ 3-12
3-12
Menu 10 Exciter Switcher Control Screen, Ext Amp Status................ 3-12
Digital Exciter/Driver System Controller Screens
3-13
Menu 01 Splash Screen #1............................................................ 3-13
3-14
Menu 02 Splash Screen #2............................................................ 3-13
3-15
Menu 10 Main Screen ................................................................... 3-13
3-16
Menu 11 Error List Access Screen................................................... 3-14
3-17
Menu 12 Transmitter Device Data Access Screen ............................. 3-14
3-18
Menu 13 Transmitter Configuration Access Screen ........................... 3-14
3-19
Menu 20 Error List Display Screen .................................................. 3-14
3-20
Menu 30 Transmitter Device Details Screen .................................. 3-15
3-21
Menu 30-1 System Details Screens.............................................. 3-15
3-22
Transmitter Device Parameters Detail Screens .............................. 3-15
3-23
Menu 40 Authorized Personnel Screen ......................................... 3-17
3-24
Menu 40-1 Transmitter Set Up: Power Control Screen ................... 3-17
3-25
Menu 40-2 Transmitter Set Up: Model Select Screen ..................... 3-18
LX Series, Digital, Rev. 4
Digital UHF Driver/Transmitter
Table of Contents
LIST OF TABLES – (continued)
TABLE
3-26
3-27
3-28
3-29
3-30
3-31
3-32
3-33
3-34
3-35
3-36
3-37
3-38
3-39
3-40
3-41
3-42
3-43
................................................................................................ PAGE
Menu 40-3 Transmitter Set Up: Upconverter Channel Select Screen 3-18
Menu 40-4 Transmitter Set Up: Serial Address Screen ................... 3-18
Menu 40-6 Transmitter Set Up: System Forward Power Cal. Screen. 3-18
Menu 40-6 Transmitter Set Up: System Reflected Power Cal. Screen . 3-19
Menu 40-7 Transmitter Set Up: Fwrd Pwr Fault Threshold Screen...... 3-19
Menu 40-8 Transmitter Set Up: Refl Power Fault Threshold Screen .... 3-19
Menu 40-10 Transmitter Set Up: Auto Standby Control Screen ......... 3-19
Menu 40-12 Transmitter Set Up: Inner Loop Gain Control Screen ...... 3-20
Menu 40-13 Transmitter Set Up: Optional System Control Screen ..... 3-20
Menu 40-14 Transmitter Set Up: DM 8 Optional Mode Control........... 3-20
Menu 40-15 Transmitter Set Up: DM 8 Source Select Control............ 3-20
Menu 40-16 Transmitter Set Up: DM 8 Nonlinear Correction Control .. 3-20
Menu 40-16 Transmitter Set Up: DM 8 Fixed Table Selection Control . 3-21
Menu 40-16 Transmitter Set Up: DM 8 Fixed Phase Selection Control 3-21
Menu 40-16 Transmitter Set Up: DM 8 Find Table Selection Control... 3-21
Menu 40-17 Transmitter Set Up: DM 8 Linear Correction Control ....... 3-21
Menu 40-18 Transmitter Set Up: AGC Mode Control ......................... 3-21
Menu 40-19 Transmitter Set Up: Remote Commands Control............ 3-22
LX Series, Digital, Rev. 4
vi
Digital UHF Driver/Transmitter
Chapter 1, Introduction
Chapter 1
Introduction
1.1 Manual Overview
1.2 Assembly Designators
This manual explains the installation,
setup, alignment, and maintenance
procedures for the LX Series modular
Digital UHF driver/transmitter. If your
transmitter contains external power
amplifier assemblies, then information
and drawings on the external amplifier
assemblies are contained in Volume 2.
Axcera has assigned assembly numbers,
Ax designations such as A1, where
x=1,2,3…etc, 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.
This instruction manual is divided into five
chapters and supporting appendices.
Chapter 1, Introduction, contains
information on the assembly numbering
system used in the manual, safety,
maintenance, return procedures, and
warranties. Chapter 2, system
description, maintenance and remote
control connections, describes the
transmitter and includes discussions on
system control and status indicators,
maintenance and remote control
connections. Chapter 3, site
considerations, installation and setup
procedures, explains how to unpack,
install, setup, and operate the transmitter.
Chapter 4, circuit descriptions, contains
circuit-level descriptions for boards and
board-level components in the
transmitter. Chapter 5, Detailed
Alignment Procedures, provides
information on adjusting the system
assemblies for optimal operation.
Appendix A contains system
specifications. Appendix B contains
drawings and parts lists. Appendix C
contains a transmitter log sheet
The cables that connect between the
boards within a tray or assembly and
that connect between the trays, racks
and cabinets are labeled using Brady
markers. Figure 1-1 is an example of a
Brady marked cable. There may be as
few as two or as many as four Markers
on any one cable. These Brady markers
are read starting furthest from the
connector. If there are four Brady
Markers, this marker is the transmitter
number such as transmitter 1 or
transmitter 2. The next or the furthest
Brady Marker is the rack or cabinet
number on an interconnect cable or the
board number within a tray. The next
number on an interconnect cable is the
Tray location or number. The Brady
marker closest to the connector is the
jack or connector number on an
interconnect cable or the jack or
connector number on the board within a
tray.
Figure 1-1 Brady Marker Identification Drawing
LX Series, Digital, Rev. 4
1-1
Digital UHF Driver/Transmitter
Chapter 1, Introduction
1.3 Safety
Replacement Parts – When
replacement parts are used, 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.
The UHF transmitter systems
manufactured by Axcera are designed to
be easy to use and repair while providing
protection from electrical and mechanical
hazards. Please review the following
warnings and familiarize yourself with the
operation and servicing procedures
before working on the transmitter
system.
1.4 Contact Information
Read All safety Instructions – All of
the safety instructions should be read
and understood before operating this
equipment.
The Axcera Field Service Department can
be contacted by phone at (724) 8738100 or by fax at (724) 873-8105.
Retain Manuals – The manuals for the
transmitter should be retained at the
transmitter site for future reference.
Axcera provides two sets of manuals for
this purpose; one set can be left at the
office while one set can be kept at the
site.
Before calling Axcera, please be prepared
to supply the Axcera technician with
answers to the following questions. This
will save time and help ensure the most
direct resolution to the problem.
1. What are the Customers’ Name
and call letters?
2. What are the model number and
type of transmitter?
3. Is the transmitter digital or
analog?
4. 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 control/power
supply LCD readings and the
status of LEDs on the front
panels of the modules. If
possible, include the
control/power supply LCD
readings before the problem
occurred.
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 Operating Instructions – All of
the operating and use instructions for the
transmitter 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 driver/transmitter, and
to protect the unit from overheating,
these openings must not be blocked.
1.5 Return Material 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#).
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.
LX Series, Digital, Rev. 4
1-2
Digital UHF Driver/Transmitter
Chapter 1, Introduction
The RMA# can be obtained from any
Axcera Field Service Engineer by
contacting the Axcera Field Service
Department at (724) 873-8100 or by fax
at (724) 873-8105. This procedure
applies to all items sent to the Field
Service Department regardless of
whether the item was originally
manufactured by Axcera.
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 Axcera's
operating instructions. This warranty
shall not apply to tubes, fuses,
batteries, bulbs or LEDs.
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.
When equipment is sent to the field on
loan, an 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 an 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 exchanged assembly.
When shipping an item to Axcera, please
include the RMA# on the packing list and
on the 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:
Equipment furnished by Axcera, but not
bearing its trade name, shall bear no
warranties other than the special hoursof-use or other warranties extended by
or enforceable against the manufacturer
at the time of delivery to the buyer.
AXCERA, LLC
103 Freedom Drive
P.O. Box 525
Lawrence, PA 15055-0525 USA
For more information concerning this
procedure, call the Axcera Field Service
Department @ (724) 873-8100.
Axcera can also be contacted through email at info@axcera.com and on the
Web at www.axcera.com.
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.
1.6 Limited One Year Warranty for
Axcera Products
Axcera warrants each new product that
it has manufactured and sold against
LX Series, Digital, Rev. 4
1-3
Digital UHF Driver/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.
LX Series, Digital, Rev. 4
1-4
Digital UHF Driver/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.
LX Series, Digital, Rev. 4
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.
1-5
Digital UHF Driver/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
77
67
57
47
TEMPERATURE CONVERSION
°F = 32 + [(9/5) °C]
°C = [(5/9) (°°F - 32)]
LX Series, Digital, Rev. 4
1-6
Digital UHF Driver/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
Ultrahigh Frequency
Superhigh Frequency
Extremely High Frequency
LETTER DESIGNATIONS FOR UPPER FREQUENCY
BANDS
LETTER
FREQ. BAND
Ku
Ka
LX Series, Digital, Rev. 4
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
1-7
Digital UHF Driver/Transmitter
Chapter 1, Introduction
RETURN LOSS VS. VSWR
-10
-20
-30
N dB
-40
-50
-60
-70
1.001
1.01
1.1
VSWR
LX Series, Digital, Rev. 4
1-8
2.0
Digital UHF Driver/Transmitter
Chapter 1, Introduction
ABBREVIATIONS/ACRONYMS
AC
Alternating Current
LED
Light emitting diode
AFC
Automatic Frequency Control
LSB
Lower Sideband
ALC
Automatic Level Control
MPEG
Motion Pictures Expert Group
AM
Amplitude modulation
O/P
Output
AGC
Automatic Gain Control
PLL
Phase Locked Loop
AWG
American wire gauge
PCB
Printed circuit board
BER
Bit Error Rate
QAM
Quadrature Amplitude Modulation
BW
Bandwidth
SMPTE Society of Motion Picture and
Television Engineers
DC
Direct Current
D/A
Digital to analog
DSP
Digital Signal Processing
DTV
Digital Television
dB
Decibel
dBm
Decibel referenced to 1 milliwatt
dBmV
Decibel referenced to 1 millivolt
dBw
Decibel referenced to 1 watt
FEC
Forward Error Correction
FM
Frequency modulation
FPGA
Field Programmable Gate Array
Hz
Hertz
ICPM
Incidental Carrier Phase Modulation
I/P
Input
IF
Intermediate Frequency
LX Series, Digital, Rev. 4
VSB
1-9
Vestigial Side Band
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
Chapter 2
System Description & Remote Control Connections
2.0 System Overview
The model number scheme for a
Innovator LX Series transmitter is as
follows (where #### = power in watts):
The LX Series are complete Digital UHF
modular television transmitters that
operate at an average output power of 5
Watts to 50 Watts. When used as a
driver, it operates at the needed drive
level to produce the desired output
power level of the PA Assembly or
Assemblies.
A1
A3
LU####ATD - LX Series UHF Digital Xmtr
(Example):
LU50ATD is a 50 Watt Digital UHF Xmtr
The LX Series digital transmitter is made
up of the modules and assemblies as
listed in Table 2-1 and shown in Figure 21.
A5
A4
A6
Figure 2-1: Digital LX Series Front View Trays and Assemblies
Table 2-1: Digital LX Series Trays and Assemblies
ASSEMBLY DESIGNATOR
TRAY/ASSEMBLY NAME
Chassis Assembly
A1
A3
A4
A5
A6
DM8 Digital Modulator Module
IF Processor Module
Control & Monitoring/Power
Supply Module
VHF/UHF Upconverter Module
Power Amplifier Module for 5-50
Watt Transmitter
OR
A6
Driver Amplifier Module for High
Power Transmitter
A11
Backplane Board, V2, LX Series
LX Series, Digital, Rev. 4
2-1
PART NUMBER
1304052 (110 VAC) or
1304053 (220 VAC
1306342
1301938
1301936 (110 VAC) or
1303229 (220 VAC)
1303829
1303770
1303771 (1kW),
1303874 (2kW) OR
1303770 (3kW & above)
1304047
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
2.1 (Optional) Exciter Switcher Tray,
110 VAC (1305727) or 220 VAC
(1305715); Appendix B
any entries in its fault log. Versions 2.0
and greater now rely on the reported
output power of the selected exciter to
determine if a changeover is required.
The (optional) Single Channel Auto
Switcher is part of the dual exciter
system. The assembly is made up of
(A1) a Single Channel Exciter Switcher
Tray (1305715) with a separate (A2)
coaxial transfer relay, mounted on a
bracket that faces toward the rear of the
cabinet, behind the Switcher Tray. The
tray is factory set for the proper voltage.
If the On Air Exciter should malfunction,
due to the driver stage of the On Air
Exciter reporting less that 50% power
while that specific exciter is enabled and
has been so enabled for more than 30
seconds, the Exciter Switcher will
attempt to switch to the Back Up Exciter
3 times, each time checking its status.
If after 3 times the back up exciter is
not operational the exciter switcher
changeover function will be disabled for
5 minutes. After 5 minutes it will start
again to switch between exciters.
Exciter Switcher operations when it is in
'Automatic Operation' have changed in
version 2.0 or newer. Older versions of
the switcher code would change exciters
if the primary exciter reported any fault
and the back-up exciter did not have
Figure 2-2. Example of switching and displayed count with two faulted exciters:
Exciter A: Becomes Faulted
Exciter Change 1: Counter 1 set
Exciter B: Faulted
Exciter Change 2: Counter 2 set
Exciter A: Faulted
Exciter Change 3: Counter 3 set
Exciter B: Faulted
No Exciter Change for 5 minutes
Remote and front panel exciter changes
are permitted during the 5 minute
lockout of the automatic exciter
changes. If the exciter switcher is
placed into Manual mode, all exciter
change counters and the lockout counter
are cleared.
determination that the selected Exciters
Driver PA is generating 50% output
power or more.
The numbers shown on the Upper right
of the second LCD screen indicates that
the Exciter has switched that many
times. An L indicates that the 5 Minute
Lock Out has occurred. The default
main menu will typically show 'MANUAL
OPERATION', or 'AUTOMATIC
There is a built in 30 second delay from
when the Exciter is changed from
Standby to Operate to allow for the
LX Series, Digital, Rev. 4
2-2
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
OPERATION', or 'AUTOMATIC LOCK XXX'
where xxx is the number of seconds
before the exciter can again
automatically switch between exciters.
During this time the switcher will not
automatically switch.
a 4 x 20 display providing a four-line
readout of the operation and control of
the exciter switcher. The LCD screens
are detailed in Chapter 3.
2.2 Exciter Amplifier Chassis
Assembly, V2, {1304052 (110 VAC)
or 1304053 (220 VAC); Appendix B}
An indication of 123L means that a 3
Fault has occurred and the 5 minute lock
out is in effect.
The chassis assembly is factory set for
operation using 110 VAC or 220 VAC. All
of the modules, except the power
amplifier module and the power supply
section of the Control & Monitoring/Power
Supply Module, plug directly into a
backplane board. The backplane board
provides module to module
interconnection as well as interconnection
to remote command and control
connectors.
Timers do not prevent manual switching
of the exciters thru the remote or the
front panel.
If the switcher attempts to change
exciters and the backup exciter is not
present or it does not change to operate
after the relay positions are changed,
the switcher returns to the primary
exciter, enables the primary exciter and
then locks out further exciter changes
for 5 minutes.
2.2.1 DM-8 Modulator Assembly,
DT1D (1306342; Appendix B)
Menu 2 is new. It reports the status of
the exciters. They can either be not
present is indicated by a 'NO COM
(OFFLINE)' message, in the standby
mode, or in the operate mode as
indicated by the display of the driver
output power. For the first 30 seconds
of operate mode, the switcher will
indicate the number of seconds
remaining in the 30 second countdown.
After 30 seconds of operation, the
display will indicate the number of
current faults on the exciter. These
faults are all inclusive and may indicate
problems with the external amplifier,
therefore it is possible to see a number
of current faults but the driver power to
be greater than 50% and the exciter to
remain in use.
The DM8 modulator is an ATSC
compliant 8 VSB modulator that slides
into the left most slot in the Innovator
LX Driver chassis assembly. The DM8
modulator accepts a SMPTE-310 MPEG
data stream input and outputs a 6 MHz
wide IF output centered at 44 MHz with
a pilot carrier at 46.69 MHz. The DM8
modulator provides linear and nonlinear
correction capability for the transmission
path as well as internal test sources that
are used during initial transmitter
installation. All of the functions of the
DM8 modulator are controlled from the
LX Controller LCD display and
pushbuttons.
The coaxial relay has the RF outputs
from both Exciters connected to its
inputs and, depending on if the
energizing voltage is applied or not, the
selected Exciter RF Output is connected
to the external amplifiers and the RF
output from the other exciter is
connected to a load. The front panel has
LX Series, Digital, Rev. 4
2-3
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
Table 2-2. Digital Modulator Status Indicators
LED
FUNCTION
Indicates the presence of a valid MPEG stream at the J1-2B
MPEG (Green)
input jack.
Indicates that the DM8 symbol clock is locked to the
PLL A (Green)
frequency of the 10 MHz reference.
Indicates that the pilot frequency is locked to the incoming
PLL B (Green)
10 MHz reference.
Table 2-3. Digital Modulator Sample
SAMPLE
DESCRIPTION
Provides a sample of the IF output from the modulator at
IF Sample
approximately a –20 dBm level.
Table 2-4. Digital Modulator Alignment Port
PORT
DESCRIPTION
RS-232
Serial port used for the initial DM8 modulator alignment.
2.2.2 (A3) IF Processor Module
Assembly (1301938; Appendix B)
If the IF Processor interlock signal is not
present, the LX Series Transmitter
Exciter Driver RF output is Muted
(turned off).
The Control & Monitoring/Power Supply
module uses the IF Processor module for
System output power control. Through
the front panel display or a remote
interface, an operator can set the
transmitter's RF output power. The
range of RF power adjustment is
between 0% (full off) and 105% (full
power plus). A front panel IF Processor
module potentiometer sets the upper
limit of RF power at 120%. The
system's Control Monitoring board
compares the RF Power Monitoring
module RF power level with the desired
level and uses the IF Power Control PWM
line to correct for errors.
The (A3) IF Processor Assembly contains
the IF Processor Board (1301977). The IF
Processor provides pre-correction to
ensure broadcast quality output signal.
The pre-correction consists of amplitude
linearity correction, Incidental Carrier
Phase Modulation (ICPM) correction and
frequency response correction.
In digital systems, a digital level control
(DLC) voltage is generated on the IF
Processor module and sent to the digital
modulator. RF power control is
implemented by changing the DLC
voltage provided to the digital
modulator. The 'RF High' potentiometer
sets the upper adjusted range of RF
control circuit output to 120%.
The IF Processor module is configured
either for an analog or digital system.
Pin 13C of the IF Processor module is
grounded in analog systems and left not
connected in digital systems. An IF
Processor Interlock signal is used to
report the presence of the IF Processor
module to the Control Monitoring board.
LX Series, Digital, Rev. 4
The IF Processor module provides a
reference ALC voltage to the system's
Upconverter. When the ALC voltage
2-4
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
decreases, the Upconverter
automatically lowers the system output
power through the AGC circuits.
modulation level is too low or nonexistent, a Modulation Present fault is
reported to the Control Monitoring
board. When the controller detects this
fault, it can be set to Automatically Mute
the transmitter or in Manual mode the
transmitter will continue to operate at
25% output.
The IF Processor module has a front
panel switch to select Auto or Manual
ALC. When Manual ALC is selected, the
reference ALC voltage is set by a front
panel potentiometer. In this condition,
the RF power level control circuit is
removed from use. When the ALC select
switch is changed to Auto, the RF power
level control circuit will start at low
power and increase the RF output until
the desired output power is attained.
The IF Processor module Input Signal
level is monitored. If the signal level is
too low or non-existent, an Input fault is
reported on the Control Monitoring
board. When the IF Processor board
detects an Input Signal fault it
automatically Mutes the transmitter.
The system controller does not Mute on
an IF Processor Input fault.
The IF Processor module Modulation
Present signal is monitored. If the
Table 2-5. IF Processor Front Panel Switch
SWITCH
FUNCTION
When Manual ALC is selected, the reference ALC voltage is set
by the ALC Gain front panel potentiometer.
MAN/AUTO ALC
When Auto ALC is selected, the IF level control circuit will
automatically increase the IF output until the desired output
power is attained.
Table 2-6. IF Processor Front Panel Status Indicators
LED
FUNCTION
When lit it indicates that there is a loss of the IF Input signal to the
INPUT FAULT (Red)
IF Processor. Transmitter can be set to Mute on an IF Input Fault.
When lit it indicates that the required gain to produce the desired
ALC Fault (Red)
output power level has exceeded the operational range of the ALC
circuit. The LED will also be lit when ALC is in Manual.
When lit it indicates that the IF input signal is cut back but the
MUTE (Red)
enable to the Power Supply is present and the +32 VDC remains on.
Table 2-7. IF Processor Front Panel Control Adjustments
POTENTIOMETERS
DESCRIPTION
FREQUENCY
These three variable resistors, R103, R106 & R274, adjust the
RESPONSE
depth of gain for the three stages of frequency response correction.
EQUALIZER
Adjusts the gain of the transmitter when the transmitter is in the
ALC GAIN
Auto ALC position.
Adjusts the gain of the transmitter when the transmitter is in the
MAN GAIN
Manual ALC position.
These three variable resistors adjust the threshold cut in for the
three stages of linearity pre-correction. R211 and R216, the top
LINEARITY
two pots, are adjusted to correct for in phase amplitude distortions.
CORRECTION
R 231, the bottom pot, is adjusted to correct for quadrature phase
distortions.
LX Series, Digital, Rev. 4
2-5
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
Table 2-8. IF Processor Front Panel Sample
SMA CONNECTOR
DESCRIPTION
IF SAMPLE
Sample of the pre-corrected IF output of the IF Processor
2.2.3 (A5) VHF/UHF Upconverter
Module Assembly (1303829;
Appendix B)
frequency centered at 1044 MHz. A
filter selects the appropriate conversion
product, which is then amplified to a
level of approximately –4 dBm. The
frequency of the first conversion LO1
can be shifted by ± 10 kHz to generate
channel offsets of 10kHz. For +offsets
the frequency is 999.99 MHz and for –
offsets the frequency is 1000.01 MHz.
This signal is applied to a second mixer
mounted on the downconverter board
that converts it back to a broadcast
channel (2-69) by an LO2 that operates
in 100kHz steps between 1.1-1.9 GHz
depending on the channel selected. The
LO2 frequency equals the Channel
center frequency plus the LO1 frequency
plus 44 MHz. (As an example CH14+:
Center Frequency is 473.01 MHz and
LO1 is 999.99 MHz therefore LO2 is
473.01 + 999.99 + 44, which equals
1517.00 MHz.)
The output of the mixer is applied to a
900 MHz Low pass filter to remove
unwanted conversion products. The
resulting signal is amplified and applied
to a Pin diode attenuator before it is
connected to the output of the
upconverter. This pin diode attenuator
adjusts the gain of the module and is
controlled by an Automatic Gain Control
circuit, which maintains a constant
power out of the upconverter, and also
the transmitter, that connects to the
power amplifier module.
The VHF/UHF Upconverter Module
Assembly contains (A1) a Downconverter
Board Assembly (1303834), (A3) a First
Conversion Board, LX Series (1303838),
(A2) a L-Band PLL Board, LX Series
(1303846) and (A4) an Upconverter
Control Board (1304760).
A 0 dBm 44 MHz IF input to the
upconverter through the backplane
board is applied to a mixer mounted on
the first conversion board. Also applied
to the mixer is a nominal 1 GHz LO1.
The mixer converts it to a nominal
Table 2-9. VHF/UHF Upconverter Front Panel Switch
SWITCH
FUNCTION
When Manual AGC is selected, the reference AGC voltage is
set by the AGC Manual Gain front panel potentiometer.
MAN/AUTO AGC
(Left Manual, Right AGC) When Auto AGC is selected, the RF power level control circuit
will automatically increase the RF output until the desired
output power is attained.
LX Series, Digital, Rev. 4
2-6
Digital UHF Driver/Transmitter
Table 2-10. VHF/UHF
LED
PLL 1 Fault
(Red)
PLL 2 Fault
(Red)
AGC Fault
(Red)
AGC Override
(Red)
Man Gain
(Amber)
Chapter 2, System Description &
Remote Control Connections
Upconverter Front Panel Status Indicators
FUNCTION
When lit it indicates that the 1 GHz PLL is unlocked
When lit it indicates that the 1.1 –1.9 GHz PLL is unlocked
When lit it indicates that the AGC is out of range.
When lit it indicates that the AGC is cutting back due to too much
drive to the driver module.
When lit it indicates that the AGC is bypassed in Manual.
Table 2-11. VHF/UHF Upconverter Front Panel Control Adjustments
POTENTIOMETERS
DESCRIPTION
Adjusts the gain of the upconverter and transmitter when in the
MAN GAIN ADJ
Manual AGC position.
Adjusts the gain of the upconverter and transmitter when in the
AGC ADJ
Auto AGC position.
AGC CUTBACK ADJ Adjusts the point at which the transmitter will cut back in power,
(AGC OVERRIDE)
due to too much drive, when the Transmitter is in Auto AGC.
Table 2-12. VHF/UHF Upconverter Front Panel Samples
SMA CONNECTOR
DESCRIPTION
Sample of the 1 GHz nominal LO1 signal in the Upconverter as
LO1 SAMPLE
generated on the L-Band PLL Board.
Sample of the 1.1-1.9 GHz LO2 signal in the Upconverter as
LO2 SAMPLE
generated on the First Conversion Board.
RF SAMPLE
Sample of the On Channel RF Output of the Upconverter
The (A4) Control & Monitoring/Power
Supply Assembly is made up of a Control
Board (1302021), a Power Protection
Board (1302837) and a Switch Board
(1527-1406). The Assembly also
contains a switching power supply that
provides ±12 VDC to the rest of the
modules in the chassis and +32 VDC to
the Power Amplifier module.
2.2.4 (A4) Control & Monitoring/
Power Supply Module Assembly
{1301936 (110VAC) or 1303229
(220VAC); Appendix B}
The Assembly provides all transmitter
control and monitoring functions. The
Front panel LCD allows monitoring of
system parameters, including forward
and reflected power, transistor currents,
module temperatures and power supply
voltages.
8A
4A
LX Series, Digital, Rev. 4
2-7
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
Table 2-13. Controller/Power Supply Display
DISPLAY
FUNCTION
A 4 x 20 display providing a four-line readout of the internal
LCD
functions, external inputs, and status. See Chapter 3,
Controller/Power Supply Display Screens, for a listing of displays.
Table 2-14. Controller/Power Supply Status Indicator
LED
FUNCTION
When lit it indicates that the transmitter is in the Operate Mode. If
OPERATE
transmitter is Muted the Operate LED will stay lit, the transmitter
( green )
will remain in Operate, until the input signal is returned.
Red indicates that a problem has occurred in the transmitter. The
FAULT
transmitter will be Muted or placed in Standby until the problem is
( red or green )
corrected.
DC OK
Green indicates that the switchable fuse protected DC outputs that
( red or green )
connect to the modules in the transmitter are OK.
Table 2-15. Controller/Power Supply Control Adjustments
POTENTIOMETERS
DESCRIPTION
DISPLAY CONTRAST Adjusts the contrast of the display for desired viewing of screen.
2.2.5 (A6) Power Amplifier Module
Assembly, Exciter, 5W-50W
Transmitter (1303770; Appendix B)
Module (1304490) and a RF Module
Pallet, Philips (1300116).
The Power Amplifier Module contains
Broadband LDMOS amplifiers that cover
the entire UHF band with no tuning
required. They amplify the RF to the
10W to 50W output power level of the
transmitter.
The Power Amplifier of the
Transmitter/Exciter Driver is used to
amplify the RF output of the
Upconverter module. A cable, located on
the rear chassis, connects the RF output
from the Upconverter at J23 to J24 the
RF input to the PA Assembly. This
module contains RF monitoring circuitry
for both an analog and a digital system.
Control and monitoring lines to the
Power Amplifier module are routed
through the floating blind-mate
connector of the Control &
Monitoring/Power Supply module.
NOTE: The (A6) Driver Amplifier Module
Assembly (1303771) replaces the Power
Amplifier Module Assembly (1303770) in
High Power Transmitters. It is also used
as a driver in 3kW or higher transmitters.
The 50 Watt Transmitter/Exciter Driver
Power Amplifier module and any
External Amplifier modules contain the
same control and monitoring board.
This board monitors RF output power,
RF reflected power, the current draw of
The (A6) Power Amplifier Module
Assembly is made up of a Coupler Board
Assembly (1301949), an Amplifier
Control Board (1303682), a 1 Watt
Module Assembly (1302891), a 40W UHF
LX Series, Digital, Rev. 4
2-8
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
amplifier sections, the supply voltage,
and the temperature of the PA heat sink.
connections are transferred through the
power supply connector to the
backplane board on a five position
header. All four positions of control
board switch SW1 must be set on to
route these lines as the system's RF
power signals. In systems of output
power greater than 50 Watts, system
power is monitored by an external
module that is connected to TB31 and
control board SW1 switches must be set
off.
The RF power detector circuit outputs
vary with operating frequency. These
circuits must be calibrated at their
intended operating frequency. Front
panel adjustment potentiometers are
used to calibrate the following:
Power Amplifier Calibration Adjustments
R201
R202
R203
R205
Reflected Power Cal
Forward Power Cal
(NOT USED) Aural Power Cal
(NOT USED) Aural Null
The Forward Power of the
Transmitter/Exciter Driver Power
Amplifier module is routed to the
Upconverter module as AGC #1. A
system over-drive condition is detected
when this value rises above 0.9 VDC.
When an over-drive condition is
detected, the Upconverter module
reduces its RF output level. For values
less than 0.9 VDC, the Upconverter uses
this voltage for automatic gain.
the Forward power of an Exciter Driver
Power Amplifier and the Forward power
of any external amplifier, is reported by
the system Control Monitoring module.
If the Control Monitoring module is
monitoring a 5-50 Watt Transmitter,
system power is measured in the Power
Amplifier module. The wired
Table 2-16. Power Amplifier Status Indicator
LED
FUNCTION
When lit Green, it indicates that the PA is in the Operate Mode. If a
ENABLED
Mute occurs, the PA will remain Enabled, until the input signal is
(Green)
returned.
DC OK
When lit Green, it indicates that the fuse protected DC inputs to the
(Green)
PA module are OK.
TEMP
When lit Green, it indicates that the temperature of the heatsink
(GREEN)
assembly in the module is below 78ûC.
MOD OK
When lit Green, it indicates that the PA Module is operating and has
(Green)
no faults.
If the Module OK LED is Red and blinking a fault is present. The
meaning of the blinking LED is as follows.
MOD OK
(RED)
Blink indicates Amplifier Current Fault.
Blinks indicate Temperature Fault.
Blinks indicate +32V Power Supply Over Voltage Fault.
Blinks indicate +32V Power Supply Under Voltage Fault.
Blinks indicate Reflected Power Fault.
Blinks indicate +12V or –12V Power Supply Fault
LX Series, Digital, Rev. 4
2-9
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
Table 2-17. Power Amplifier Control Adjustments
POTENTIOMETERS
DESCRIPTION
RFL CAL
Adjusts the gain of the Reflected Power monitoring circuit
FORWARD CAL
Adjusts the gain of the Forward Power monitoring circuit
AURAL CAL
(NOT USED) Adjusts the gain of the Aural Power monitoring circuit
(NOT USED) Adjusts the offset of the Forward Power monitoring
AURAL NULL
circuit based on the Aural signal level..
Table 2-18. Power Amplifier Sample
DISPLAY
FUNCTION
FWD SAMPLE
RF sample of the amplified signal being sent out the module on J25.
2.2.6 (A6) Driver Amplifier Module
Assembly {1303771(500W) or
1303874(1kW; Appendix B)}
external amplifiers to the output power
level of the transmitter.
The Driver Power Amplifier is used to
amplify the RF output of the
Upconverter module. A cable, located on
the rear chassis, connects the RF output
from the Upconverter at J23 to J24 the
RF input to the driver PA Assembly. This
module contains RF monitoring circuitry
for both an analog and a digital system.
Control and monitoring lines to the
Driver Power Amplifier module are
routed through the floating blind-mate
connector of the Control &
Monitoring/Power Supply module.
NOTE: The (A6) Driver Amplifier Module
Assembly {1303771(500W) or
1303874(1kW)} replaces the Power
Amplifier Module Assembly (1303770)
when the amplifier module is used as a
driver for any external PA assemblies.
The (A6) Power Amplifier Module
Assembly is made up of a Coupler Board
Assembly (1227-1316), an Amplifier
Control Board (1303682), a 1 Watt
Module Assembly (1302891), a 40W UHF
Module (1304490) and in a 1303874
Assembly there is also a RF Module Pallet
(1300116).
The Driver Power Amplifier Module
contains Broadband LDMOS amplifiers
that cover the entire UHF band with no
tuning required. They amplify the RF to
the power level, 3.5 Watts Average is
maximum, that is needed to drive the
LX Series, Digital, Rev. 4
The Driver Power Amplifier module and
any External Amplifier modules contain
the same control and monitoring board.
This board monitors RF output power,
RF reflected power, the current draw of
amplifier sections, the supply voltage,
and the temperature of the PA heat sink.
The RF power detector circuit outputs
vary with operating frequency. These
circuits must be calibrated at their
intended operating frequency. Front
panel adjustment potentiometers are
used to calibrate the following:
Power Amplifier Calibration Adjustments
R201
R202
R203
R205
Reflected Power Cal
Forward Power Cal
(NOT USED) Aural Power Cal
(NOT USED) Aural Null
The Forward power of an Exciter Driver
Power Amplifier and the Forward power
of any external amplifiers, are reported
2-10
Digital UHF Driver/Transmitter
by the system Control Monitoring
module.
If the Control Monitoring module is
monitoring a 5-50 Watt Transmitter,
system power is measured in the Power
Amplifier module. The wired
connections are transferred through the
power supply connector to the
backplane board on a five position
header. All four positions of control
board switch SW1 must be set on to
route these lines as the system's RF
power signals. In systems of output
power greater than 50 Watts, system
power is monitored by an external
Chapter 2, System Description &
Remote Control Connections
module that is connected to TB31. In
this configuration switches SW1 on the
control board must be set off.
The Forward Power of the Exciter Driver
Power Amplifier module is routed to the
Upconverter module as AGC #1. A
system over-drive condition is detected
when this value rises above 0.9 VDC.
When an over-drive condition is
detected, the Upconverter module
reduces its RF output level.
For values less than 0.9 VDC, the
Upconverter uses this voltage for
automatic gain.
Table 2-19. Driver Amplifier Status Indicator
LED
FUNCTION
When lit Green, it indicates that the PA is in the Operate Mode. If a
ENABLED
Mute occurs, the PA will remain Enabled, until the input signal is
(Green)
returned.
DC OK
When lit Green, it indicates that the fuse protected DC inputs to the
(Green)
PA module are OK.
TEMP
When lit Green, it indicates that the temperature of the heatsink
(Green)
assembly in the module is below 78ûC.
MOD OK
When lit Green, it indicates that the PA Module is operating and has
(Green)
no faults.
If the Module OK LED is Red and blinking a fault is present. The
meaning of the blinking LED is as follows.
MOD OK
(RED)
Blink indicates Amplifier Current Fault.
Blinks indicate Temperature Fault.
Blinks indicate +32V Power Supply Over Voltage Fault.
Blinks indicate +32V Power Supply Under Voltage Fault.
Blinks indicate Reflected Power Fault.
Blinks indicate +12V or –12V Power Supply Fault
Table 2-20. Driver Amplifier Control Adjustments
POTENTIOMETERS
DESCRIPTION
REFLECTED CAL
Adjusts the gain of the Reflected Power monitoring circuit
FORWARD CAL
Adjusts the gain of the Forward Power monitoring circuit
AURAL CAL
(NOT USED) Adjusts the gain of the Aural Power monitoring circuit
(NOT USED) Adjusts the offset of the Forward Power monitoring
AURAL NULL
circuit based on the Aural signal level.
Table 2-21. Driver Amplifier Sample
DISPLAY
FUNCTION
FWD SAMPLE
RF sample of the amplified signal being sent out the module on J25.
LX Series, Digital, Rev. 4
2-11
Digital UHF Driver/Transmitter
2.3 RF Output Assemblies
The driver/power amplifier RF output jack
is at an “N” connector J25, PA RF Output.
The RF output of the PA module is wither
connected to the input of the power
amplifier module assembly or to a digital
mask filter and then to the output
coupler assembly. The digital mask filter
must be tuned to meet the NTSC Digital
Mask standards. The filtered signal is
next connected to a coupler assembly
that provides a forward and a reflected
power sample for test purposes.
2.4 Control and Status
The control and status of the
exciter/amplifier Chassis assembly is found
by operating the front panel display screen
on the assembly. Detailed information on
the use of the screen is found in Chapter 3
of this manual.
2.4.1 Front Panel Display Screen
A 4 x 20 display located on the front of
the Control & Monitoring/Power Supply
Module is used in the LX Series
transmitter for control of the operation
and display of the operating parameters
of the transmitter.
2.5 System Operation
When the transmitter is in operate, as set
by the menu screen located on the
Control & Monitoring Module. The IF
Processor will be enabled, the mute
indicator on the front panel will be
extinguished. The +32 VDC stage of the
Power Supply in the Control & Monitoring
Module is enabled, the operate indicator
on the front panel is lit and the DC OK on
the front panel should also be green.
The enable and DC OK indicators on the
PA Module will also be turned to green.
When the transmitter is in standby. The
IF Processor will be disabled, the mute
indicator on the front panel will be red.
The +32 VDC stage of the Power Supply
LX Series, Digital, Rev. 4
Chapter 2, System Description &
Remote Control Connections
in the Control & Monitoring Module is
disabled, the operate indicator on the
front panel will be extinguished and the
DC OK on the front panel should remain
green. The enable and indicator on the
PA Module is also extinguished.
If the transmitter does not switch to
Operate when the operate menu is
switched to Operate, check that all faults
are cleared and that the remote control
terminal block stand-by signal is not
active.
The transmitter can be controlled by the
presence of the modulated input signal.
If the input signal to the transmitter is
lost, the transmitter will automatically
cutback and the input fault indicator on
the IF Processor module will light. When
the video input signal returns, the
transmitter will automatically return to
full power and the input fault indicator
will be extinguished.
2.5.1 Principles of Operation
Operating Modes
This transmitter is either operating or in
standby mode. The sections below
discuss the characteristics of each of
these modes.
Operate Mode
Operate mode is the normal mode for
the transmitter when it is providing RF
power output. To provide RF power to
the output, the transmitter will not be in
mute. Mute is a special case of the
operate mode where the power supply's
32 VDC section is enabled but there is
no RF output power, because of a fault
condition that causes the firmware to
hold the IF Processor module in a mute
state.
Operate Mode with Mute Condition
The transmitter will remain in operate
mode but will be placed in mute when
2-12
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
the following fault conditions exists in
the transmitter.
•
•
•
•
Auto Standby Mode
Upconverter is unlocked
Upconverter module is not present
IF Processor module is not present
Entering Operate Mode
Entering the operate mode can be
initiated a few different ways by the
transmitter control board. A list of the
actions that cause the operate mode to
be entered is given below:
•
•
•
A low on the Remote Transmitter
Operate line.
User selects "OPR" using switches
and menus of the front panel.
Receipt of an “Operate CMD” over
the serial interface.
Receipt of a “Standby CMD” over the
serial interface.
The FCC requires that certain
transmitters automatically switch to
standby operation on loss of input. The
LX Series transmitter incorporates this
feature as a user configurable setting.
When Auto Stand-By on modulation loss
is selected in the set-up menus, the
transmitter temporarily switches to
standby after ten seconds of modulation
loss. When the modulated signal as
reported by the IF Processor module is
again present, the transmitter
automatically returns to Operate mode.
Feature implemented in transmitter
software version 1.4 and above.
RF System Interlock
There are several fault or interlock
conditions that may exist in the
transmitter that will prevent the
transmitter from entering the operate
mode. These conditions are:
•
•
•
Power Amplifier heat sink
temperature greater than 78ûC.
Transmitter is Muted due to
conditions listed above.
Power Amplifier Interlock is high
indicating that the amplifier is not
installed.
Standby Mode
The standby mode in the transmitter
indicates that the transmitters output
amplifier is disabled.
Entering Standby Mode
Similar to the operate mode, the
standby mode is entered various
different ways. These are:
•
•
A low on the Remote Transmitter
Stand-By line.
Depressing the “STB” key on
selected front panel menus.
LX Series, Digital, Rev. 4
A RF System Interlock signal is provided
through TB30-5. When this signal's
circuit is completed to ground such as
through a wire between TB30-5 and
TB30-15, the transmitter is allowed to
operate. If this circuit is opened, the
transmitter switches to a Mute condition.
This circuit may be completed through
coax relay contacts and reject load
contact closures to assure the RF output
system is available to receive the
transmitter's output RF signal. This
feature is implemented in transmitter
software version 1.4 and above.
Operating Frequency
The LX Series transmitter/translator
controller is designed to operate on UHF
frequencies. The exact output frequency
of the transmitter can be set to one of
the standard UHF frequencies, or to a
custom frequency using the software
channel set-up menu on the Controller
Module. Since RF performance of the
transmitter requires different hardware
for different frequency bands, not all
frequency configurations are valid for a
specific transmitter. The Power
detectors in the transmitter are
2-13
Digital UHF Driver/Transmitter
frequency dependent, therefore
detectors of power amplifiers are
calibrated at their frequency of use. The
detectors for System RF monitoring are
also calibrated at the desired frequency
of use. Refer to Chapter 5 for the
Channel Change Procedure.
2.6 Maintenance
The Innovator LX Series Driver/
Transmitter is designed with components
that require little or no periodic
maintenance except for the routine
cleaning of the fans and the front panels
of the modules and the periodic check of
general tightness of hardware.
It is recommended that periodically, the
time interval depends on the amount of
movement the cabinet receives, all
mounting hardware, holding tray slides,
shelving and mounting plates inside the
cabinet are checked for tightness. All
screws and bolts that are accessible
should be tightened initially when the
transmitter is received and periodically
thereafter if the transmitter is moved by
vehicle. All coaxial connectors, hard-line
connections and hardware holding
combiners, splitters, or any other
mounted items should be checked and
tightened. Check the front panel
thumbscrews that hold the Exciter/Driver
Sleds, Amplifier Module and Power
Supply Sleds in place are tight. This is
especially important after the transmitter
has been transported.
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 the
premature failure of the affected
modules.
When the front panels of the modules
become dust covered, the top covers
LX Series, Digital, Rev. 4
Chapter 2, System Description &
Remote Control Connections
should be taken off and any accumulated
foreign material should be removed. A
vacuum cleaner, utilizing a small, wandtype 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 components or the silkscreened markings on the modules and
boards. Water-based cleaners can be
used, but do not saturate the
components. The fans and heatsinks
should be cleaned of all dust or dirt to
permit the free flow of air for cooling
purposes.
It is recommended that the operating
parameters of the amplifier assembly and
transmitter be recorded from the LEDs on
the modules and the LCD system
metering on the control/monitoring
module at least once a month. It is
suggested that this data be retained in a
rugged folder or envelope.
2.7 Customer Remote Connections
The remote monitoring and operation of
the transmitter is provided through jacks
TB30 and TB31 located on the rear of the
chassis assembly. If remote connections
are made to the transmitter, they must
be made through plugs TB30 and TB31
at positions noted on the transmitter
interconnect drawing and Table 2-22.
TB30 and TB31 are 18 position terminal
blocks that are removable from their
sockets to make connections easier. Just
grasp and pull connector straight out.
After connections are made, replace the
connector and push firmly to seat the
connector in the socket.
If your system contains the Optional
Exciter Switcher Assembly, there are also
remote connections that can be made to
the Exciter Switcher Assembly. They
connect to TB1 on the rear of the exciter
switcher tray. Refer to Table 2-23 and to
the Exciter Switcher Board schematic
drawing (1305705) located in Appendix B
for the pin out and descriptions.
2-14
Digital UHF Driver/Transmitter
Chapter 2, System Description &
Remote Control Connections
TB30
TB31
Figure 2-3: Rear View LX Series Chassis Assembly
Table 2-22: LX Series Chassis Assembly Hard Wired Remote Interface Connections to
TB30 or TB31, 18 pos. Terminal Blocks Located on the Rear of the Assembly
Pin
Signal Name
Signal Type/Description
Designations
RMT Transmitter
Discrete Open Collector Output - A low indicates that
TB30-1
State
the transmitter is in the operate mode.
Discrete Open Collector Output - A low indicated the
RMT Transmitter
transmitter is OK or completes a interlock daisy
TB30-2
Interlock
chain. When the transmitter is not faulted, the
interlock circuit is completed.
Ground - Configurable ground return which can be
either jumpered directly to ground or it can be the
RMT Transmitter
“source” pin of an FET so that the transmitter
Interlock
TB30-3
interlock can be daisy chained with other
Isolated Return
transmitters. This signal does not directly interface
to the microcontroller.
Discrete Open Collector Inputs, Discrete Open Drain
Outputs, or 0 - 5 VDC Analog Input - When used as
an output, this line is pulled to +5 VDC with a 1.0 kΩ
resistor for logic high and pulled to ground for a low.
RMT AUX IO 1
TB30-4
A diode allows this line to be pulled up to 12 VDC.
When used as a digital input, this line considers all
values over 2 Volts as high and those under 1 volt as
low. As an analog input, this line is protected by a
5.1 Zener diode.
When this signal's circuit is completed to ground such
as through a wire between TB30-5 and TB30-15, the
RMT RF System
transmitter is allowed to operate. If this circuit is
TB30-5
Interlock
opened, the transmitter switches to a Mute condition.
Implemented in transmitter software version 1.4 and
above.
RMT
Discrete Open Collector Input - A pull down to ground
TB30-7
Transmitter
on this line indicates that the transmitter is to be
Stand-By
placed into the standby mode.
LX Series, Digital, Rev. 4
2-15
Digital UHF Driver/Transmitter
Signal Name
Pin
Designations
RMT Power
Raise
TB30-8
RMT Power
Lower
TB30-9
RMT
System Reflect
Power
TB30-10
RMT System
Forward Power
TB30-11
RMT
System Aural
Power
(NOT USED)
RMT Spare 1
RMT Spare 2
TB30-12
TB30-13
TB30-14
System Reflect
Power
TB31-13
System Forward
Power
TB31-14
System Aural
Power
(NOT USED)
TB31-15
IF Processor
IF Signal Select
TB31-3
IF Processor
DLC Voltage
TB31-4
UC AGC #2
Voltage
TB31-5
RMT Ground
TB30-15, and
17
LX Series, Digital, Rev. 4
Chapter 2, System Description &
Remote Control Connections
Signal Type/Description
Discrete Open Collector Input - A pull down to ground
on this line indicates that the transmitter power is to
be raised.
Discrete Open Collector Input - A pull down to ground
on this line indicates that the transmitter power is to
be lowered.
Analog Output - 0 to 4.0 V- This is a buffered loop
through of the calibrated “System Reflected Power ”
and indicates the transmitter's reflected output
power. The scale factor is 25 % / 3.2V.
Analog Output - 0 to 4.0 V- This is a buffered loop
through of the calibrated “System Average Power ”.
Indicates the transmitter's Average power. Scale
factor is 100 % / 3.2V.
Analog Output - 0 to 4.0 V- This is a buffered loop
through of the calibrated “System Aural Power ”.
Indicates the transmitter's forward Aural output
power. The scale factor is 100 % / 3.2V.
Remote connection to spare module - Use is TBD.
Remote connection to spare module - Use is TBD.
Analog Input - 0 to 1.00 V- This is the input of the
“System Reflected Power ” indicating the
transmitter's reflected output power. The scale factor
is 25 % / 0.80V.
Analog Input - 0 to 1.00 V- This is the input of the
“System Forward Power ” indicating the transmitter's
Forward output power. The scale factor is 100 % /
0.80V.
Analog Input - 0 to 1.00 V- This is the input of the
“System Aural Power ” indicating the transmitter's
forward Aural output power. The scale factor is 100
% / 0.80V.
Discrete Open Collector Input - A low indicates that
the modulator IF source is to be used by the IF
Processor module. When floating an analog IP
Processor module may use the Modulated IF Input if
the IF Processor sled is so configured.
Analog Output - 0 to 5.00 V- This is the input of IF
Processor module for digital system RF output power
control.
Auxiliary Analog Input - 0 to 1V- This voltage is used
by the Upconverter for gain control. Linear signal
with display resolution of 0.01 %. Primary signal
source is J34-1.
Ground pins available through Remote
2-16
Digital UHF Driver/Transmitter
Signal Name
RMT Ground
RMT +12 VDC
RMT -12 VDC
Chapter 2, System Description &
Remote Control Connections
Pin
Designations
TB31-1, 2, 6
to 12, and 17
TB30-16
TB31-16
TB30-18
TB31-18
Signal Type/Description
Ground pins available through Remote
+12 VDC available through Remote w/ 2 Amp
re-settable fuse
-12 VDC available through Remote w/ 2 Amp
re-settable fuse
Table 2-23: (Optional) Exciter Switcher Hard Wired Remote Interface Connections to TB1,
18 pos. Terminal Block are located on the Rear of the Exciter Switcher Tray Assembly.
Pin
Signal Name
Signal Type/Description
Designations
Select Automatic
TB1-1
0 = SET, NC = No Change
Operation
Select Manual Operation
TB1-2
0 = SET, NC = No Change
Select Exciter A (1)
TB1-3
0 = SET, NC = No Change
Select Exciter B (2)
TB1-4
0 = SET, NC = No Change
Selected Exciter to
Operate
TB1-5
0 = SET, NC = No Change
TB1-6
0 = SET, NC = No Change
TB1-7
0 = SET, NC = No Change
TB1-8
0 = SET, NC = No Change
TB1-9
NOT USED IN THIS CONFIGURATION
TB1-10
NOT USED IN THIS CONFIGURATION
TB1-11
NOT USED IN THIS CONFIGURATION
Selected Operation
TB1-12
0 = Auto, Open = Manual
Selected Exciter
TB1-13
0 = A, Open = B
TB1-14
0 = None, 1 = 1 or More
TB1-15
0 = None, 1 = 1 or More
TB1-16
0 = None, 1 = 1 or More
TB1-17
0 = None, 1 = 1 or More
TB1-18
Ground
Selected Exciter to
Standby
Selected Exciter Power
Raise
Selected Exciter Power
Lower
Selected Exciter Logged
Faults
Selected Exciter Current
Errors
Alternate Exciter Logged
Faults
Alternate Exciter
Current Errors
Ground
NOTE: In versions previous to 2.0, for the automatic switching to the back up exciter,
the Error, Fault, Log in the back up exciter must be cleared of all Previous Faults..
LX Series, Digital, Rev. 4
2-17
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Chapter 3
Site Considerations, Installation and Setup Procedures
Table 3-1: LX Series Digital Transmitters/Drivers AC Input and Current Requirements.
Transmitter/
Voltage
Current
Driver
5 Watt
117/220 VAC
5 Amps
50 Watt
117/220 VAC
10 Amps
125 Watt
220 VAC
10 Amps to the Exciter/Amplifier Cabinet
250 Watt
220 VAC
15 Amps to the Exciter/Amplifier Cabinet
500 Watt
220 VAC
25 Amps to the Exciter/Amplifier Cabinet
1000 Watt
220 VAC
45 Amps to the Exciter/Amplifier Cabinet
1500 Watt
220 VAC
65 Amps to the Exciter/Amplifier Cabinet
220 VAC
45 Amps to the Exciter/Amplifier Cabinet
2000 Watt
220 VAC
40 Amps to the Amplifier Cabinet
220 VAC
45 Amps to the Exciter/Amplifier Cabinet
2500 Watt
220 VAC
60 Amps to the Amplifier Cabinet
220 VAC
65 Amp to the Exciter/Amplifier Cabinet
3000 Watt
220 VAC
60 Amps to the Amplifier Cabinet
3.1 Site Considerations
environment in which they are placed is
important and certain precautions must
be taken. The three greatest dangers to
the transmitter are heat, dirt, and
moisture. Heat is usually the greatest
problem, followed by dirt, and then
moisture. Over-temperature can cause
heat-related problems such as thermal
runaway and component failure. Each
amplifier module in the transmitter
contains a thermal interlock protection
circuit that will shut down that module
until the temperature drops to an
acceptable level.
There are special considerations that
need to be taken into account before the
LX Series digital driver/transmitter can
be installed. For example, if the
installation is completed during cool
weather, a heat-related problem may not
surface for many months, suddenly
appearing during the heat of summer.
This section provides planning
information for the installation and set up
of the transmitter.
The AC input and current requirements
for LX Series digital transmitter/drivers
are shown in Table 3-1.
A suitable environment for the
transmitter can enhance the overall
performance and reliability of the
transmitter and maximize revenues by
minimizing downtime. A properly
designed facility will have an adequate
supply of cool, clean air, free of airborne
particulates of any kind, and no
excessive humidity. An ideal environment
will require temperature in the range of
40° F to 70° F throughout the year,
reasonably low humidity, and a dust-free
room. It should be noted that this is
rarely if ever attainable in the real world.
However, the closer the environment is
NOTES: The transmitter is factory set
for either 110 VAC or 220 VAC
operation as directed by customer.
Transmitters above 125 Watts use
220 VAC Input only.
Transmitters 2000 Watts and above
require two 220 VAC Inputs, one to
each cabinet.
The LX Series Digital Transmitters are
designed and built to provide long life
with a minimum of maintenance. The
LX Series, Digital, Rev. 4
3-1
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
to this design, the greater the operating
capacity of the transmitter.
method and is the only way to create
anything close to an ideal environment.
The fans are designed and built into the
transmitter will remove the heat from
within the modules, but additional means
are required for removing this heat from
the building. To achieve this, a few issues
need to be resolved. The first step is to
determine the amount of heat to be
removed from the transmitter room.
There are generally three sources of heat
that must be considered. The first and
most obvious is the heat from the
transmitter itself. This amount can be
determined for a 50W digital transmitter
by subtracting the average power to the
antenna (50 watts) from the AC input
power (650 watts) and taking this
number in watts (600) and then
multiplying it by 3.41. This gives a result
of 2,046, the BTUs to be removed every
hour. 12,000 BTUs per hour equals one
ton. Therefore, a 1/4-ton air conditioner
will easily cool a 50W digital transmitter.
Ventilation will work quite well if the
ambient air temperature is below 100° F,
or about 38° C, and the humidity is kept
at a reasonable level. In addition, the air
stream must be adequately filtered to
ensure that no airborne particulates of
any kind will be carried into the
transmitter. The combination of air
conditioning for summer and ventilation
during the cooler months is acceptable
when the proper cooling cannot be
obtained through the use of ventilation
alone and using air conditioning
throughout the year is not feasible.
Caution: The use of air conditioning
and ventilation simultaneously is not
recommended. This can cause
condensation in the transmitters.
The following precautions should be
observed regarding air conditioning
systems:
The second source of heat is other
equipment in the same room. This
number is calculated in the same way as
the equation for BTUs. The third source
of heat is equally obvious but not as
simple to calculate. This is the heat
coming through the walls, roof, and
windows on a hot summer day. Unless
the underside is exposed, the floor is
usually not a problem. Determining this
number is usually best left up to a
qualified HVAC technician. There are far
too many variables to even estimate this
number without reviewing the detailed
drawings of the site that show all of the
construction details. The sum of these
three sources is the bulk of the heat that
must be removed. There may be other
sources of heat, such as personnel, and
all should be taken into account.
Now that the amount of heat that must
be removed is known, the next step is to
determine how to accomplish this. The
options are air conditioning, ventilation,
or a combination of the two. Air
conditioning is always the preferred
LX Series, Digital, Rev. 4
3-2
1.
Air conditioners have an ARI
nominal cooling capacity rating. In
selecting an air conditioner, do not
assume that this number can be
equated to the requirements of
the site. Make certain that the
contractor uses the actual
conditions that are to be
maintained at the site in
determining the size of the air
conditioning unit.
2.
Do not have the air conditioner
blowing directly onto the
transmitter. Under certain
conditions, condensation may
occur on, or worse in, the
transmitter.
3.
Do not separate the front of the
transmitter from the back with the
thought of air conditioning only
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
the front of the unit. Cooling air is
drawn in at the front of all
transmitters and in the front and
back of others. Any attempt to
separate the front of the
transmitter from the rear of the
unit will adversely affect the flow
of cooling air.
4.
5.
complete flushing of heated air
with no stagnant areas.
Interlocking the transmitter with
the air conditioner is
recommended to keep the
transmitter from operating without
the necessary cooling.
The periodic cleaning of all filters
is a must.
6.
The filter area must be large
enough to insure a maximum air
velocity of 300 feet per minute
through the filter. This is not a
conservative number but a neverexceed number. In a dusty or
remote location, this number
should be reduced to 150 CFM.
7.
The inlet and outlet(s) must have
automatic dampers that close any
time the ventilation blower is off.
8.
In those cases in which
transmitters are regularly off for a
portion of each day, a
temperature-differential sensor
that controls a small heater must
be installed. This sensor will
monitor inside and outside
temperatures simultaneously. If
the inside temperature falls to
within 5° F of the outside
temperature, the heater will come
on. This will prevent condensation
when the ventilation blower comes
on and should be used even in the
summer.
9.
A controlled-air bypass system
must be installed to prevent the
temperature in the room from
falling below 40° F during
transmitter operation.
10.
The blower should have two
speeds, which are thermostatically
controlled, and be interlocked with
the transmitter.
11.
The blower on high speed must be
capable of moving the required
volume of air into a half inch of
water pressure at the required
elevation. The free air delivery
method must not be used.
12.
Regular maintenance of the filters,
if used, can not be
overemphasized.
When using ventilation alone, the
following general statements apply:
1.
The blower, with attendant filters,
should be on the inlet, thereby
pressurizing the room and
preventing dirt from entering the
transmitter.
2.
The inlet and outlet vents should
be on the same side of the
building, preferably the leeward
side. As a result, the pressure
differential created by wind will be
minimized. Only the outlet vent
may be released through the roof.
3.
4.
5.
The inlet and outlet vents should
be screened with 1/8-inch
hardware cloth (preferred) or
galvanized hardware cloth
(acceptable).
Cooling air should enter the room
as low as practical but in no case
higher than four feet above the
floor. The inlet must be located
where dirt, leaves, snow, etc., will
not be carried in with the cooling
air.
The exhaust should be located as
high as possible. Some ducting is
usually required to insure the
LX Series, Digital, Rev. 4
3-3
Digital UHF Driver/Transmitter
13.
14.
Chapter 3, Site Considerations,
Installation and Setup Procedures
Above 4000 feet, for external
venting, the air vent on the
cabinet top must be increased to
an 8-inch diameter for a 1-kW
transmitter and to a 10-inch
diameter for 5-kW and 6-kW
transmitters. An equivalent
rectangular duct may be used but,
in all cases, the outlet must be
increased by 50% through the
outlet screen.
filter must be a minimum of seven
square feet, larger for dusty and remote
locations, for each 5000 watts or 17,000
BTUs. The exhaust must be at least four
square feet at the exhaust screen for
each 5000 watts or 17,000 BTUs.
The information presented in this section
is intended to serve only as a general
guide and may need to be modified for
unusually severe conditions. A
combination of air conditioning and
ventilation should not be difficult to
design (see Figure 3-1).
It is recommended that a site plan
be submitted to Axcera for
comments before installation
begins.
System interlocking and thermostat
settings should be reviewed with Axcera.
As with any equipment installation, it is
always good practice to consult the
manufacturer when questions arise.
Axcera can be contacted at (724) 8738100.
In calculating the blower requirements,
filter size, and exhaust size, if the total
load is known in watts, 2000 CFM into ½
inch of water will be required for each
5000 watts. If the load is known in BTUs,
2000 CFM into ½ inch of water will be
required for each 17,000 BTUs. The inlet
Figure 3-1. 500 Watt Minimum Ventilation Configuration
LX Series, Digital, Rev. 4
3-4
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
3.2 Unpacking the Chassis
w/modules, Digital Mask filter and
coupler assembly
tightened. Check the front panel
thumbscrews that hold the Exciter/Driver
Sleds, Amplifier Module and Power Supply
Sleds in place are tight. This is especially
important after the transmitter has been
transported.
Thoroughly inspect the chassis with
modules and all other materials upon
their arrival. Axcera certifies that upon
leaving our facility the equipment was
undamaged and in proper working order.
The shipping containers should be
inspected for obvious damage that
indicates rough handling.
3.3 Installing the Chassis w/modules,
Digital Mask filter and coupler
assembly
The chassis assembly is made to mount in
a standard 19” rack. The chassis assembly
mounts using the four #10 clearance
mounting holes on the ends. The chassis
should be positioned; to provide adequate
air intake into the front and the air exhaust
of the fan in the rear; the ability to slide
the modules out for replacement purposes;
the installation of the digital mask filter;
the coupler assembly; and output
transmission line. The chassis or cabinet in
which it is mounted should be grounded
using copper strapping material.
Remove the chassis and modules, the
digital mask filter and directional coupler,
from the crates and boxes.
Check for dents and scratches or broken
connectors, switches or display. Any
claims against in-transit damage should
be directed to the carrier. Inform Axcera
as to the extent of any damage as soon
as possible.
The modules are mounted to the chassis
assembly with slides that are on the top
and the bottom of the modules. There
are two thumb screws on the front panel
that hold each of the modules in place.
The chassis assembly is mounted in the
cabinet using Chassis Trak cabinet slides.
The tray slides are on the side of the
assembly. Inspect the assembly for any
loose hardware or connectors, tightening
where needed.
NOTE: To remove the driver/power
amplifier module, mounted in the
exciter/driver assembly, the input and
output cables must be removed from the
rear of the module and also a 6/32” x ½”
Philips screw, mounted between the two
connectors, needs to be removed before
the module will pull out. After removal of
the screw, which is used to hold the
module in place during shipping, it does
not need to be replaced.
After placement of cabinet, all mounting
hardware, holding tray slides, shelving
and mounting plates inside the cabinet
should be checked for tightness. All
screws and bolts that are accessible
should be tightened initially when the
transmitter is received and periodically
thereafter if the transmitter is moved by
vehicle. All coaxial connectors, hard-line
connections and hardware holding
combiners, splitters, or any other
mounted items should be checked and
LX Series, Digital, Rev. 4
Connect the digital mask filter and coupler
assembly to the output of the chassis
assembly.
Connect the transmission line for the
antenna system to the coupler output. The
Incident and Reflected outputs of the
coupler assembly may be used for test
purpose.
3-5
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Figure 3-2. Tray Slides Cabinet Mounting Diagram
Figure 3-3. Front and Rear View Reconnection Drawing
LX Series, Digital, Rev. 4
3-6
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Figure 3-4. Cabinet Front and Rear View Reconnection Drawing
3.4 AC Input
Ground to Ground on the terminal
block. See Figure 3-5.
Once the chassis and output
connections are in place, connect the
AC power cord from the chassis
assembly of the 5W or 50W digital
transmitter/driver to an AC outlet
The AC input and current requirements
for LX Series digital transmitter/drivers
are indicated in the Table 3-1 located
at the beginning of this chapter.
NOTES: The transmitter is factory
set for either 110 VAC or 220 VAC
operation as directed by customer.
Transmitters above 125 Watts use
220 VAC Input only.
Transmitters 2000 Watts and
above require two 220 VAC Inputs,
one to each cabinet.
The AC Input to the high power
transmitter connects to the terminal
block mounted in the AC input box
located toward the rear, right side near
the top of the cabinet. Connect the AC
Input Line 1 to Line 1 on the terminal
block, the AC Input Line 2 to Line 2 on
the terminal block and the AC Input
LX Series, Digital, Rev. 4
Figure 3-5: AC Input Box Assembly
NOTE: An AC On/Off Circuit Breaker is
located on the rear of the Exciter/Driver
Chassis Assembly, near the AC input
jack. In high power transmitters, there
is one On/Off Circuit Breaker, located
on the rear of the Power Amplifier
Assembly, for each power supply
assembly.
This completes the unpacking and
installation of the LX Series UHF
television transmitter. Refer to the
setup and operation procedures that
follow before applying power to the
transmitter.
3-7
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
3.5 Set Up and Operation
on the rear of the exciter/driver chassis
assembly. NOTE: In dual exciter
systems input connections must be
made to the rear of both exciters.
Initially, the transmitter should be
turned on with the RF output at the
coupler assembly terminated into a
dummy load of a value dependent on
the power rating of the transmitter. If a
load is not available, check that the
output of the coupler assembly is
connected to the antenna for your
system.
The DM8 modulator accepts an MPEG2 transport stream input at J12 and
outputs an 8-VSB IF signal at J13
centered at 44 MHz. This 8-VSB IF is
jumpered to J6 the modulated IF input
jack to the IF Processor assembly.
3.5.1 Input Connections
Refer to the table 3-2 that follows for
detailed information.
The input connections to the
transmitter are made to jacks mounted
Figure 3-6: Rear View of the Digital Exciter Driver Chassis Assembly
J25
TB30
J21
TB02
J18
TB31
J15
J24
J9
J8
J10
J33
J1
J32
J19
J11
J34
Table 3-2: Rear Chassis Connections for the LX Series Digital Exciter Driver.
Port
Type
Function
Impedance
J1
IEC
AC Input
N/A
TB02 Term
(NOT USED) Base Band Audio Input
600Ω
J3
BNC
(NOT USED) Composite Audio Input
75Ω
J4
BNC
(NOT USED) SAP / PRO Audio Input
50Ω
J5
BNC
(NOT USED) CW IF Input
50Ω
J6
BNC
Modulated IF Input (Jumpered from J13)
50Ω
J7
BNC
(NOT USED) Video Input (Isolated)
75Ω
(NOT USED) Visual IF Loop-Thru Output
J8
BNC
50Ω
(Jumpered to J18)
(NOT USED) Aural IF Loop-Thru Output
J9
BNC
50Ω
(Jumpered to J19)
J10
BNC
External 10 MHz Reference Input
50Ω
J11
BNC
System 10 MHz Reference Output
50Ω
J12
BNC
MPEG RF Input
50Ω
LX Series, Digital, Rev. 4
3-8
J13
J4
J6
J23
J3
J14
J7
J17
J5
J12
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Port
J13
J14
J15
J17
Type
BNC
BNC
BNC
BNC
J18
BNC
J19
BNC
J23
J24
J25
BNC
BNC
Function
DTV IF Output (Jumpered to J6)
RF Spare 2
RF Spare 1
(NOT USED) Video Loop-Thru (Isolated)
(NOT USED) Visual IF Loop-Thru Input
(Jumpered to J8)
(NOT USED) Aural IF Loop-Thru Input
(Jumpered to J9)
Upconverter RF Output
Power Amplifier RF Input
Power Amplifier RF Output
J32
J33
J34
RJ-45
RJ-45
RJ-45
SCADA (Input / Loop-Thru)
SCADA (Input / Loop-Thru)
System RS-485 Serial
Termination
Termination
Remote Control & Monitoring
Remote Control & Monitoring
TB30
TB31
3.5.2 Initial Turn On
50Ω
50Ω
50Ω
50Ω
50Ω
CAT5
CAT5
CAT5
N/A
N/A
3.5.2.1 DM8 Digital Modulator
Module LEDs on Front Panel
Once the unit has been installed and all
connections have been made, the
process of turning on the equipment can
begin. First verify that AC power is
present and connected to the
transmitter. Verify all cables are
properly connected and are the correct
type. Once things are completed, the
unit is ready to be turned on following
the procedures below.
Status Indicators:
MPEG: This illuminates Green if the
MPEG stream at the J1-2B input jack is
valid.
PLL A: This illuminates Green if the DM8
symbol clock is locked to the frequency
of the 10 MHz reference.
PLL B: This illuminates Green if the pilot
frequency is locked to the 10 MHz
reference.
NOTE: In systems with two exciters and
an exciter switcher, repeat the following
procedure with Exciter B as the On Air
exciter. The exciter switcher must in
Manual.
3.5.2.2 IF Processor Module LEDs on
Front Panel
Turn on the main AC power source that
supplies the AC to the transmitter.
Check that the AC power plug is
connected to the AC Input jack on the
back of the assembly and that the
On/Off circuit breaker located on the
rear chassis is On. In high power
transmitters, check that the On/Off
circuit breaker(s) located on the rear of
the Power Amplifier Assembly(ies) are
On.
LX Series, Digital, Rev. 4
Impedance
50Ω
50Ω
50Ω
75Ω
Fault Indicators:
INPUT FAULT: This illuminates Red if the
input to the module is missing or low.
ALC FAULT: This illuminates RED when
the needed ALC value to maintain the
output level is beyond the range of the
circuitry.
MUTE: This indicator will illuminate Red
when the transmitter is muted.
3-9
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
3.5.2.3 VHF/UHF Upconverter
Module LEDs on Front Panel
Status Indicators:
Fault Indicator:
AGC FAULT: This illuminates Red if the
required gain to produce the desired
output level is beyond the value set by
the AGC circuit. AGC out of range.
AGC OVERRIDE: This illuminates Red if
the drive to the driver module is too
high.
MAN GAIN: This illuminates Red if the
AGC is bypassed in Manual.
PLL 1: This illuminates Red if the 1 GHz
PLL is unlocked.
PLL 2: This illuminates Red if the 1.11.9 GHz PLL is unlocked.
3.5.2.4 Controller Module LEDs on
Front Panel
Status Indicators:
OPERATE - This illuminates Green when
transmitter is in operate.
FAULT - This illuminates Red when a
fault has occurred in the transmitter.
DC OK - This illuminates Green when the
DC outputs that connect to the modules
in the transmitter are present.
3.5.2.5 Driver Power Amplifier
Module LEDs on Front Panel
NOTE: Both the PA Module and Driver
Module have the same front panel LEDs.
LX Series, Digital, Rev. 4
ENABLED - This illuminates Green when
the PA is in operate.
DC OK - This illuminates Green when the
DC inputs to the PA module are present.
TEMP - This illuminates Green when the
temperature of the heatsink in the PA is
below 78°C.
MOD OK - This illuminates Green when
the PA module is operating and has no
faults.
If the Module OK LED is Red and blinking,
a fault is present. The meaning of the
blinking LED is as follows.
1 Blink indicates Amplifier Current Fault.
2 Blinks indicate Temperature Fault.
3 Blinks indicate +32V Power Supply
Over Voltage Fault.
4 Blinks indicate +32V Power Supply
Under Voltage Fault.
5 Blinks indicate Reflected Power Fault.
6 Blinks indicate +12V or –12V Power
Supply Fault
3.5.3 Front Panel Screens for the
(Optional) Exciter Switcher
Assembly
(Used in Dual Exciter Systems only)
The following screens are found on the 4
x 20 display located on the front of the
single channel exciter switcher tray.
NOTES: For automatic switching to the
back up exciter, the Error, Fault, Log in
the back up exciter must be cleared of
all Previous faults. Also, for remote
control of the exciter switcher, the
exciter switcher must be in Manual.
3-10
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Display Menu Screens for the (Optional) Exciter Switcher Tray
Table 3-3: Menu 01 - Splash Screen #1
This is the first of the two exciter switcher splash screens that is shown for the first few
seconds after reset or after pushing the SPL button on the Main Screen. Will
automatically switch to the second splash screen.
Table 3-4: Menu 02 - Splash Screen #2
This is the second of the two exciter switcher splash screens. Will automatically switch
to the Main Screen. The Name, Model Number, Code Version Number and Firmware
Number for your system are displayed on this screen. Make note of these two numbers
when conferring with Axcera on software problems.
Table 3-5: Menu 03 – Exciter Switcher Control Screen
This screen indicates that the exciter switcher is in automatic back-up and that Exciter A
is selected as the On Air Exciter. By selecting MANUAL the screen is shown as below.
Table 3-6: Menu 04 – Exciter Switcher Control Screen
This screen indicates that the exciter switcher is in Manual operation and that Exciter A
is selected as the On Air Exciter.
Table 3-7: Menu 05 – Exciter Switcher Control Screen
This screen indicates that there are 20 External Amplifiers reporting serial data in the
system. Also indicates that Exciter A is selected as the On Air Exciter and that the
system is in Manual, because the USE B option is present on the screen. By pushing the
button under USE B you are able to select Exciter B as the ON Air Exciter.
LX Series, Digital, Rev. 4
3-11
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Table 3-8: Menu 06 – Exciter Switcher Control Screen
This screen allows you to cancel the automatic back-up and that Exciter B is selected as
the On Air Exciter.
Table 3-9: Menu 07 – Exciter Switcher Control Screen
This screen indicates that Exciter B is selected as Back up to the On Air Exciter A.
Table 3-10: Menu 08 – Exciter Switcher Control Screen
This screen is only displayed when an exciter back up sequence is initiated. The backup
sequence runs through 10 steps that are displayed on 10 different screens. 9) Exciter
A/B On, 8) Disabling Exciter A, 7) Disabling Exciter B, 6) Changing Relay 1 of 2, 5)
Changing Relay 2 of 2, 4) Waiting for Relays, 3) Relay Change Done, 2) Enabling Exciter
A, 1) Enabling Exciter B; 0) Exciter Change Done. If a problem occurs during the
sequence it will stop on the screen where the problem occurred.
Table 3-11: Menu 09 – External Amplifier Status
These screens indicate the Status of the different Amplifier Modules. This screen is
monitoring the power supply for Module 1 in Amplifier Set 1. By arrowing down, the
next parameter for that module is viewed and these screens will continue for each
individual module in each Amplifier Set.
Table 3-12: Menu 10 – External Amplifier Status with Serial Link Error Icon
Serial Link Icon
Indicates that this module is not
present in your System or the
module may be present but no serial
communication commands are being
received from the device.
LX Series, Digital, Rev. 4
3-12
Digital UHF Driver/Transmitter
3.5.4 Front Panel Screens for the
Exciter Chassis Assembly
A 4 x 20 display located on the front of
the Control & Monitoring/Power Supply
Module is used in the LX Series exciter
for control of the operation and display
of the operating parameters of the
transmitter. Below are the display
screens for the system. The ↑ and ↓
characters are special characters used to
navigate up or down through the menu
screens. Display text flashes on discrete
Chapter 3, Site Considerations,
Installation and Setup Procedures
fault conditions for all screens that
display a fault condition. When the
transmitter is in operate mode, the STB
menu appears. When the transmitter is
in standby mode, the OPR menu
appears. NOTE: The following screens
are typical and may be different from the
screens in your system.
NOTE: In systems with two exciters and
an exciter switcher the following screens
are typical on the exciter that is selected
as the On Air Exciter.
Display Menu Screens for the LX Series Exciter
Table 3-13: Menu 01 - Splash Screen #1
This is the first of the two transmitter splash screens that is shown for the first few
seconds after reset or after pushing the SPL button on the Main Screen. Will
automatically switch to the second splash screen.
Table 3-14: Menu 02- Splash Screen #2
This is the second of the two transmitter splash screens. Will automatically switch to the
Main Screen. The Model Number, Code Version Number and Firmware Number for your
system are displayed on this screen. Make note of these two numbers when conferring
with Axcera on software problems.
Table 3-15: Menu 10 - Main Screen:
This is the default main screen of the transmitter. When the transmitter is in
operate, the 'STB' characters appear, allowing an operator to place the transmitter in
STANDBY, by pushing the right most button located under to display. When the
transmitter is in standby the 'STB' characters are replaced with 'OPR' and the forward
power values are displayed as OFF. An operator can change the transmitter from
STANDBY to OPERATE by pressing the right most button on the front panel display. If the
transmitter is in operate mode but off due to a modulation fault, the display reports the
system power as Auto Off. Pushing the SPL button will display the two splash screens.
If the ↓ key is activated the display changes to Menu 11, the System Error List Access
Screen. If the ↑ key is activated the display changes to Menu 13, the Transmitter
Configurations Access Screen.
LX Series, Digital, Rev. 4
3-13
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Table 3-16: Menu 11 - Error List Access Screen
This screen of the transmitter shows the current number of errors, displayed in upper,
right of screen (0), and provides operator access to view Menu 20, the error list screens,
by pushing the ENT button. When ENT is pushed, Menu 20, the Error List Display Screen
is displayed. See Table 3-9 below. If the ↓ key is pushed the display changes to Menu 12,
Table 3-17, the Transmitter Device Data Access Screen. If the ↑ key is activated the
display returns to Menu 10, the Main Screen.
Table 3-17: Menu 12 - Transmitter Device Data Access Screen
This screen of the transmitter allows access to various parameters of the transmitter
system. This is the entry point to Menu 30, the System Details Screens, by pausing the
ENT button. When the ENT button is pushed, Menu 30 is accessed. Go to Menu 30, Table
3-20 for set up details. Before pushing the ENT button: if the ↓ key is activated the
display changes to Menu 13, Transmitter Configurations Access Screen. If the ↑ key is
activated the display returns to Menu 11, the Error List Access Screen.
Table 3-18: Menu 13 - Transmitter Configuration Access Screen
This screen of the transmitter allows access to various software settings of the
transmitter system. If ENT is pushed, go to Menu 40, Table 3-23, the access to
transmitter configuration and set up. Before pushing the ENT button: if the ↓ key is
activated the display returns to Menu 10, Main Screen. If the ↑ key is activated the
display returns to Menu 12, the Transmitter Device Data Access Screen.
Table 3-19: Menu 20 - Error List Display Screen
This screen indicates System Errors 1/8, which is System Error 1 screen of 8 total System
Errors that have occurred. Fault logging is stored in non-volatile memory. The
transmitter's operating state can not be changed in this screen. The 'CLR' switch is used
to clear the displayed previously detected fault that is no longer active. If the fault is still
present it will not clear. The ↑ key and ↓ key allow an operator to scroll through the list of
errors that have occurred. The ESC button is used to leave this screen and return to
Menu 11, Table 3-16, the Error List Access Screen. NOTE: Shown is an example of a
typical screen and may be different for your system.
LX Series, Digital, Rev. 4
3-14
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Menu 30 is entered by selecting ENT at Menu 12, Table 3-17.
Table 3-20: Menu 30 - Transmitter Device Details Screen
This screen allows access to the transmitter parameters of installed devices. The system
is configured to know which devices are present. Current values for all installed devices
are shown. If a module is not installed, only a "MODULE NOT PRESENT" message will be
displayed. The first screen displayed is Menu 30-1, Table 3-21, the System Details
Screen.
Table 3-21: Menu 30-1 – System Details Screen
This is the default System Details Screen. The ↓ and ↑ arrows allow you to scroll through
the different parameters of each device as shown in Table 3-22. Each System
Component is a different screen.
Table 3-22: Transmitter Device Parameters Detail Screens
System
Parameter
Normal
Component
DM8 Digital
Modulator
Details
IF Processor
MODE
SOURCE
LINEAR EQ
NON-LINEAR EQ
(Settings Customized per
System)
EQL PEAK LEVEL
PSF PEAK LEVEL
AGC MODE
AGC LEVEL
D/A PEAK DETECT
TAP ENERGY
CLIP DETECTOR STATUS
AGG
ISL
D/A
HBF
IFC
COR
ODC
CODE VERSION
INPUT SIGNAL STATE
LX Series, Digital, Rev. 4
NORMAL
EXTERNAL
ON
PRESET
TABLE = XXX
PHASE = X
<127
<127
TRACKING
<127
<127
0 to 15%
X.X
OK
3-15
Choice
TEST CW
ZERO
INTERNAL
OFF
See NonLinear SetUp Eq Screen
FIXED
Faulted
(Blinking)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
FAULT
Digital UHF Driver/Transmitter
System
Component
Details
Upconverter
Details
System
Control
Details
Driver and PA
Details
Ext. Power
Amplifier
Modules
Details (Only
in high power
systems).
Will indicate
Amp Set and
Module within
the Set. Will
step through
each Set and
Module.
Chapter 3, Site Considerations,
Installation and Setup Procedures
Choice
Faulted
(Blinking)
Parameter
Normal
MODULATION
INPUT IF
DLC CONTROL LOCK
OK
MODULATOR
0 - 5.00 V
ALC LEVEL
0 - 5.00 V
ALC MODE
AFC 1 LEVEL
AFC 2 LEVEL
PLL 1 CIRCUIT
PLL 2 CIRCUIT
AGC 1 LEVEL
AGC 2 LEVEL
INT. 10 MHz
IF INPUT LEVEL
AUTO
0 – 5.00 V
0 - 5.00 V
LOCKED
LOCKED
0 - 5.00 V
0 - 5.00 V
IS USED
OK
SUPPLY ENABLED FOR
POWER SUPPLY STATE,
32V
±12V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP 1 CURRENT
AMP 2 CURRENT
TEMPERATURE
CODE VERSION
PA HAS OPERATED FOR
POWER SUPPLY VOLTAGE,
32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
xxx HOURS
N/A
32 VDC
OK or OFF
xxx%
xxx%
xx.xA
xx.xA
xxC
x.x
xxx HOURS
N/A
FAULT
xxx%
xxx%
xx.xA
xx.xA
xxC
N/A
N/A
31 – 32 VDC
ENABLED or DISABLED
xxx%
xxx%
xx.xA
xx.xA
xx.xA
xxC
x.x
N/A
FAULT
xxx%
xxx%
xx.xA
xx.xA
xx.xA
xxC
N/A
PA HAS OPERATED FOR
xxx HOURS
N/A
J6
FAULT
N/A
N/A
N/A
MANUAL
EXTERNAL
N/A
N/A
N/A
FAULT
FAULT
N/A
N/A
N/A
FAULT
Pushing the ↓ Down Arrow, after scrolling through all the detail screens, will put you back
to Menu 30, Table 3-20. Push the ESC button to exit the Transmitter Device Parameter
Screens to Menu 12, Table 3-17 to the Transmitter Device Parameter Access Screen.
LX Series, Digital, Rev. 4
3-16
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Menu 40 (Table 3-13) is entered by selecting ENT at Menu 13.
Table 3-23: Menu 40 - Authorized Personnel Screen
This screen of the transmitter notifies an operator that they are only to proceed if they
are authorized to make changes to the transmitter's operation. Changes made within the
following set-up screens can affect the transmitters output power level, output frequency,
and the general behavior of the transmitter. Please do not make changes within the
transmitter's set-up screens unless you are familiar with the operation of the transmitter.
Pressing ENT will put you into the Transmitter Set Up Screens for Menu 40.
A safeguard is added to the Set Up Menus in software version 2.5 and above. If a change
is made to a screen within the Set Up Menus, when you go to the next menu, a new
screen asks if you accept the change or want to return to the previous menu to
reconsider the changes made.
To accept the changes, the two buttons located under ACCEPT must be pushed
simultaneously.
To return to the previous Menu to make corrections, the two buttons located under the
RETURN must be pushed simultaneously. Upon returning to the previous Menu the
correct input must be entered and the above procedure repeated, this time accepting the
changes
Accept or Return to previous Menu Screen
Pushing these two buttons
Simultaneously will accept
the change.
Pushing these two buttons
Simultaneously will return you
to the previous Menu.
The Set Up Screens are shown in Table 3-24 Menu 40-1 through Table 3-43 Menu 40-19
that follow.
Table 3-24: Menu 40-1 - Transmitter Set-up: Power Control Screen
This screen of the transmitter is the first of several that allows access to transmitter setup parameters. When + is selected, the Power will increase. When - is selected, the
Power will decrease.
LX Series, Digital, Rev. 4
3-17
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Table 3-25: Menu 40-2 - Transmitter Set-up: Model Select Screen
This screen is used to specify which components are expected to be part of the system.
By specifying the model number, the transmitter control firmware knows which
components should be installed and it will be able to display faults for components that
are not properly responding to system commands.
Table 3-26: Menu 40-3 - Transmitter Set-up: Upconverter Channel Select Screen
The choices of this screen are to the standard UHF / VHF channels. The + and – buttons
change the desired channel of the transmitter. The PLL frequency is set for custom
Offsets within the Upconverter frequency. Any change to the channel is immediately set
to the LO / Upconverter Frequency Synthesizer PLL circuit.
Table 3-27: Menu 40-4 - Transmitter Set-up: Serial Address Screen
This screen allows the user to set the serial address of the transmitter. The default
address is 5. This value and all other set-up parameters, are stored in non-volatile
memory.
Table 3-28: Menu 40-6 - Transmitter Set-up: System Forward Power Calibration
This screen is used to adjust the calibration of the system's forward power. A symbol
placed under the '6' character indicates changes in the calibration value. When the
calibration value is at full value, the character will be full black. As the value decreases,
the character pixels are gradually turned off. The calibration value is a value between 0
and 255 but the calibration value symbol only has 40 pixels. Therefore small changes in
actual calibration value may not affect the symbol's appearance.
(NOTE: Menu 40-5 is not used)
LX Series, Digital, Rev. 4
3-18
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Table 3-29: Menu 40-6 - Transmitter Set-up: System Reflected Power Calibration
This screen is used to adjust the calibration of the system's reflected power. A calibration
value symbol is also used for this screen as on the previous screens.
Table 3-30: Menu 40-7 - Transmitter Set-up: Forward Power Fault Threshold Screen
This screen is used to set the minimum forward power fault threshold. When the
transmitter is operating, it must operate above this value otherwise the system will shut
down with fault for 5 minutes. If after five minutes the fault is not fixed, the transmitter
will enable, measure power less than this value and again shut down for five minutes.
Table 3-31: Menu 40-8 - Transmitter Set-up: Reflected Power Fault Threshold
This screen is used to set the maximum reflected power fault threshold. When the
transmitter is operating, it must not operate above this value otherwise the system will
slowly begin to reduce the forward output power. If the system's reflected output power
exceeds the maximum reflected power threshold by five percent or more, the transmitter
will shut down with fault for 5 minutes. If after five minutes the fault is not fixed, the
transmitter will enable, measure power above this value plus five percent and again shut
down for five minutes. If the system's reflected output power exceeds the maximum
reflected power threshold due to some condition like the formation of ice on an antenna,
the transmitter reduces forward power to a level where the reflected power is less than
this threshold. The transmitter will automatically increase its output power to normal
operation when the cause of higher than normal reflected power is corrected.
Table 3-32: Menu 40-10 - Transmitter Set-up: Auto Stand-By Control
Certain LX transmitter locations are required to reduce the output power to zero on the
loss of video input. When a LX transmitter is configured for Auto Stand-By On
Modulation Loss, the transmitter will switch to stand-by, if a modulated input signal fault
is detected by the IF Processor module and it lasts for more than ten seconds. Once the
modulated input signal fault is cleared, a transmitter in operate mode will return to
normal operation. This feature is implemented in transmitter software version 1.4 and
above. (NOTE: Menu 4-9 is not used in this configuration)
LX Series, Digital, Rev. 4
3-19
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Table 3-33: Menu 40-12 - Transmitter Set-up: Inner Loop Gain Control
This screen is used to set up the Inner Loop Gain of the exciter/amplifier assembly. This
feature is implemented in transmitter software version 2.0 and above.
(NOTE: Menu 40-11 is not used)
Table 3-34: Menu 40-13 - Transmitter Set-up: Optional System Control
This screen is used to set up any optional system, including the addition of the optional
Modulator in a translator system. This feature is implemented in transmitter software
version 2.0 and above.
Table 3-35: Menu 40-14 - Transmitter Set-up: DM8 Optional Mode Control
This screen is used to select in the OPERATE MODE either NORMAL or TEST CW ZERO. In
NORMAL mode, the modulator outputs an ATSC compliant 8 VSB IF signal. In the TEST
CW ZERO mode, the IF output is reduced to zero.
Table 3-36: Menu 40-15 - Transmitter Set-up: DM8 Source Select Control
This screen is used to select the source of the MPEG input. In normal operation, the
transmitter will use the MPEG signal at the rear of the chassis. For test purposes and
initial transmitter installation, the user can use the internal test MPEG stream by selecting
INTERNAL PRBS23.
Table 3-37: Menu 40-16 - Transmitter Set-up: DM8 Nonlinear Correction Control
This screen is used to select the type of nonlinear correction that is applied to the IF
output. In the OFF mode, there is no nonlinear precorrection applied. In the ON mode,
your choices are, the PRESET 1, or PRESET 2 Mode, which apply a preset correction that
was loaded in the factory or a Fixed Table, which when selected allows for the selection of
the desired Fixed Table from the next menu.
LX Series, Digital, Rev. 4
3-20
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Table 3-38: Menu 40-16 - Transmitter Set-up: DM8 Fixed Table Selection Control
This screen provides for the selection of one of the 255 different Fixed Tables, which is
used for nonlinear precorrection that is applied to the IF output.
Table 3-39: Menu 40-16 - Transmitter Set-up: DM8 Fixed Phase Selection Control
This screen is used to select the Fixed Phase for the nonlinear precorrection that is
applied to the IF output.
Table 3-40: Menu 40-16 - Transmitter Set-up: DM8 Find Table Selection Control
The FIND TABLE menu is a screen that applies each of the fixed nonlinear tables to the IF
output and determines which table provides the best performance. This procedure is
done with a spectrum analyzer and should only be performed at the factory.
Table 3-41: Menu 40-17 - Transmitter Set-up: DM8 Linear Correction Control
The LINEAR EQ menu screen allows the user to turn on or off the preset linear correction
loaded into the modulator at the factory.
Table 3-42: Menu 40-18 - Transmitter Set-up: AGC Mode Control
The AGC MODE menu allows the user to select between a fixed output level from the DM8
Modulator or an output level that will track the power setting as set on the Innovator LX
Controller Card. The normal mode of operation is the TRACKING mode with the FIXED
mode typically used only for test purposes. The DM8 Modulator will store the last value
of this parameter and restore it to this value on power up.
LX Series, Digital, Rev. 4
3-21
Digital UHF Driver/Transmitter
Chapter 3, Site Considerations,
Installation and Setup Procedures
Table 3-43: Menu 40-19 - Transmitter Set-up: Remote Commands Control
This screen is used to allow or deny the use of remote control commands. When
disabled, remote commands are not used. Remote commands are commands received
either through the rear terminal blocks or through serial messages.
Push the ESC button to exit the Transmitter Set Up Screens to Menu 13, Table 3-18, the
Transmitter Configuration Access Screen.
This completes the description of the menu screens for the LX Series exciter/amplifier
chassis assembly.
3.5.5 Operation Procedure
If necessary, connect to the transmitter
to the antenna. Check that the output is
100% and if needed adjust the ALC Gain
adjust pot on the front panel of the IF
Processor to attain 100%. The power
raise / lower settings, in the menus, are
only to be used for temporary reductions
in power.
LX Series, Digital, Rev. 4
The power set-back values do not directly
correspond to the output power of the
transmitter.
This completes the Installation, Set Up
and Turn On of the Driver/Transmitter.
If a problem occurred during the setup
and operation procedures, refer to
Chapter 5, Detailed Alignment
Procedures, of this manual for more
information.
3-22
Digital UHF Driver/Transmitter
Chapter 4, Circuit Descriptions
Chapter 4
Circuit Descriptions
4.0 (Optional) Exciter Switcher Tray,
(110 VAC 1305727 or 220 VAC
1305715); Appendix B)
4.1 (A1) DM8 Digital Modulator
Module (1306342; Appendix B)
The DM8 modulator is an ATSC compliant
8 VSB modulator, which is mounted on a
slide in bracket assembly. The DM8
modulator accepts an SMPTE-310 MPEG
data stream input and outputs a 6 MHz
wide IF output centered at 44 MHz with a
pilot carrier at 46.69 MHz. The Digital
Modulator is made up of the (A1) Digital
Modulator Board (1304883) and the VSB
Front Panel Board (1305939).
NOTE: Part of a dual exciter system.
4.0.1 Exciter Switcher Control Board
(220 VAC 1305704 or 110 VAC
1305725; Appendix B)
The Exciter Switcher Control Boards for
220 VAC and 110 VAC are the same
except for the location of the T1
transformer. Location T1-110 is used
with 110VAC input and location T1-230
is used with 230VAC input. Refer to the
schematic for the board 1305705 Page 3
of 4, located in Appendix B, for a visual
representation of the wiring.
4.1.1 (A1) Digital Modulator, DT1D
Board (1304883; Appendix B)
4.1.1.1 SMPTE-310 Input
The DM8 modulator accepts a SMPTE-310
input on through the backplane of the
Innovator LX chassis on connector J1-25B.
This input is routed through to SMA
connector J3 on the card, which is
connected to J42 via a small RG-179
cable. This input is applied to a high
speed window comparator that adjust the
level to a low voltage TTL signal to be
used by the Altera FPGA, U3. The
SMPTE-310 signal is input to the FPGA to
recover the clock and the data. A portion
of the clock and recovery circuit is
performed by a high-speed comparator,
U17, which functions as an external delay
circuit.
The Exciter Switcher Control Board
monitors and controls both Exciters and
controls automatic switching of the
Exciters in case of malfunction in the OnAir Exciter using a coaxial relay. ICs on
the board monitor the operating
parameters of the Exciters and determine
if the Exciters are functioning properly.
The front panel of the Exciter Switcher
has an LCD display, which provides set
up screens for the operation of the
switching process.
The coaxial relay has four “N” connectors
that provide input and output
connections to the relay. The RF Output
from Exciter “A” connects to J21. The RF
Output from Exciter “B” connects to J23.
The Selected Exciter RF Output to the
external amplifiers connects to J24. The
Exciter “A/B” Load connects to J22, to
which the RF output of the Off Air Exciter
is connected. An internal wire harness
connects the relay to J14 on the Exciter
Switcher Control Board. These
connections provide the control voltages
to the relay from the control board and
status indication connections back to the
control board.
LX Series, Digital, Rev. 4
4.1.1.2 Channel Coder
The FPGA subsequently uses the SMPTE310 clock and data as the input to the
channel coder contained inside the FPGA.
The channel coder is a series of DSP
blocks defined by the ATSC standard for 8
VSB data transmission. These blocks
include the data randomizer, Reed
Solomon Encoder, data interleaver, trellis
coder, and sync inserter. The channel
coder portion inside the FPGA generates
the 8 distinct levels in an 8 VSB
4-1
Digital UHF Driver/Transmitter
transmitter. These levels are
subsequently input to a linear equalizer
that provides for frequency response
correction in the transmission path. The
linear equalizer is a 67 tap FIR filter that
is loaded with tap values from the
microntroller, U1, located on this board.
The output of the linear equalizer is then
input to two pulse shaping filters, an in
phase (I) and a quadrature (Q) filter
that are also located inside the FPGA.
The pulse shaping filters are FIR filters
that have fixed tap values that are
preset inside the FPGA. The output of
the pulse shaping filters is then applied
to a Pre-Distortion Linearizer chip, U4,
which can be used to correct for
nonlinearities in the data transmission
path. The output of the Pre-Distortion
chip is gain scaled and output to a dual
D/A converter that output a baseband I
and Q analog signal.
4.1.1.3 Analog Output Section
The baseband I and Q signals from the
D/A converter are applied to differential
analog filters that remove some of
digital artifacts from the D/A conversion
process. The output of the I channel
filter is then mixed with the pilot
frequency, 46.69 MHz, using mixer U30.
The output of the Q filter is mixed with
the pilot frequency that is phase shifted
90 degrees using mixer U34. The
mixers are current driven devices so
that when the outputs of U30 and U34
are connected together, they provide a
combined output. This combined output
is subsequently input to a final
differential output filter which provides
the final IF output at the SMA connector,
J38. To maintain signal integrity, this IF
output is connected to the SMA
connector J39 with a small semi-rigid
cable assembly. The final IF output then
appears at J21-2B.
4.1.1.4 Pilot Frequency Generation
The 46.69 MHz pilot, that is used in the
mixing process is generated from a
46.69 MHz VCXO that is phase locked to
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
a 10 MHz reference. The VCXO and the
10 MHz are divided down to a common
frequency, which is then compared
internal to the FPGA. The FPGA
subsequently provides error signals to a
analog phase locked implemented with op
amp stages U45-A, B and C. The output
of these compensation stages is used as
the control voltage to the VCXO, U37.
The phase locked output of U37 is applied
to an analog filter to remove harmonics of
the pilot and then input to the quadrature
splitter Z1. The outputs of Z1 are used as
the inputs to the mixers in the analog
output section.
4.1.1.5 Voltage Requirements
The ±12 VDC connect to the board at J18.
The +12V SYS connects to J18A, B & C and
is filtered by L2, L3, C105 and C106 before
it is applied to the rest of the board as
+12VQ and +12VI. The -12 VDC SYS
connects to J19A, B & C and is filtered by
L6, L7, C111 and C112 before it is applied
to the rest of the board as
-12VI and –12VQ.
The +12V SYS also connects through the
resistor R81 to provide +5V EXT to the rest
of the board, and to the regulators U23
that provides +3.3V to the rest of the
board and to U27 that provides +1.8V
output.. The +3.3V also connects to U24
that supplies +1.5V output. The +12V SYS
connects to the regulator U25 and U26 to
supply the +5VA output. The output of
U25 also connects to U28 which provides
the +5V output to the rest of the board.
+12V SYS is filtered by L4 and C107 to
provide the +12V output to the board.
The –12V SYS also connects to the
regulator U22 that provides the –5V VA to
the rest of the board. -12V SYS is filtered
by L5 and C108 to provide the -12V output
to the board.
The externally mounted resistor R1,
5.6Ω/25W, is used to reduce the +12 VDC
power supply voltage to a lower level
voltage which cuts down the power
dissipation on the USB card.
4-2
Digital UHF Driver/Transmitter
4.1.2 (A2) VSB Front Panel Board
(1305939; Appendix B)
The VSB front panel board provides the
mounting of the status LEDs that are
viewed through the front panel. These
LEDs include the MPEG, which
illuminates Green if the MPEG stream at
the J1-2B input jack is valid, the PLL A,
which illuminates Green if the DM8
symbol clock is locked to the frequency
of the 10 MHz reference and the PLL B,
which illuminates Green if the pilot
frequency is locked to the 10 MHz
reference.
4.2 (A3) IF Processor Module
Assembly (1301938; Appendix B)
The IF from the DM8 modulator enters
the module and the signal is precorrected as needed for amplitude
linearity correction, Incidental Carrier
Phase Modulation (ICPM) correction and
frequency response correction.
The Module contains the following board.
4.2.1 IF Processor Board (1301977;
Appendix B)
The automatic level control (ALC) portion
of the board provides the ALC and
amplitude linearity correction of the IF
signal. The ALC adjusts the level of the IF
signal that controls the output power of
the transmitter.
The IF from the DM8 modulator enters
the board at J42B pin 32B. If the
(optional) receiver tray is present, the IF
input (-6 dBm) from the DM8 modulator
connects to the DM8 modulated IF input
jack J42C Pin 21C. The DM8 modulated
IF input connects to relay K3 and the
receiver IF input connects to relay K4.
The two relays are controlled by the
Modulator Select command that is
connected to
J42C Pin 14C on the board. Modulator
select enable/disable jumper W11 on J29
controls whether the Modulator Select
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
command at J42C Pin 14C controls the
operation of the relays. With jumper W11
on J29 between pins 1 and 2, the
Modulator Select command at J42C Pin
14C controls the operation of the relays;
with jumper W11 on J29, pins 2 and 3, the
modulator is selected all of the time.
4.2.1.1 DM8 Modulator Selected
With the modulator selected, J42C-14C
low, this shuts off Q12 and causes Pin 8 on
the relays to go high that causes relays K3
and K4 to de-energize. When K4 is deenergized, it connects the receiver IF input
at J42C-21C, if present, to a 50Ω load.
When K3 is de-energized, it connects the
modulator IF input at J42B-32B to the rest
of the board; Modulator Enable LED DS5
will be illuminated.
4.2.1.2 External Modulated IF Selected
With the External Modulated IF selected,
J42C-14C high, this turns on Q12 and
makes pin 8 on the relays low that causes
the relays K3 and K4 to energized. When
K4 is energized, it connects the receiver IF
input at J42C-21C, if present, to the rest of
the board. When K3 is energized, it
connects to the modulator IF input at
J42B-32B to a 50Ω load. The Modulator
Enable LED DS5 will not be illuminated.
4.2.1.3 Main IF Signal Path (Part 1 of 3)
The selected IF input (-6 dBm average)
signal is split, with one half of the signal
entering a bandpass filter that consists of
L3, L4, C4, L5, and L6. This bandpass filter
can be tuned with C4 and is substantially
broader than the IF signal bandwidth. It is
used to slightly steer the frequency
response of the IF to make up for any
small discrepancies in the frequency
response in the stages that precede this
point. The filter also serves the additional
function of rejecting unwanted frequencies
that may occur if the tray cover is off and
the tray is in a high RF environment. (If
this is the case, the transmitter will have to
be serviced with the tray cover off in spite
of the presence of other RF signals). The
4-3
Digital UHF Driver/Transmitter
filtered IF signal is fed through a pi-type
matching pad consisting of R2, R3, and
R4 to the pin-diode attenuator circuit
consisting of CR1, CR2, and CR3.
4.2.1.4 Input Level Detector Circuit
The other part of the split IF input is
connected through L2 and C44 to U7. U7
is an IC amplifier that is the input to the
input level detector circuit. The amplified
IF is fed to T4, which is a step-up
transformer that feeds diode detector
CR14. The positive-going detected signal
is then low-pass filtered by C49, L18, and
C50. This allows only the positive digital
peaks to be applied through emitter
follower Q1. The signal is then connected
to detector CR15 to produce a peak
digital voltage that is applied to op-amp
U9A. There is a test point at TP3 that
provides a voltage-reference check of the
input level. The detector serves the dual
function of providing a reference that
determines the input IF signal level to
the board and also serves as an input
threshold detector.
The input threshold detector prevents the
automatic level control from reducing the
attenuation of the pin-diode attenuator to
minimum, the maximum signal output, if
the IF input to the board is removed. The
ALC, input loss cutback, and the
threshold detector circuits will only
operate when jumper W2 on jack J5 is in
the Enabled position, between pins 2 and
3. Without the threshold detector, and
with the pin-diode attenuator at
minimum, the signal will overdrive the
stages following this board when the
input is restored.
As part of the threshold detector
operation, the minimum IF input level at
TP3 is fed through detector CR15 to opamp IC U9A, pin 2. The reference voltage
for the op-amp is determined by the
voltage divider that consists of R50 and
R51, off the +12 VDC line. When the
detected input signal level at U9A, pin 2,
falls below this reference threshold,
approximately 10 dB below the normal
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
input level, the output of U9A at pin 1 goes
high, toward the +12 VDC rail. This high is
connected to the base of Q2 that is forward
biased and creates a current path. This
path runs from the -12 VDC line and
through red LED DS1, the input level fault
indicator, which lights, resistor R54, and
transistor Q2 to +12 VDC. The high from
U9A also connects through diode CR16 and
R52, to U24D pin 12, whose output at pin
14 goes high. The high connects through
the front panel accessible ALC Gain pot
R284 and the full power set pot R252 to
U24C Pin 9. This high causes U24C pin 8
to go low. A power raise/lower input from
the Control/Monitoring Module connects to
J42C pin 24C and is wired to Q14. This
input will increase or decrease the value of
the low applied to U24B and therefore
increase or decrease the power output of
the transmitter.
The low connects to U24B pin 5 whose
output goes low. The low is wired to U24A
pin2 whose output goes high. The high is
applied to U10A, pin 2, whose output goes
low. The low connects through the switch
SW1, if it is in the auto gain position, to
the pin-diode attenuator circuit, CR1, CR2
& CR3. The low reverse biases them and
cuts back the IF level, therefore the output
level, to 0. When the input signal level
increases above the threshold level, the
output power will increase, as the input
level increases, until normal output power
is reached.
The digital input level at TP3 is also fed to
a pulse detector circuit, consisting of IC
U8, CR17, Q3, and associated components,
and then to a comparator circuit made up
of U9C and U9D. The reference voltage for
the comparators is determined by a
voltage divider consisting of R243, R65,
R66, and R130, off the -12 VDC line. When
the input signal level to the detector at TP3
falls below this reference threshold, which
acts as a loss-of-digital peak detector
circuit, the output of U9C and U9D goes
towards the -12 VDC rail and is split, with
one part biasing on transistor Q5. A current
path is then established from the +12 VDC
line through Q5, the resistors R69 and
4-4
Digital UHF Driver/Transmitter
R137, and the red LED DS3, input loss
indicator, which is illuminated. When Q5
is on, it applies a high to the gate of Q6.
This causes it to conduct and apply a
modulation loss pull-down output to J42C
pin 7C, which is applied to the front panel
display on the Control/Monitor module.
The other low output of U9C and U9D is
connected through CR18, CR19 & CR20
to jack J5. Jumper W2 on J5, in the
Cutback Enable position, which is
between pins 2 and 3, connects the low
to the base of Q4 that is now forwardbiased. NOTE: If jumper W2 is in the
Disable position, between pins 1 and 2,
the auto cutback will not operate. With
Q4 biased on, a negative level
determined by the setting of cutback
level pot R71 is applied to U24D pin 12.
The level is set at the factory to cut back
the output to approximately 25%. The
output of U24D at pin 14 goes low and is
applied through the power adjust pot to
U24C, pin 9, whose output goes low.
The low connects to U24B, pin 5, whose
output goes low. The low then connects
to U24A, pin 2, whose output goes high.
The high is applied to U10A, pin 2, whose
output goes low. The low connects
through the switch SW1, if it is in the
auto gain position, to the to the pin-diode
attenuator circuit, CR1, CR2 & CR3. The
low reverse biases them and cuts back
the level of the output to approximately
25%.
4.2.1.5 Pin-Diode Attenuator Circuit
The input IF signal is fed to a pin-diode
attenuator circuit that consists of CR1,
CR2 & CR3. Each of the pin diodes
contains a wide intrinsic region; this
makes the diodes function as voltagevariable resistors at this intermediate
frequency. The value of the resistance is
controlled by the DC bias supplied to the
diode. The pin diodes are configured in a
pi-type attenuator configuration where
CR1 is the first shunt element, CR3 is the
series element, and CR2 is the second
shunt element. The control voltage,
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
which can be measured at TP1, originates
either from the ALC circuit when the switch
SW1 is in the ALC Auto position, between
pins 2 and 3, or from pot R87 when SW1 is
in the Manual Gain position, between pins
1 and 2.
In the pin diode attenuator circuit,
changing the amount of current through
the diodes by forward biasing them
changes the IF output level of the board.
There are two extremes of attenuation
ranges for the pin-diode attenuators. In
the minimum attenuation case, the
voltage, measured at TP1, approaches the
+12 VDC line. There is a current path
created through R6, through series diode
CR3, and finally through R9 to ground. This
path forward biases CR3 and causes it to
act as a relatively low-value resistor. In
addition, the larger current flow increases
the voltage drop across R9 that tends to
turn off diodes CR1 and CR2 and causes
them to act as high-value resistors. In this
case, the shunt elements act as a high
resistance and the series element acts as a
low resistance to represent the minimum
loss condition of the attenuator (maximum
signal output). The other extreme case
occurs as the voltage at TP1 is reduced and
goes towards ground or even slightly
negative. This tends to turn off (reverse
bias) diode CR3, the series element,
causing it to act as a high-value resistor.
An existing fixed current path from the
+12 VDC line, and through R5, CR1, CR2,
and R9, biases series element CR3 off and
shunt elements, diodes CR1 and CR2, on,
causing them to act as relatively low-value
resistors. This represents the maximum
attenuation case of the pin attenuator
(minimum signal output). By controlling
the value of the voltage applied to the pin
diodes, the IF signal level is maintained at
the set level.
4.2.1.6 Main IF Signal Path (Part 2 of 3)
When the IF signal passes out of the pindiode attenuator through C11, it is applied
to modular amplifier U1. This device
contains the biasing and impedancematching circuits that makes it operate as
4-5
Digital UHF Driver/Transmitter
a wide-band IF amplifier. The output of
U1 connects to J40 that is jumpered to
J41. The J40 jack is available, as a
sample of the pre-correction IF for
troubleshooting purposes and system
setup. The IF signal is connector to a
splitter Z1 that has an in phase output
and a 90° Quadrature output, which are
then connected to the linearity corrector
portion of the board.
4.2.1.7 Amplitude and Phase
Pre-Correction Circuits
The linearity corrector circuits use three
stages of correction, two adjust for any
amplitude non-linearities and one for
phase non-linearities of the output signal.
Two of the stages are in the in phase
amplitude pre-correction path and one
stage is in the quadrature phase precorrection path. Each stage has a
variable threshold control adjustment,
R211 and R216, in the in phase path,
and R231, in the quadrature path, that
determines the point at which the gain is
changed for that stage.
Two reference voltages are needed for
the operation of the corrector circuits.
The Zener diode VR3, through R261,
provides the +6.8 VDC reference. The
VREF is produced using the path through
R265 and the diodes CR30 and CR31.
They provide a .9 VDC reference, which
temperature compensates for the two
diodes in each corrector stage.
The first corrector stage in the in phase
path operates as follows. The in phase IF
signal is applied to transformer T6, which
doubles the voltage swing by means of a
1:4 impedance transformation. Resistors
R222 and R225 form an L-pad that
lowers the level of the signal. The input
signal level when it reaches a certain
level causes the diodes CR24 and CR25
to turn on, generating current flow that
puts them in parallel with the L-pad.
When the diodes are put in parallel with
the resistors, the attenuation through the
L-pad is lowered, causing signal stretch.
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
The signal is next applied to amplifier U17
to compensate for the loss through the
L-pad. The breakpoint, or cut-in point, for
the first corrector is set by controlling
where CR24 and CR25 turn on. This is
accomplished by adjusting the threshold
cut-in resistor R211. R211 forms a
voltage-divider network from +6.8 VDC to
ground. The voltage at the wiper arm of
R211 is buffered by the unity-gain
amplifier U16B. This reference voltage is
then applied to R215, R216, and C134
through L44 to the CR24 diode. C134
keeps the reference from sagging during
the vertical interval. The .9 VDC reference
voltage is applied to the unity-gain
amplifier U16D. The reference voltage is
then connected to diode CR25 through
choke L45. The two chokes L44 and L45
form a high impedance for RF that serves
to isolate the op-amp ICs from the IF.
After the signal is amplified by U17, it is
applied to the second corrector stage in the
in phase path through T7. These two
correctors and the third corrector stage in
the quadrature path operate in the same
fashion as the first. All three corrector
stages are independent and do not interact
with each other.
The correctors can be disabled by moving
jumper W12 on J30 to the Disable position,
between pins 1 and 2, this moves all of the
breakpoints past the greatest peaks of
digital so that they will have no affect.
The pre-distorted IF signal in the in phase
path, connects to an op amp U18 whose
output level is controlled by R238. R238
provides a means of balancing the level of
the amplitude pre-distorted IF signal that
then connects to the combiner Z2.
The pre-distorted IF signal in the
quadrature path connects to op amp U20
and then step up transformer T9, next op
amp U21 and step up transformer T10 and
finally op amp U22 whose output level is
controlled by R258. R258 provides a
means of balancing the level of the Phase
pre-distorted IF signal that then connects
to the combiner Z2.
4-6
Digital UHF Driver/Transmitter
The amplitude and phase pre-distorted IF
signals are combined by Z2 and
connected to J37 that is jumpered to J36
on the board. J37 can be used for
testing or monitoring purposes of the IF
signal after amplitude and phase predistortion. The pre-distorted IF signal
connects through a resistor buffer
network that prevents loading of the
combiner before it is wired to the
frequency response circuitry.
4.2.1.8 Main IF Signal Path (Part 3 of 3)
The IF signal, at the input to the
frequency-response corrector circuit, is
split using L24, L25 and R89. One path
is through L24, which is the main IF path
through the board. The main IF is fed
through a resistor network that controls
the level of the IF by adjusting the
resistance of R99, the output level
adjust. The IF signal is then applied to a
three-stage, frequency-response
corrector circuit that is adjusted as
needed.
The frequency-response corrector circuit
operates as follows. Variable resistors
R103, R106 and R274 are used to adjust
the depth and gain of the notches and
variable caps C71, C72 and C171 are
used to adjust the frequency position of
the notches. These are adjusted as
needed to compensate for frequency
response problems.
The frequency-response corrected IF is
connected to J38 that is jumpered to J39
on the board. J38 can be used for
testing or monitoring purposes of the IF
signal after frequency response
pre-correction. The IF is next amplified
by U13 and U14. After amplification, the
IF is split with one path connected to
J42C pin 1C the IF output to the
LO/Upconverter Module. The other path
is fed through a divider network to J35 a
SMA IF Sample Jack, located on the front
panel, that provides a sample of the
corrected IF for test purposes.
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
4.2.1.9 ALC Circuit
The other path of the corrected IF signal at
the input to the frequency response
corrector circuit is used in the ALC circuit.
The IF flows through L25, of the L24 L25
splitter, and connects to the op-amp U12.
The IF signal is applied through a resistor
divider network to transformer T5. T5
doubles the voltage swing by means of a
1:4 impedance transformation before it is
connected to the ALC detector circuit,
consisting of C70, CR23 and R91. The
detected ALC level output is amplified by
U10B and wired to U10A, pin 2, where it is
summed with the power control setting,
which is the output power setting that is
maintained by the ALC. The output of
U10A connects through SW1, if it is in the
auto gain position, to the pin-diode
attenuator circuit, CR1, CR2 & CR3. The
high forward biases them more or less,
that increases or decreases the IF level,
therefore the output level, opposite the
input level. When the input signal level
increases, the forward bias on the pin
attenuator decreases, therefore the output
power will decrease, which keeps the
output power the same as set by the
customer.
An external power raise/lower switch can
be used by connecting it to TB30, at TB308 power raise and TB30-9 power lower, on
the rear of the exciter/amplifier chassis.
The ALC voltage is set for .8 VDC at TP4
with a 0-dBm output at J42C pin 1C of the
module. A sample of the ALC at J42C pin
11C, is wired to the Control
Monitoring/Power Supply module where it
is used on the front panel display and in
the AGC circuits.
The ALC voltage, and the DC level
corresponding to the IF level after signal
correction, are fed to U10A, pin 2, whose
output at pin 1 connects to the ALC pindiode attenuator circuit. If there is a loss of
gain somewhere in an IF circuit, the output
power of the transmitter will drop. The ALC
circuit senses this drop at U10A and
automatically decreases the loss through
the pin-diode attenuator circuit therefore
4-7
Digital UHF Driver/Transmitter
increasing its gain maintaining the same
output power level.
The ALC action starts with the ALC
detector level monitored at TP4. The
detector output at TP4 is nominally +.8
VDC and is applied through resistor R77
to a summing point at op-amp U10A, pin
2. The current available from the ALC
detector is offset, or complemented, by
current taken away from the summing
junction. In normal operation, U10A, pin
2, is at 0 VDC when the loop is satisfied.
If the recovered or peak-detected IF
signal level at IF input to this board
should drop, which normally means that
the output power will decrease, the null
condition would no longer occur at U10A,
pin 2. When the level drops, the output
of U10A, pin 1, will go more positive. If
SW1 is in the Automatic position, it will
cause the ALC pin-diode attenuators CR1,
CR2, and CR3 to have less attenuation
and increase the IF level; this will
compensate for the decrease in the level.
If the ALC cannot increase the input level
enough to satisfy the ALC loop, due to
there not being enough range, an ALC
fault will occur. The fault is generated
because U10D, pin 12, increases above
the trip point set by R84 and R83 until it
conducts. This makes U10D, pin 14, high
and causes the red ALC Fault LED DS2 to
light.
4.2.1.10 Fault Command
The board also has circuitry for an
external mute fault input at J42 pin 10C.
This is a Mute command that protects the
circuits of high-gain output amplifier
devices against VSWR faults. This action
needs to occur faster than just pulling
the ALC reference down. Two different
mechanisms are employed: one is a very
fast-acting circuit to increase the
attenuation of the pin-diode attenuator,
CR1, CR2, and CR3, and the second is
the reference voltage being pulled away
from the ALC amplifier device. An
external Mute is a pull-down applied to
J42 pin 10C, that completes a current
path from the +12 VDC line through R78
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
and R139, the LED DS4 (Mute indicator),
and the LED section of opto-isolator U11.
These actions turn on the transistor section
of U11 that applies -12 VDC through CR21
to U10A pin 3, and pulls down the
reference voltage. This is a fairly slow
action controlled by the low-pass filter
function of R81 and C61. When the
transistor section of U11 is on, -12 VDC is
also connected through CR22 directly to
the pin-diode attenuator circuit. This
establishes a very fast muting action, by
reverse biasing CR3. This action occurs in
the event of an external VSWR fault.
4.2.1.11 ±12 VDC Needed to Operate the
Board
The ±12 VDC connects to the board at
J42C. The +12 VDC connects to J42C pin
16C and is filtered by L30, L41, and C80
before it is applied to the rest of the board.
The -12 VDC connects to J42C pin 18C and
is filtered by L31 and C81 before it is
applied to the rest of the board.
The +12 VDC also connects through R261
to the zener diode VR3 that connects to
ground, which generates the +6.8 VDC
output to the rest of the board.
The +12 VDC also connects through R265
to the diodes CR30 and CR31 provide a .9
VDC reference output voltage VREF that
temperature compensates for the two
diodes in each corrector stage.
4.3 (A5) VHF/UHF Upconverter
Module (1303829; Appendix B)
This module contains the Downconverter
Board Assembly, the First Conversion
Board, LX Series, L-Band PLL Board, LX
Series and the Upconverter Control Board,
LX Series. This module takes an external
IF and converts it to the final RF output
frequency using two internally generated
local oscillator frequencies.
4-8
Digital UHF Driver/Transmitter
4.3.1 (A1) Downconverter Board
Assembly (1303834; Appendix B)
This board converts a signal at an input
frequency of 1044 MHz to a broadcast
VHF or UHF TV channel.
The IF at 1044MHz is applied to the
board at J7, and is converted down to
VHF or UHF by the mixer IC U6. The LO
frequency is applied to the board at a
level of +20 dBm at J8. The output of
the mixer is applied to a 6 dB attenuator
and then to a 900 MHz Low Pass filter.
The filter is intended to remove any
unwanted conversion products. The
signal is next connected to the amplifier
U2, and then a pin diode attenuator
consisting of DS4, DS5 and their
associated components. The attenuator
sets the output level of the board and is
controlled either by a manual gain pot
R7, or an external AGC circuit. This
automatic or manual mode of operation
is controlled by the switch SW1. When
in manual mode, the LED DS6 is
illuminated.
The output of the pin attenuator is
applied to another amplifier U3 and
another low pass filter, before reaching
the final amplifier U1. The output of the
board is at J5 with a sample of the
output available at J6, which is 20 dB in
level below the signal at J5.
4.3.2 (A2) L-Band PLL Board
(1303846; Appendix B)
This board generates an LO at a
frequency of 1.1-1.9 GHz. The board
contains a PLL IC U6, which controls the
output frequency of a VCO. The PLL IC
divides the output of the VCO down to
100kHz, and compares it to a 100kHz
reference created by dividing down an
external 10 MHz reference that is
applied to the board at J1 pin 4. The IC
generates an error current that is
applied to U3 and its associated
components to generate a bias voltage
for the VCO's AFC input.
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
There are two VCOs on the board, U4,
which operates at 1.1-1.3 GHz for VHF
channels, and U5, which operates at 1.51.9 GHz for UHF channels. The VCO in
use is selected by a signal applied to J1
pin 20. This input enables the power
supply either U1 or U2 for the appropriate
VCO for the desired channel. U7 is a
power supply IC that generates +5V for
the PLL IC U6.
The output of each VCO is filtered by a
low pass filter to remove any harmonic
content and applied to a pin diode switch
consisting of CR1, CR2, and their
associated components. The selected
signal is amplified by U9 and U10, then
applied to a high pass filter and finally
amplified to a level of approximately +21
dBm by U11. The output is connected to
a low pass filter to remove any unwanted
harmonic content and leaves the board at
J3 at a level of +20 dBm.
4.3.3 (A3) First Conversion Board
(1303838; Appendix B)
This board generates a 1 GHz LO signal
using the VCO U9, the PLL IC U12, and
the loop filter, C30-C33 and R49. The PLL
IC compares a divided down sample of the
VCO to a divided down sample of the
transmitter's system 10 MHz reference.
The output of the VCO is amplified by U10
and U11 and applied to a low pass filter
before being connected to an image
rejection mixer consisting of U1, U2, U3
and U6. The 44 MHz IF input is connected
to the board at J2, and then to the image
rejection mixer. This mixer converts the
44 MHz input to an output frequency of
1044 MHz. The output of the mixer is
amplified by U4 and applied to a band
pass filter consisting of C2-C4 and some
microstrip line sections. This filter rejects
any LO leakage at 1 GHz and also any
unwanted out of band products. The
output of the filter is amplified by U5 and
then filtered before exiting the board at
J1.
4-9
Digital UHF Driver/Transmitter
4.3.4 (A4) Upconverter Control
Board (1304760; Appendix B)
This board performs a variety of
functions, which include an interface
between the other boards in the
upconverter and the rest of the
transmitter. It also has a
microcontroller U8, which controls and
monitors the functions of the other
boards in the assembly.
The microcontroller communicates via
an RS-485 interface with the
transmitter's system control module. It
reports any faults and metering
information and receives channel
information, which it passes along to the
PLLs on the L-Band PLL Board and the
First Conversion Board.
The board also generates various
voltages used by the rest of the boards
in the upconverter. U9 converts the
+12V input to the board to +20V. U15
converts +12V to +5V for the on board
10 MHz crystal oscillator. U12 converts
+12V to +9V for the L-Band PLL board
and the First Conversion board. U13
and U14 generate +5V for the
microcontroller.
The board also selects whether the
internal or external 10 MHz reference
source will be used. There is an
onboard 10 MHz oscillator, U3, which is
used when no external 10 MHz source is
present. The Relay K1 is automatically
switched to the external 10 MHz
reference whenever it is present. The
LED DS1 illuminates whenever the
internal 10 MHz reference is used. The
diode detector CR1 detects the presence
of the 10 MHz external reference that
connects to U2, which compares the
detected level to a reference level and
switches the relay whenever the
reference is present. It also disables the
internal oscillator whenever the external
10 MHz reference is being used.
The output of the relay is split to drive
multiple outputs, some internal and
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
some external. The external outputs
leave the board at J1-22C and J1-31B and
are used by the external receiver and
modulator modules.
The board also contains AGC circuitry,
which controls a pin diode attenuator on
the Downconverter Board. There are
three references used by the AGC circuit.
The first is the AGC reference #1, which
comes from the transmitter's driver
module. The second is the AGC reference
#2, which is a diode ORed sample of the
output stages of the transmitter. The IC
U5 normalizes the level of the AGC
reference # 1 and sets it at a level that is
0.2V less than the level of AGC reference
#2. The AGC reference #1 and #2 are
diode ORed with only the highest
reference used by the AGC circuit.
The highest reference is compared to the
ALC reference, which originated on the IF
processor module, and the error voltage
generated by U4D and applied to the
external pin attenuator. The AGC will try
to maintain a constant ratio between the
ALC voltages and the higher of the two
AGC voltages. If something in the output
amplifier of the transmitter fails, the AGC
reference #1 voltage will take over and
the power will be regulated at the output
of the driver.
4.4 (A4) Control Monitoring/Power
Supply Module (1301936,110VAC or
1303229, 220VAC; Appendix B)
The Control Monitoring/Power Supply
Module Assembly contains (A1) a Power
Protection Board (1302837), (A2) a 600
Watt Switching Power Supply, (A3) a
Control Board (1302021), (A4) a Switch
Board (1527-1406) and (A5) a LCD
Display.
AC Input to LX Series Exciter/Amplifier
Chassis Assembly
The AC input to the LX Series
Exciter/Amplifier Chassis Assembly is
connected from J1, part of a fused entry
4-10
Digital UHF Driver/Transmitter
module, located on the rear of the
chassis assembly to J50 on the Control
Monitoring/Power Supply Module. J50-10
is line #1 input, J50-8 is earth ground
and J50-9 is line #2 input. The input AC
connects to J1 on the Power Protection
Board where it is fuse protected and
connected back to J50, at J50-11 AC Line
#1 and J50-12 AC Line #2, for
distribution to the cooling Fan.
4.4.1 (A1) Power Protection Board
(1302837; Appendix B)
The input AC connects through J1 to two
10 Amp AC fuses F1 and F2. The AC
line #1 input connects from J1-1 to the
F1 fuse. The AC line #1 input after the
F1 fuse is split with one line connected
back to Jack J1 Pin 4, which becomes
the AC Line #1 to the Fan. The other
line of the split connects to J4. The AC
line #2 input connects from J1-3 to the
F2 fuse. The AC line #2 input after the
F2 fuse is split with one line connected
back to Jack J1 at Pin 5, which becomes
the AC Line #2 to the Fan. The other
line of the split connects to J2. J1-2 is
the earth ground input for the AC and
connects to J3.
Three 150-VAC, for 115 VAC input, or
three 275-VAC, for 230 VAC input, MOVs
are connected to the input AC for
protection. One connects from each AC
line to ground and one connects across
the two lines. VR1 connects from J4 to
J2, VR2 connects from J4 to J3 and VR3
connects from J2 to J3.
Chapter 4, Circuit Descriptions
current is 4.86 Amps at 50ûC, 6 Amps at
25ûC or 6.6 Amps at 0ûC.
PS3 protects the +12 VDC 2 Amp circuits
for the System Controller, the Amplifier
Controller and the Spare Slot through J62
pins 7, 8, 9 and 10. If this circuit is
operational, the Green LED DS3, mounted
on the board, will be lit.
PS4 protects the +12 VDC 2 Amp circuits
for the Modulator and the IF Processor
through J62 pins 13, 14, 15 and 16. If
this circuit is operational, the Green LED
DS4, mounted on the board, will be lit
PS5 protects the +12 VDC 2 Amp circuits
for the Upconverter through J62 pins 17,
18, 19 and 20. If this circuit is
operational, the Green LED DS5, mounted
on the board, will be lit
PS6 protects the +12 VDC 2 Amp circuits
for the Remote through J63 pins 17, 18,
19 and 20. If this circuit is operational,
the Green LED DS6, mounted on the
board, will be lit
-12 VDC Circuits
-12 VDC from the Switching Power Supply
Assembly connects to J5 on the board.
The -12 VDC is divided into two separate
circuits each with a 3 amp self resetting
fuse, PS1 and PS2.
+12 VDC Circuits
PS1 protects the -12 VDC 2 Amp circuits
for the System through J63 pins 1, 2, 3
and 4. If this circuit is operational, the
Green LED DS1, mounted on the board,
will be lit
+12 VDC from the Switching Power
Supply Assembly connects to J6 on the
board. The +12 VDC is divided into four
separate circuits each with a 3 amp self
resetting fuse, PS3, PS4, PS5 and PS6.
PS2 protects the -12 VDC 2 Amp circuits
for the Remote through J62 pins 1, 2, 3
and 4. If this circuit is operational, the
Green LED DS2, mounted on the board,
will be lit
The polyswitch resettable fuses may
open on a current as low as 2.43 Amps
at 50ûC, 3 Amps at 25ûC or 3.3 Amps at
0ûC. They definitely will open when the
The connections from J62 and J63 of the
Power Protection Board are wired to J62
and J63 on the Control Board.
LX Series, Digital, Rev. 4
4-11
Digital UHF Driver/Transmitter
4.4.2 (A3) Control Board (1302021;
Appendix B)
In this transmitter, control monitoring
functions and front panel operator
interfaces are found on the Control
Board. Front panel operator interfaces
are brought to the control board using a
26 position conductor ribbon cable that
plugs into J60. The control board
controls and monitors the Power Supply
and Power Amplifier module through a
16 position connector J61 and two 20
position connectors J62 & J63.
4.4.2.1 Schematic Page 1
U1 is an 8 bit RISC microcontroller that
is in circuit programmed or programmed
using the serial programming port J4 on
the board. When the microcontroller,
U1, is held in reset, low on pin 20, by
either the programming port or the
external watchdog IC (U2), a FET Q1
inverts the reset signal to a high that
connects to the control lines of U5, an
analog switch. The closed contacts of
U5 connects the serial programming
lines from J4 to U1. LED DS10 will be lit
when programming port J4 is used.
U2 is a watchdog IC used to hold the
microcontroller in reset, if the supply
voltage is less the 4.21 VDC; (1.25 VDC
< Pin 4 (IN) < Pin 2 (Vcc). The
watchdog momentarily resets the
microcontroller, if Pin 6 (ST) is not
clocked every second. A manual reset
switch S1 is provided but should not be
needed.
Diodes DS1 through DS8 are used for
display of auto test results. A test board
is used to execute self test routines.
When the test board is installed,
Auto_Test_1 is held low and
Auto_Test_2 is allowed to float at 5
VDC. This is the signal to start the auto
test routines.
U3 and U4 are used to selectively enable
various input and output ICs found on
pages 2 & 3 of the schematic.
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
U1 has two serial ports available. In this
application, one port is used to
communicate with transmitter system
components where U1 is the master of a
RS-485 serial bus. The other serial port is
used to provide serial data I/O where U1
is not the master of the data port. A dual
RS-232 port driver IC and a RS-485 Port
driver is also in the second serial data I/O
system. The serial ports are wired such
that serial data input can come through
one of the three serial port channels.
Data output is sent out through each of
the three serial port channels.
Switch SW1, transmitter operation select,
is used to select either transmitter
operation or exciter/driver operation.
When the contacts of SW1 are closed,
transmitter operation is selected and the
power monitoring lines of the transmitter’s
power amplifier are routed to the system
power monitoring lines.
4.4.2.2 Schematic Page 2
U9 is a non-inverting transceiver IC that
provides 2 way asynchronous
communication between data busses. The
IC is used as an input buffer to allow the
microcontroller to monitor various digital
input values.
Digital output latch circuits are used to
control system devices. Remote output
circuits are implemented using open drain
FETs, Q13, Q14, Q16, and Q17, with
greater than 60 Volt drain to source
voltage ratings.
Remote digital inputs are diode protected,
using CR6, CR7, CR8 and CR9 with a 1 kΩ
pull-up resistor, to +5 VDC. If the remote
input voltage is greater than about 2 Volts
or floating, the FET is turned on and a
logic low is applied to the digital input
buffer, U9. If the remote input voltage is
less than the turn on threshold of the FET
(about 2 VDC), a logic high is applied to
the digital input buffer, U9.
Four of the circuits on page two of the
schematic, which include Q2, Q9, Q19 and
4-12
Digital UHF Driver/Transmitter
Chapter 4, Circuit Descriptions
Q21, are auxiliary I/O connections wired
for future use. They are wired similar to
the remote digital inputs but include a
FET, Q5, Q12, Q20 and Q22, for digital
output operations. To operate these
signals as inputs, the associated output
FET must be turned off. The FETs are
controlled by U10 and U12, analog input
multiplexer ICs.
being fuse protected on the Power
Protection Board.
4.4.2.3 Schematic Page 3
There are three, the fourth is a spare,
identical circuits that drive the front panel
mounted LED indicators. The levels on
the 1, 2, 3 and 4 LED Control Lines, for
both the red and green LEDs, are
generated by the IC U11 as controlled by
the DATABUS from the microprocessor U1.
U13, U14, U15, U16, U17 and U18 are 3
state non-inverting transceiver ICs that
provide 2 way asynchronous
communication between data busses.
The ICs are used as input buffers to
allow the microcontroller to monitor
various digital input values. The digital
inputs to the ICs utilize a 10 kΩ pull-up
resistor. The buffer IC, U18, used for
data transfer to the display is wired for
read and write control.
4.4.2.4 Schematic Page 4
U19 and U20 are digitally controlled
analog switches that provide samples
back to the microprocessor. Each
analog input is expected to be between
0 and 5 VDC. If a signal exceeds 5.1
VDC, a 5.1 Volt zener diode clamps the
signals voltage, to prevent damage to
the IC. Most signals are calibrated at
their source, however two dual serial
potentiometers ICs are used to calibrate
four signals, System Visual/Average
Power, System Aural Power, System
Reflected Power and the Spare AIN 1.
For these four circuits, the input value is
divided in half before it is applied to an
op-amp. The serial potentiometer is
used to adjust the output signal level to
between 80 and 120% of the input
signal level. Serial data, serial clock and
serial pot enables are supplied by the
microprocessor to the dual serial
potentiometer ICs. J62 and J63 are two
20 position connectors that provide the
+12 VDC and –12 VDC power through
the Power Protection Board. The ±12
VDC generated by the switching power
supply connects to J62 and J63 after
LX Series, Digital, Rev. 4
4.4.2.5 Schematic Page 5
There are three dual element, red/green,
common cathode LED indicators mounted
on the front panel of the sled assembly;
DC OK, Operate and Fault.
Each LED controller circuit consists of an
N-Channel MOSFET w/internal diode that
controls the base of an N-P-N transistor in
an emitter follower configuration. The
emitter of the transistor connects the LED.
With the LED control line LOW, the
MOSFET is Off, which causes the base of
the transistor to increase towards +12
VDC, forward biasing the transistor. With
the transistor forward biased, current will
flow from ground through the LED, the
transistor and the current limiting
resistors in the collector to the +12 VDC
source. The effected LED will light.
With the LED control line HIGH, the
MOSFET is On, which causes the base of
the transistor go toward ground potential,
reverse biasing the transistor. With the
transistor reverse biased, no current
through the transistor and LED, therefore
the effected LED will not light.
A third color, amber, can also be
generated by having both transistors
conducting, both control lines LOW. The
amber color is produced because the
current applied to the green element is
slightly greater than the red element.
This occurs because the current limiting
resistors have a smaller ohm value in the
green circuit.
4-13
Digital UHF Driver/Transmitter
There are four voltage regulators, three
for +5 VDC and one for +7 VDC, which
are used to power the Control Board.
+12 VDC is applied to U25 the +7 VDC
regulator that produces the +7V, which
is applied to the LEDs mounted on the
board. The +7V is also connected to the
input of U26 a precision +5.0 Volt
regulator. The +5.0Vdc regulator output
is used to power the analog circuits and
as the microcontroller analog reference
voltage. Another two +5 Volt regulator
circuits U27, +5V, and U8, +5 Vserial,
are used for most other board circuits.
4.4.3 (A4) Switch Board (1527-1406;
Appendix B)
The switch board provides five frontpanel momentary contact switches for
user control and interface with the frontpanel LCD menu selections. The
switches, SW1 to SW5, complete the
circuit through connector J1 to
connector J2 that connects to J1 on (A5)
the 20 Character by 4 line LCD Display.
J1 on the switch board is also cabled to
the Control Board. When a switch is
closed, it connects a logic low to the
control board that supplies the
information from the selected source to
the display. By pushing the button
again, a different source is selected.
This occurs for each push button. Refer
to Chapter 3 Section 3.5.3, for more
information on the Display Menu
Screens.
Chapter 4, Circuit Descriptions
configured for three output voltages
+12V, -12V, at the 8 position terminal
block, and a main output power of +32
VDC at J50 pin A (+) and J50 pin B (Rtn).
The power supply is power factor
corrected to .98 for optimum efficiency
and decrease in energy consumption. For
safety purposes all outputs are over
voltage and over current protected. This
supply accepts input voltages from 85 to
264 volts AC, but the power entry module,
for the exciter/amplifier chassis, must be
switched to the proper input voltage
setting, for the transmitter to operate.
4.5 (A4) Power Amplifier Module
Assembly (1303770; Appendix B)
NOTE: Used in 5W-50W Transmitters.
The Power Amplifier Module Assembly
contains (A1) a 1 Watt UHF Amplifier
Module Assembly (1302891), (A2) a 40
Watt UHF Module Assembly (1304490),
(A3) UHF RF Module Pallet Assembly
(1300116), (A4) a Coupler Board
Assembly (1301949), (A5) an Amplifier
Control Board (1303682) and (A6) a
Temperature Sensor IC.
The RF from the Upconverter Module
Assembly connects from the Upconverter RF
Output BNC Jack J23, through a cable, to
the PA RF Input BNC Jack J24, located on
the rear of the exciter/amplifier chassis
assembly.
4.4.4 (A2) Switching Power Supply
Assembly
4.5.1 (A1) 1-Watt UHF Module
Assembly (1302891; Appendix B)
The power supply module contains a
switching power supply, an eight
position terminal block for distributing
the DC voltages, a three position
terminal block to which the AC Input
connects, Jacks J1, V1 and V2. Jack J1
connects to the Control Board and
supplies DC OK, at J1-4 & 3, and AC OK,
at J1-2 & 1, status to the control board.
A Power Supply enable connects from
the control board to the power supply at
V1-6 & 7. The power supply is
The 1-watt UHF module assembly provides
radio frequency interference (RFI) and
electromagnetic interference (EMI)
protection, as well as the heatsink, for the
1-watt UHF amplifier board (1302762) that
is mounted inside the assembly. The
assembly has approximately 17 dB of gain.
The RF input to the assembly connects to
SMA Jack J3. The amplified RF output of
the assembly is at the SMA Jack J4.
Typically, with an input signal of +4 dBm
at J1 of the assembly, an output of
LX Series, Digital, Rev. 4
4-14
Digital UHF Driver/Transmitter
Chapter 4, Circuit Descriptions
+21 dBm can be expected at J2.
4.5.3 (A4-A1) 40 Watt UHF Amplifier
Assembly (1304490; Appendix B)
The +12-VDC bias voltage connects
through J5, a RF-bypassed, feed-through
capacitor, to the amplifier board. The
-12-VDC bias voltage connects through
J6, a RF-bypassed, feed-through
capacitor, to the amplifier board. E1 on
the assembly connects to Chassis
ground.
The output of the UHF filter is connected to
the input J1 of (A2) the 40 Watt UHF
amplifier assembly (Figure 4-1). The
assembly is made up of a (51-5378-30800) module, which operates class AB and is
a highly linear broadband amplifier for the
frequency range of 470 to 860 MHz. It can
deliver an output power of 40 watts (CW)
with approximately 14 dB of gain.
4.5.2 (A1-A1) 1-Watt UHF Amplifier
Board (1302761; Appendix B)
The amplification circuit consists of
LDMOS transistors V804 and V805
connected in parallel and operating in
class AB. The paralleling network is
achieved with the aid of 3 dB couplers
Z802 and Z803. A further 3 dB coupler
Z801, in conjunction with capacitors C800
and C819, serves as a phase shifter.
Phase alignment (for the complete
amplifier), as well as quiescent current
settings are achieved by means of
potentiometers R807 and R808. The
settings are factory implemented and
should not be altered.
The 1-watt UHF amplifier board is
mounted in the 1-watt UHF amplifier
assembly (1302891) and provides
approximately +17 dB of gain.
The UHF signal enters the board at J3, a
SMA connector, and is applied to U3 an
IC hybrid coupler assembly that splits the
input signal into two equal parts. The
two amplifier paths are identical using Q4
and Q5, 1-Watt HFETs as the amplifier
devices. Each HFET has approximately
14 dB of gain. The drain voltage needed
to operate each HFET is obtained from
the +12 VDC line that connects to the
board at J5 and is regulated down to
+8.25 volts by U4. The gate negative
bias voltage is obtained from the -12
VDC line that connects to the board at
J6.
PIN diodes V810 & V811 form a variabledamping circuit that is used to adjust the
amplification of the 40-watt module. The
adjustment is performed with the Gain
potentiometer R838. A readjustment of
the amplification may be required, after
repair work, to ensure that the PAs in
multiple PA transmitters deliver the same
output power.
The amplified outputs of the HFETs are
applied to U2 an IC hybrid coupler
assembly that combines the amplified
signals into a single output that connects
to J4 of the board.
3 dB Coupler
Z 802
V 810
V 811
C 800
3 dB Coupler
Z 803
R 802, ..4, ..5
3 dB Coupler
Z 801
RF
Input
V 804
C 819
R 814
V 805
R 838
X 801
V 812
+32V
Detector
Output
Figure 4-1: 40 Watt UHF Amplifier Module
LX Series, Digital, Rev. 4
4-15
RF
Output
Digital UHF Driver/Transmitter
Chapter 4, Circuit Descriptions
Figure 4-2. UHF Amplifier Module, 250 Watts
4.5.4 (A3) UHF Module Assembly, RF
Module Pallet, Philips (1300116;
Appendix B)
samples of the output to (A5) the amplifier
control board where it connects to the
input of the overdrive-protection circuit.
The UHF Module Assembly, 250-watt
module (Figure 4-2) is a broadband
amplifier for the frequency range 470 to
860 MHz. The amplifier is capable of
delivering an output power of 70 Wrms.
The amplification is approximately 13
dB.
The RF input to the UHF coupler assembly,
from the 250 Watt UHF amplifier module,
connects to SMA jack J1. The RF is
connected by a stripline track to the SMA
type connector RF Output jack J2. A
hybrid-coupler circuit picks off a power
sample that is connected to SMA type
connector jack J3 as the forward power
sample. Another power sample is taken
from the coupler circuit that is connected
to SMA type connector jack J6 as the
reflected power sample. Two 50Ω
terminations, used as dissipation loads,
connect to the reject and reflected ports,
J5 and J4, of the coupler.
The amplification circuit consists of the
parallel connected push-pull amplifier
blocks V1 and V2 operating in class AB.
In order to match the transistor
impedance to the characteristic
impedance of the input and output
sides, matching networks are placed
ahead and behind the amplifier blocks.
Transformers Z3 to Z6 serve to balance
the input and output signals. The
paralleling circuit is achieved with the
aid of 3-dB couplers Z1 and Z2.
The working point setting is factory
implemented by means of
potentiometers R9, R11, and R12 and
should not be altered.
4.5.5 (A4) Coupler Board Assembly
(1301949; Appendix B)
The UHF coupler board assembly
provides a forward and reflected power
LX Series, Digital, Rev. 4
4.5.6 (A5) Amplifier Control Board
(1303682; Appendix B)
The amplifier control board provides LED
fault and enable indications on the front
panel of the module and also performs the
following functions: overdrive cutback,
when the drive level reaches the amount
needed to attain 110% output power; and
overtemperature, VSWR, and overdrive
faults. The board also provides connections
to the LCD Display for monitoring the %
Reflected Power, % Output Power, and the
power supply voltage
4-16
Digital UHF Driver/Transmitter
If the Module OK LED, located on the
front panel, is Red and blinking, a fault is
present. The meaning of the blinking
LED is as follows.
1 Blink indicates Amplifier Current Fault.
2 Blinks indicate Temperature Fault.
3 Blinks indicate +32V Power Supply
Over Voltage Fault.
4 Blinks indicate +32V Power Supply
Under Voltage Fault.
5 Blinks indicate Reflected Power Fault.
6 Blinks indicate +12V or –12V Power
Supply Fault.
4.5.6.1 Schematic Page 1
U4, located upper center of page, is an in
circuit microcontroller. The controller is
operated at the frequency of 3.6864 MHz
using crystal Y1. Programming of this
device is performed through the serial
programming port J2. U4 selects the
desired analog channel of U1 through the
settings of PA0-PA3. The outputs of Port
A must be set and not changed during an
analog input read of channels PA5-PA7.
PA4 of U4 is a processor operating LED
that monitors the +/-12 VDC. PA5 is
used to monitor the +12VDC supply to
the board. PA6 is the selected channel of
analog switch U1. PA7 is connected to a
via, V10, for future access.
U6 is a serial to RS-485 driver IC. U7 is
a watchdog IC used to hold the
microprocessor in reset, if the supply
voltage is less than 4.21 VDC. U7
momentarily resets the microcontroller if
Pin 6 (!ST) is not clocked every second.
A manual reset switch is provided but
should not be needed.
Upper left corner U3 is used to determine
where the amplifier control board is
located. The eight inputs come from the
main amp connector and are used to set
the SCADA address of the controller.
Pull-up resistors set a default condition of
logic high.
U5 below U3 is used for getting digital
input information of the board. Page two
has several monitoring circuits that
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
provide information on the amplifier’s
status. Many of these circuits
automatically shut down the amplifier if a
specific fault occurs.
U8 below U5 is used to control four board
mounted status LEDs. A FET is turned On
to shunt current away from the LED to turn
it Off. U9 below U8 is used to enable
different features within the software.
Actual use is to be determined.
4.5.6.2 Schematic Page 2
In the lower right corner are voltage
regulator circuits. U22 should allow for
0.14 amps of power using its 92 C/W
rating if Ta = 60°C max and Tj = 125°C
max 0.26 amps can be obtained from U22
if the mounting pad is 0.5 square inches.
The controller will not need this much
current.
U23 and U24 are low drop out +5 VDC,
voltage regulators with a tolerance greater
than or equal to 1%. 100mA of current is
available from each device but again the
controller will not need this much current.
In the upper left section are circuits with
U12 and U13. U12 is used to generate a
regulated voltage that is about 5 volts less
than the +32 VDC supply, approximately
+26.25 VDC. When the +32 VDC supply is
enabled, the circuitry around U13B is used
to provide gate voltage to Q10 that is 5
volts greater than the source pin of this
FET. The gate of Q10 can be turned Off by
any one of a few different circuits.
U10A is used to turn Off the gate of Q10 in
the event of high current in amplifier #1.
At 0.886 VDC the current to amplifier #1
should be greater than 5 Amps. U11B is
used to turn off the Q10 FET, if high
current is detected in amplifier #2. U11A
is used to turn off the Q10 FET, if high
current is detected in amplifier #3. With
2.257 VDC at Pin 5 of U11B or Pin 3 of
U11A, the voltage output of current sense
amplifier U17 or U18 at high current shut
down should be greater than 15 Amps.
U14B is used to turn Off the gate of Q10 in
the event of high power supply voltage,
4-17
Digital UHF Driver/Transmitter
approximately +35.4 VDC. U14A is used
to keep the FET disabled in the event of
low power supply voltage, approximately
+25.4 VDC.
Chapter 4, Circuit Descriptions
generates a Fault alert at U15A and
disables Amplifier #1.
Aural, Visual/Average and Reflected power
detector sections of the board.
Current monitoring sections of the board.
4.5.6.3 Schematic Page 3
The ICs U16, U17 and U18 along with
associated components set up the
current monitoring sections of the board.
R67, R68 and R69 are 0.01Ω/5W 1%
through hole resistor is used for
monitoring the current through several
sections of the amplifier. The voltage
developed across these resistors are
amplified for current monitoring by U16,
U17 or U18. The LT1787HVCS8 precision
high side current sense IC amplifier
accepts a maximum voltage of 60 VDC.
The 43.2 kΩ resistor from pin 5 to
ground sets the gain of the amplifier to
about 17.28. This value is not set with
much accuracy since the manufacturer
internally matches the resistors of this
part but their actual resistance value is
not closely defined. A trimming resistor
is suggested to give a temperature
stability of –200 ppm/C, but instead the
microcontroller will determine the exact
gain of the circuit and use a correction
factor for measurements. Circuit loading
components are located in the lower
portion of each current monitoring circuit.
These components allow for short
duration high current loading of the
supply. By measuring the current
through the sense resistor with and
without the additional four 30.1 Ω 1%
resistors. For very short duration pulses,
a 1206 resistor can handle up to 60
watts. The processor requires 226 uSec
per conversion. A supply voltage of +32
VDC will pass 1.06 amps + 1% through
the load resistors.
A6 is a temperature sensor thermistor
that is used to monitor the temperature
of the module's heat sink. It connects
to J6 pins 1 & 2 on the board wand is
wired to the comparator IC U10B. If the
temperature increases above 75°C the
output will go Low that is used as a
temperature fault output, which
LX Series, Digital, Rev. 4
A Forward Power Sample enters the board
at SMA Jack J3 and is split. One part
connects to J4 on the board that is cabled
to J1, the SMA Forward Power Sample
Jack, located on the front panel of the
assembly. The other part of the split
forward power sample is detected by CR17
and the DC level amplified by U25A. The
output of U25A at pin 1 is split with one
part connected to the Aural Power sample,
which is not used in this digital transmitter.
The other split output connects to U265A
that is part of the Forward Average Power
circuit. The detected level is connected to
L4 that is part of an intercarrier notch filter
circuit that is tuned to eliminate the 4.5
MHz aural intercarrier, if present. The
Average power sample is amplified by
U26D and connected through the average
calibration pot R166 to U26C. The output
of U26C is connected to the comparator IC
U26B that has Aural Null and Offset Null, if
present in the system, connected to the
other input. The output Average Forward
power level connects to J9 pin 2 of the
board.
A Reflected Power Sample enters the board
at SMA Jack J5 and is detected by CR20
and the DC level amplified by U28B. The
output of U28B at pin 7 is connected
through the reflected calibration pot R163
to U28C. The output is split with one part
connected to J9 pin 5, the Reflected Power
Output level of the board. The other part
of the split from U28C connects to the
comparator IC U28D that has a reference
level connected to the other input. If the
reflected level increases above the
reference level a low output is produced
and connected to the Reflected Power
Shutdown circuit at CR28. The low shuts
off Q14 causing pin 3 to go high that is
connected to the inverter U15C. The
output of U15C goes low producing a
Reflected Power Fault that is connected to
4-18
Digital UHF Driver/Transmitter
Chapter 4, Circuit Descriptions
an output of the board, the Fault Alert
circuit and also shuts down Amplifier #1.
The 1-watt UHF module assembly provides
radio frequency interference (RFI) and
electromagnetic interference (EMI)
protection, as well as the heatsink, for the
1 watt UHF amplifier board (1302761) that
is mounted inside the assembly.
Gain of the power measurements is
completed through software. Only the
Aural Null and Offset Null need to be
done through front panel pots.
The +12-VDC bias voltage connects
through J5, a RF-bypassed, feed-through
capacitor, to the amplifier board. The
-12-VDC bias voltage connects through J6,
a RF-bypassed, feed-through capacitor, to
the amplifier board. E1 on the assembly
connects to Chassis ground.
4.6 (A4) Driver Amplifier Module
Assembly {1303771(500W) or
1303874(1kW); Appendix B}
NOTE: In a 500W system a 1303771
Driver PA Assembly is used and in a
1kW system a 1303874 Driver PA
Assembly is used as the driver for high
power transmitters with external PA
assemblies. A 1303770 Power Amplifier
is used in a 5W-50W Transmitter or it is
used as a driver in Systems above 1kW.
4.6.2 (A1-A1) 1 Watt UHF Amplifier
Board (1302761; Appendix B)
The 1 watt UHF amplifier board provides
approximately +17 dB of gain. Typically, in
a 500 or 1kW system with an input signal
of +3 dBm at J1 of the assembly, an
output of +20 dBm can be expected at J2.
The Driver Amplifier Module Assembly
contains (A1) a 1 Watt UHF Amplifier
Module Assembly (1302891), (A2) a 40
Watt UHF Module Assembly (1304490)
in a 500W system or a RF Module Pallet,
Philips (1300116) in a 1kW system, (A4)
a Coupler Board Assembly (1227-1316),
(A5) an Amplifier Control Board
(1301962) and (A6) a Temperature
Sensor IC.
The UHF signal enters the board at J3, a
SMA connector, and is applied to U3 an IC
hybrid coupler assembly that splits the
input signal into two equal parts. The two
amplifier paths are identical using Q4 and
Q5, 1-Watt HFETs as the amplifier devices.
Each HFET has approximately 14 dB of
gain. The drain voltage needed to operate
each HFET is obtained from the +12 VDC
line that connects to the board at J5 and is
regulated down to +8.25 volts by U4. The
gate negative bias voltage is obtained from
the -12 VDC line that connects to the
board at J6. The amplified outputs of the
HFETs are applied to U2 an IC hybrid
coupler assembly that combines the
amplified signals into a single output that
connects to J4 of the board.
The RF from the Upconverter Module
Assembly connects from the Upconverter
RF Output BNC Jack J23, through a cable,
to the PA RF Input BNC Jack J24, located
on the rear of the exciter/amplifier chassis
assembly.
4.6.1 (A1) 1-Watt UHF Module
Assembly (1302891; Appendix B)
3 dB Coupler
Z 802
V 810
V 811
C 800
3 dB Coupler
Z 803
R 802, ..4, ..5
3 dB Coupler
Z 801
RF
Input
V 804
C 819
R 814
V 805
R 838
X 801
V 812
+32V
Detector
Output
Figure 4-3: 40 Watt UHF Amplifier Module
LX Series, Digital, Rev. 4
4-19
RF
Output
Digital UHF Driver/Transmitter
Chapter 4, Circuit Descriptions
V1
Z3
Matching
Network
RF
Input
Z5
Matching
Network
3 dB Coupler
Z1
3 dB Coupler
Z2
Dynamic
R 10
R2
R9
N1
R 11
+Uop
RF
Output
R 12
R1
Matching
Network
Z4
Matching
Network
Z6
V2
Figure 4-4. 250 Watt UHF Amplifier Module
4.6.3 (A2) 40 Watt UHF Amplifier
Assembly (1304490; Appendix B)
(NOTE: Used in 500W Systems)
The output of the UHF filter is connected
to the input J1 of (A2) the 40 Watt UHF
amplifier assembly (Figure 4-3). The
assembly is made up of a (51-5378-30800) module, which operates class AB and
is a highly linear broadband amplifier for
the frequency range of 470 to 860 MHz.
It can deliver an output power of 40
watts (CW) with approximately 13 dB of
gain. With a typical input of +23dBm an
output of +36.2dBm is expected. The
output is set as needed to provide the
drive level to the external PA
Assemblies.
The amplification circuit consists of
LDMOS transistors V804 and V805
connected in parallel and operating in
class AB. The paralleling network is
achieved with the aid of 3 dB couplers
Z802 and Z803. A further 3 dB coupler
Z801, in conjunction with capacitors
C800 and C819, serves as a phase
shifter. Phase alignment, for the
complete amplifier, as well as quiescent
current settings are achieved by means
of potentiometers R807 and R808. The
settings are factory implemented and
should not be altered.
PIN diodes V810 & V811 form a
variable-damping circuit that is used to
adjust the amplification of the 40-watt
module. The adjustment is performed
with the Gain potentiometer R838. A
LX Series, Digital, Rev. 4
readjustment of the amplification may be
required, after repair work, to ensure that
the PAs in multiple PA transmitters deliver
the same output power.
OR 4.6.3.1 (A3) 250 Watt UHF
Amplifier Assembly (1300116;
Appendix B)
(NOTE: Used in 1kW Systems)
The UHF Module Assembly, 250-watt
module (Figure 4-4) is a broadband
amplifier for the frequency range 470 to
860 MHz. The amplifier is capable of
delivering an output power of 70 Wrms. The
amplification is approximately 12 dB. With
a typical input of +27dBm an output of
+39dBm is expected.
The amplification circuit consists of the
parallel connected push-pull amplifier
blocks V1 and V2 operating in class AB. In
order to match the transistor impedance to
the characteristic impedance of the input
and output sides, matching networks are
placed ahead and behind the amplifier
blocks. Transformers Z3 to Z6 serve to
balance the input and output signals. The
paralleling circuit is achieved with the aid
of 3-dB couplers Z1 and Z2.
The working point setting is factory
implemented by means of potentiometers
R9, R11, and R12 and should not be
altered.
4-20
Digital UHF Driver/Transmitter
4.6.4 (A4) Coupler Board Assembly
(1227-1316; Appendix B)
The UHF coupler board assembly
provides forward and reflected power
samples of the output to (A5) the
amplifier control board where it connects
to the input of the overdrive-protection
circuit.
The RF input to the UHF coupler
assembly, from the 40 Watt UHF
amplifier module, connects to SMA jack
J1. The RF is connected by a stripline
track to the SMA type connector RF
Output jack J2. A hybrid-coupler circuit
picks off a power sample that is
connected to SMA type connector jack J3
as the forward power sample. Another
power sample is taken from the coupler
circuit that is connected to SMA type
connector jack J6 as the reflected power
sample. Two 50Ω terminations, used as
dissipation loads, connect to the reject
and reflected ports, J5 and J4, of the
coupler.
4.6.5 (A5) Amplifier Control Board
(1303682 or 1301962; Appendix B)
The amplifier control board provides LED
fault and enable indications on the front
panel of the module and also performs
the following functions: overdrive
cutback, when the drive level reaches the
amount needed to attain 110% output
power; and overtemperature, VSWR, and
overdrive faults. The board also provides
connections to the LCD Display for
monitoring the % Reflected Power, %
Output Power, and the power supply
voltage.
If the Module OK LED, located on the
front panel, is Red and blinking, a fault is
present. The meaning of the blinking
LED is as follows.
1 Blink indicates Amplifier Current Fault.
2 Blinks indicate Temperature Fault.
3 Blinks indicate +32V Power Supply
Over
Voltage Fault.
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
4 Blinks indicate +32V Power Supply
Under Voltage Fault.
5 Blinks indicate Reflected Power Fault.
6 Blinks indicate +12V or –12V Power
Supply Fault
4.6.5.1 Schematic Page 1
U4, located upper center of page, is an in
circuit microcontroller. The controller is
operated at the frequency of 3.6864 MHz
using crystal Y1. Programming of this
device is performed through the serial
programming port J2. U4 selects the
desired analog channel of U1 through the
settings of PA0-PA3. The outputs of Port A
must be set and not changed during an
analog input read of channels PA5-PA7.
PA4 of U4 is a processor operating LED that
monitors the +/-12 VDC. PA5 is used to
monitor the +12VDC supply to the board.
PA6 is the selected channel of analog switch
U1. PA7 is connected to a via, V10, for
future access.
U6 is a serial to RS-485 driver IC. U7 is a
watchdog IC used to hold the
microprocessor in reset, if the supply
voltage is less than 4.21 VDC. U7
momentarily resets the microcontroller if Pin
6 (!ST) is not clocked every second. A
manual reset switch is provided but should
not be needed.
Upper left corner U3 is used to determine
where the amplifier control board is located.
The eight inputs come from the main amp
connector and are used to set the SCADA
address of the controller. Pull-up resistors
set a default condition of logic high.
U5 below U3 is used for getting digital input
information of the board. Page two has
several monitoring circuits that provide
information on the amplifier’s status. Many
of these circuits automatically shut down
the amplifier if a specific fault occurs.
U8 below U5 is used to control four board
mounted status LEDs. A FET is turned On
to shunt current away from the LED to turn
it Off. U9 below U8 is used to enable
4-21
Digital UHF Driver/Transmitter
different features within the software.
Actual use is to be determined.
4.6.5.2 Schematic Page 2
In the lower right corner are voltage
regulator circuits. U22 should allow for
0.14 amps of power using its 92 C/W
rating if Ta = 60°C max and Tj = 125°C
max 0.26 amps can be obtained from
U22 if the mounting pad is 0.5 square
inches. The controller will not need this
much current.
U23 and U24 are low drop out +5 VDC,
voltage regulators with a tolerance
greater than or equal to 1%. 100mA of
current is available from each device but
again the controller will not need this
much current.
In the upper left section are circuits with
U12 and U13. U12 is used to generate a
regulated voltage that is about 5 volts
less than the +32 VDC supply,
approximately +26.25 VDC. When the
+32 VDC supply is enabled, the circuitry
around U13B is used to provide gate
voltage to Q10 that is 5 volts greater
than the source pin of this FET. The gate
of Q10 can be turned Off by any one of a
few different circuits.
U10A is used to turn Off the gate of Q10
in the event of high current in amplifier
#1. At 0.886 VDC the current to
amplifier #1 should be greater than 5
Amps. U11B is used to turn off the Q10
FET, if high current is detected in
amplifier #2. U11A is used to turn off
the Q10 FET, if high current is detected
in amplifier #3. With 2.257 VDC at Pin 5
of U11B or Pin 3 of U11A, the voltage
output of current sense amplifier U17 or
U18 at high current shut down should be
greater than 15 Amps.
U14B is used to turn Off the gate of Q10
in the event of high power supply
voltage, approximately +35.4 VDC.
U14A is used to keep the FET disabled in
the event of low power supply voltage,
approximately +25.4 VDC.
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
Current monitoring sections of the board.
The ICs U16, U17 and U18 along with
associated components set up the current
monitoring sections of the board. R67, R68
and R69 are 0.01Ω/5W 1% through hole
resistor is used for monitoring the current
through several sections of the amplifier.
The voltage developed across these
resistors are amplified for current
monitoring by U16, U17 or U18. The
LT1787HVCS8 precision high side current
sense IC amplifier accepts a maximum
voltage of 60 VDC. The 43.2 kΩ resistor
from pin 5 to ground sets the gain of the
amplifier to about 17.28. This value is not
set with much accuracy since the
manufacturer internally matches the
resistors of this part but their actual
resistance value is not closely defined. A
trimming resistor is suggested to give a
temperature stability of –200 ppm/C, but
instead the microcontroller will determine
the exact gain of the circuit and use a
correction factor for measurements. Circuit
loading components are located in the lower
portion of each current monitoring circuit.
These components allow for short duration
high current loading of the supply. By
measuring the current through the sense
resistor with and without the additional four
30.1 Ω 1% resistors. For very short
duration pulses, a 1206 resistor can handle
up to 60 watts. The processor requires 226
uSec per conversion. A supply voltage of
+32 VDC will pass 1.06 amps + 1% through
the load resistors.
A6 is a temperature sensor thermistor that
is used to monitor the temperature of the
module's heat sink. It connects to J6 pins
1 & 2 on the board wand is wired to the
comparator IC U10B. If the temperature
increases above 75°C the output will go
Low that is used as a temperature fault
output, which generates a Fault alert at
U15A and disables Amplifier #1.
4-22
Digital UHF Driver/Transmitter
Visual/Average and Reflected power
detector sections of the board.
NOTE: The aural sections of this board
are not used with digital signals.
4.6.5.3 Schematic Page 3
A Forward Power Sample enters the
board at SMA Jack J3 and is split. One
part connects to J4 on the board that is
cabled to J1, the SMA Forward Power
Sample Jack, located on the front panel
of the assembly. The other part of the
split forward power sample is detected by
CR17 and the DC level amplified by
U25A. The output of U25A at pin 1 is
split with one part connected to the Aural
Power sample, which is not used in this
digital transmitter. The other split output
connects to U265A that is part of the
Forward Average Power circuit. The
detected level is connected to L4 that is
part of an intercarrier notch filter circuit
that is tuned to eliminate the 4.5 MHz
aural intercarrier, if present. The
Average power sample is amplified by
U26D and connected through the
average calibration pot R166 to U26C.
The output of U26C is connected to the
comparator IC U26B that has Aural Null
and Offset Null, if present in the system,
connected to the other input. The output
Average Forward power level connects to
J9 pin 2 of the board.
A Reflected Power Sample enters the
board at SMA Jack J5 and is detected by
CR20 and the DC level amplified by
U28B. The output of U28B at pin 7 is
connected through the reflected
calibration pot R163 to U28C. The
output is split with one part connected to
J9 pin 5, the Reflected Power Output
level of the board. The other part of the
split from U28C connects to the
comparator IC U28D that has a reference
level connected to the other input. If the
reflected level increases above the
reference level a low output is produced
and connected to the Reflected Power
Shutdown circuit at CR28. The low shuts
off Q14 causing pin 3 to go high that is
LX Series, Digital, Rev. 4
Chapter 4, Circuit Descriptions
connected to the inverter U15C. The output
of U15C goes low producing a Reflected
Power Fault that is connected to an output
of the board, the Fault Alert circuit and also
shuts down Amplifier #1.
Gain of the power measurements is
completed through software. Only the Aural
Null and Offset Null need to be done
through front panel pots.
This completes the description of the Driver
Amplifier Module Assembly, which is used in
high power transmitters with external PA
assemblies.
The output of the driver amplifier module
assembly connects to the output of the
Exciter/Amplifier chassis assembly at the
“N” type connector Jack J25. The RF output
at J25 connects to J200 the RF input to the
external Power Amplifier Assembly.
4.7 (A4, A13, A44 or A45) Dual Peak
Detector Board (1159965; Appendix B)
NOTE: Only used in systems above 50
Watts with external Amplifier Modules.
The function of the dual peak detector
board is to detect forward and reflected
output power samples and generate output
voltages that are proportional to the power
levels of the sampled signals for use by the
control monitoring assembly in the exciter.
There are two identical signal paths on the
board: one for forward power and one for
reflected power. A sample of forward
output power, from the external DTV mask
filter, enters the board at the SMA jack J1.
Resistors R1 and R2 form an input
impedance-matching network of 50Ω. The
forward power signal is detected by CR1,
R7, R25, C1, and C7. For digital operation
the jumpers, W1 on J6 and W3 on J8, are
both between pins 1 & 2. The detected
output is buffered by the operational
amplifier U1C before it is split. One part is
connected to the forward uncalibrated
power output jack J4. The other split
output is connected to forward power adjust
pot R9, which adjusts the gain of U1D. The
4-23
Digital UHF Driver/Transmitter
Chapter 4, Circuit Descriptions
output of U1D is split with one part
connected to J3-4 Forward Power
Metering Output #1. The other output of
U1D is connected to J3-6 Forward Power
Metering Output #2.
J3-9 Reflected Power Metering Output #3.
The other output of U1A is connected to J311 Reflected Power Metering Output #4.
A sample of reflected output power, from
the external DTV mask filter, enters the
board at the SMA jack J2. Resistors R3
and R4 form an input impedancematching network of 50Ω. The reflected
power signal is detected by CR2, R26,
R8, C3, and C8. For digital operation the
jumper W2 on J7 is between pins 1 & 2.
The detected output is buffered by the
operational amplifier U1B before it is
split. One part is connected to the
reflected uncalibrated power output jack
J5. The other split output is connected to
reflected power adjust pot R10, which
adjusts the gain of U1A. The output of
U1A is split with one part connected to
The +12 VDC needed for the operation of
U1 on the board enters the board at J3-2
from TB31-16 on the Driver/Amplifier
Assembly and is connected through a filter
and isolation circuit consisting of C5, C9 and
L3 before it is connected to U1. The -12
VDC needed for the operation of U1 on the
board enters the board at J3-8 from TB3118 on the Driver/Amplifier Assembly and is
connected through a filter and isolation
circuit consisting of C6, C12 and L6 before it
is connected to U1.
LX Series, Digital, Rev. 4
Voltages for Circuit Operation
This completes the description for the entire
Exciter/Amplifier chassis assembly.
4-24
Digital UHF Driver/Transmitter
Chapter 5, Detailed Alignment Procedures
Chapter 5
Detailed Alignment Procedures
5.1 System Preparation
rear of the exciter/amplifier chassis
assembly. The 6/32” x ½” shipping
screw does not need to be replaced. It
is only used during shipping. If the
replacement module does not slide in
easily, verify it is properly aligned in the
nylon tracks, located on both the top
and bottom of the module.
This transmitter was aligned at the
factory and should not require additional
adjustments to achieve normal operation.
This exciter/amplifier of the LX Series
driver/transmitter is of a Modular design
and when a Module fails that module
needs to be changed out with a
replacement module. The replacement
module can then be sent back to Axcera
for repair. Contact Axcera Customer
Service Department at 724-873-8100 or
fax to 724-873-8105, before sending in
any module.
Note: Each Module has an assigned slot
and will not fit properly or operate in the
incorrect slot. Do not try to place a
Module in the wrong slot as this may
damage the slot or the connectors on
the backplane board. Each module has
the name of the module on the front,
bottom for identification and correct
placement. The Modules are placed in
the unit from left to right; (1) DM8
Modulator, (2) Blank panel, (3) IF
Processor, (4) VHF/UHF Upconverter,
(5) Controller/Power Supply and (6)
Driver Power Amplifier.
5.1.1 Module Replacement
Module replacement on the LX series
products is a relatively simple process.
All modules plug directly into the
backplane board except for the power
amplifier module, and in higher power
units, the power supply and power
amplifier modules, that plug into a blind
mating connector. To replace a module,
refer to the following procedure.
5.1.2 Initial Test Set Up
This exciter operates using a single MPEG
input to J12 on the rear of the Exciter
assembly. Check that the RF output at
the coupler is terminated into a dummy
load of at least the rated output of the
transmitter. 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 or tray.
The readings should be very similar. If a
reading is way off, the problem is likely
to be in that module or tray. Switch On
the main AC for the system and the
ON/OFF circuit breaker on the rear of the
amplifier chassis assembly.
Loosen the two grip lock connectors,
located on the front panel, at the top
and bottom of the module,
counterclockwise until the module
releases. The Modulator, IF Processor,
Upconverter and Controller/Power
Supply can then be gently pulled from
the unit. To remove the Driver/Power
Amplifier Module in the exciter/amplifier
chassis assembly, the two cables, Input
and Output, connected to the rear of the
chassis must be removed. These two
cables and also a 6/32” x ½” shipping
screw, located between the two
connectors, must be removed before the
module will slide out. After removal of
the failed module, slide the replacement
module in place and make certain it
connects to the backplane board. If the
replacement module is a driver/PA
Module replace the two cables to the
LX Series, Digital, Rev. 4
5.2 LX Series Exciter Chassis
Assembly
The exciter chassis assembly operates
using a digital IF input from the DM8
modulator output jack J13 that connects
5-1
Digital UHF Driver/Transmitter
Chapter 5, Detailed Alignment Procedures
through a cable to J6, the modulated IF
Input jack, on the rear of the chassis
assembly. The digital IF connects to the
IF Processor module.
Switch the transmitter to Standby. The
ALC is muted when the transmitter is in
Standby. To monitor the ALC, preset R3,
manual gain adjust, on the front panel of
the Upconverter module, fully CCW.
Move switch SW1, Auto/Man AGC, on the
front panel of the Upconverter module, to
the Manual position. Place the
transmitter in Operate. Adjust the ALC
GAIN pot on the front panel of the IF
Processor to obtain +0.8 VDC on the LCD
Display on the Controller/Power Supply in
the ALC screen. Move the MAN/AUTO
ALC switch back to Auto, which is the
normal operating position.
NOTE: In systems that contain two
exciters with an exciter switcher, both
exciters must have a digital MPEG input
connected to J12 on the rear of each
exciter/driver assembly. Each exciter
should be operated one at a time using
the following procedure by first selecting
Exciter A as the On Air exciter then
selecting Exciter B as the On Air exciter.
The Exciter Switcher must be in the
manual mode.
To adjust the AGC Cutback setting, raise
the output power of the transmitter to
110%. Adjust R2, AGC Cutback, located
on the front panel, CCW until the LED
DS1, AGC Cutback, just starts to flash.
Return the output power of the
transmitter to 100%.
On the LCD Display, located on the
Controller/Power Supply Module, push
the button to switch the transmitter to
Operate. The setup of the RF output
includes adjustments to the drive level of
the Upconverter, and the adjustment of
the linearity and phase predistortion to
compensate for any nonlinear response
of the external amplifier, using controls
accessed through the front panel of the
IF Processor module.
5.3 Setting Up the Drive Level of the
Transmitter Procedure up to 50
Watts
5.2.1 IF Processor Module Assembly
5.3.1 Setting the Manual AGC
Verify that all red LEDs located on the IF
Processor front panel are extinguished.
The following details the meaning of each
LED when illuminated:
Preset the front panel “Man Gain” pot on
the Upconverter full Counterclockwise,
and the Man/Auto Gain Switch to the
Left, Man.
•
DS1 (input fault) – Indicates that
either abnormally low or no IF is
present at the input of the module.
•
NOTE: The MAN/AUTO switch on this
upconverter is the opposite polarity to
the switch on the old upconverter for the
LX transmitter.
DS2 (ALC fault) – Indicates that the
ALC circuit is unable to maintain the
signal level requested by the ALC
reference. This is normally due to
excessive attenuation in the linearity
signal path or the IF phase corrector
signal path, or that switch SW1 is in
the Manual ALC Gain position.
•
Turn the transmitter to Operate, and
slowly adjust the Man Gain pot until the
desired % output power, as read on the
LCD display, has been reached.
The Manual AGC is now set. Normal
operation of the Transmitter is in the
Auto AGC position.
DS4 (Mute) – Indicates that a Mute
command is present to the system.
LX Series, Digital, Rev. 4
5-2
Digital UHF Driver/Transmitter
Chapter 5, Detailed Alignment Procedures
5.3.2 Setting the Auto AGC
Configuration Access Screen, on the LCD
Display by pushing the down arrow on
the default main screen and each
succeeding screen until the Transmitter
Set-Up Main Screen appears.
With the transmitter in Standby, preset
the AGC pot on the Upconverter full
Counterclockwise. Preset the AGC
Cutback pot on the Upconverter full
Clockwise. Move the Man/Auto Gain
Switch on the Upconverter to the Right,
Auto. Switch the transmitter to
Operate and slowly adjust the AGC pot
until the desired output power has been
reached.
Transmitter Set-Up, Configuration
Access Screen
Monitor the output of the transmitter
with a Spectrum Analyzer and turn the
power up 1 dB higher than desired using
the AGC pot. Enter the Transmitter SetUp menu on the LCD Control Panel and
step through the screens until the
screen labeled “Inner Loop Gain” is
reached. The inner loop is adjustable
from 0-255. Use the + button to
increase the Inner Loop Gain until the
power on the spectrum analyzer just
begins to decrease. Use the – button to
decrease the inner loop gain by 10%. (If
it begins to affect power at setting 160,
drop it back down to 160-16=144, if it
affects power at 100, drop it down by 10
to 90, etc….).
Enter the Set-Up screens by pushing the
ENT button. The following screen will
appear.
Authorized Personnel Screen
This screen of the transmitter notifies an
operator that they are only to proceed if
they are authorized to make changes to
the transmitter's operation. This screen is
implemented in transmitter software
version 1.4 and above. Push the ENT
button and step through the Set Up
screens by pushing the Down Arrow
button until the screen labeled
“Upconverter CH xx” is reached, as shown
below. The example below shows the
Transmitter set to Channel 39.
Slowly turn the AGC Cutback Pot
Counterclockwise until the AGC
Override light begins to flicker, and the
output power begins to drop. Turn the
pot Clockwise slightly, so the light just
goes out and the power stabilizes. Turn
the AGC pot down to get back to the
desired % output power level. The Auto
AGC is now set. Normal operation of the
Transmitter is in the Auto AGC position.
Transmitter Set-up: Upconverter
Channel Select Screen
5.4 Changing the Transmitter
Channel Procedure
NOTE: Depending on the new channel
frequency, the bandpass filter may need
to be retuned or replaced to achieve
maximum output power.
The choices of this screen are to the
standard UHF/VHF channels. The
channel number should be blinking. To
change the channel, hit the + button to
step through the channels until the
desired channel is reached.
Place the transmitter in Standby and go
to the Set Up Menu, Transmitter
LX Series, Digital, Rev. 4
5-3
Digital UHF Driver/Transmitter
Chapter 5, Detailed Alignment Procedures
To select a 10kHz offset to the channel
frequency, use the > button to move
the curser to the LO frequency listed
below the Channel number, and keep
pressing the > button until the desired
digit is blinking, and then use the +
button to change the frequency.
Accepting the changes will put you back
to the Main Set-Up Screen.
This completes the channel change
procedure for the LX Series transmitter.
If a problem occurred during the
procedure, help can be found by calling
Axcera field support at 724-873-8100.
Example:
Nominal LO frequency for Channel 39 =
0667.00 MHz. To generate a + offset,
change the LO frequency to 0667.01
MHz. To generate a – offset, change the
LO frequency to 0666.99 MHz.
A safeguard is added to the Set Up
Menus in software version 2.5 and
above. If a change is made to a screen
within the Set Up Menu, as was just
completed with the channel change,
when you go to the next menu, by
pushing the Down or Up Arrow, a screen
appears that asks if you accept the
change or want to return to the previous
menu to reconsider the changes made.
See the Accept or Return to previous
Menu Screen shown below.
5.5 Calibration of Output and
Reflected Power for transmitters up
to 50W Digital
NOTE: Only perform the following
procedures if the output power
calibration is suspect.
NOTE: If your transmitter is higher than
50W with external Power Amplifiers then
proceed to the next section.
5.5.1 Calibration of Output Power
for transmitters up to 50W Digital
Switch the transmitter to Standby and
place the Upconverter into Manual Gain.
Adjust R204, the null offset pot on the
Amp Control board, for 0%
forward/visual output. Switch the
transmitter to Operate.
To accept the changes, the two buttons
located under ACCEPT must be pushed
simultaneously. To return to the
previous Menu to make corrections, the
two buttons located under the RETURN
must be pushed simultaneously. Upon
returning to the previous Menu the
correct input must be entered and the
above procedure repeated, this time
accepting the changes.
Next, set up the transmitter for the
appropriate average output power level:
Adjust R202, forward/visual calibration,
on the Amp Control board for 100% on
the front panel LCD display in the %
Forward Output position. (Examples of
the screens are shown below).
Accept or Return to previous Menu
Screen
Pushing these two
buttons together
will accept the
change.
Pushing these
two buttons
together will return
you to the previous
Menu.
LX Series, Digital, Rev. 4
5-4
Digital UHF Driver/Transmitter
Chapter 5, Detailed Alignment Procedures
5.5.2 Calibration of Reflected Power
for transmitters up to 50W Digital
enable the transmitter and begin the
following procedure.
To calibrate the reflected output power
reading of the transmitter. Reduce the
manual gain pot R3 to a 10% reading on
the LCD front panel display in the %
Output Power position. Place the
transmitter in Standby. Remove the PA
Module Sled. Remove the load from J4
on the (A4) Directional Coupler Board
and switch the LCD Display screen to the
Reflected Output Power position.
Reinstall the PA Module. Switch the
transmitter to operate. Adjust the
reflected power calibration adjust pot
R163 on the power amplifier module to a
10% reading. A reflected power fault
should be present on the LCD Display.
Reconnect the load to J4 in the module.
The ALC switch should already be in the
Manual mode. Adjust the ALC Man Gain
pot, located on the front panel of the IF
Processor module, to 0.8 volts. Next,
set the IF ALC to the Auto mode. Turn
the ALC Adj. pot, located on the front of
the IF Processor, clockwise until the ALC
is at 0.8 volts, which stays constant to
control the loop around the correction.
AGC1 is at RF and controls the loop to
the output of the driver. The AGC
switch on the front of the Upconverter
should be in the Manual mode. Turn the
AGC Man Gain pot clockwise until the
output of the transmitter is at full
power. Calibrate the output metering on
the driver to 100%. AGC1 should be at
.8 volts with the Driver at 100% output.
After this calibration is completed, move
switch SW1 on the upconverter module
to the Automatic AGC position. This is
the normal operating position for the
switch. Switch to Manual Gain (Manual
AGC) and adjust the Manual Gain pot for
100 % output power. Switch the
upconverter back to Automatic AGC.
With the AGC still in the manual mode
and the transmitter at full power,
calibrate the Transmitter output metering
to 100%. In transmitters that utilize
external amplifier modules and with the
transmitter at full power and 100% O/P
metering, the Forward Power readings for
each of the amplifier modules should be
readjusted to a 100% Forward Power
reading. NOTE: The transmitter AGC
must be in the Manual Gain position
when readjusting the module forward
power. These amplifier readings can be
found under the Transmitter Details Main
Screen, by arrowing down to each Amp
Set and each Module in turn.
5.6 Adjusting the IF ALC Gain, the
AGC 1, AGC 2, and the Overdrive
Cutback Protection (AGC Cutback) in
Transmitters with Output Power
above 50 Watts
NOTE: Only perform the following
procedure on transmitters above 50W
with external Power Amplifiers present.
Set the Man/Auto AGC Switch, located on
the front of the Upconverter, to Auto and
readjust the transmitter output power
level to 100% with the AGC Adj pot. The
external amplifiers should have all been
set up for 100% Forward Power readings
previously and should return to 100%
after setting the transmitter output level
to 100% in the Auto mode.
Before beginning this procedure, put the
transmitter into standby and preset the
following pots and switches. Put the
Man/Auto ALC switch in the Man mode,
turn the ALC Manual Gain Pot and ALC
mode Pot, on the IF processor, full
counter clockwise, also put the
Man/Auto AGC switch in the Man mode
and turn the AGC Man Gain pot and AGC
Adj pot on the upconverter module full
counter clockwise. Set the AGC cut-in
Adj pot full clockwise. Now you can re-
LX Series, Digital, Rev. 4
Next, the Inner Loop Gain is adjusted
until the power starts to decrease, this
means that AGC1 and AGC2 are at the
5-5
Digital UHF Driver/Transmitter
Chapter 5, Detailed Alignment Procedures
same voltage. When at the cut-in point,
look on the display at the gain value of
the inner loop (0 to 255). Whatever the
value is, decrease the inner loop gain
level by 10%. (Example, if the display
shows 200, decrease to 180). This sets
the difference between AGC1 and AGC2.
There is no adjustment for AGC2,
therefore AGC2 is what it is, but should
be around 0.9 Volts.
Next, set up the transmitter for the
appropriate average output power level
using the Manual Gain pot on the
Upconverter sled.
Adjust R9, forward calibration, on the
dual peak detector board, mounted on
the inside, left side panel, toward the
rear of the cabinet, for .8V, as measured
at TB30-14 and TB30-12 return, on the
terminal block TB30 located on the rear
of the exciter/driver chassis assembly.
Then adjust the LCD display to read
100% on the front panel meter in the
System Forward Power position.
(Example of the screen follows).
Overdrive Protection Setup (AGC
Cutback): Adjust the output power to
110%, 10% above 100%. Next, setup
the overdrive cut-in by adjusting the
AGC Cutback Pot. Slowly turn the AGC
Cutback Pot, located on the front of the
upconverter, Counterclockwise until
the AGC Override light begins to flicker,
and the output power begins to drop.
Turn the pot Clockwise slightly, so the
light just goes out and the power
stabilizes. Repeat if needed. Re-adjust
the AGC ADJ pot as needed until the
power level returns to the 100% output
power level.
5.7.2 Calibration of the Transmitter
Reflected Output Level for
transmitters above 50W with
external Power Amplifiers
The Transmitter is ready for normal
operation.
Move the Reflected cable on the (A11)
coupler to the unused “INC” port on the
coupler while adding a 10 dB pad. Then
adjust R10 on the dual peak detector
board for a .2VDC, at TB30-13 and TB3012 return, on the terminal block TB30
mounted on the rear of exciter/driver
chassis assembly. Next adjust the LED
display for 10% reading in the System
Reflected Power position. At this 10%
reference power reading, a reflected
power fault should appear on the System
Errors Menu, if the Fault is set at 10%
under the set up menu. Turn the power
adjust pot slightly CCW and the fault
should be clearable on the System Error
Menu. Turn the pot CW until the Fault
appears. The reflected output power is
now calibrated.
5.7 Calibration of Output and
Reflected Power for transmitters
above 50W with external Power
Amplifiers
NOTE: If your transmitter is 50W or less
in power, then use Section 5.5 to
recalibrate the system.
5.7.1 Calibration of the Transmitter
Forward Output Power Level for
transmitters above 50W with
external Power Amplifiers
Switch the transmitter to Standby.
Switch the Upconverter sled to Manual
Gain. Adjust R48, the null offset pot on
the visual/aural metering board, full CW.
Adjust CCW until 0% visual output is
displayed on the LCD Display in the
System Forward Power position. Switch
the transmitter to Operate.
LX Series, Digital, Rev. 4
Switch the transmitter to Standby and
move the Reflected power cable on the
A11 Coupler back to the “Reflected Port”
and remove the 10dB pad.
5-6
Digital UHF Driver/Transmitter
Chapter 5, Detailed Alignment Procedures
When the transmitter utilizes external
amplifier modules, the Forward Power
readings for each of the amplifier
modules will need to be readjusted to a
100% Forward Power reading. NOTE:
The transmitter must be in the Manual
Gain position when readjusting the
forward power. These amplifier readings
can be found under the Transmitter
Details Main Screen, by arrowing down to
each Amp Set and each Module. These
adjustments are completed after the
System Forward and Reflected Powers
have been calibrated to 100% power.
(Example of screen is shown below).
The Transmitter is ready for normal
operation.
5.8 Linearity Correction Adjustment
As shipped, the exciter was preset to
include amplitude and phase predistortion. The pre-distortion was
adjusted to approximately compensate
the corresponding non-linear distortions
of the Power Amplifier.
NOTE: On the IF processor board inside
the module the correction enable/disable
jumper W12 on J30 must be in the
Enable position, on pins 2 & 3.
Set up a spectrum analyzer for 30 kHz
resolution bandwidth and 30 kHz video
bandwidth. Connect the spectrum
analyzer to monitor the intermodulation
products of the RF output signal of the
Power Amplifier. A typical digital
spectrum is shown in Figure 5-1.
The Driver PA Assembly’s Visual
Calibration adjust pot should be adjusted
for .8V AGC 1 on the Upconverter Details
Screen found in the Transmitter Details
Screens. After the Amplifiers are all
calibrated for 100% Forward Power
readings, the AGC 2 voltage found on the
same Upconverter Details screen should
be at .9V. (Example of screen is shown
below).
There are three Linearity Corrector stage
adjustments located on the front panel of
the IF Processor Module. The adjustments
are threshold settings that are adjusted as
needed to correct for any amplitude or
phase intermodulation problems. Adjust
the top linearity correction adjustment
R211 threshold cut in for the in phase
amplitude distortion pre-correction that is
needed. Next adjust the middle linearity
correction adjustment R216 threshold cut
in also for the in phase amplitude
distortion pre-correction that is needed.
Finally, adjust the bottom linearity
correction adjustment R231 threshold cut
in for the quadrature phase distortion precorrection that is needed. The above pots
are adjusted for the greatest separation
between the digital signal and the
intermodulation at the channel edges.
Switch the transmitter to Operate and
adjust the front panel power pot for a
100% visual power reading. Switch the
LO/Upconverter to the Auto AGC position.
(Example of screen is shown below).
LX Series, Digital, Rev. 4
5-7
Digital UHF Driver/Transmitter
Chapter 5, Detailed Alignment Procedures
6 MHz
-35 dB
-110 dB
6 MHz
3 MHz
Figure 5-1. Typical 6 MHz Digital Spectrum
5.9 Frequency Response Delay
Equalization Adjustment
The center frequency for the third stage
is 44 MHz. Adjust R274, the bottom
frequency response equalizer pot, located
on the front panel of the IF Processor
Module, for the best depth of frequency
response correction at 44 MHz.
The procedure for performing a
frequency response delay equalization
adjustment for the transmitter is
described in the following steps:
CAUTION: Making the following
adjustments will change the linearity
correction table loaded in the DM8 Digital
Modulator and a new file may need
reloaded.
After the three delay attenuation
equalizers have been adjusted, fine tune,
as needed, for the best frequency
response across the channel.
The Transmitter is now aligned,
calibrated, and ready for normal
operation.
The center frequency for the first stage is
46.5 MHz. Adjust R103, the top
frequency response equalizer pot, located
on the front panel of the IF Processor
Module, for the best depth of frequency
response correction at 46.5 MHz.
This completes the detailed alignment
procedures for the Digital LX Series
transmitter.
The center frequency for the second
stage is 41.5 MHz. Adjust R106, the
middle frequency response equalizer pot,
located on the front panel of the IF
Processor Module, for the best depth of
frequency response correction at 41.5
MHz.
LX Series, Digital, Rev. 4
If a problem occurred during the
alignment, help can be found by calling
Axcera field support at 724-873-8100.
5-8
APPENDIX A
INNOVATOR LX SERIES SPECIFICATIONS
Innovator LX
LU1000AT Shown
Low Power DTV Transmitter 5W - 3kW
Designed to provide broadcasters with a product that will meet their needs like
no other solution on the market, this new low to medium power transmitter
line uses the latest LDMOS devices for broadband operation across the entire
UHF band. This allows users to minimize spare parts stock, which is especially
important to group owners and networks, and also enables simple and
inexpensive channel changes.
The very compact and completely modular design uses a chassis/backplane
configuration with parallel amplifier and power supply modules which can be
removed and replaced while the transmitter is on the air.
Configurations are available in power levels from 10 watts to 6 kilowatts
analog and up to 3 kilowatts DTV, and all are manufactured in the USA by
Axcera - The RF Experts.
Innovator LX
Low Power DTV Transmitter 5W - 3kW
Performance
Options
Frequency Range1
470 to 860 MHz
Output Impedance
50 Ω
Frequency Stability
w/Precise Frequency Option
±1kHz (max 30 day variation)
±2Hz
Regulation of RF Output Power
3%
Dual Exciter with Automatic Switcher
AC Surge Protector
Precise Frequency Kit
Spare Parts Kit
Other Frequencies - Consult Factory
Measured in 30 KHz RBW, relative to total average power
Above 8,500 feet - Consult Factory
Out of Band -Compliant with FCC Mask
Channel Edge ±500kHz
6MHz from Channel Edge
-47 dB or better
-110 dB or better
Signal to Noise (SNR)
27 dB or better
Data Interface
Input Rate
Input Interface
19.39 Mbps, 6 MHz Channel
SMPTE 310M, Serial Differential
ECL & TTL
Test Signals
Internal PRBS 23 MPEG Stream
General
Model Number
LU5ATD
LU50ATD LU125ATD LU250ATD LU500ATD LU1000ATD LU1500ATD
Power Output (Average)
5W
50 W
125 W
250 W
500 W
1000 W
1500 W
7/ ” EIA
Output Connector
Power Consumption (Watts)
250 W
650 W
1000 W
1700 W
3400 W
6700 W
10,500 W
Input Power
Line Voltage (Volts)
117/230 ±10%
230 ± 10%
Power Requirements
Single Phase, 50 or 60 Hz
Size (H x W x D)
55”x22”x34”
76”x22”x34”
Weight (lbs.)
300
300
340
360
400
550
700
Operational Temperature Range
0 to +50°, derate 2°C/1000 ft.
Maximum Altitude
8500 feet (2600m) AMSL
Operational Humidity Range
0% to 95% non-condensing
RF Load Impedance
50 Ω
LU2000ATD LU2500ATD LU3000ATD
2000 W
31/8” EIA
2500 W
3000 W
13,500 W
17,000 W
20,500 W
76”x44”x34”
1030
1180
1330
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.
0311R4
© 2004 AXCERA
All Rights Reserved
103 Freedom Drive, PO Box 525, Lawrence, PA 15055
An Equal Opportunity Employer
t: 724-873-8100
f: 724-873-8105
APPENDIX B
DRAWINGS LIST
Digital UHF Driver/Transmitter
Appendix B, Drawings and Parts Lists
Innovator LX Series Digital System
LX Series Driver/Transmitter Typical Block Diagram................................ 1302139
LX Series Digital Transmitter Interconnects.......... (125W, 250W & 500W) 1303940
LX Series 50-1000 Watt Digital Transmitter Typical Racking Plan ............. 1303596
LX Series 2500 Watt Digital Transmitter Racking Plan ............................. 1305703
(Optional) Dual Peak Detector Board
Schematic.......................................................................................... 1159976
(Optional) Single Channel Exciter Switcher Tray, 110VAC
Interconnect....................................................................................... 1305739
Exciter Switcher Control Board, 110VAC
Schematic.......................................................................................... 1305705
OR (Optional) Single Channel Exciter Switcher Tray, 220VAC
Interconnect....................................................................................... 1305739
Exciter Switcher Control Board, 220VAC
Schematic.......................................................................................... 1305705
Chassis Assembly, 110 VAC Exciter, V2, LX Series
Interconnect....................................................................................... 1304064
OR Chassis Assembly, 220 VAC Exciter, V2, LX Series
Interconnect....................................................................................... 1304064
Backplane Board, V2, LX Series
Schematic.......................................................................................... 1304049
DM8 Modulator Assembly, DT1D
Interconnect....................................................................................... 1306330
Digital Modulator, DT1D Board
Schematic.......................................................................................... 1304884
8 VSB Front Panel Board, LX Series
Schematic.......................................................................................... 1305940
IF Processor Assembly
IF Processor Board
Schematic.......................................................................................... 1301983
VHF/UHF Upconverter Assembly
Block Diagram .................................................................................... 1303830
Interconnect....................................................................................... 1303831
Downconverter Board Assembly
Schematic.......................................................................................... 1303836
First Conversion Board, LX Series
Schematic.......................................................................................... 1303840
LX Series, Digital, Rev. 4
B-1
Digital UHF Driver/Transmitter
Appendix B, Drawings and Parts Lists
L-Band PLL Board, LX Series
Schematic.......................................................................................... 1303848
Upconverter Control Board, LX Series
Schematic.......................................................................................... 1304761
Control/Power Supply Assembly, 110 VAC
Block Diagram .................................................................................... 1303889
Interconnect....................................................................................... 1302062
OR Control/Power Supply Assembly, 220 VAC
Block Diagram .................................................................................... 1303889
Interconnect....................................................................................... 1302062
Control Board
Schematic.......................................................................................... 1302023
Power Protection Board
Schematic.......................................................................................... 1302839
Switch Board
Schematic....................................................................................... 1527-3406
NOTE: Your Transmitter will contain one of the following Power Amplifier or
Driver Power Amplifier Assemblies as indicated.
Power Amplifier Assembly, (Used as the final PA in 5-50 Watt Systems
or as the Driver PA in Systems above 1kW)
Block Diagram .................................................................................... 1303850
Interconnect....................................................................................... 1303814
Driver Power Amplifier Assembly, (Used as Driver in 250W & 500W Systems)
Block Diagram .................................................................................... 1303851
Interconnect....................................................................................... 1303817
Driver Power Amplifier Assembly, (Used as Driver in 1kW Systems)
Block Diagram .................................................................................... 1305138
Interconnect....................................................................................... 1305137
NOTE: Your Power Amplifier or Driver Power Amplifier Assembly will contain
some of the following Boards and Assemblies as indicated.
Coupler Board Assembly, (Used in Driver PA Assemblies 1303771 and 1303874)
Schematic....................................................................................... 1227-3316
RF Module Pallet w/o Transistors, (Used in PA Assembly 1303770 and in Driver PA
Assembly 1303874)
Schematic........................................................................51-5379-309-00 WSP
RF Module Pallet, Philips, (Used in PA Assembly 1303770 and in
Driver PA Assembly 1303874)
LX Series, Digital, Rev. 4
B-2
Digital UHF Driver/Transmitter
Appendix B, Drawings and Parts Lists
Coupler Board Assembly, (Used in PA Assembly 1303770)
Schematic.......................................................................................... 1303152
1 Watt UHF Amplifier Board, (Used in PA Assembly 1303770 and Driver PA Assemblies
1303771 and 1303874)
Schematic.......................................................................................... 1302762
1 Watt Module Assembly, (Used in PA Assembly and 1303770 and in
Driver PA Assemblies 1303771 and 1303874)
Amplifier Control Board, (Used in PA Assembly 1303770 and in
Driver PA Assemblies 1303771 and 1303874)
Schematic.......................................................................................... 1303683
40W UHF Module, Tested, (Used in PA Assembly 1303770 and in
Driver PA Assembly 1303771)
TFS 40W UHF Module, Stork, (Used in PA Assembly 1303770 and in
Driver PA Assembly 1303771)
Schematic........................................................................51-5379-308-00 WSP
LX Series, Digital, Rev. 4
B-3
APPENDIX C
TRANSMITTER LOG SHEET
UHF LX Series Digital Transmitter
DESCRIPTION OF
PARAMETER
DATE READINGS TAKEN
Model Number
Code Version
Firmware Number
Appendix C, Log Sheet
TRANSMITTER READING FROM LCD DISPLAY
OUTPUT MEASUREMENTS
% FORWARD POWER
% REFLECTED POWER
DM8 DIGITAL MODULATOR
DETAILS
MODE
SOURCE
LINEAR EQ
NON-LINEAR EQ
(Settings Customized per
System)
EQL PEAK LEVEL
PSF PEAK LEVEL
AGC MODE
AGC LEVEL
D/A PEAK DETECT
TAP ENERGY
CLIP DETECTOR STATUS
AGG
ISL
D/A
HBF
IFC
COR
ODC
CODE VERSION
IF PROCESSOR DETAILS
INPUT SIGNAL STATE
MODULATION
INPUT IF
DLC CONTROL LOCK
ALC LEVEL
ALC MODE
UPCONVERTER DETAILS
AFC 1 LEVEL
AFC 2 LEVEL
PLL 1 CIRCUIT
PLL 2 CIRCUIT
AGC 1 LEVEL
AGC 2 LEVEL
- Page 1 of 1 -
UHF LX Series Digital Transmitter
DESCRIPTION OF
PARAMETER
INT. 10 MHz
IF INPUT LEVEL
Appendix C, Log Sheet
TRANSMITTER READING FROM LCD DISPLAY
SYSTEM CONTROL DETAILS
Power Supply Enable For
DRIVER AND PA DETAILS
POWER SUPPLY STATE, 32V
FORWARD POWER
REFLECTED POWER
AMP 1 CURRENT
AMP 2 CURRENT
TEMPERATURE
CODE VERSION
EXT. PA AMPLIFIER MODULES
AMP SET 1 MODULE 1
ONLY IN HIGH POWER SYSTEMS
Will indicate Amp Set and Module within the
Set. Will step through each Set and Module.
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 1 MODULE 2
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 1 MODULE 3
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
- Page 2 of 2 -
UHF LX Series Digital Transmitter
DESCRIPTION OF
PARAMETER
Appendix C, Log Sheet
TRANSMITTER READING FROM LCD DISPLAY
AMP SET 1 MODULE 4
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 2 MODULE 1
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 2 MODULE 2
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 2 MODULE 3
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
- Page 3 of 3 -
UHF LX Series Digital Transmitter
DESCRIPTION OF
PARAMETER
Appendix C, Log Sheet
TRANSMITTER READING FROM LCD DISPLAY
AMP SET 2 MODULE 4
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 3 MODULE 1
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 3 MODULE 2
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 3 MODULE 3
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
- Page 4 of 4 -
UHF LX Series Digital Transmitter
DESCRIPTION OF
PARAMETER
Appendix C, Log Sheet
TRANSMITTER READING FROM LCD DISPLAY
AMP SET 3 MODULE 4
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 4 MODULE 1
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 4 MODULE 2
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 4 MODULE 3
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
- Page 5 of 5 -
UHF LX Series Digital Transmitter
DESCRIPTION OF
PARAMETER
Appendix C, Log Sheet
TRANSMITTER READING FROM LCD DISPLAY
AMP SET 4 MODULE 4
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 5 MODULE 1
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 5 MODULE 2
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 5 MODULE 3
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
- Page 6 of 6 -
UHF LX Series Digital Transmitter
DESCRIPTION OF
PARAMETER
Appendix C, Log Sheet
TRANSMITTER READING FROM LCD DISPLAY
AMP SET 5 MODULE 4
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 6 MODULE 1
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 6 MODULE 2
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
AMP SET 6 MODULE 3
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
- Page 7 of 7 -
UHF LX Series Digital Transmitter
DESCRIPTION OF
PARAMETER
Appendix C, Log Sheet
TRANSMITTER READING FROM LCD DISPLAY
AMP SET 6 MODULE 4
POWER SUPPLY VOLTAGE, 32V
32V SUPPLY
FORWARD POWER
REFLECTED POWER
AMP CURRENT 1
AMP CURRENT 2
AMP CURRENT 3
AMP TEMPERATURE
CODE VERSION
NOTE: The previous Log Sheet readings can be taken from the System Details
Screen, Menu 30-1, on the 4 x 20 Display located on the front of the Control &
Monitoring/Power Supply Module.
- Page 8 of 8 -
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