OUSLU100AL100-Watt UHF Translator

INSTRUCTION MANUAL PIONEER SERIES 10W - 100W UHF 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 • [email protected]

10W-100W UHF Translator Table of Contents Pioneer, Translator, Rev. 0 August 29, 2003 i TABLE OF CONTENTS SECTION PAGE CHAPTER 1 INTRODUCTION 1.1 Manual Overview................................................................................. 1-1 1.2 Assembly Designation Numbers ............................................................ 1-1 1.3 Safety................................................................................................ 1-1 1.4 Maintenance ....................................................................................... 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 2.1 System Overview............................................................................... 2-1 2.1.1 Receiver Tray............................................................................. 2-2 2.1.2 IF Processor Module.................................................................... 2-3 2.1.3 LO/Upconverter Module............................................................... 2-5 2.1.4 Control & Monitoring/Power Supply Module.................................... 2-7 2.1.5 Power Amplifier Module ............................................................... 2-8 2.1.6 RF Output Assemblies ................................................................. 2-9 2.2 Control and Status............................................................................... 2-9 2.2.1 Front Panel LCD Display Screen...................................................2-10 2.3 System Operation...............................................................................2-10 2.3.1 Principles of Operation ...............................................................2-11 2.4 Customer Remote Connections.............................................................2-12 CHAPTER 3 SITE CONSIDERATIONS, INSTALLATION AND SETUP PROCEDURES 3.1 Site Considerations .............................................................................. 3-1 3.2 Unpacking the Chassis w/Modules and Receiver Tray ............................... 3-4 3.3 Installing the Chassis w/Modules and Receiver Tray ................................. 3-4 3.4 AC Input ............................................................................................ 3-6 3.5 Setup and Operation............................................................................ 3-6 3.5.1 Input Connections ...................................................................... 3-7 3.5.2 Front Panel Screens for the Exciter/Amplifier Chassis Assembly ........ 3-9 CHAPTER 4 CIRCUIT DESCRIPTIONS 4.1 Receiver Tray...................................................................................... 4-1 4.1.1 50-Ohm Filter ............................................................................ 4-1 4.1.2 Dual Stage Amplifier Assembly..................................................... 4-1 4.1.3 Channel Filter ............................................................................ 4-1 4.1.4 Downconverter Amplifier Assembly ............................................... 4-2 4.1.5 Channel Oscillator Assembly ........................................................ 4-2 4.1.6 x8, x2, x4 Multiplier Board........................................................... 4-2 4.1.7 L.O. Filter .................................................................................. 4-2 4.1.8 IF Filter/ALC Board ..................................................................... 4-2 4.1.9 SAW Board (Optional) ................................................................. 4-2 4.1.10 IF Amplifier Board (Optional)...................................................... 4-3 4.1.11 IF Filter/Limiter Board (Optional) ................................................ 4-3 4.1.12 IF PLL Board (Optional) ............................................................. 4-3 4.1.13 IF Carrier Oven Oscillator (Optional) ........................................... 4-3 10W-100W UHF Translator Table of Contents Pioneer, Translator, Rev. 0 August 29, 2003 ii TABLE OF CONTENTS - (Continued) SECTION ...............................................................................................PAGE 4.1.14 +/- 12V Power Supply Board...................................................... 4-4 4.2 IF Processor Module............................................................................. 4-4 4.2.1 IF Processor Board ..................................................................... 4-4 4.3 LO/Upconverter Module.......................................................................4-10 4.3.1 UHF Generator Board .................................................................4-10 4.3.2 UHF Filters................................................................................4-11 4.3.3 LO/Upconverter Board ...............................................................4-11 4.4 Control Monitoring/Power Supply Module ...............................................4-15 4.4.1 Power Protection Board ..............................................................4-16 4.4.2 Control Board ...........................................................................4-16 4.4.3 Switch Board ............................................................................4-19 4.4.4 Switching Power Supply Assembly ...............................................4-19 4.5 Power Amplifier Module Assembly.........................................................4-19 4.5.1 1-Watt Amplifier Module Assembly...............................................4-19 4.5.2 1-Watt UHF Amplifier Board ........................................................4-19 4.5.3 40 Watt UHF Amplifier Assembly .................................................4-20 4.5.4 UHF Module Assembly, RF Module Pallet .......................................4-…

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10W-100W UHF Translator Chapter 1, Introduction Pioneer, UHF Translator, Rev. 0 1-1 Chapter 1 Introduction This manual explains the installation, setup, alignment, and maintenance procedures for the Pioneer Series 10W to 100W modular UHF 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. 1.1 Manual Overview 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. The second chapter describes the translator and includes discussions on system control and status indicators and remote control connections. Chapter 3 explains how to unpack, install, setup, and operate the translator. Chapter 4 contains circuit-level descriptions for boards and board-level components in the translator. Chapter 5, Detailed Alignment Procedures, provides information on adjusting the system assemblies for optimal operation. The appendices contain a sample log sheet, test data sheet, assembly and subassembly drawings and parts lists, and system specifications. 1.2 Assembly Designators Axcera has assigned assembly numbers, such as Ax (x=1,2,3...), to all assemblies, trays, and boards that are referenced in the text of this manual and shown on the block diagrams and interconnect drawings provided in the appendices. These supporting documents are arranged in increasing numerical order in the appendices. Section titles in the text for assembly or tray descriptions or alignment procedures contain the associated part number(s) and the relevant appendix that contains the drawings for that item. 1.3 Safety The UHF translators manufactured by Axcera are designed to be easy to use and repair while providing protection from electrical and mechanical hazards. Listed throughout the manual are notes, cautions, and warnings concerning possible safety hazards that may be encountered while operating or servicing the translator. Please review these warnings and familiarize yourself with the operation and servicing procedures before working on the translator. Read All Instructions – All of the operating and safety instructions should be read and understood before operating this equipment. Retain Manuals – The manuals for the translator should be retained at the translator site for future reference. We provide 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 Instructions – All of the operating and use instructions for the translator 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 cabinets and tray front panels are provided for ventilation. To ensure the reliable 10W-100W UHF Translator Chapter 1, Introduction Pioneer, UHF Translator, Rev. 0 1-2 operation of the translator, 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 Maintenance The Pioneer Series Translator 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 trays. 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 trays. When the front panels of the trays become dust covered, the top covers should be taken off and any accumulated foreign material should be removed. A vacuum cleaner, utilizing a small, wand- type attachment, is an excellent way to suction out the dirt. Alcohol and other cleaning agents should not be used unless you are certain that the solvents will not damage components or the silk- screened markings on the trays 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 translator be recorded from the meters on the trays and the system metering control panel at least once a month. It is suggested that this data be retained in a rugged folder or envelope. A sample format for a log sheet is provided in Appendix A. Photocopies of the log sheet should be made to allow for continued data entries. 1.5 Material Return Procedure To insure the efficient handling of equipment or components that have been returned for repair, Axcera requests that each returned item be accompanied by a Material Return Authorization Number (MRA#). An MRA# 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 MRA# i…

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10W-100W UHF Translator Chapter 2, System Description & Remote Control Connections Pioneer, UHF Translator, Rev. 0 2-1 IF Processor Module LO/Upconverter Module Chapter 2 System Description & Remote Control Connections The Pioneer Series of translators are complete 10W to 100W analog UHF translators that operate at nominal visual output power of 10 to 100 watts peak sync and an aural output power of 1 to 10 watts at an A/V ratio of 10dB, 10% sound or .5 to 5 watts at 13 dB, 5% sound. 2.1 System Overview The Pioneer Series translator is made up of a Receiver Tray and an exciter amplifier chassis assembly. The modules and assemblies that make up the translator are listed in Table 2-1. Table 2-1: 10W - 100W Pioneer Series Translator Trays and Assemblies ASSEMBLY DESIGNATOR TRAY/ASSEMBLY NAME PART NUMBER Receiver Tray 1265-1100 A3 IF Processor Module 1301938 A4 Control & Monitoring/Power Supply Module 1301936 A5 LO/Upconverter Module 1301930 A6 Power Amplifier Module, 100 Watt Translator 1301923 A11 Backplane Board 1301941 A12 Switch Board 1527-1406 A20 LCD Display Board Receiver Tray Controller/ Power Supply Module Power Amplifier Module 10W-100W UHF Translator Chapter 2, System Description & Remote Control Connections Pioneer, UHF Translator, Rev. 0 2-2 2.1.1 8 Receiver Tray (1265-1100; Appendix B) The Receiver Tray receives a VHF or UHF Channel input at Jack (J1) and converts it to an internally diplexed Visual + Aural IF Output (+0 dBm) at J4. The Visual + Aural IF output of the Receiver Tray at J4 is fed to J6 the IF Input Jack of the exciter. Table 2-5. Receiver Samples SAMPLE DESCRIPTION Front panel sample – f (IF) Sample of the IF output Front panel sample – f (s) Sample of the channel oscillator Exciter Amplifier Chassis Assembly All of the modules except the power amplifier module and the power supply section, located in the Control & Monitoring/Power Supply Module, plug directly into a backplane board, which provides module to module interconnection as well as interconnection to remote command and control connectors. RECEIVER TRAY INPUT LEVEL: -61 dBm to –16dBm OUTPUT LEVEL: 0 dBm POWER REQUIREMENTS: 110 or 220 VAC 10W-100W UHF Translator Chapter 2, System Description & Remote Control Connections Pioneer, UHF Translator, Rev. 0 2-3 2.1.2 (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. If the IF Processor interlock signal is not present, the Pioneer 100 Watt Translator/Exciter Driver RF output is Muted (turned off). If an analog IF Processor module is installed and the Modulation Present signal is not true, the Pioneer 100 Watt Translator / Exciter Driver 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 translator'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 an external digital modulator (DT1C or DT2B). 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. 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 non- existent, 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 10W-100W UHF Translator Chapter 2, System Description & Remote Control Connections Pioneer, UHF Translator, Rev. 0 2-4 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 2-6. IF Processor Front Panel Switch SWITCH FUNCTION MAN/AUTO ALC When Manual ALC is selected, the reference ALC voltage is set by the ALC Gain front panel potentiometer. When Auto ALC is selected, the IF level control circuit will automatically increase the IF output until the desired output power is attained. Table 2-7. IF Processor Front Panel Status Indicators LED…

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10W-100W UHF Translator Chapter 3, Site Considerations, Installation and Setup Procedures Pioneer, UHF Translator, Rev. 0 3-1 Chapter 3 Site Considerations, Installation and Setup Procedures There are special considerations that need to be taken into account before the Pioneer Series translator can be installed. For example, if the installation is completed during cool weather, a heat- related problem may not surface for many months, suddenly appearing during the heat of summer. This section provides planning information for the installation and set up of the translator. 3.1 Site Considerations The translator requires an AC input line of 117 VAC @ 5 amps for the 10W translator or 117 VAC @ 10 amps for the 100W Translator. The Pioneer Series Translators are designed and built to provide long life with a minimum of maintenance. The environment in which they are placed is important and certain precautions must be taken. The three greatest dangers to the translator are heat, dirt, and moisture. Heat is usually the greatest problem, followed by dirt, and then moisture. Over-temperature can cause heat-related problems such as thermal runaway and component failure. Each amplifier module in the translator contains a thermal interlock protection circuit that will shut down that module until the temperature drops to an acceptable level. A suitable environment for the translator can enhance the overall performance and reliability of the translator and maximize revenues by minimizing downtime. A properly designed facility will have an adequate supply of cool, clean air, free of airborne particulates of any kind, and no excessive humidity. An ideal environment will require temperature in the range of 40° F to 70° F throughout the year, reasonably low humidity, and a dust-free room. It should be noted that this is rarely if ever attainable in the real world. However, the closer the environment is to this design, the greater the operating capacity of the translator. The fans are designed and built into the translator will remove the heat from within the modules, but additional means are required for removing this heat from the building. To achieve this, a few issues need to be resolved. The first step is to determine the amount of heat to be removed from the translator room. There are generally three sources of heat that must be considered. The first and most obvious is the heat from the translator itself. This amount can be determined for a 100W translator by subtracting the average power to the antenna (69.5 watts) from the AC input power (675 watts) and taking this number in watts (605.5) and then multiplying it by 3.41. This gives a result of 2,065, the BTUs to be removed every hour. 12,000 BTUs per hour equals one ton. Therefore, a 1/4- ton air conditioner will cool a 100W translator. The second source of heat is other equipment in the same room. This number is calculated in the same way as the equation for BTUs. The third source of heat is equally obvious but not as simple to calculate. This is the heat coming through the walls, roof, and windows on a hot summer day. Unless the underside is exposed, the floor is usually not a problem. Determining this number is usually best left up to a qualified HVAC technician. There are far too many variables to even estimate this number without reviewing the detailed drawings of the site that show all of the construction details. The sum of these three sources is the bulk of the heat that must be removed. There may be other sources of heat, such as personnel, and all should be taken into account. 10W-100W UHF Translator Chapter 3, Site Considerations, Installation and Setup Procedures Pioneer, UHF Translator, Rev. 0 3-2 Now that the amount of heat that must be removed is known, the next step is to determine how to accomplish this. The options are air conditioning, ventilation, or a combination of the two. Air conditioning is always the preferred method and is the only way to create anything close to an ideal environment. Ventilation will work quite well if the ambient air temperature is below 100° F, or about 38° C, and the humidity is kept at a reasonable level. In addition, the air stream must be adequately filtered to ensure that no airborne particulates of any kind will be carried into the translator. The combination of air conditioning for summer and ventilation during the cooler months is acceptable when the proper cooling cannot be obtained through the use of ventilation alone and using air conditioning throughout the year is not feasible. Caution: The use of air conditioning and ventilation simultaneously is not recommended. This can cause condensation in the translators. The following precautions should be observed regarding air conditioning systems: 1. Air conditioners have an ARI nominal cooling capacity rating. In selecting an air conditioner, do not assume that this number can be equated to the requirements of the site. Make certain that the contractor uses the actual conditions that are to be maintained at the site in determining the size of the air conditioning unit. With the desired conditioned room temperature under 80° F, the unit must be derated, possibly by a substantial amount. 2. Do not have the air conditioner blowing directly onto the translator. Under certain conditions, condensation may occur on, or worse in, the translator. 3. Do not separate the front of the translator from the back with the thought of air conditioning only the front of the unit. Cooling air is drawn in at the front of all translators and in the front and back of others. Any attempt to separate the front of the translator from the rear of the unit will adversely affect the flow of cooling air. 4. Interlocking the translator with the air conditioner is recommended to keep the translator from operating without the necessary cooling. 5. The periodic cleaning of all filters is a must. When using ventilation alone, the following general statements apply: 1. The blower, …

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10W-100W UHF Translator Chapter 4, Circuit Descriptions Pioneer, UHF Translator, Rev. 0 4-1 Chapter 4 Circuit Descriptions 4.1 (A1) UHF/VHF Receiver Tray (1265-1100) The UHF/VHF Receiver Tray w/(Optional) Frequency Correction selects the desired UHF or VHF On Channel Input Signal and converts it to a Combined IF Signal of 45.75 MHz Visual + 41.25 MHz Aural. The Tray also has provisions for a Frequency Correction Option that consists of a VCXO Channel Oscillator Assembly with a PLL Circuit which maintains an exact IF Output Frequency, over the capture range of the PLL circuit, even if the Input UHF or VHF Frequency may vary. RF Signal Path 4.1.1 (A7) 50Ω Filter, DC Multiplexed, UHF (1035-1204), VHF L.B. (1035-1902) or VHF H.B. (2065- 1024) or 75Ω, UHF (1035-1207), VHF L.B. (1035-1903) or VHF H.B. (2065-1023) The RF Input to the Tray, (-61 dBm to - 16 dBm in Level), is fed through J1 for 50Ω to (A7) the input 50Ω Filter, DC Multiplexed (1035-1204 UHF, 1035-1902 VHF LB or 2065-1024 VHF HB) or through J5 for 75Ω to (A7) the 75Ω input Filter, DC Multiplexed (1035-1207 UHF, 1035-1903 VHF LB or 2065-1023 VHF HB), which is of a double tuned design that is adjusted to the desired Input UHF or VHF Channel Frequency. Note: If the input signal is greater than -25dBm, an attenuator should be used to limit the level to -25dBm. +12 VDC, for use by an (Optional) external Preamplifier Assembly, connects to the filter through F1 a 1 Amp Fuse. This +12 VDC is DC Multiplexed onto the input signal cable from the Preamplifier. DS1 a Red LED located on TB1 in the Tray will be lit if the +12 VDC is present on the input cable. If a Preamplifier is not used, F1 should be removed and DS1 should not be lit. 4.1.2 (A8) Dual Stage Amplifier Assembly (1227-1503) The signal is next amplified +12 dB to approximately the -49 to -4 dBm level by a low noise amplifier located on (A8-A1) the Dual Stage Amplifier Board (1227-1501) that is contained in (A8) the Dual Stage Amplifier Assembly (1227-1503). The board has approximately +13 dB or +26 dB of gain, depending on whether Jumper W1 on J5 is in place. The amplified output connects out of the board at J2. 4.1.3 (A9) Channel Filter, UHF (1007- 1101), VHF L.B. (1034-1202) or VHF H.B. (2065-1000) The signal is then filtered in (A9) a Channel Filter (1007-1101 UHF, 1034-1202 VHF LB or 2065-1000 VHF HB) and then applied back to (A8-A1) the Dual Stage Board at J3. More amplification of the signal takes place on the Dual Stage Board, if needed. Jumper W1 on J7 should be removed if the Receiver Input level is greater than - 40dBm. 4.1.4 (A10) Downconverter Amplifier Assembly, 45.75 MHz. (1227-1505) The output is connected to (A10) the Downconverter Amplifier Assembly (1227- 1505) that contains (A10-A1) the Downconverter Amplifier Board (1227- 1502). The RF, at the -47 dBm to -2 dBm Level, connects to the "R" Input Jack of the Mixer Z1 located on the Downconverter Amplifier Board. Local Oscillator Signal Path The Local Oscillator Signal is derived from a cut to channel crystal mounted in an oven that is factory set at 45° C. The Oscillator operates at 1/8 for UHF, 1/4 for 10W-100W Digital UHF Transmitter Chapter 4, Circuit Descriptions Pioneer, UHF Translator, Rev. 0 4-2 VHF High Band or 1/2 for VHF Low Band of the desired local oscillator frequency. 4.1.5 (A4) Channel Oscillator Assembly (1145-1202) The crystal is mounted on (A4-A1) the Channel Oscillator Board, Dual Oven (1145-1201), that is part of the Channel Oscillator Assembly (1145-1202). The oscillator circuitry is a modified Colpitts design operating in a separate oven set at 50° C. for improved stability. If the Frequency Correction Option is purchased, the VCXO Channel Oscillator Assembly (1145-1206), which contains the VCXO Channel Oscillator Board (1145-1204), is used in place of the standard Channel Oscillator Assembly, and an AFC voltage from the PLL circuit maintains the frequency of the VCXO. 4.1.6 (A5-A1) x8 Multiplier Board (1227-1002), x2 Multiplier Board (1227-1524) or x4 Multiplier Board (1227-1525) The output of the Channel Oscillator is connected to the (A5-A1) the x8 Multiplier Board (1227-1002) for UHF, the x4 Multiplier Board (1227-1525) for VHF HB or the x2 Multiplier Board (1227-1524) for VHF LB, which is located in (A5) the Multiplier Enclosure (1265- 1125). The proper multiplier board takes the output of the Channel Oscillator (+3 dBm) and multiplies it eight, four or two times by a series of three, two or one x2 Broadband Doublers (2x2x2 = x8), which produces the L.O. signal on the desired frequency needed for the upconversion process. The signal is then amplified to the +16 dBm level. A sample of the multiplied L.O. Signal is fed to a detector circuit which lights the Green LED DS1 that indicates that the L.O. is present at the Output Jack J2 of the Multiplier Board. This Green LED is seen through a hole the lid of the Multiplier Assembly and is an indication, when lit, that there is a signal present at the output of the Multiplier Board. 4.1.7 (A6) L.O. Filter, UHF (1007- 1101), VHF L.B. (1034-1211) or VHF H.B. (2065-1000) The L.O. signal is filtered in (A6) a L.O. Filter 1007-1101 UHF, 2065-1000 VHF HB or 1034-1211 VHF LB) and then sent (+15 dBm) to J2 on (A10-A1) the Downconverter Amplifier Board. The L.O. Input to the Downconverter Amplifier Board is connected thru a 3 dB matching pad to the "L" Input of the Mixer (Z1) at a +12 dBm level. Combined IF Signal Path The L.O. and the RF signals are mixed in the Mixer Stage of the Downconverter Amplifier Board to produce the desired IF difference frequency at -55 dBm to -10 dBm in level, depending on the RF Input Level. 4.1.8 (A11-A1) IF Filter/ALC Board (1227-1504) The Combined IF Signal is routed to (A11- A1) the IF Filter/ALC Board (1227-1504), which is …

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