UBS Axcera LU50ATD, LU500ATD, LU3000BTD, LU3000ATD User Manual

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 Site Considerations................................................................................3-1

3.2 Unpacking the Chassis w/Modules...........................................................3-5

3.3 Installing the Chassis w/Modules.............................................................3-5

3.4 AC Input...............................................................................................3-7

3.5 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 March 8, 2007

Digital UHF Driver/Transmitter Table of Contents

iii

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 March 8, 2007

Digital UHF Driver/Transmitter Table of Contents

LIST OF FIGURES

FIGURE PAGE

1-1 Brady Marker Identification Drawing.................................................1-1

2-1 Digital LX Series Front View Trays and Assemblies.............................2-1

2-2 Example of switching and displayed count with two faulted exciters.....2-2

2-3 Rear View LX Series Chassis Assembly............................................2-15

3-1 1 kW Minimum Ventilation Configuration...........................................3-4

3-2 Tray Slide Cabinet Mounting Diagram...............................................3-6

3-3 Front and Rear View Reconnection Drawing.......................................3-6

3-4 Cabinet Front and Rear View Reconnection Drawing...........................3-7

3-5 AC Input Box Assembly...................................................................3-7

3-6 Rear View of Exciter Driver..............................................................3-8

4-1 40 Watt UHF Amplifier Module .......................................................4-15

4-2 250 Watt UHF Amplifier Module .....................................................4-16

4-3 40 Watt UHF Amplifier Module .......................................................4-19

4-4 250 Watt UHF Amplifier Module .....................................................4-20

5-1 Typical Digital Spectrum .................................................................5-8

LX Series, Digital, Rev. 4

Digital UHF Driver/Transmitter Table of Contents

LIST OF TABLES

TABLE PAGE

2-1 Digital LX Series Assemblies and Tray...............................................2-1

2-2 Digital Modulator Status Indicators...................................................2-4

2-3 Digital Modulator Sample ................................................................2-4

2-4 Digital Modulator Alignment Port......................................................2-4

2-5 IF Processor Front Panel Switch .......................................................2-5

2-6 IF Processor Front Panel Status Indicators ........................................2-5

2-7 IF Processor Front Panel Control Adjustments....................................2-5

2-8 IF Processor Front Panel Sample......................................................2-6

2-9 VHF/UHF Upconverter Front Panel Switch..........................................2-6

2-10 VHF/UHF Upconverter Front Panel Status Indicators...........................2-7

2-11 VHF/UHF Upconverter Front Panel Control Adjustments......................2-7

2-12 VHF/UHF Upconverter Front Panel Samples.......................................2-7

2-13 Controller/Power Supply Front Panel Display .....................................2-8

2-14 Controller/Power Supply Front Panel Status Indicators .......................2-8

2-15 Controller/Power Supply Front Panel Control Adjustments...................2-8

2-16 Power Amplifier Front Panel Status Indicators....................................2-9

2-17 Power Amplifier Front Panel Control Adjustments.............................2-10

2-18 Power Amplifier Front Panel Sample ...............................................2-10

2-19 Driver Amplifier Front Panel Status Indicators..................................2-11

2-20 Driver Amplifier Front Panel Control Adjustments.............................2-11

2-21 Driver Amplifier Front Panel Sample...............................................2-11

2-22 LX Series Exciter Driver Customer Remote Connections.......... 2-15

2-23 (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 ................................................................................................PAGE

3-26 Menu 40-3 Transmitter Set Up: Upconverter Channel Select Screen 3-18

3-27 Menu 40-4 Transmitter Set Up: Serial Address Screen...................3-18

3-28 Menu 40-6 Transmitter Set Up: System Forward Power Cal. Screen.3-18 3-29 Menu 40-6 Transmitter Set Up: System Reflected Power Cal. Screen.3-19

3-30 Menu 40-7 Transmitter Set Up: Fwrd Pwr Fault Threshold Screen......3-19

3-31 Menu 40-8 Transmitter Set Up: Refl Power Fault Threshold Screen....3-19

3-32 Menu 40-10 Transmitter Set Up: Auto Standby Control Screen .........3-19

3-33 Menu 40-12 Transmitter Set Up: Inner Loop Gain Control Screen......3-20

3-34 Menu 40-13 Transmitter Set Up: Optional System Control Screen .....3-20

3-35 Menu 40-14 Transmitter Set Up: DM 8 Optional Mode Control...........3-20

3-36 Menu 40-15 Transmitter Set Up: DM 8 Source Select Control............3-20

3-37 Menu 40-16 Transmitter Set Up: DM 8 Nonlinear Correction Control..3-20 3-38 Menu 40-16 Transmitter Set Up: DM 8 Fixed Table Selection Control .3-21 3-39 Menu 40-16 Transmitter Set Up: DM 8 Fixed Phase Selection Control 3-21 3-40 Menu 40-16 Transmitter Set Up: DM 8 Find Table Selection Control...3-21

3-41 Menu 40-17 Transmitter Set Up: DM 8 Linear Correction Control.......3-21

3-42 Menu 40-18 Transmitter Set Up: AGC Mode Control.........................3-21

3-43 Menu 40-19 Transmitter Set Up: Remote Commands Control............3-22

LX Series, Digital, Rev. 4

Digital UHF Driver/Transmitter Chapter 1, Introduction

Chapter 1

Introduction

1.1 Manual Overvi ew

This manual ex plains the installat ion, 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.

This inst ruction man u al i s divided int o 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 descrip t io n , m a in t e n a nc e a n d r em o te control connections, descr ibes the transmitter and includes discussions on system control and status indicators, maintenance and remote control connections. Chapte r 3, s ite consideration s , in s t a lla t i on and set u p procedures, explains how to unpack, install, setup, and operate the transmitter. Chapter 4, circuit descriptions, contains circuit - le v el descrip t io n s fo r boards and board-level compo ne n ts in the transmitter. Chapter 5, Detailed Alignment Procedures, provides inform a t io n on a d ju s t in g t h e s y s te m assemblies for opt im a l o p eration. Appendix A contains system specificatio ns. Appendix B contains drawings and parts lists. Appendix C contains a transmitter log sheet

1.2 Asse mbl y Desig na to rs

Axcera has assigned assembly number s, Ax designations such as A1, where x=1,2,3…etc, to all assemb lie s, mo dule s, and boards in the system. These designations are referenced in the text of this man ua l a n d shown on the b lo c k diagrams and interconnect drawings provided in the a ppendices. The B lo ck Diagrams, Interconnects, Schematics, Assembly Drawings and Parts Lists are arrange d in increasing n um erical or de r in the appendices. Section titles in the text for assembly or module descriptions or alignment procedures contain the associated part number(s) and the relevant appendix that contains the drawings for that item.

The cables that connect between the boards within a tray or assembly and that connect between the trays, racks and cabinets are labeled using 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

The UHF transmitter syste ms manufactured by Axcera are designed to be easy to use and rep a ir while pr ov id in g protection from electrical and mechanical hazards. Please review the following warnings and fa mil ia r iz e yo u rself with the operation and servicing procedures before working on the transmitter system.

Read All safet y Instructions – All o f the safety instructions should be read and unde rstood be fo r e ope r a t in g t his equipment.

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.

Heed all Notes , Warnings, and Cautions – All of the notes, warnings,

and caut ions liste d in t his safety se c t io n and throughout the manual must be followed.

Follow Operating In stru cti ons – A ll o f the opera t ing a nd us e in s t r uc tions for the transmit t e r s ho uld b e 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 – Open in gs in the ca b in e t and module front pa nels are pro v ided for ventilat io n . To e nsu r e th e re lia b le operation of the driver/transmitter, and to protect the unit from overheating, these openings must not be blocked.

Servicing – Do not attempt to service this product yourself until becoming familiar with the equipment. If in doubt, refer all s e r v icing ques tions to qualified Axcera service personnel.

Replacemen t Pa r ts – 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 contac t the Axce ra Technical Service Department if you have any questions regarding service or replacement parts.

1.4 Contact Information

The Axcera Field Service Department can be contacted by phone a t (724) 873- 8100 or by fax at (724) 873-8105.

Before calling Axcera, please be pre pared to supply the Axcera te chn ician w it h 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.

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 a cc ompan ied by a Return Material Authorization Number (RMA#).

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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. Th is pr oc e dure applies to all items sent to the Field Service Department regardless of whether the item was originally manufactured by Axcera.

When equipment is sent to the field on loan, an RM A# is i nc l ud e d w it h the un i t. The RMA# is intended to be used when the unit is returned to Axcera. In addition, all shipping mater ial shou ld 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 ty pe o f 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 inc lude c ontac t information and a brief description of why the unit is being returned.

Please forward all RMA items to:

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) 873-810 0. Axcera can also be co ntac ted thr o ug h email at info@axcera.com and on the Web at www.axcera.com.

1.6 Limited One Year Warranty for Axcera Products

Axcera warrants each new product that it has manufactured and sold against

defects in material and workmanship under normal use and service for a period of one (1) year from the date of shipment from Axcera's plant, when operated in accordance with 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.

Equipment furnished by Axcera, but not bearing its trade name, shall bear no warranties other than the special hour sof-use or other warranties extended by or enforceable against the manufacturer at the time of delivery to the buyer.

NO WAR R ANTIE S, WHETHER STATUTORY, EXPRESSED, OR IMPLIED, AND NO WARRANTIES OF MERCHANTABIL IT Y, FIT NE SS FOR ANY PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, OR THE LIKE, OTHER THAN AS SPECIFIED IN PATENT LIABILITY ARTICLES, AND IN T H IS AR T ICLE, SHALL APPLY TO THE EQUIPMENT FURNISHED HEREUNDER.

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.

$$$$ RADIO FREQUE NCY RAD IAT ION HAZ ARD $$$$

MICROWAVE, RF AMPLIFIERS AND TUBES GENERATE HAZARDOUS RF RADIATION THAT CAN CAUSE SEVERE INJURY INCLUDING CATARACTS, WHICH CAN RESULT IN BLINDNESS. SOME CARDIA C 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 INTERVA LS.

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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 follo wing rules both in theory and p ractice. It is the duty of all op erating 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 e ar close to his mouth and loo k at his chest. If he is breathing y ou 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.

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 bur ned area to prevent burn fr om going deeper into skin tissue .

3. If he is still not breathing, begin rescue breath i n g.

-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 CLOTHING - KEEP WARM

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.

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.

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Digital UHF Driver/Transmitter Chapter 1, Introduction

dBm, dBw, dBmV, dBµµµµV, & VOLTAGE

EXPRESSED IN WATTS

50 Ohm System

WATTS PREFIX dBm dBw dBmV dBµV VOLTAGE 1,000,000,000,000 1 TERAWATT +150 +120 100,000,000,000 100 GIGAWATTS +140 +110 10,000,000,000 10 GIGAWATTS +130 +100 1,000,000,000 1 GIGAWATT +120 + 99 100,000,000 100 MEGAWATTS +110 + 80 10,000,000 10 MEGAWATTS +100 + 70 1,000,000 1 MEGAWATT + 90 + 60 100,000 100 KILOWATTS + 80 + 50 10,000 10 KILOWATTS + 70 + 40 1,000 1 KILOWATT + 60 + 30 100 1 HECTROWATT + 50 + 20 50 + 47 + 17 20 + 43 + 13 10 1 DECAWATT + 40 + 10 1 1 WATT + 30 0 + 77 +137 7.07V

0.1 1 DECIWATT + 20 - 10 + 67 +127 2.24V

0.01 1 CENTIWATT + 10 - 20 + 57 +117 0.707V

0.001 1 MILLIWATT 0 - 30 + 47 +107 224mV

0.0001 100 MICROWATTS - 10 - 40

0.00001 10 MICROWATTS - 20 - 50

0.000001 1 MICROWATT - 30 - 60

0.0000001 100 NANOWATTS - 40 - 70

0.00000001 10 NANOWATTS - 50 - 80

0.000000001 1 NANOWATT - 60 - 90

0.0000000001 100 PICOWATTS - 70 -100

0.00000000001 10 PICOWATTS - 80 -110

0.000000000001 1 PICOWATT - 90 -120

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) 1.609347 inch (in) millimeter (mm) 25.4 inch (in) centimeter (cm) 2.54 inch (in) meter (m) 0.0254 foot (ft) meter (m) 0.3048 yard (yd) meter (m) 0.9144 mile per hour (mph) kilometer per hour(km/hr) 1.60934 mile per hour (mph) meter per second (m/s) 0.44704 pound (lb) kilogram (kg) 0.4535924 gallon (gal) liter 3.7854118 U.S. liquid (One U.S. gallon equals 0.8327 Canadian gallon) fluid ounce (fl oz) milliliters (ml) 29.57353 British Thermal Unit watt (W) 0.2930711 per hour (Btu/hr) horsepower (hp) watt (W) 746

NOMENCLATURE OF FREQUENCY BANDS

FREQUENCY RANGE DESIGNATION

30 to 300 kHz LF - Low Frequency 300 to 3000 kHz MF - Medium Frequency 3 to 30 MHz HF - High Frequency 30 to 300 MHz VHF - Very High Frequency 300 to 3000 MHz UHF - Ultrahigh Frequency 3 to 30 GHz SHF - Superhigh Frequency 30 to 300 GHz EHF - Extremely High Frequency

3 to 30 kHz VLF - Very Low Frequency

LETTER DESIGNATIONS FOR UPPER FREQUENCY

BANDS

LETTER FREQ. BAND

L 1000 - 2000 MHz S 2000 - 4000 MHz C 4000 - 8000 MHz X 8000 - 12000 MHz Ku 12 - 18 GHz K 18 - 27 GHz Ka 27 - 40 GHz V 40 - 75 GHz W 75 - 110 GHz

LX Series, Digital, Rev. 4 1-7

Digital UHF Driver/Transmitter Chapter 1, Introduction

RETURN LOSS VS. VSWR

-10

-20

R E T U R N

L O S S

-30

-40

-50

-60

-70

1.001 1.01 1.1 2.0

VSWR

LX Series, Digital, Rev. 4 1-8

Digital UHF Driver/Transmitter Chapter 1, Introduction

ABBREVIATIONS/ACRONYMS

AC Alternating Current AFC Automatic Frequency Control ALC Automatic Level Control AM Amplitude modulation AGC Automatic Gain Control AWG American wire gauge BER Bit Error Rate BW Bandwidth 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 Correctio n FM Frequency modulation FPGA Field Programmable Gate Array Hz Hertz ICPM Incidental Carrier Phase Modulation I/P Input IF Intermediate Frequency

LED Light emitting diode LSB Lower Sideband MPEG Mot ion Pictures Expert Group O/P Output PLL Phase Locked Loop PCB Printed circuit board QAM Quadrature Amplitude Modulation SMPTE Society of Motion Picture and

Television Engineers VSB Vestigial Side Band

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Digital UHF Driver/Transmitter Chapter 2, System Description & Remote Control Connections

Chapter 2

System Description & Remote Control Connections

2.0 System Overview

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.

The model number scheme for a Innovator LX Series transmitter is as follows (where #### = power in watts):

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 2-

A1 A3 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 PART NUMBER

Chassis Assembly

A1 DM8 Digital Modulator Module 1306342 A3 IF Processor Module 1301938

A5 VHF/UHF Upconverter Module 1303829

A11 Backplane Board, V2, LX Series 1304047

LX Series, Digital, Rev. 4 2-1

Control & Monitoring/Power Supply Module

Power Amplifier Module for 5-50 Watt Transmitter

Driver Amplifier Module for High Power Transmitter

1304052 (110 VAC) or 1304053 (220 VAC

1301936 (110 VAC) or 1303229 (220 VAC)

1303770

1303771 (1kW), 1303874 (2kW) OR 1303770 (3kW & above)

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

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.

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

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.

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.

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.

There is a built in 30 second delay from when the Exciter is changed from Standby to Operate to allow for the

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

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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.

An indication of 123L means that a 3 Fault has occurred and the 5 minute lock out is in effect.

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.

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 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

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 Chassi s Assembly, V2, {1304052 (110 VAC) or 1304053 (220 VAC); Appendix B}

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.

2.2.1 DM-8 Modulator Assembly, DT1D (1306342; Appendix B)

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.

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Table 2-2. Digital Modulator Status Indicators

LED FUNCTION

MPEG (Green)

PLL A (Green)

PLL B (Green)

Table 2-3. Digital Modulator Sample

SAMPLE DESCRIPTION

IF Sample

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)

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.

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.

Indicates the presence of a valid MPEG stream at the J1-2B input jack. Indicates that the DM8 symbol clock is locked to the frequency of the 10 MHz reference. Indicates that the pilot frequency is locked to the incoming 10 MHz reference.

Provides a sample of the IF output from the modulator at approximately a –20 dBm level.

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.

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 provides a reference ALC voltage to the system's Upconverter. When the ALC voltage

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decreases, the Upconverter automatically lowers the system output power through the AGC circuits.

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 Modulation Present signal is monitored. If the

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 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.

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

INPUT FAULT (Red)

When lit it indicates that there is a loss of the IF Input signal to the 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.

MUTE (Red)

When lit it indicates that the IF input signal is cut back but the 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

RESPONSE

EQUALIZER

ALC GAIN

MAN GAIN

These three variable resistors, R103, R106 & R274, adjust the depth of gain for the three stages of frequency response correction.

Adjusts the gain of the transmitter when the transmitter is in the Auto ALC position. Adjusts the gain of the transmitter when the transmitter is in the Manual ALC position. These three variable resistors adjust the threshold cut in for the

LINEARITY

CORRECTION

three stages of linearity pre-correction. R211 and R216, the top two pots, are ad

usted to correct for in phase amplitude distortions. R 231, the bottom pot, is adjusted to correct for quadrature phase distortions.

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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)

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.

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.

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Table 2-10. VHF/UHF Upconverter Front Panel Status Indicators

LED FUNCTION

PLL 1 Fault

(Red)

PLL 2 Fault

(Red)

AGC Fault

(Red)

AGC Override

(Red)

Man Gain

(Amber)

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

MAN GAIN ADJ

AGC ADJ

AGC CUTBACK ADJ

(AGC OVERRIDE)

Adjusts the gain of the upconverter and transmitter when in the Manual AGC position. Adjusts the gain of the upconverter and transmitter when in the Auto AGC position. Adjusts the point at which the transmitter will cut back in power, due to too much drive, when the Transmitter is in Auto AGC.

Table 2-12. VHF/UHF Upconverter Front Panel Samples

SMA CONNECTOR DESCRIPTION

LO1 SAMPLE

LO2 SAMPLE

Sample of the 1 GHz nominal LO1 signal in the Upconverter as generated on the L-Band PLL Board. Sample of the 1.1-1.9 GHz LO2 signal in the Upconverter as generated on the First Conversion Board.

RF SAMPLE Sample of the On Channel RF Output of the Upconverter

2.2.4 (A4) Control & Monitoring/ Power Supply Mo dul e Asse mbl y {1301936 (110VAC) or 1303229 (220VAC); Ap pendix B}

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.

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.

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Table 2-13. Controller/Power Supply Display

DISPLAY FUNCTION

A 4 x 20 display providing a four-line readout of the internal

LCD

Table 2-14. Controller/Power Supply Status Indicator

LED FUNCTION

OPERATE

( green )

FAULT

( red or green )

DC OK

( red or green )

Table 2-15. Controller/Power Supply Control Adjustments

POTENTIOMETERS DESCRIPTION

DISPLAY CONTRAST Adjusts the contrast of the display for desired viewing of screen.

functions, external inputs, and status. See Chapter 3,

Controller/Power Supply Display Screens, for a listing of displays.

When lit it indicates that the transmitter is in the Operate Mode. If transmitter is Muted the Operate LED will stay lit, the transmitter will remain in Operate, until the input signal is returned. Red indicates that a problem has occurred in the transmitter. The transmitter will be Muted or placed in Standby until the problem is corrected. Green indicates that the switchable fuse protected DC outputs that connect to the modules in the transmitter are OK.

2.2.5 (A6) Power Amplifier Module Assembly, Exci te r, 5W-5 0W Transmitter (1303770; Appendix B)

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 (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

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.

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

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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 Reflected Power Cal R202 Forward Power Cal R203 (NOT USED) Aural Power Cal R205 (NOT USED) Aural Null

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

ENABLED

(Green)

DC OK

(Green)

TEMP

(GREEN)

MOD OK

(Green)

MOD OK

(RED)

When lit Green, it indicates that the PA is in the Operate Mode. If a Mute occurs, the PA will remain Enabled, until the input signal is returned. When lit Green, it indicates that the fuse protected DC inputs to the PA module are OK. When lit Green, it indicates that the temperature of the heatsink assembly in the module is below 78ûC. When lit Green, it indicates that 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

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 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.

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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

AURAL NULL

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) Dri ver Amplifier Module Assembly {1303771(500W) or 1303874(1kW; Appendix B)}

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

(NOT USED) Adjusts the offset of the Forward Power monitoring circuit based on the Aural signal level..

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.

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.

Power Amplifier Calibration Adjustments

R201 Reflected Power Cal R202 Forward Power Cal R203 (NOT USED) Aural Power Cal R205 (NOT USED) Aural Null

The Forward power of an Exciter Driver Power Amplifier and the Forward power of any external amplifiers, are reported

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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

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

ENABLED

(Green)

DC OK

(Green)

TEMP

(Green)

MOD OK

(Green)

MOD OK

(RED)

Table 2- 20 . Driver Ampl ifier Cont ro l A d ju s t me n ts

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

AURAL NULL

(NOT USED) Adjusts the offset of the Forward Power monitoring 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.

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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

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

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the following fault conditions exists in the transmitter.

• Upconverter is unlocked

• Upconverter module is not present

• IF Processor module is not present

Entering Opera te M ode

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.

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.

• Receipt of a “Standby CMD” over the

serial interface.

Auto Standby Mode

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

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

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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

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 Custome r Re mot e Co nn e cti ons

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.

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