AM–500A 500 WATT AM–1A 1 KILOWATT AM BROADCAST TRANSMITTERS October, 1999 IM No. 597–1112 IMPORTANT INFORMATION EQUIPMENT LOST OR DAMAGED IN TRANSIT. When delivering the equipment to you, the truck driver or carrier’s agent will present a receipt for your signature. Do not sign it until you have: 1) inspected the containers for visible signs of damage and 2) counted the containers and compared with the amount shown on the shipping papers. If a shortage or evidence of damage is noted, insist that notation to that effect be made on the shipping papers before you sign them. Further, after receiving the equipment, unpack it and inspect thoroughly for concealed damage. If concealed dam- age is discovered, immediately notify the carrier, confirming the notification in writing, and secure an inspection re- port. This item should be unpacked and inspected for damage WITHIN 15 DAYS after receipt. Claims for loss or damage will not be honored without proper notification of inspection by the carrier. RF PRODUCT TECHNICAL ASSISTANCE – REPAIR SERVICE – REPLACEMENT PARTS. Technical assistance is available from Broadcast Electronics by letter, prepaid telephone, fax, or E–mail. Equip- ment requiring repair or overhaul should be sent by common carrier, prepaid, insured, and well protected. If proper shipping materials are not available, contact the Customer Service Department for a shipping container. Do not the mail equipment. We can assume no liability for inbound damage, and necessary repairs become the obligation of the shipper. Prior arrangement is necessary. Contact the Customer Service Department for a Return Authoriza- tion. Emergency and warranty replacement parts may be ordered from the following address. Be sure to include the equipment model number, serial number, part description, and part number. Non–emergency replacement parts may be ordered directly from the Broadcast Electronics stock room by fax at the number shown below. FACILITY CONTACTS – Broadcast Electronics, Inc. – Quincy Facility 4100 N. 24th St. P.O. BOX 3606 Quincy, Illinois 62305 Telephone: (217) 224–9600 Fax: (217) 224–9607 E–Mail: General – [email protected] Web Site: www.bdcast.com RF PRODUCT TECHNICAL ASSISTANCE – REPAIR – EMERGENCY/WARRANTY REPLACEMENT PARTS – Telephone: (217) 224–9600 E–Mail: [email protected] Fax: (217) 224–9607 NON–EMERGENCY REPLACEMENT PARTS – Fax: (217) 224–9609 RETURN, REPAIR, AND EXCHANGES. Do not return any merchandise without our written approval and Return Authorization. We will provide special ship- ping instructions and a code number that will assure proper handling and prompt issuance of credit. Please furnish complete details as to circumstances and reasons when requesting return of merchandise. All returned merchan- dise must be sent freight prepaid and properly insured by the customer. WARRANTY ADJUSTMENT. Broadcast Electronics, Inc. warranty is included in the Terms and Conditions of Sale. In the event of a warranty claim, replacement or repair parts will be supplied F.O.B. factory. At the discretion of Broadcast Electronics, the customer may be required to return the defective part or equipment to Broadcast Electronics, Inc. F.O.B. Quincy, Illinois. Warranty replacements of defective merchandise will be billed to your account. This billing will be cleared by a credit issued upon return of the defective item. PROPRIETARY NOTICE. This document contains proprietary data of Broadcast Electronics, Inc. No disclosure, reproduction, or use of any part thereof may be made except by prior written permission. MODIFICATIONS. Broadcast Electronics, Inc. reserves the right to modify the design and specifications of the equipment in this manu- al without notice. Any modifications shall not adversely affect performance of the equipment so modified. WARNING OPERATING HAZARDS READ THIS SHEET AND OBSERVE ALL SAFETY PRECAUTIONS ALL PERSONS WHO WORK WITH OR ARE EXPOSED TO POWER TRANSISTORS MUST TAKE PRECAUTIONS TO PROTECT THEMSELVES AGAINST POSSIBLE SERIOUS BODILY INJURY. EXERCISE EXTREME CARE AROUND SUCH PRODUCTS. UNINFORMED OR CARELESS OPERATION OF THESE DEVICES CAN RESULT IN POOR PERFORMANCE, DAMAGE TO THE DEVICE OR PROPERTY, SERIOUS BODILY INJURY, AND POSSI- BLY DEATH. DANGEROUS HAZARDS EXIST IN THE OPERATION OF POWER TRANSISTORS The operation of power tubes and power transistors involves one or more of the following hazards, any one of which, in the absence of safe operating practices and precautions, could result in serious harm to personnel. A. HIGH VOLTAGE – Normal operating voltages can be deadly. Additional information follows. B. RF RADIATION – Exposure to RF radiation may cause serious bodily injury possibly resulting in blindness or death. Cardiac pacemakers may be affected. Additional information follows. C. BERYLLIUM – OXIDE POISONING – Dust or fumes from BeO ceramics used as thermal links with power transistors are highly toxic and can cause serious injury or death. Additional information follows. D. HOT SURFACES – Surfaces of air–cooled heat sinks radiators can reach temperatures of 100 degrees centigrade and cause burns if touched. Additional information follows. E. RF BURNS – Circuit boards with RF power transistors contain high RF potentials. Do not operate an RF power module with the cover removed. HIGH VOLTAGE The transmitter operates at voltages high enough to kill through electrocution. Personnel should always break the primary circuits when access to the transmitter is required. RADIO FREQUENCY RADIATION Exposure of personnel to RF radiation should be minimized, personnel should not be permitted in the vicinity of open energized RF generating circuits, or RF transmission systems (waveguides, cables, connectors, etc.), or energized antennas. It is generally accepted that exposure to “high levels” of radiation can result in severe bodily injury includ- ing blindness. Cardiac pacemakers may be affected. The effect of prolonged exposure to “low level” RF radiation continues to be a subject of investigation and controver- sy. It is generally agreed that prolonged exposure of personnel to RF radiation should be limited to an absolute mini- mum. It is also generally agreed that exposure should be reduced in working areas where personnel heat load is above normal. A 10 mW/cm2 per one tenth hour average level has been adopted by several U.S. Government agen- cies including the Occupational Safety and Health Administration (OSHA) as the standard protection guide for em- ployee work environments. An even stricter standard is recommended by the American National Standards Institute which recommends a 1.0 mW/cm2 per one tenth hour average level exposure between 30 Hz and 300 MHz as the standard employee protection guide (ANSI C95.1–1982). RF energy must be contained properly by shielding and transmission lines. All input and output RF connections, such as cables, flanges and gaskets must be RF leakproof. Never operate a power tube without a properly matched RF energy absorbing load attached. Never look into or expose any part of the body to an antenna, open RF generating circuit, or RF transmission system while energized. Monitor the tube and RF system for RF radiation leakage at regu- lar intervals and after servicing. DANGER –– BERYLLIUM OXIDE CERAMICS (BeO) – AVOID BREATHING DUST OR FUMES BeO ceramic material is used as a thermal link to carry heat from a transistor to the heat sink. Do not perform any operation on any BeO ceramic which might produce dust or fumes, such as grinding, grit blasting, or acid cleaning. Beryllium oxide dust or fumes are highly toxic and breathing them can result in serious personal injury or death. BeO ceramics must be disposed of only in a manner prescribed by the device manufacturer. HOT SURFACES Heat sinks and reject loads are air–cooled or conduction–cooled. The air–cooled external surface can operate at a high temperature (up to 100°C). All hot surfaces may remain hot for an extended time after the transmitter is oper- ated to off. To prevent serious burns, take care to prevent and avoid any bodily contact with these surfaces both dur- ing and for a reasonable cooling down period after operation. BROADCAST ELECTRONICS, INC. TRANSMITTER WARRANTY VOID NOTICE THE PRODUCT WARRANTY WILL BE VOID IF THE TRANSMITTER IS INSTALLED AT A SITE WITH INADEQUATE LIGHTNING PROTECTION AND A DEFECTIVE TRANSMISSION LINE SYSTEM. The transmitter is covered by a two year limited product warranty from Broadcast Elec(cid:6) tronics. However, the transmitter must be properly installed at a site with adequate lightning protection and transmission line systems. TO ENSURE THE TRANSMIT(cid:6) TER WARRANTY IS VALID, the transmitter must be installed: 1) as described by the INSTALLATION procedures presented in SECTION II of this manual, 2) at a transmitter site with a lightning protection system described in TRANSMITTER SITE LIGHTNING PROTECTION SYSTEM CHECKOUT (refer to SECTION II of this manual), and 3) at a transmitter site with a transmission line system described in TRANSMISSION LINE AND ANTENNA CHECKOUT (refer to SECTION II of this manual). FAILURE TO PROPERLY INSTALL THE TRANSMITTER, PROVIDE AN ADEQUATE LIGHT(cid:6) NING PROTECTION SYSTEM, OR PROVIDE AN ADEQUATE TRANSMISSION LINE SYSTEM WILL VOID THE WARRANTY ON THE TRANSMITTER. If any questions develop concerning the transmitter warranty and installation site systems, con(cid:6) tact the Broadcast Electronics Customer Service Department. BROADCAST ELECTRONICS, INC. NOTICE TO THE EQUIPMENT USER FCC Rule 73.1590 mandates the licensee of each AM station to make measurements for spurious and harmonic emissions to show compliance with the transmission system re(cid:6) quirements of Section 73.44 of the Commission’s Rules. It is the broadcast station’s respon(cid:6) sibility to ensure that the audio signal input to the Broadcast Electronics A-Series trans(cid:6) mitters conforms to the audio standard NRSC-1 (published as ANSI/EIA-549-1988). This is a mandatory requirement to ensure that the equipment complies to Section 73.44 and Section 73.128(C) of the Commission’s Rules. WARNING WARNING OPERATING HAZARDS WARNING THE TRANSMITTER CONTAINS MULTIPLE CIRCUIT GROUNDS WITH HIGH AC AND DC POTENTIALS WITH WARNING RESPECT TO THE CABINET WHICH IS AT EARTH PO(cid:6) TENTIAL. DO NOT ENERGIZE THE TRANSMITTER WITH TEST EQUIPMENT CONNECTED TO THE TRANSMITTER OUTPUT NETWORK, RF POWER MOD(cid:6) ULE, RF COMBINER, OR POWER SUPPLY COMPO(cid:6) NENTS. The Broadcast Electronics AM transmitters contain high voltages and currents. If safety precautions are not practiced, contact with the high voltages and currents could cause serious injury or death. The trans(cid:6) mitter is equipped with many built-in safety features, however good judgement, care, and common sense must be practiced to prevent accidents. In addition to high voltages and currents, the AM transmitters contain multiple circuit grounds with high ac and dc potentials with respect to the cabinet which is at earth potential. The potentials could cause serious injury or death if maintenance personnel simultaneously touch a circuit ground and the cabinet. As a result, operation of the transmitter with test equipment connected to transmitter output network, RF power module, RF combiner, or power supply components is extremely dangerous and must not be attempted. Therefore, never energize the transmitter with test equipment connected to the trans(cid:6) mitter output network, RF power module, RF combiner, or power supply components. Test equipment may be connected to the ECU circuit boards from the front of the transmitter using the supplied extender circuit board with power energized if required. TABLE OF CONTENTS PARAGRAPH PAGE NO. SECTION I GENERAL INFORMATION 1-1 INTRODUCTION 1-1 1-3 EQUIPMENT DESCRIPTION 1-1 1-4 GENERAL 1-1 1-6 EXCITER/CONTROL UNIT 1-1 1-12 OUTPUT NETWORK CHASSIS 1-3 1-16 TRANSMITTER CONFIGURATIONS 1-3 1-18 ACCESSORIES AND SPARE PARTS KITS 1-3 1-20 EQUIPMENT SPECIFICATIONS 1-3 SECTION II INSTALLATION 2-1 INTRODUCTION 2-1 2-3 UNPACKING 2-1 2-6 ENVIRONMENTAL REQUIREMENTS 2-1 2-8 INSTALLATION 2-1 2-10 EQUIPMENT PLACEMENT 2-1 2-12 RACK PREPARATION 2-1 2-14 EQUIPMENT INSTALLATION 2-2 2-15 TRANSMITTER MOUNTING 2-2 2-19 COMPONENT INSTALLATION 2-8 2-22 ECU CIRCUIT BOARDS 2-8 2-23 RF POWER MODULE 2-8 2-24 BATTERY INSTALLATION 2-8 2-25 CIRCUIT BOARD PROGRAMMING 2-8 2-27 EXCITER CIRCUIT BOARD 2-10 2-36 STEREO CIRCUIT BOARD 2-10 2-41 CONTROLLER CIRCUIT BOARD 2-13 2-54 POWER SUPPLY CIRCUIT BOARD 2-15 2-57 REMOTE CONTROL CONNECTIONS 2-15 2-58 GENERAL 2-15 2-83 WIRING 2-18 2-85 AUDIO INPUT CONNECTION 2-18 2-87 EXTERNAL STEREO RF INPUT 2-19 2-88 RF TRANSMISSION LINE CONNECTION 2-19 2-89 EXTERNAL INTERLOCK 2-19 2-90 MODULATION MONITOR 2-20 2-91 AC POWER CONNECTIONS 2-20 2-94 GROUND 2-20 2-95 TRANSMITTER SITE LIGHTNING PROTECTION 2-22 SYSTEM CHECKOUT 2-97 ANTENNA BALL-GAP LIGHTNING 2-22 ARRESTOR 2-101 ANTENNA-TUNING-UNIT SPARK-GAP 2-22 LIGHTNING ARRESTOR 2-102 TRANSMITTER SITE GROUNDING SYSTEM 2-24 2-103 CABLE PROTECTION 2-24 2-110 ANTENNA RF FEED LINE 2-24  Broadcast Electronics 1996 ALL RIGHTS RESERVED i Printed in the U.S.A. PARAGRAPH PAGE NO. 2-111 TRANSMISSION LINE AND ANTENNA 2-25 CHECKOUT 2-113 ANTENNA VSWR 2-25 2-114 COAXIAL SWITCH CONTROLLER. 2-25 2-115 ATU AND PHASOR CHECKOUT 2-25 2-116 INITIAL CHECKOUT 2-25 2-118 PRELIMINARY OPERATION AND ADJUSTMENT 2-26 2-123 POWER LEVEL AND MODULATION MONITOR 2-26 CALIBRATION ADJUSTMENTS 2-135 STEREO ADJUSTMENT 2-28 2-146 SINGLE CHANNEL LEVEL 2-30 SECTION III OPERATION 3-1 INTRODUCTION 3-1 3-3 CONTROLS AND INDICATORS 3-1 3-5 OPERATION 3-12 3-6 TURN-ON 3-12 3-7 OPERATION 3-12 3-14 TURN OFF 3-12 3-16 METERING 3-13 3-17 FORWARD POWER 3-13 3-18 REFLECTED POWER 3-13 3-19 POWER ADJUST 3-13 3-21 MONO/STEREO OPERATION 3-13 3-23 STEREO OPERATION 3-13 3-24 MONO OPERATION 3-13 3-27 PILOT CONTROL 3-14 3-29 EXCITER MONITOR OPERATION 3-14 3-31 MONO/STEREO INDICATIONS 3-14 3-32 INPUT SELECTION 3-14 3-33 POLARITY SELECTION 3-14 3-34 X10 AUTORANGE INDICATIONS 3-14 3-35 FAULT RESET 3-15 3-37 POWER SUPPLY FAULT RESET 3-15 3-39 OVER-CYCLE OFF 3-15 3-41 OVER-MODULATION PWM MUTE 3-15 3-43 TRANSMITTER MONITOR 3-15 3-45 BATTERY TEST 3-15 3-47 CONTROLLER PWM MUTE INDICATOR 3-15 3-49 CONTROLLER REMOTE FAIL(cid:6)SAFE 3-16 INDICATOR. 3-51 EXCITER LOCK INDICATOR 3-16 3-53 EXCITER +5V/+15V/-15V INDICATORS 3-16 3-55 STEREO EQUALIZATION INDICATORS 3-16 3-57 RF POWER MODULE INDICATORS 3-16 3-59 HIGH AC LINE CONDITIONS 3-16 SECTION IV THEORY OF OPERATION 4-1 INTRODUCTION 4-1 4-3 OVERALL OPERATION 4-1 ii PARAGRAPH PAGE NO. 4-5 POWER SUPPLY CIRCUITRY OPERATION 4-1 4-7 POWER SUPPLY CIRCUIT BOARD OPERATION 4-1 4-9 RF CIRCUITRY OPERATION 4-1 4-11 RF POWER MODULE MODULATOR CIRCUIT 4-1 BOARD OPERATION 4-13 RF POWER MODULE AMPLIFIER CIRCUIT 4-1 BOARD OPERATION 4-15 CONTROLLER CIRCUIT BOARD OPERATION 4-1 4-17 EXCITER CIRCUIT BOARD OPERATION 4-1 4-19 STEREO CIRCUIT BOARD OPERATION 4-1 SECTION V MAINTENANCE 5-1 INTRODUCTION 5-1 5-3 SAFETY CONSIDERATIONS 5-1 5-7 FIRST LEVEL MAINTENANCE 5-1 5-9 ROUTINE MAINTENANCE 5-2 5-10 INSPECTION AND CLEANING 5-2 5-11 CONTROLLER BATTERY 5-2 5-12 AIR FILTER 5-2 5-13 FLUSHING FAN 5-2 5-15 SPARK GAP 5-2 5-16 SECOND LEVEL MAINTENANCE 5-2 5-19 OVERALL TRANSMITTER 5-3 5-20 ELECTRICAL ADJUSTMENTS 5-3 5-21 TRANSMITTER FREQUENCY 5-3 RE-PROGRAMMING 5-23 TROUBLESHOOTING 5-3 5-25 TRANSMITTER INDICATORS 5-4 5-26 TRANSMITTER TROUBLESHOOTING 5-6 PROCEDURES 5-27 TRANSMITTER COMPONENT LOCATIONS 5-6 5-28 POWER SUPPLY CIRCUIT BOARD 5-11 5-29 SAFETY CONSIDERATIONS 5-11 5-31 REMOVING/INSTALLING A POWER SUPPLY 5-11 CIRCUIT BOARD 5-35 TROUBLESHOOTING PROCEDURES 5-11 5-37 RF POWER MODULE 5-17 5-38 SAFETY CONSIDERATIONS 5-17 5-40 RF POWER MODULE ASSEMBLY PROCEDURE 5-17 5-42 RF POWER MODULE EXCHANGE PROGRAM 5-18 5-44 TROUBLESHOOTING PROCEDURES 5-18 5-46 DIRECTIONAL COUPLER/LIGHTNING 5-20 DETECTION/LIGHTNING PROTECTION CIRCUIT BOARDS 5-47 SAFETY CONSIDERATIONS 5-20 5-49 ELECTRICAL ADJUSTMENTS 5-21 5-50 MODULATION CALIBRATION CONTROLS 5-21 5-51 DIRECTIONAL COUPLER NULL CONTROLS 5-21 5-52 TROUBLESHOOTING PROCEDURES 5-21 5-55 ECU 5-22 iii PARAGRAPH PAGE NO. 5-56 SAFETY CONSIDERATIONS 5-22 5-58 ECU CIRCUIT BOARD INSTALLATION/REMOVAL 5-22 5-61 ELECTRICAL ADJUSTMENTS 5-23 5-63 ECU EXTENDER CIRCUIT BOARD OPERATION 5-23 5-65 CONTROLLER CIRCUIT BOARD ADJUSTMENTS 5-23 5-66 P1 SET - P5 SET CONTROLS 5-23 5-67 FWD AND RFL CALIBRATIONS 5-24 5-68 ECU METER SWITCH CIRCUIT BOARD 5-24 ADJUSTMENTS 5-69 FORWARD POWER METER LOW AND HIGH 5-24 SCALE CALIBRATIONS 5-70 REFLECTED POWER METER LOW AND HIGH 5-24 SCALE CALIBRATIONS 5-71 FWD AND RFL CALIBRATIONS 5-24 5-72 STEREO CIRCUIT BOARD ADJUSTMENTS 5-24 5-73 STEREO ADJUSTMENT 5-24 5-74 EXCITER CIRCUIT BOARD ADJUSTMENTS 5-24 5-75 MODULATION CALIBRATION 5-24 5-76 PHASE MODULATOR CALIBRATION 5-24 5-77 SYMMETRY CONTROL 5-24 5-78 IPM CORRECTION CIRCUIT CONTROLS 5-25 5-79 SINGLE CHAN MONO LEVEL CONTROL 5-25 5-80 AVERAGE MODULATION LIMIT CONTROL 5-25 5-81 NEG LIMIT CONTROL 5-25 5-94 FREQUENCY CALIBRATION CONTROL 5-26 5-104 DISPLAY CIRCUIT BOARD ADJUSTMENTS 5-27 5-105 L/L+R AND R/L-R DISPLAY CALIBRATION 5-27 CONTROL 5-117 TROUBLESHOOTING PROCEDURES 5-27 5-119 COMPONENT REPLACEMENT PROCEDURE 5-32 5-125 INTEGRATED CIRCUITS 5-33 SECTION VI PARTS LIST 6-1 INTRODUCTION 6-1 SECTION VII DRAWINGS 7-1 INTRODUCTION 7-1 SECTION A APPENDIX Introduction A-1 LIST OF TABLES TABLE NO. TITLE PAGE NO. 1-1 ELECTRICAL CHARACTERISTICS 1-4 1-2 PHYSICAL AND ENVIRONMENTAL 1-7 CHARACTERISTICS 3-1 AM-1A/AM-500A CONTROLS AND INDICATORS 3-1 3-2 ECU CONTROLS AND INDICATORS 3-3 iv