UBS Axcera LLV20AL User Manual

INSTRUCTION MANUAL
Innovator
LX Series
Analog
VHF Translator
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
LX Series VHF Translator Table of Contents
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION SECTION PAGE
1.1 Manual Overview...................................................................................1-1
1.2 Assembly Designators............................................................................1-1
1.3 Safety..................................................................................................1-2
1.4 Contact Information...............................................................................1-2
1.5 Return Material Procedure ......................................................................1-2
1.6 Limited One Year Warranty for Axcera Products........................................1-3
CHAPTER 2 SYSTEM DESCRIPTION, MAINTENANCE & REMOTE CONTROL CONNECTIONS
2.0 System Overview ..................................................................................2-1
2.2 Exciter/Amplifier Chassis Assembly .........................................................2-2
2.2.1 Receiver Module...........................................................................2-2
2.2.2 IF Processor Module .....................................................................2-2
2.2.3 VHF/UHF Upconverter Module........................................................2-5
2.2.4 Control & Monitoring/Power Supply Module.....................................2-6
2.2.5 Exciter Power Amplifier Module, VHF HB .........................................2-8
2.3 RF Output Assemblies..........................................................................2-10
2.4 Control and Status...............................................................................2-10
2.5 System Operation................................................................................2-10
2.5.1 Principles of Operation................................................................2-10
2.6 Maintenance .......................................................................................2-11
2.7 Customer Remote Connections .............................................................2-12
CHAPTER 3 SITE CONSIDERATIONS, INSTALLATION AND SETUP PROCEDURES
3.1 Site Considerations................................................................................3-1
3.2 Unpacking the Cabinet, Chassis w/Modules and DTV mask filter .................3-4
3.3 Installing the Chassis w/Modules and filters..............................................3-4
3.4 AC Input...............................................................................................3-6
3.5 Setup and Operation..............................................................................3-6
3.5.1 Input Connections........................................................................3-6
3.5.2 Initial Turn On .............................................................................3-7
3.5.2.2 Receiver Module LEDs on Front Panel ....................................3-8
3.5.2.3 IF Processor Module LEDs on Front Panel...............................3-8
3.5.2.4 VHF/UHF Upconverter Module LEDs on Front Panel .................3-8
3.5.2.5 Controller Module LEDs on Front Panel ..................................3-8
3.5.2.6 Power Amplifier Module LEDs on Front Panel..........................3-8
3.5.3 Front Panel Screens for the Exciter/Amplifier Chassis Assembly.........3-9
3.5.5 Operation Procedure...................................................................3-18
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LX Series VHF Translator Table of Contents
TABLE OF CONTENTS - (Continued)
CHAPTER 4 CIRCUIT DESCRIPTIONS
4.2 Receiver Module (not used in the digital translator system)........................4-1
4.2.1 IF ALC Board ...............................................................................4-1
4.2.2 VHF Mixer/PLL Board ....................................................................4-2
4.2.3 VHF High Band Preamplifier Board .................................................4-2
4.3 IF Processor Module...............................................................................4-2
4.3.1 IF Processor Board .......................................................................4-3
4.3.1.1 Modulator Selected..............................................................4-3
4.3.1.2 External Modulated IF Selected.............................................4-3
4.3.1.3 Main IF Signal Path (Part 1 of 3)...........................................4-3
4.3.1.4 Input Level Detector Circuit..................................................4-3
4.3.1.5 Pin-Diode Attenuator Circuit.................................................4-5
4.3.1.6 Main IF Signal Path (Part 2 of 3)...........................................4-5
4.3.1.7 Amplitude and Phase Pre-Correction Circuits..........................4-6
4.3.1.8 Main IF Signal Path (Part 3 of 3)...........................................4-7
4.3.1.9 ALC Circuit .........................................................................4-7
4.3.1.10 Fault Command.................................................................4-8
4.3.1.11 ±12 VDC needed to operate Board......................................4-8
4.4 VHF/UHF Upconverter Module.................................................................4-8
4.4.1 Downconverter Board ...................................................................4-8
4.4.2 L-Band PLL Board.........................................................................4-9
4.4.3 First Conversion Board..................................................................4-9
4.4.4 Upconverter Control Board ............................................................4-9
4.5 Control Monitoring/Power Supply Module ...............................................4-10
4.5.1 Power Protection Board...............................................................4-10
4.5.1.1 +12 VDC Circuits ..............................................................4-11
4.5.1.2 -12 VDC Circuits ...............................................................4-11
4.5.2 Control Board ............................................................................4-11
4.5.2.1 Schematic Page 1..............................................................4-11
4.5.2.2 Schematic Page 2..............................................................4-12
4.5.2.3 Schematic Page 3..............................................................4-12
4.5.2.4 Schematic Page 4..............................................................4-13
4.5.2.5 Schematic Page 5..............................................................4-13
4.5.3 Switch Board .............................................................................4-14
4.5.4 Switching Power Supply Assembly................................................4-14
4.8 Power Amplifier Module, VHF Low Band .................................................4-14
4.8.1 VHF Low Band Driver Assembly ...................................................4-14
4.8.2 VHF Low Band Amplifier Board.....................................................4-15
4.8.3 VHF Coupler Board .....................................................................4-15
4.8.4 Amplifier Control Board...............................................................4-16
4.8.4.1 Schematic Page 1..............................................................4-16
4.8.4.2 Schematic Page 2..............................................................4-16
4.8.4.3 Current Monitoring Sections of the Board.............................4-17
4.8.4.4 Schematic Page 3, RF Power Detector Circuits......................4-17
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LX Series VHF Translator Table of Contents
TABLE OF CONTENTS - (Continued)
SECTION PAGE CHAPTER 5 DETAILED ALIGNMENT PROCEDURES
5.1 Module Replacement..............................................................................5-1
5.1.1 Initial Test Setup..........................................................................5-1
5.2 LX Series Exciter/Amplifier Chassis Assembly ...........................................5-2
5.2.1 Receiver Module Assembly ............................................................5-2
5.2.2 IF Processor Module Assembly.......................................................5-2
5.2.3 VHF/UHF Upconverter Assembly ....................................................5-2
5.3 Changing the Analog Translator Output Channel Procedure........................5-3
5.4 Adjusting Manual AGC, Auto AGC and AGC cutback in Analog Translator .....5-4
5.4.1 Setting the Manual AGC................................................................5-4
5.4.2 Setting the Auto AGC....................................................................5-4
5.4.3 Setting the AGC Cutback...............................................................5-4
5.5 Calibration of Forward & Reflected Power of Analog Translator ...................5-4
5.5.1 Calibration of the Translator Forward Output Power .........................5-5
5.5.2 Calibration of the Translator Reflected Power ..................................5-5
5.6 Linearity Correction Adjustment for the Analog Translator..........................5-6
5.7 Frequency Response Delay Equalization Adjustment for Analog Translator...5-6
APPENDICES
APPENDIX A SYSTEM AND EXCITER/AMPLIFIER DRAWINGS
LX Series, Rev. 0
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LX Series VHF Translator Chapter 1 Introduction
Chapter 1
Introduction
1.1 Manual Overview
This manual explains the installation, setup, alignment, and maintenance procedures for the Innovator LX Series VHF translator. It is important that you read all of the instructions, especially the safety information in this chapter, before you begin to install or operate the unit.
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 & 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 the System, Remodulator & Exciter/Amplifier drawings and parts lists.
1.2 Assembly Designators
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.
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.
LX Series, Rev. 0 1-1
Figure 1-1 Brady Marker Identification Drawing
LX Series VHF Translator Chapter 1 Introduction
1.3 Safety
The VHF translator 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.
Read All safety Instructions – All of the safety instructions should be read and understood before operating this 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 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.
Servicing – Do not attempt to service this product yourself until becoming familiar with the equipment. If in doubt, refer all servicing questions to qualified Axcera service personnel.
Replacement Parts – When replacement parts are 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.
1.4 Contact Information
The Axcera Field Service Department can be contacted by phone at (724) 873- 8100 or by fax at (724) 873-8105.
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.
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#).
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LX Series VHF Translator 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.
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:
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.
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 hours­of-use or other warranties extended by or enforceable against the manufacturer at the time of delivery to the buyer.
NO WARRANTIES, WHETHER STATUTORY, EXPRESSED, OR IMPLIED, AND NO WARRANTIES OF MERCHANTABILITY, FITNESS FOR ANY PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, OR THE LIKE, OTHER THAN AS SPECIFIED IN PATENT LIABILITY ARTICLES, AND IN THIS ARTICLE, SHALL APPLY TO THE EQUIPMENT FURNISHED HEREUNDER.
LX Series, Rev. 0 1-3
LX Series VHF Translator Chapter 1 Introduction
F WARNING!!!
× HIGH VOLTAGE Ø
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.
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LX Series VHF Translator 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.
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.
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 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.
BURNS
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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LX Series VHF Translator Chapter 1 Introduction
dBm, dBw, dBmV, dBµV, & 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, Rev. 0 1-6
LX Series VHF Translator 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 3 to 30 kHz VLF - Very Low Frequency
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
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, Rev. 0 1-7
LX Series VHF Translator Chapter 1
0 -10 -20 -30 -40 -50 -60
-70
N
dB
Introduction
RETURN LOSS VS. VSWR
R E T U R
L O S S
1.001 1.01 1.1 2.0
VSWR
LX Series, Rev. 0 1-8
LX Series VHF Translator Chapter 1 Introduction
ABBREVIATIONS/ACRONYMS
AC Alternating Current AFC Automatic Frequency Control ALC Automatic Level Control AM Amplitude modulation AGC Automatic Gain Control ATSC Advanced Television Systems
Committee AWG American wire gauge BER Bit Error Rate BW Bandwidth DC Direct Current D/A Digital to analog 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 Hz Hertz ICPM Incidental Carrier Phase
Modulation I/P Input IF Intermediate Frequency LED Light emitting diode LSB Lower Sideband MPEG Motion 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
LX Series, Rev. 0 1-9
LX Series VHF Translator Chapter 2, System Description,
A3
A5
A4
A6
A1 A2 A24
Maintenance & Remote Control Connections
Chapter 2
System Description, Maintenance & Remote Control Connections
2.0 System Overview
This analog translator is a complete VHF internally diplexed modular television translator. There are three systems, one that operates at CH:6 at a nominal visual output power of 20W or a DTV output of 10W, one that operates at CH:10 at a nominal visual output power of 20W or a
DTV output of 10W, and one that operates at CH:8 at a nominal visual output power of 100W or a DTV output of 50W..
The Analog LX Series translator is made up of the modules and assemblies as listed in Table 2-1.
Figure 2-1:Exciter/Amplifier w/Remodulator Front View
Table 2-1: Exciter/Amplifier w/Remodulator Translator Assemblies
ASSEMBLY DESIGNATOR
A2
A2-A11 Backplane Board, V2, LX Series 1304047
A1 A3 IF Processor Module 1301938
A4 Control/Power Supply Module 1301936 (110 VAC) A5 VHF/UHF Upconverter Module 1303829
A6
TRAY/ASSEMBLY NAME PART NUMBER Exciter Amplifier Chassis Assembly, V2, LX Series
Receiver Module (used in the analog translator system)
Power Amplifier Module, 20 W Analog
1304052 (110 VAC)
1304001 (VHF High Band)
1305833 (VHF High Band
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LX Series VHF Translator Chapter 2, System Description, Maintenance & Remote Control Connections
2.2 (A2) Exciter Amplifier Chassis Assembly, 110 VAC (1304052; Appendix A)
This chassis assembly is factory set for operation using 110 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 (A1) Receiver Module Assembly, VHF High Band (1304001; Appendix A)
NOTE: The Receiver module is not used in the digital system.
NOTE: For analog translator operation the Receiver IF output at A2-J13 is connected to the Modulated IF input Jack A2-J6 and the On Channel RF input is connected to A2-J12.
Table 2-5: Receiver Front Panel Switch
SWITCH FUNCTION
When Manual ALC is selected, the level is set by the Manual ALC Pot R57 located on the mixer/PLL board. (NOTE: The pot is factory set and needs no adjustment
MAN/AUTO ALC
SW1
by the customer). When Auto ALC is selected, the level control circuit will
automatically increase or decrease the ALC to maintain the desired output level.
The VHF Receiver converts a low level RF input signal (-65 to –15 dBm) to an IF frequency of 44 MHz, filters off any unwanted out of band energy, and normalizes the level so that it can be applied to the IF processor assembly. The receiver consists of three boards, the VHF High Band Preamplifier Board (1306445), the Mixer/PLL Board (1306472), and the IF ALC Board (1304003). The RF input is applied first to the VHF preamplifier board, which filters off out of channel energy and amplifies the input signal. The RF output is connected to the Mixer/PLL board, which converts the signal down to an IF frequency of 44 MHz. The IF output is cabled to the IF ALC board, which amplifies the signal, filters off any unwanted out of band energy and controls its own IF gain to make sure that the IF output level is constant.
There is also a provision to apply +12V to the RF input center conductor to power an external preamplifier.
CAUTION: Do not hook up the RF input to any test equipment with the DC bias applied. Always move the jumper W1 on J2, on the UHF Preamplifier Board, to the Bias off position, between pins 2 & 3, to prevent possible damage to the test equipment.
LX Series, Rev. 0 2-2
LX Series VHF Translator Chapter 2, System Description, Maintenance & Remote Control Connections
Table 2-6: Receiver Front Panel Status Indicators
LED FUNCTION
PLL1 Fault DS6 Displays the status of the Local oscillator PLL
PLL 2 Fault DS8 Displays status of optional input frequency correcting PLL
DC on center conductor DS4
Displays whether or not DC is applied to the RF input center conductor
Man ALC Gain DS7 Displays when ALC is switched to Manual bypass
ALC Fault DS5 Displays ALC status
Table 2-7: Receiver Front Panel Control Adjustments
POTENTIOMETERS DESCRIPTION
Manual Gain R57 Adjusts the gain of the receiver when the ALC is bypassed.
A/V Ratio R50 Adjusts the ratio between the visual and aural carriers.
Table 2-8: Receiver Front Panel Samples
SMA CONNECTORS DESCRIPTION
Receiver IF J13 Sample of the IF output of the IF ALC Board.
Receiver LO J2 Sample of the LO generated on the UHF Mixer PLL Board.
2.2.2 (A3) IF Processor Module Assembly (1301938; Appendix A)
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 RF output power level of the translator. The range of RF power adjustment is between 0% (full off) and 105% (full
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. If the IF Processor interlock signal is not present, the LX Series translator RF output is Muted (turned off). If an analog IF Processor module is installed and the Modulation Present signal is not true, the LX Series Translator output is Muted (turned off).
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 an external digital modulator (DT1B/C). RF power control is implemented by changing the DLC voltage provided to the external 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 decreases, the Upconverter automatically lowers the system output power through the AGC circuits.
LX Series, Rev. 0 2-3
LX Series VHF Translator Chapter 2, System Description, Maintenance & Remote Control Connections
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 translator or in Manual mode the translator 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 translator. The system controller does not Mute on an IF Processor Input Fault.
Table 2-9: 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 2-10: 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. Translator 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 2-11: IF Processor Front Panel Control Adjustments
POTENTIOMETERS
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 translator when the translator is in the Auto ALC position. Adjusts the gain of the translator when the translator is in the Manual ALC position.
DESCRIPTION
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 adjusted to correct for in phase amplitude distortions. R 231, the bottom pot, is adjusted to correct for quadrature phase distortions.
Table 2-12: IF Processor Front Panel Sample
SMA CONNECTOR DESCRIPTION
IF SAMPLE Sample of the pre-corrected IF output of the IF Processor
LX Series, Rev. 0 2-4
LX Series VHF Translator Chapter 2, System Description, Maintenance & Remote Control Connections
2.2.3 (A5) VHF/UHF Upconverter Module Assembly (1303829; Appendix A)
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 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
Table 2-13: 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.
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 translator, that connects to the power amplifier module.
LX Series, Rev. 0 2-5
LX Series VHF Translator Chapter 2, System Description, Maintenance & Remote Control Connections
Table 2-14: 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)
Table 2-15: VHF/UHF Upconverter Front Panel Control Adjustments
POTENTIOMETERS
MAN GAIN ADJ
AGC ADJ
AGC CUTBACK ADJ
(AGC OVERRIDE)
Table 2-16: VHF/UHF Upconverter Front Panel Samples
SMA CONNECTOR DESCRIPTION
LO1 SAMPLE
LO2 SAMPLE
RF SAMPLE Sample of the On Channel RF Output of the Upconverter
2.2.4 (A4) Control/Power Supply Module Assembly, 110VAC (1301936; Appendix A)
This (A4) Control & Monitoring/Power Supply Assembly was configured at the factory for operation at 110 VAC. The assembly is made up of a Control Board (1302021), a Power Protection Board (1302837) and a Switch Board (1527-
1406).
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.
DESCRIPTION
Adjusts the gain of the upconverter and translator when in the Manual AGC position. Adjusts the gain of the upconverter and translator when in the Auto AGC position. Adjusts the point at which the translator will cut back in power, due to too much drive, when the Translator is in Auto AGC.
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.
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 translator 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. The LCD screens are detailed in Chapter 3.
LX Series, Rev. 0 2-6
LX Series VHF Translator Chapter 2, System Description, Maintenance & Remote Control Connections
Table 2-17: Controller/Power Supply Display
DISPLAY FUNCTION
A 4 x 20 display providing a four-line readout of the internal
LCD
Table 2-18: Controller/Power Supply Status Indicator
LED FUNCTION
OPERATE
(green)
FAULT
(red or green)
DC OK
( red or green )
Table 2-19: Controller/Power Supply Control Adjustments
POTENTIOMETERS
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 translator is in the Operate Mode. If translator is Muted the Operate LED will stay lit, the translator will remain in Operate, until the input signal is returned. Red indicates that a problem has occurred in the translator. The translator 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 translator are OK.
DESCRIPTION
LX Series, Rev. 0 2-7
LX Series VHF Translator Chapter 2, System Description, Maintenance & Remote Control Connections
2.2.6 (A6) Power Amplifier Module Assembly, VHF High Band, (1305833; Appendix A)
NOTE: This 20W Analog power amplifier module is used in the VHF High Band Translator.
The (A6) Power Amplifier Module Assembly is made up of a VHF High Band Coupler Board (1211-1004), a VHF Amplifier Control Board (1308260), and a High Band VHF Amplifier Pallet Assembly (1305820).
The Power Amplifier Module contains Broadband LDMOS amplifiers that cover the VHF High Band with no tuning required. The module amplifies the RF output of the Upconverter to approximately 22 watts Peak of Sync Visual. 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. The High Band VHF Amplifier Pallet Assembly (1305820) is made from a Delta RF Technology pallet PA25-VHF-HB.
The PA 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 Driver Power Amplifier module contains a 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 in Analog Systems
R201 Reflected Power Cal R202 Visual/Forward Power Cal R203 Aural Power Cal R204 Visual Offset Zero R205 Aural Null
In analog systems, the Aural power of an Exciter Driver Power Amplifier and the Aural power of any external PA amplifiers will not be reported by the system Control Monitoring module. Additionally the Visual power of these amplifiers is reported as Forward Power just like in digital systems. In analog systems, aural and visual power will only be reported for the final system RF output.
In this translator, 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.
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.
LX Series, Rev. 0 2-8
LX Series VHF Translator Chapter 2, System Description, Maintenance & Remote Control Connections
Table 2-23: Power Amplifier Status Indicator
LED FUNCTION
ENABLED
(Green)
DC OK
(Green)
TEMP
(Green)
MOD OK
(Green)
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 78°C.
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.
1 Blink indicates Amplifier Current Fault. If the Module OK LED is Red and blinking a fault is present, as indicated below by the number of blinks and a
MOD OK
(Red)
pause then a repeat of the number of blinks and a pause.
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.
MOD OK (Amber)
A blinking Amber Mod OK LED indicates the power output of the amplifier module is below 65%. (NOTE: Only in Amplifier Code Versions 3.7A or later & System Controller Code Versions 3.9C or later.)
Table 2-24: Power Amplifier Control Adjustments
POTENTIOMETERS
DESCRIPTION
RFL CAL Adjusts the gain of the Reflected Power monitoring circuit
VISUAL CAL Adjusts the gain of the Visual / Forward Power monitoring circuit
AURAL CAL Adjusts the gain of the Aural Power monitoring circuit
VISUAL ZERO Adjusts the offset of the Forward Power monitoring circuit
AURAL NULL
Adjusts the offset of the Forward Power monitoring circuit based on the Aural signal level.
Table 2-25: Power Amplifier Sample
DISPLAY FUNCTION
FWD SAMPLE RF sample of the amplified signal being sent out the module on J25.
LX Series, Rev. 0 2-9
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