NHB NRB4 Tim 1.0 PDF

NRB4 Beacon Monitor Receiver (190 kHz to 650 kHz and 1600 kHz to 1800 kHz) Single Sideband NRB4-0000 NRB4-0001 NRB4-0100 NRB4-0101

Double Sideband NRB4-1000 NRB4-1001 NRB4-1010 NRB4-1011 NRB4-1100 NRB4-1101 NRB4-1110 NRB4-1111

Variations included NAY08A/01 and /02

Technical Instructions Original Issue 1.0 .....................15 June 2004 Nautel Limited 10089 Peggy's Cove Road, Hackett's Cove, NS, Canada B3Z 3J4 T. 877 6 nautel (628835) or +1.902.823.2233 F.+1.902.823.3183 [email protected] U.S. customers please contact: Nautel Inc. 201 Target Industrial Circle, Bangor ME 04401 T. 877 6 nautel (628835) or +1.207.947.8200 F.+1.207.947.3693 [email protected] e-mail: [email protected] www.nautel.com © Copyright 2004 NAUTEL. All rights reserved.

Warranty by Nautel Limited/Nautel Inc. (herein after referred to as Nautel) Nautel Limited/Nautel Incorporated, hereinafter referred to as Nautel, guarantees all mechanical and electrical parts of the equipment for a period of thirteen months from date of shipment. 1.

A "Part Failure" shall be deemed to have occurred when the part has become defective, or does not have the characteristics required for the specified equipment performance: (a)

When the equipment is operated within the design parameters, and

(b)

When the equipment is installed and adjusted according to Nautel's prescribed procedures as stated in the instruction manual.

2.

Nautel shall provide replacements for all "Parts" at no cost to the Customer when they become defective during the warranty period, and upon the return of the defective part.

3.

In the event that a "Part" fails during the warranty period and causes damage to a sub-assembly that cannot be readily repaired in the field, the entire sub-assembly so damaged may be returned to Nautel for repair. The repairs will be made without charge to the Customer.

4.

Where warranty replacements or repair are provided under items 2 or 3, Nautel will pay that part of the shipping costs incurred in returning the part/assembly to the Customer.

5.

Warranty replacement parts and repair, which are provided under items 2 or 3, shall be guaranteed for a period of ninety days from date of shipment or until the end of the original warranty period, whichever occurs later.

6.

Nautel will not assume responsibility for any charges incurred by other than Nautel employees.

7.

Nautel shall have the privilege of investigating whether failures have been caused by factors beyond its control.

8.

Nautel shall in no event be liable for any consequential damages arising from the use of this equipment.

9.

When requesting a warranty repair/replacement, please provide complete and accurate information. Observe the instructions regarding 'Equipment Being Returned to Nautel' on page two of this warranty and provide the information requested.

10.

When ordering spare/replacement parts, please provide complete and accurate information. Refer to the parts list of the Repair manual for ordering information. Provide as much of the information requested for 'Equipment Being Returned to Nautel' on page two of this warranty as is practical. The information identified by an asterisk is the minimum required.

Nautel Limited 10089 Peggy's Cove Road Hackett's Cove NS Canada B3Z 3J4 T. 877 6 nautel (628835) or +1.902.823.2233 F. +1.902.823.3183 24hr. Answering Service 1.902.823.3900

Nautel Inc. 201 Target Industrial Circle Bangor ME USA 04401 T. 877 6 nautel (628835) or +1.207.947.8200 F. +1.207.947.3693

Customer Service Notice A ‘Technical Assistance’ and ‘Plug-in Module Exchange’ service is available to Nautel users.

NRB4 Technical Instructions Jun.15.04

Factory Support TECHNICAL ASSISTANCE Nautel's field service department provides telephone technical assistance on a 24 hour, seven days a week basis. Requests by other media (facsimile or e-mail) will be responded to the next working day if received after Nautel's normal working hours. Contact the appropriate field service centre from the following: U.S.A. customers use:

Nautel Incorporated 201 Target Industrial Circle Bangor, Maine 04401

T. +207-947-8200 (24 hours) or 877 6 nautel (628835) F. +207-947-3693

All other customers use:

Nautel Limited 10089 Peggy’s Cove Road, Hackett’s Cove, NS, Canada B3Z 3J4

T. +902-823-3900 (24 hours) or 877 6 nautel (628835) F. +902-823-3183 E-Mail [email protected] Web www.nautel.com

MODULE EXCHANGE SERVICE In order to provide Nautel customers with a fast and efficient service in the event of a problem, Nautel operates a factory rebuilt, module exchange service which takes full advantage of the high degree of module redundancy in Nautel equipment. This module exchange service is operated from Nautel’s factory in Bangor, Maine and Hackett’s Cove, Nova Scotia. These two locations allow us to provide a quick turn around service to keep our customers on the air. During the transmitter’s warranty period, up to thirteen months from shipment, repair and exchange of modules is at no charge to the customer. When the warranty has expired, a charge of 80% of the list price for all exchanged modules is made. If the faulty module is returned to Nautel within 30 days, a credit is issued reducing this charge by one half to 40% of the list price. U.S.A. customers are required to contact our Bangor, Maine facility. Canadian and overseas customers should contact our Nova Scotia, Canada facility.

EQUIPMENT BEING RETURNED TO NAUTEL For all equipment being returned to Nautel and all requests for repairs or replacements: • • • •

Obtain an RMA number from Nautel (you must have an RMA number to return equipment) Mark the item as 'field return' Mark the item with the RMA number assigned by Nautel Address the item to the appropriate Nautel facility

Complete and accurate information regarding the equipment being returned will ensure prompt attention and will expedite the dispatch of replacements. Refer to the nameplate on the transmitter and/or the appropriate module/assembly to obtain name, type, part and serial number information. Refer to the parts list of this manual or the appropriate service instruction manual for additional ordering information. The following information should accompany each request: * * * * * * *

Model of Equipment Serial number of Equipment Name of Part/Assembly Serial number of Part/Assembly Complete reference designation of Part/Assembly Nautel's part number of Part/Assembly OEM's part number of Part/Assembly Number of hours in Use Nature of defect Return shipping address * Denotes minimum information required to order spare/replacement parts

NRB4 Technical Instructions Jun.15.04

Safety Symbols General definitions of safety symbols used on equipment or in manuals. DANGER – HIGH VOLTAGE Indicates dangerous voltages (in excess of 72 volts), capable of causing a fatal electrical shock, are present on or near parts bearing this label.

GROUND (EARTH) Used with wiring terminals to indicate the terminal must be connected to earth ground before operating equipment. If power is supplied without grounding the equipment, there is a risk of receiving a severe or fatal electrical shock. Also used on electrical schematics to indicate a part that is connected to earth ground.

GROUND (PROTECTIVE or SAFETY) Used with protective (safety) conductor terminals to indicate the terminal must be connected to ground before operating the equipment. If power is supplied without grounding the equipment, there is a risk of receiving a severe or fatal electrical shock.

ELECTROSTATIC SENSITIVE Indicates part or assembly is or contains devices that are electrostatic sensitive. To prevent damage to these devices, ensure the handling procedures outlined in this manual are observed. WARNING

A WARNING denotes a hazard. It identifies an operating procedure, condition, etc. which, if not strictly observed or adhered to, could result in injury or death to personnel. Throughout the technical manual, a WARNING shall immediately precede the text to which it applies.

CAUTION

A CAUTION denotes a hazard. It identifies an operating procedure, condition, etc., which, if not strictly observed or adhered to, could result in damage to, or destruction of the equipment. Throughout the technical manual, a CAUTION shall immediately precede the text to which it applies.

NOTE

A NOTE denotes important information pertaining to an operating procedure, condition, statement, etc., which is essential to highlight. A NOTE may precede or follow the text to which it applies.

NRB4 Technical Instructions Jun.15.04

Artificial Respiration (Mouth-to-Mouth) (a) START MOUTH-TO-MOUTH BREATHING IMMEDIATELY. SECONDS COUNT. Do not wait to loosen clothing, warm the casualty, or apply stimulants.

1

(b) ASSESS RESPONSIVENESS OF CASUALTY. Do not jar casualty or cause further physical injury (Figure 1). (c) IF POSSIBLE, SEND A BYSTANDER TO GET MEDICAL HELP. Do not leave casualty unattended (Figure 2). (d) CHECK CAROTID PULSE (Figure 3).

2

(e) LAY CASUALTY ON HIS/HER BACK and place any available jacket or blanket under his/her shoulders. (f) TILT THE HEAD BACK AND LIFT THE CHIN to open the airway (Figure 4) (g) PINCH CASUALTY’S NOSE AND EXHALE TWO SLOW BREATHS INTO CASUALTY (Figure 5)

3

(h) REMOVE YOUR MOUTH and check for breathing (Figure 6) (i) CONTINUE GIVING ONE BREATH EVERY FIVE SECONDS without interruption. If any air is retained in the stomach after exhalation by casualty, press gently on stomach to expel air.

4 (j) IF CHEST DOES NOT RISE CHECK for obstruction in casualty’s mouth: clear foreign material using your finger, tissues, etc. Use chin lift and recommence mouth-to-mouth breathing. (k) WHILE MOUTH-TO-MOUTH BREATHING IS CONTINUED have someone else: - Loosen casualty’s clothing. - Keep the casualty warm.

5

(l) DON’T GIVE UP. Continue without interruption until the casualty is revived, or until a doctor pronounces the casualty dead. Four hours or more may be required. (m) DO NOT PROVIDE ANYTHING ORALLY while victim is unconscious.

NRB4 Technical Instructions Jun.15.04

6

General Rules for Treatment for Burns, Bleeding, and Shock 1. After casualty has revived, treat for injuries and shock. 2. Reassure casualty. 3. Try to make the person comfortable. 4. Keep the person reasonably warm but do not apply heat. 5. If thirsty, liquids may be given but no alcohol (no liquids should be given in cases of severe burns). 6. Treat burns or wounds. Infection danger in treating burns or wounds is very great so ensure hands are clean and do not handle affected areas more than necessary. 7. Do not apply salves, grease, etc. to burns. 8. Do not remove burned clothing that adheres to the skin or breaks blisters. 9. Cover the burn with a dry sterile dressing, piece of sheeting, etc. 10. Bandage lightly over blisters where care must be taken to cover and not to break. 11. If severe bleeding of wound, elevate affected area, except in the case of a fracture. 12. Expose wound and apply pressure. 13. Apply dressing, pad and bandage. 14. For burns and bleeding, immobilize injured part using splints if necessary and keep patient in restful position during removal to hospital or expert medical attention. 15. In all cases, send for medical aid immediately.

NRB4 Technical Instructions Jun.15.04

Electric Shock - Rescue Methods Electricity can damage the body in a number of ways. It may interfere with the proper functioning of the nervous system and the heart action, it can subject the body to extreme heat and can cause severe muscular contractions. The path that the current of electricity takes through the body is important. Currents that pass from hand to hand or from hand to foot may pass directly through the heart and upset its normal functioning. This threat to life is related to the amount of current or amperage that flows through a victim's body. Very little current (as little as 10 mA) can result in severe shock or death. Speed in the application of first aid measures is absolutely essential in cases of electrical injury. As soon as the victim is freed safely from the source of the electrical current, if breathing has stopped, artificial respiration should be commenced immediately. If the carotid pulse cannot be felt, external cardiac massage should be commenced simultaneously. Resuscitation should be continued until the patient is breathing on his own or until medical aid arrives. Survival rates can be quite high if cardiopulmonary resuscitation is started within 3 to 4 minutes of the injury being received.

Act At Once - Delay or Indecision May Be Fatal 1. Turn OFF the electrical source. 2. Commence artificial respiration immediately. 3. Treat for burns, bleeding and shock.

Removing a Casualty From Electrical Contact LOW VOLTAGE - 0 to 240 volts (household use) Switch off the current, if possible and time permits. If the switch cannot be located immediately and the supply is through a flexible cord or cable, the current may be shut off by removing the plug or even breaking the cable or wrenching free. Never attempt to shut off current by cutting cord with a knife or scissors. If the current cannot be shut off, the greatest care is necessary in removing the casualty. Household rubber gloves, rubber or plastic hose (if there is no water in them), a dry unpainted stick or a clean dry rope can be used to free victim. HIGH VOLTAGE - 240 volts and up (industrial machines and power lines) Do not touch any person or equipment in contact with a wire. Use a dry unpainted pole, clean dry rope, dry rubber or plastic water hose to separate the casualty from the contact. Keep as far away as possible. Do not touch the casualty until the casualty is free.

NRB4 Technical Instructions Jun.15.04

Toxic Hazard Warning There are devices used in this equipment containing beryllium oxide ceramic, which is nonhazardous during normal device operation and under normal device failure conditions. These devices are specifically identified in the equipment manual’s parts list(s). DO NOT cut, crush or grind devices because the resulting dust may be HAZARDOUS IF INHALED. Unserviceable devices should be disposed of as harmful waste.

NRB4 Technical Instructions Jun.15.04

Contents 1

GENERAL INFORMATION 1.1 1.2 1.3 1.4 1.5

1.6 1.7 1.8 2

Page

INTRODUCTION PURPOSE AND SCOPE OF MANUAL PURPOSE OF EQUIPMENT DESIGN CHARACTERISTICS 1.4.1 Emission Modes 1.4.2 Antenna Configuration MECHANICAL DESCRIPTION 1.5.1 Front Panel 1.5.1.1 DDS RF Amplifier PWB (A1) 1.5.1.2 Switch Bracket Assembly (A5) 1.5.2 Chassis 1.5.2.1 IF Amplifier/Monitor PWB (A2) 1.5.2.2 Audio Amplifier PWB (A3) 1.5.2.3 Power Supply Assembly TECHNICAL SUMMARY SPECIAL TOOLS AND TEST EQUIPMENT GLOSSARY OF TERMS

1-1 1-1 1-1 1-1 1-1 1-1 1-1 1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-1 1-1 1-1

THEORY OF OPERATION 2.1 2.2

2.3

2.4

INTRODUCTION SYSTEM OVERVIEW 2.2.1 RF Attenuator 2.2.2 RF Tuning 2.2.3 RF Amplifier/Oscillator 2.2.4 Envelope Detector and Audio Amplifier 2.2.5 Carrier Monitor 2.2.6 Modulation Monitor 2.2.7 -48 Volt Decoupling RECEIVER DESCRIPTION 2.3.1 RF Input 2.3.2 DDS RF Amplifier 2.3.3 IF Amplifier/Monitor 2.3.4 Audio Outputs 2.3.5 Carrier Alarm 2.3.6 Modulation Alarm 2.3.7 Power Supply (A4) DDS RF AMPLIFIER (A1) DESCRIPTION 2.4.1 RF Amplifier 2.4.2 Synthesized Local Oscillator 2.4.3 Mixer 2.4.4 Crystal Filter

NRB4 Technical Instructions Jun.15.04

2-1 2-1 2-1 2-1 2-1 2-1 2-1 2-1 2-1 2-2 2-2 2-2 2-2 2-2 2-2 2-2 2-2 2-3 2-3 2-3 2-3 2-3

Contents 2

Page

THEORY OF OPERATION (continued) 2.5

2.6 3

2-3 2-3 2-3 2-3 2-3 2-4 2-4 2-5 2-5 2-5

INSTALLATION AND PREPARATION FOR USE 3.1 3.2 3.3

3.4 3.5 3.6 3.7

3.8 4

IF AMPLIFIER/MONITOR DESCRIPTION (A2) 2.5.1 IF Amplifier 2.5.2 Detector 2.5.3 600 Ohm Balanced Audio 2.5.4 Carrier Monitor Meter 2.5.5 Carrier Monitoring 2.5.6 Modulation Monitor 2.5.7 Monitor Test 2.5.8 -48 Volt Dc Decoupling AUDIO AMPLIFIER (A3) DESCRIPTION

GENERAL TEST EQUIPMENT SITE REQUIREMENTS 3.3.1 Electrical Power 3.3.2 Antenna 3.3.3 External Remote Cabling UNPACKING USER DETERMINED INFORMATION USER SUPPLIED PARTS 3.6.1 Remote Alarm Monitor Capability INSTALLATION INSTRUCTIONS 3.7.1 Connection of Input Power Transformer Primary 3.7.2 Antenna Considerations 3.7.3 Installation PREPARATION FOR USE

3-1 3-1 3-1 3-1 3-1 3-1 3-1 3-1 3-1 3-1 3-3 3-3 3-3 3-3 3-3

OPERATING INSTRUCTIONS 4.1 4.2 4.3

GENERAL EMERGENCY SHUTDOWN PROCEDURE CONTROLS AND INDICATORS 4.3.1 Front Panel Controls and Indicators 4.3.2 DDS RF Amplifier PWB Controls 4.3.3 RF Amplifier/Monitor PWB Controls 4.3.4 Switch PWB Controls

NRB4 Technical Instructions Jun.15.04

4-1 4-1 4-1 4-1 4-1 4-1 4-1

Contents 4

OPERATING INSTRUCTIONS (continued) 4.4 4.5 4.6 4.7 4.8

5

PRESTART-UP CHECKS FIELD OPERATION OPERATIONAL INDICATIONS ABNORMAL INDICATION GO/NO GO TEST

4-1 4-1 4-2 4-2 4-2

ALIGNMENT, CALIBRATION AND TESTING 5.1 5.2 5.3 5.4 5.5

5.6 5.7 6

Page

GENERAL TEST EQUIPMENT OPERATION OF EQUIPMENT ALIGNMENT CALIBRATION 5.5.1 Pre-Calibration Procedures 5.5.2 Local Oscillator Calibration 5.5.3 Calibration of RF/IF Circuits 5.5.4 Carrier Alarm Check 5.5.5 Modulation Alarm Calibration 5.5.6 Audio Calibrations 5.5.7 Audio Distortion Check OPERATIONAL ADJUSTMENTS 5.6.1 NRB4 Configured With 0.2-3 Second Time Delay 5.6.2 NRB4 Configured With 0.5-60 Second Time Delay GO/NO GO TEST

5-1 5-1 5-1 5-1 5-1 5-1 5-1 5-2 5-2 5-3 5-4 5-4 5-5 5-5 5-7 5-8

MAINTENANCE 6.1 6.2

6.3 6.4

GENERAL MAINTENANCE AIDS 6.2.1 Parts Information 6.2.2 Wiring Information 6.2.3 Electrical Schematics 6.2.4 Mechanical Drawings SCHEDULED MAINTENANCE CORRECTIVE MAINTENANCE 6.4.1 Semiconductors and Integrated Circuits 6.4.2 Transistor Bias Voltages 6.4.3 Semiconductor Checking

NRB4 Technical Instructions Jun.15.04

6-1 6-1 6-1 6-1 6-1 6-1 6-1 6-1 6-1 6-1 6-1

Contents 7

8

Page

PARTS LIST 7.1 INTRODUCTION 7.2 FAMILY TREE 7.3 MANUFACTURERS INDEX 7.4 HOW TO LOCATE INFORMATION FOR A SPECIFIC PART 7.4.1 When Nautel Configuration Control Number Is Known 7.4.2 When Ref Des Is Known 7.5 REFERENCE DESIGNATION INDEXES 7.6 COLUMN CONTENT EXPLANATION 7.6.1 Use Code Column 7.6.2 Ref Des Column 7.6.3 Name of Part and Description Column 7.6.4 Nautel’s Part No Column 7.6.5 Vendor No. Column 7.6.6 OEM Code Column 7.7 OEM CODE TO MANUFACTURER CROSSREFERENCE

7-1 7-1 7-1 7-1 7-1 7-2 7-2 7-2 7-2 7-2 7-2

INTRODUCTION WIRING LISTS NOT PROVIDED PRINTED WIRING PATTERNS WIRE COLORS WIRING LISTS PROVIDED

8-1 8-1 8-1 8-1 8-1

ELECTRICAL SCHEMATICS 9.1 9.2 9.3 9.4 9.5 9.6

10

7-1

WIRING INFORMATION 8.1 8.2 8.3 8.4 8.5

9

7-1 7-1 7-1

INTRODUCTION COMPONENT VALUES GRAPHIC SYMBOLS LOGIC SYMBOLS REFERENCE DESIGNATIONS LOCATING LOGIC/SCHEMATIC DIAGRAMS

9-1 9-1 9-1 9-1 9-1 9-1

MECHANICAL DRAWINGS 10.1 INTRODUCTION 10.2 LOCATING ASSEMBLY DETAIL DRAWINGS 10.3 CONTENT OF MECHANICAL DRAWINGS

NRB4 Technical Instructions Jun.15.04

10-1 10-1 10-1

Contents

Page

LIST OF ILLUSTRATIONS 1-1 1-2 3-1 3-2 4-1 5-1 6-1 6-2 7-1 SD-1 SD-2 SD-3 SD-4 SD-5 MD-1 MD-2 MD-3 MD-4 MD-5 MD-6 MD-7

NRB4 Beacon Monitor Receiver Nautel’s Identification External Electrical Connections for Extended Alarm Operation External Electrical Connections for Remote Alarm Operation RF TUNE Capacitor Settings (End View) RF TUNE Capacitor Settings (End View) Semiconductor Checking Waveforms Family Tree – NRB4 Beacon Monitor Receiver Block Diagram – NRB4 Beacon Monitor Receiver Electrical Schematic – NRB4 Beacon Monitor Receiver Electrical Schematic – NAPA15 DDS RF Amplifier PWB Electrical Schematic – NAPC15 IF Amplifier/Monitor PWB Electrical Schematic – NAPA01 Audio Amplifier PWB Assembly Detail – NRB4 Beacon Monitor Receiver Hinged Panel (Front & Rear Views) Assembly Detail – NRB4 Beacon Monitor Receiver Chassis (Inside & Rear Views) Assembly Detail – NAPA15 DDS RF Amplifier PWB Assembly Detail – NAPC15 IF Amplifier/Monitor PWB Assembly Detail – NAPA01 Audio Amplifier PWB Assembly Detail – NAS22 +24/+12 V dc Power Supply Assy Assembly Detail – NRB4 Switch Bracket Assy (P/N 172-5116)

NRB4 Technical Instructions Jun.15.04

1-1 1-6 3-2 3-3 4-2 5-3 6-6 6-7 7-3 SD-1 SD-2 SD-3 SD-4 SD-5 MD-1 MD-2 MD-3 MD-4 MD-5 MD-6 MD-7

Contents

Page

LIST OF TABLES 1-1 1-2 3-1 3-2 4-1 5-1 6-1 6-2 7-1 SD-1 SD-2 SD-3 SD-4 SD-5 MD-1

NRB4 Beacon Monitor Receiver Nautel’s Identification External Electrical Connections for Extended Alarm Operation External Electrical Connections for Remote Alarm Operation RF TUNE Capacitor Settings (End View) RF TUNE Capacitor Settings (End View) Semiconductor Checking Waveforms Family Tree – NRB4 Beacon Monitor Receiver Block Diagram – NRB4 Beacon Monitor Receiver Electrical Schematic – NRB4 Beacon Monitor Receiver Electrical Schematic – NAPA15 DDS RF Amplifier PWB Electrical Schematic – NAPC15 IF Amplifier/Monitor PWB Electrical Schematic – NAPA01 Audio Amplifier PWB Assembly Detail – NRB4 Beacon Monitor Receiver

NRB4 Technical Instructions Jun.15.04

1-1 1-6 3-2 3-3 4-2 5-3 6-6 6-7 7-3 SD-1 SD-2 SD-3 SD-4 SD-5 MD-1

Release Control Record

Issue

Date

Reason

1.0

15 June 2004

Original Issue

NRB4 Technical Instructions Jun.15.04

NRB4 TECHNICAL INSTRUCTIONS Section 1

GENERAL INFORMATION 1.1 INTRODUCTION The subject beacon monitor receiver is a fix-tuned, one-channel, synthesizercontrolled receiver. It operates in the LF/MF (190 to 650 kHz and 1600 to 1800 kHz) band. A superheterodyne circuit provides high selectivity. 1.2 PURPOSE AND SCOPE OF MANUAL This manual provides the information necessary to install, operate and maintain NRB4 beacon monitor receivers. 1.3 PURPOSE OF EQUIPMENT The purpose of this equipment is to monitor a radiobeacon transmitter's performance. Aural, visual and remote alarms provide warning that: - Beacon output power has decreased by more than 3 dB. - Modulation has decreased by more than 3 dB. - Keying has stopped or become continuous.

1.4 DESIGN CHARACTERISTICS The beacon monitor receiver is fail-safe. Component failure cannot increase the possibility of the normal state persisting during unsatisfactory beacon performance. 1.4.1 Emission Modes The receiver maybe configured to monitor either amplitude modulated, double sideband, (A2A) emissions or amplitude modulated, single sideband, (H2A), emissions. 1.4.2 Antenna Configuration The receiver is designed to operate with an active antenna, such as Nautel NLA/2 antennas and has 12 V dc on the antenna mating connector. If a non-active antenna is used, this 12 V dc must be disconnected. 1.5 MECHANICAL DESCRIPTION The receiver is assembled in a chassis that fits into a size C (5-1/4 inch) opening in a standard type 19-inch rack and requires a minimum depth clearance of eight inches when installed. The chassis contains a hinged, front panel, four printed circuit boards and a power supply assembly. All external electrical connections are made at the rear of the chassis.

Figure 1-1 NRB4 Beacon Monitor Receiver NRB4 Technical Instructions Section 1 General Information

Page 1-1 Original Issue 1.0

1.5.1 Front Panel See Figure MD-1. The front panel contains operator controls and indicators and is hinged to permit access to the printed circuit board and power supply assemblies without removing the receiver from its mounting rack. It consists of a formed, heavy-gauge metal plate that is the mounting base for the electrical components. The components mounted on, or protruding through, the front panel are the POWER switch, a 1/4 ampere fuse, a 1 ampere fuse, the POWER on indicating lamp, two ALARM (CARRIER and MOD) lamps, a CARRIER LEVEL indicating meter, a loudspeaker, a TEST switch, and an AUDIO LEVEL adjustment potentiometer. The components mounted on the rear of the panel include the DDS RF amplifier PWB and switch bracket assembly. 1.5.1.1 DDS RF Amplifier PWB (A1) The DDS RF amplifier PWB (see Figure MD-3) contains the electrical components for the RF amplifier and DDS local oscillator circuits. Interconnection between the PWB and the front panel is made by mating electrical connectors. 1.5.1.2 Switch Bracket Assembly (A5) The switch bracket assembly (see Figure MD-7) is mounted on a formed metal support and contains the PWB mounted RF ATTENUATION (dB) selection switches, RF TUNE selection switches, FINE TUNE variable capacitor and associated components. 1.5.2 Chassis The chassis (see Figures MD-1 and MD-2) is a formed metal case that contains, in addition to the hinged front panel, the IF amplifier/ monitor PWB, audio amplifier PWB, power supply assembly, two relays and a terminal board that provides the electrical interface with external circuits.

Page 1-2 Original Issue 1.0

1.5.2.1 IF Amplifier/Monitor PWB (A2) The IF amplifier/monitor PWB (see Figure MD-4) contains the electrical components for the IF amplifier and monitoring circuits. Interconnection between PWB and chassis is made by mating electrical connectors. 1.5.2.2 Audio Amplifier PWB (A3) The audio amplifier PWB (see Figure MD-5) contains the electrical components for the audio amplifier circuits. Interconnection between the PWB and the chassis is made by mating electrical connectors. 1.5.2.3 Power Supply Assembly (A4) The power supply assembly (see Figure MD-6) contains the electrical components for the 12/28 V dc power supply circuits. Electrical interconnection between the assembly and the chassis is made via screw tightened connections to an assembly mounted terminal board. 1.6 TECHNICAL SUMMARY A Technical Summary is provided at in the specifications brochure at the front of this manual. 1.7 SPECIAL TOOLS AND TEST EQUIPMENT There are no special tools required. Table 1-1 - Test Equipment, lists the test equipment that is required to operate and maintain the subject receivers. 1.8 GLOSSARY OF TERMS Table 1-2 - Glossary of Terms, provides a list of unique terms, abbreviations and acronyms used in this publication.

NRB4 Technical Instructions Section 1 General Information

Table 1-1: Test Equipment NOMENCLATURE

PART/MODEL NUMBER OR TYPE (EQUIVALENTS MAY BE USED)

RF Signal Generator

Hewlett Packard, Model 606A

Frequency Counter

Advanced Instruments, TC11, with high impedance probe

Digital Multimeter

Fluke, Model 8030A

Oscilloscope

Tektronix, Model 321A Dc to 5 MHz with X10 probe Hewlett Packard, Model HP400E

Ac Voltmeter

APPLICATION

Provides RF signal during calibration and troubleshooting Measure RF frequency during calibration and troubleshooting only Measure voltages/ resistance during calibration and troubleshooting Monitor waveforms during testing and troubleshooting Precise measurement of RF voltages

Table 1-2: Glossary of Terms TERM Key-down Key-up NLA/2 NRB4 PWB

NRB4 Technical Instructions Section 1 General Information

DESCRIPTION Carrier is being modulated (sideband is being transmitted) Carrier not being modulated (sideband is not being transmitted) Nautel designation for an active ferrite receiving loop antenna Nautel designation for the beacon monitor receiver Printed Wiring (circuit) Board

Page 1-3 Original Issue 1.0

Nautel’s NRB4 family of beacon monitor receivers are identified by a multi-part identifier. This identifier is stamped on the receiver’s nameplate and identifies a specific configuration in accordance with the following:

Denotes Type of Emission 0 = Single Sideband 1 = Double Sideband

Denotes Time Delay for Modulation Alarm 0 = 0.2 to 3.0 seconds 1 = 0.5to 60 seconds

NRB4 X X X X

Denotes Input Power Source Voltage/ Frequency 0 = 115 V ac, 50/60 Hz 1 = 230 V ac, 50/60 Hz

Denotes Remote Audio Options 0 = 600 Ohm Remote Audio Installed 1 = No Remote Audio Installed

Figure 1-2 Nautel’s Identification

Page 1-4 Original Issue 1.0

NRB4 Technical Instructions Section 1 General Information

NRB4 TECHNICAL INSTRUCTIONS Section 2

THEORY OF OPERATION 2.1 INTRODUCTION The theory of operation for the NRB4 beacon monitoring receiver is presented in this section. The information is initially presented as a system overview based on the block diagram depicted in Figure SD-1. This information is then expanded and presented in more detail using the electrical schematics as the reference. 2.2 SYSTEM OVERVIEW The block diagram shown in Figure SD-1 provides an overview of the signal flow and control circuitry. The receiver is designed to work with the input from an active antenna with a nominal input impedance of 50/70Ω, such as the Nautel NLA/2 antenna. +12 V dc, at 50 milliamps, is phantom fed to the antenna through the RF input connector. 2.2.1 RF Attenuator The RF attenuator circuit selects the coarse signal level. Using DIP switches A5A1S1:1 through A5A1S1:5 and A5A1S2:1 through A5A1S2:5, the RF input signal can be attenuated from 0 to 80 dB in 20 dB steps. 2.2.2 RF Tuning RF tuning is accomplished by a seriestuned L/C circuit. It is tuned to pass the desired RF input frequency. The inductor (A5A1L2 or A5A1L3 and A5A1L4) and capacitor(s) (A5A1C3 through A5A1C7) used for tuning are switched in-circuit depending on the operating frequency. The RF signal is transformer coupled to match the input impedance of the RF amplifier.

NRB4 Technical Instructions Section 2 Theory of Operation

2.2.3 RF Amplifier/Oscillator The RF signal is amplified and switched through the appropriate low band (190 650 kHz) or high band (1600 - 1800 kHz) filter. It is then applied to the balance mixer. If the NRB4 is configured to monitor double sideband transmissions, the output of a DDS local oscillator, which is operating at 4.4MHz - ƒc, is also applied to the balanced mixer. The mixer suppresses the RF input and local oscillator frequencies and applies their sum to a 4.4 MHz crystal filter that passes 4.4 MHz ± 1000 Hz as the intermediate frequency. If the NRB4 is configured to monitor single sideband transmissions, the output of the synthesized local oscillator, which is operating at 4.4 MHz - (ƒc + 500 Hz) when upper sideband is being monitored or 4.4 MHz - (ƒc - 500 Hz) when lower sideband is being monitored, is also applied to the balanced mixer. The mixer suppresses the RF input and oscillator frequencies and applies their sum to a 4.4 MHz crystal filter that passes 4.4 MHz ± 750 Hz as the intermediate frequency. 2.2.4 Envelope Detector and Audio Amplifier The envelope detector produces a dc output that is proportional to the carrier level and a superimposed ac output that is proportional to the modulation level. The modulation ac is amplified by the audio amplifier and applied to the front panel speaker. It is also transformed and passed as an optional balanced 600Ω audio output. The carrier level dc is applied to the carrier monitor and the modulation level ac signal is applied to the modulation monitor.

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2.2.5 Carrier Monitor The carrier monitor detects a 3 dB reduction in carrier level. An alarm signal is generated if this condition persists for more than 15 seconds. The alarm signal inhibits the relay driver and de-energizes the carrier alarm relay. The carrier alarm relay provides a set of contacts for remote use. The carrier alarm lamp will turn on when the carrier alarm relay is de-energized. A power failure at the beacon monitoring receiver site will also cause the relay to de-energize. 2.2.6 Modulation Monitor The modulation monitor compares the modulation level to a pre-set reference level. If the modulation level is reduced by more than 3 dB or beacon keying stops, a modulation alarm signal will be produced after an adjustable time delay of 0.2 to 3.0 seconds or 0.5 to 60 seconds depending on the configuration of the NRB4. The adjustable time delay is set to generate an alarm signal if a key-up (no modulation) condition occurs for longer than the preset time delay. If a continuous modulation condition occurs, a modulation alarm signal will be generated after twenty seconds. The alarm signal is amplified by the relay driver and energizes the modulation alarm relay. The modulation alarm relay provides a set of contacts for remote use. The modulation alarm lamp will turn on when the modulation alarm relay is energized. 2.2.7 -48 Volt Decoupling Decouples any audio superimposed on the -48 V dc line, when it is connected for remote alarm operation (see Figure 3-2). 2.3 RECEIVER DESCRIPTION The following description provides a reader with an in-depth understanding of complex or non-obvious circuit functions. The descriptions are keyed to the functional blocks referenced in paragraph 2.2 and expand on the associated descriptions. See Figure SD-2.

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2.3.1 RF Input The RF input signal from an active antenna, such as the Nautel NLA/2, is applied to coaxial connector J1. The setting of shorting jumper A5A1E1 - determined by the antenna type connects inductor A5A1L1 to 12V or ground. Switches A5A1S1, A5A1S2 and associated resistors form selectable voltage divider networks to attenuate the RF signal from 0 dB to 80 dB in 20 dB steps. Inductor A5A1L2 or A5A1L3/A5A1L4 and capacitors A5A1C3 through A5A1C7 form a series-tuned bandpass filter circuit, with RF TUNE capacitor A5A1C2 providing the fine tuning control. The RF signal is coupled to the DDS RF amplifier by transformer A5T1. A5T1 and A5A1T1 provide 50Ω impedance matching to the DDS RF amplifier. 2.3.2 DDS RF Amplifier The DDS RF amplifier processes the RF signal and produces an intermediate frequency of 4.4 MHz. See paragraph 2.4 for a detailed description. 2.3.3 IF Amplifier/Monitor The IF amplifier/monitor detects the modulation component and monitors the level of the IF signal. The monitor circuit provides an audio output for local monitoring and a 600Ω balanced audio output for remote monitoring. It also controls the operation of carrier alarm relay K1 and modulation alarm relay K2. Refer to paragraph 2.5 for a detailed description. 2.3.4 Audio Outputs The modulation audio is passed as an optional 600Ω balanced output to terminal board TB1, for transmission via a 600Ω, 2-conductor telephone line for remote monitoring. The audio signal is also applied through AUDIO LEVEL potentiometer R16 to audio amplifier A3 for local monitoring on speaker LS1. Refer to paragraph 2.6 for a detailed description.

NRB4 Technical Instructions Section 2 Theory of Operation

2.3.5 Carrier Alarm Carrier alarm relay K1 is normally held energized by the application of a ground thru P2-5 from the carrier level monitoring circuit. When the carrier level decreases by 3 dB for more than 15 seconds, the ground from P2-5 to K1 will be removed and K1 will de-energize. CARRIER ALARM lamp DS2 will turn on. A set of K1's contacts is connected to terminal board TB1 for remote monitoring of the carrier alarm status. 2.3.6 Modulation Alarm Modulation alarm relay K2 is normally de-energized. When an abnormal modulation condition occurs, a ground will be applied thru P2-8 to K2. K2 will energize and the MOD ALARM lamp will turn on. A set of K2's contacts is connected to terminal board TB1 for remote monitoring of the modulation alarm status. 2.3.7 Power Supply (A4) The power supply provides regulated 28 V and 12 V supplies. The ac line voltage is applied to transformer T3, via ac line filter U1, when POWER switch S3 is set to ON. T3 has two 115 V ac primary windings. When the line voltage is 115 V ac, these windings must be connected in parallel; when it is 230 V ac, the windings must be connected in series (see Figure SD-2). The voltage on T3's secondary is full-wave rectified by diode bridge CR1/CR4 and smoothed by capacitor C2. Transistor Q1 is a series regulator that provides the regulated 28 V dc output. Zener diode (27 V) CR5 normally sets the base/emitter bias voltage. Transistor Q2 acts as a current limiter. When excessive current is drawn, Q2 will be forward biased by the voltage drop across resistor R2 and start to conduct, changing the biasing of Q1 and reducing the 28 V dc output. Transistor Q3 is a series regulator that provides the regulated 12 V dc output. It is shunt stabilized by the action of transistor Q4 and zener diode CR6. There is also provision to operate from a dc power supply. This power supply must provide between 24 V and 28 V and is applied between the V DC NRB4 Technical Instructions Section 2 Theory of Operation

IN (+) (TB1-14) and V DC IN (-) (TB1-15) terminals. The dc voltage is applied to A4TB1-1, via diode CR3 and fuse F2, when POWER switch S3 is set to ON. 2.4 DDS RF AMPLIFIER (A1) DESCRIPTION The operation of the DDS RF amplifier and oscillator circuits is as follows (see Figure SD-3): 2.4.1 RF Amplifier Transistor Q1 is connected as a grounded base amplifier with a fixed RF gain of 20 dB. Selectable capacitor/inductor combination C23/C28/L8, used for low band operation, forms a low-pass filter to reject IF and image signals. Selectable capacitor/inductor combination C17/C18/C24/C25/C29/C49/ L6/L7/L9, used for high band operation, forms a band-pass filter to reject IF and image signals. Transistor Q2 is used as a buffer/driver amplifier for the RF signal. Potentiometer R13 provides fine attenuation control for the RF carrier level. 2.4.2 Synthesized Local Oscillator Microprocessor U5, direct digital synthesizer U6 and associated components form the synthesized local oscillator. The operating frequency of the synthesizer depends on the type of transmission [double sideband (DSB), single sideband (upper, USB or lower, LSB)]. When configured to monitor double sideband transmissions, the synthesizer operates at 4.4 MHz - ƒc. When configured to monitor single sideband transmissions, the synthesizer operates at 4.4 MHz - (ƒc + 500 Hz) for upper sideband monitoring or 4.4 MHz - (ƒc – 500 Hz) for lower sideband monitoring. Shorting jumper E1 is configured for the type of transmission (USB/LSB or DSB) being monitored. The system clock frequency (10 MHz) is provided by U4. The local oscillator frequency is set using binary coded decimal (BCD) switches S1 through S5. Transistor Q4 and associated components are used as a buffer/driver amplifier for the digitized local oscillator signal.

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2.4.3 Mixer Transistors Q3 and Q5 and their associated components form a double balanced mixer for the RF and local oscillator signals. Transformers T1 and T2 are phase splitters for the RF input and local oscillator signals respectively. The configuration of the circuit suppresses both input frequencies and provides the sum and difference of the two, with both sidebands present, as the output. 2.4.4 Crystal Filter Crystal filter FL1 is a 4.4 MHz bandpass filter with a passband of ±1000 Hz for double sideband monitoring receivers or ±750 Hz for single sideband monitoring receivers. The passband defines the receiver bandwidth. Since the sum of the local oscillator and the RF signal will be within this frequency range, they are passed as the intermediate frequency. Transformer T3 provides impedance matching to the IF amplifier. 2.5 IF AMPLIFIER/ MONITOR (A2) DESCRIPTION The operation of the IF amplifier and monitor circuits is as follows (see Figure SD-4): 2.5.1 IF Amplifier Transistors Q1 through Q4 and their associated components form the IF amplifier. The transistors are connected as common, grounded-base amplifiers. Capacitors C2, C4 and C10 fine-tune the collector tank circuits. The IF output is taken from the collector of Q4. 2.5.2 Detector Diode CR2 is used as the AM detector. The resultant mean dc level is proportional to the carrier level, while the superimposed ac component is proportional to the modulation. Transistor Q5 is connected as an emitter follower to buffer the IF amplifier from the audio and monitoring circuits.

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2.5.3 600 Ohm Balanced Audio The modulation component of the detector output is applied through capacitor C25 to transistor Q9’s base. The amplitude of this signal is determined by the setting of potentiometer R16. Q9 is a class 'A' amplifier employed as a driver for transistor Q10, which is biased as a class 'A' amplifier. Transformer T1 provides an optional balanced 600Ω output across its secondaries for transmission over a 600Ω telephone line to a remote monitoring site. The audio signal is also passed by buffer amplifier transistor Q11 for local audio monitoring. 2.5.4 Carrier Monitor Meter The detected carrier dc level and superimposed modulation components are passed through resistor R17 to the front panel's CARRIER LEVEL meter for monitoring. The carrier level is set to 0 dB using RF ATTENUATION (dB) switches A5A1S1 and A5A1S2 (coarse adjustment) and SENSITIVITY potentiometer A1R13 (fine adjustment). 2.5.5 Carrier Monitoring The detected carrier dc level and superimposed modulation components are also passed through resistor R20 to the positive input of comparator U1C. The modulation component is shunted to ground by capacitor C28. The voltage at the junction of resistors R21/R23 is the -3 dB carrier level reference voltage. 2.5.5.1 Normally the detected carrier dc level will be greater than the -3dB reference threshold. The output of U1C will be high allowing capacitor C21 to fully charge through CR4 and resistor R26. Comparator U1D’s will be low, causing capacitor C23 to fully discharge through resistor R32. Comparator U1A input will be a positive differential and its output will be high, causing transistor Q7 to be forward biased. When Q7 is forward biased a ground is applied through P2-5 to carrier alarm relay K1, holding K1 energized.

NRB4 Technical Instructions Section 3 Theory of Operation

2.5.5.2 When the detected carrier dc level falls below the -3 dB reference threshold, U1C input will be a negative differential. The output of U1C will go low and capacitor C21 will discharge through resistor R27. R27/C21 form a relatively long discharge time constant. After approximately 15 seconds the voltage on C21 will fall below the reference voltage on the positive input of comparator U1D. U1D's input will be a positive differential and its output will go high. Capacitor C23 will charge through diode CR6 and resistor R29, which have a relatively short time constant. Comparator U1A input will be a negative differential and its output will go low, causing transistor Q7 to be reverse biased. When Q7 is reverse biased the ground is removed from P2-5 and carrier alarm relay K1 will de-energize. Relay K1 will de-energize if the RF input remains 3 dB below normal for more than 15 seconds. 2.5.5.3 When the detected carrier dc level returns to a level above the -3 dB reference threshold, U1C input will be a positive differential. The output of U1C will go high and capacitor C21 will charge through diode CR4 and resistor R26. R26 and C21 form a relative short time constant, therefore, the voltage on C21 will exceed the reference voltage on the positive input of comparator U1D in a very short time. Comparator U1D input will be a negative differential and its output will go low. Capacitor C23 will discharge through resistor R32. R32 and C23 form a relative long discharge time constant. After approximately 15 seconds the voltage on C23 will fall below the reference voltage on the positive input of comparator U1A, comparator U1A input will be a positive differential and its output will go high, causing transistor Q7 to be forward biased. When Q7 is forward biased, a ground is applied through P2-5 and carrier alarm relay K1 is energized. Carrier alarm relay K1 will energize if the RF input remains above the -3 dB threshold for more than 15 seconds. NRB4 Technical Instructions Section 2 Theory of Operation

2.5.6 Modulation Monitor The 1020/400 Hz modulation component of the detected signal is ac coupled to the negative input of comparator U1B via capacitors C29/C16 and potentiometer R12. The modulation amplitude is set, by R12, to overcome the -3 dB reference threshold, established by voltage divider network R11/R13/R15, on the positive input of comparator U1B when the modulation signal is within 3 dB of its normal level. The input to U1B will be at a positive differential during the portion of the negative going edge, of the 1000/400 Hz waveform, that exceeds the -3 dB reference and U1B's output will be a positive pulse. The application of this positive pulse to U2-6 will reset programmable timer U2's count to zero. The output of programmable timer U2 will go high when the counter is reset and will remain high until a count of 4096 (32,768) has been obtained. U2's clock frequency is controlled by resistor R24, potentiometer R25 and capacitor C20 and may be adjusted, by R25, to any frequency between 21,000 and 1350 Hz (48,000 and 546 Hz). This frequency range translates to a time interval of 0.2 to 3.0 seconds (0.5 to 60 seconds) before a count of 4096 (32,768) has been obtained and the output of the programmable timer at U2-8 goes low. The clock frequency is normally set to obtain a time interval - for the timer to count to 4096 (32,768) - that is greater than the longest key-up interval when the beacon is operating in its 'main' mode of operation; but less than extended key-up interval that identifies when the beacon is in its 'standby' operating mode. 2.5.6.1 In normal operation the output of the programmable timer, at U2-8, will never go low, since U2 will be reset prior to a count of 4096 (32,768).

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2.5.6.2 If any key-up interval exceeds the time delay established by potentiometer R25, such as when the beacon being monitored changes from its 'main' to 'standby' operating mode or modulation is lost, programmable counter U2 will not be reset. U2 will count to 4096 (32,768), its output at U2-8 will go low and remain low until a key-down condition occurs. When U2-8 goes low, U3D-11 will go high. Transistor Q6 will be forward biased and it will turn on, passing a ground through P2-8 to modulation alarm relay K2. Modulation alarm relay K2 will be energized and MOD ALARM lamp DS3 on the front panel will flash once every keying cycle if the beacon being monitored has changed to standby or will turn on and remain on until the next key-down condition if modulation has been lost. 2.5.6.3 If the modulation signal level falls below the -3 dB reference level, the reset pulse from comparator U1B will not be generated. Programmable counter U2's output will go low after 4096 (32,768) counts and remain low until the modulation signal level returns to a level that is greater than the -3 dB reference level. Modulation alarm relay K2 will be energized and MOD ALARM lamp DS3 on the front panel will turn on for the period of time the modulation signal level is less than the -3dB reference level. NOTE Counts indicated in parentheses are those used in the 0.5 to 60 second adjustable time delay. 2.5.6.4 Resistors R19/R28, capacitors C19/C22, diode CR5 and gate U3C form a continuous tone detection circuit. Capacitor C19 charges to +10 V through diode CR3 and resistor R18 (short time constant) during the positive pulse output of U1B and discharges thru resistor R19 during the period when the output of U1B is low. During key-down periods (continuous tone), capacitor C19 will be charged to +10 V and the output of gate U3C will be Page 2-6 Original Issue 1.0

held low. Capacitor C22 will discharge through resistor R28. Since C22/R28 form a relatively long time constant, the input to U3D-13 will be maintained high for a time delay of approximately 20 seconds. If a key-up (no modulation) condition occurs, capacitor C19 will discharge through resistor R19 (100 ms), U3C-10 will go high and C22 will charge to +12 V thru CR5. U3D-13 will go to or remain at a high. If a key-up (no modulation) condition occurs for a period longer than 100 milliseconds, within twenty seconds of the last occurrence of a key-up condition, U3D-13 will be maintained in a high state and a continuous tone alarm will not be generated. 2.5.6.5 If a key-up (no modulation) condition does not occur within twenty seconds of the previous occurrence, U3D-13 will be switched to a low state and be maintained in low state until the next occurrence of a 100 ms or greater key-up condition. When U3D-13 goes low, U3D-11 will go high. Transistor Q6 will be forward biased and it will turn on, passing a ground through P2-8 to modulation alarm relay K2. Modulation alarm relay K2 will be energized and MOD ALARM lamp DS3 on the front panel will turn on if a continuous tone (key-down) condition is maintained for more than twenty seconds. They will remain in this state until a key-up condition that is longer than 100 milliseconds occurs. 2.5.7 Monitor Test The application of a ground, from TEST switch S2, through P2-1 and resistor R14 to the junction of resistors R17/R20/R48 reduces the carrier level and the modulation level by 3 dB. The modulation alarm should function as described in paragraph 2.5.6.3 and MOD ALARM lamp DS3 shall turn on. The carrier alarm should function as described in paragraph 2.5.5.2 and CARRIER ALARM lamp DS2 shall turn on.

NRB4 Technical Instructions Section 2 Theory of Operation

2.5.8 48 Volt Dc Decoupling Transistor Q8 and its associated components are employed as an audio decoupling circuit. The circuit will appear as a relatively low resistance to the external -48 V dc, which may be used when the receiver is connected for remote alarm operation as depicted in Figure 3-2, but will appear to be a large capacitor to ground (Q8's hfe x C24 capacitance) for audio that has been superimposed on the -48 V dc line by the remote alarm circuit.

NRB4 Technical Instructions Section 2 Theory of Operation

2.6 AUDIO AMPLIFIER (A3) DESCRIPTION (See Figure SD-5) The local audio signal from P2-7 is applied through AUDIO LEVEL potentiometer R10 to the base of Q1. The level of the signal is determined by the setting of R10. Transistors Q1/Q2 act as a driver for transistors Q3 and Q4 which are connected in a push-pull configuration and drive the 45Ω, panel mounted speaker LS1. The gain of 10:1 is derived from the ratio of resistors R4 and R3. Capacitor C2 acts as a high frequency, roll-off capacitor.

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NRB4 TECHNICAL INSTRUCTIONS Section 3

INSTALLATION AND PREPARATION FOR USE 3.1 GENERAL This section contains the information required to unpack and install the beacon monitoring receiver and prepare it for use. 3.2 TEST EQUIPMENT The test equipment required is listed in Table 1-1. 3.3 SITE REQUIREMENTS The receiver is designed for mounting in a 5-1/4 inch opening in a standard 19-inch rack, with a minimum depth clearance of 8-inches. 3.3.1 Electrical Power The NRB4 can be operated from an ac power source (115 V ac or 230 V ac, 50/60 Hz; at 30 VA) or a dc power source (between 24 and 28 V). 3.3.2 Antenna An active antenna, such as the Nautel NLA/2 should be used as the RF signal source. The antenna and the receiver should be interconnected using a suitable RF, coaxial cable. If a non-active antenna is used, see paragraph 3.7.2. 3.3.3 External Remote Cabling Figures 3-1 and 3-2 depict typical external cable interconnection for extended or remote alarm operation of the receiver. The method of external connection is the responsibility of the user and is not included in this publication.

3.5 USER DETERMINED INFORMATION The user must determine the following: (a) The exact carrier frequency of the beacon transmitter to be monitored. If the NRB4 is configured to monitor single sideband transmissions, the sideband (upper or lower) that is to be monitored must also be determined. (b) The method of external alarm monitoring (extended or remote). (c) The type of antenna to be used (active or non-active). (d) The ac power source voltage (115 V ac or 230 V ac). A dc supply option is also provided. 3.6 USER SUPPLIED PARTS User is required to supply the following: 3.6.1 Remote Alarm Monitoring Capability The electrical components, interconnecting wiring and electrical power required for extended/remote alarm monitoring must be supplied by the user. Information other than that depicted by Figures 3-1 and 3-2 is beyond the scope of this document and is not included.

3.4 UNPACKING The receiver is shipped in a cardboard carton. There are no special unpacking instructions. The normal care and handling extended to electronic equipment should be observed.

NRB4 Technical Instructions Section 3 Installation and Preparation for Use

Page 3-1 Original Issue 1.0

MODULATION ALARM

T4

1

2

3

4

5

6

7

CARRIER ALARM

8

9

600 Ω AUDIO RED

GRN

OFF

ON

10

11

12

GRN

RED

ON

OFF

RECEIVER TERMINAL STRIP

13

ALARM LAMP DC SUPPLY

CARRIER ALARM LAMPS

MODULATION ALARM LAMPS

S1720031 V1

EXTENDED CONSOLE

Figure 3-1 External Electrical Connections for Extended Alarm Operation

MODULATION ALARM

T4

CARRIER ALARM DECOUPLER

1

2

3

4

5

6

7

8

9

10

11

12

13

RECEIVER TERMINAL STRIP -48V SUPPLY INPUT

REMOTE 600 Ω AUDIO

AUDIO TRANSFORMER

AUDIO TO CONSOLE

RED

GRN

OFF

ON

MODULATION ALARM LAMPS S1720033 V1

ALARM LAMP SUPPLY

GRN

RED

ON

OFF

CARRIER ALARM LAMPS

REMOTE CONSOLE

Figure 3-2 External Electrical Connections for Remote Alarm Operation

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NRB4 Technical Instructions Section 3 Installation and Preparation for Use

3.7 INSTALLATION INSTRUCTIONS Prepare the receiver for installation as follows: CAUTION The primary windings of input power transformer T3 must be correctly interconnected prior to connecting to an Ac power source. 3.7.1 Connection of Input Power Transformer Primary When an ac power source is used, connect or verify the primary windings of input power transformer T3 are properly connected for the input ac line voltage to be used. Refer to Table 8-2 for point-to-point wiring information and to Figure SD-2 for the electrical schematic.

NRB4 Technical Instructions Section 3 Installation and Preparation for Use

3.7.2 Antenna Considerations If an active antenna is used, such as the Nautel NLA2, shorting jumper E1 on switch PWB A5A1 should be installed in its +V DC position (shorting pins 2 and 3). If a non-active antenna is used, shorting jumper E1 on switch PWB A5A1 should be installed in its GND position (shorting pins 1 and 2). Refer to Figure MD-7 to locate shorting jumper A5A1E1. 3.7.3 Installation Install the receiver in a 19-inch mounting rack and secure using four screws. External electrical connections are made at the rear of the receiver (see Figure MD-2). Make extended/ remote alarm electrical connections to the terminal board as depicted in Figure 3-1 or Figure 3-2. 3.8 PREPARATION FOR USE Perform the Field Operation procedure described in paragraph 4.5.

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NRB4 TECHNICAL INSTRUCTIONS Section 4

OPERATING INSTRUCTIONS 4.1 GENERAL This section provides the information required to place the beacon monitoring receiver in operation. The receiver tuning and monitoring circuits are precisely calibrated during maintenance procedures and should not be adjusted during normal operation. The only controls that are intended for operator use are AUDIO LEVEL potentiometer R10 and TEST switch S2. The following instructions are intended for persons involved in testing or maintenance. 4.2 EMERGENCY SHUTDOWN PROCEDURE There are no special precautions to be taken if an emergency shutdown is required. Disconnect the source of power (ac or dc) from the beacon monitor receiver by placing the front panel POWER switch to its OFF position or turn off the power at its source (ac service entrance, dc power supply, etc.). 4.3 CONTROLS AND INDICATORS The following paragraphs list assemblies that contain controls and indicators, identify illustrations that depict their location and markings, and reference tables that describe their purpose and function.

4.3.2 DDS RF Amplifier PWB Controls Figure MD-3 depicts the controls on the DDS RF amplifier PWB (A1). Table 4-3 is keyed to the reference designations assigned to the controls and explains their functions. 4.3.3 IF Amplifier/Monitor PWB Controls Figure MD-4 depicts the controls on the IF amplifier/monitor PWB (A2). Table 4-3 is keyed to the reference designations assigned to the controls and explains their functions. 4.3.4 Switch PWB Controls Figure MD-7 depicts the controls on the switch PWB (A5A1). Table 4-3 is keyed to the reference designations assigned to the controls and explains their functions. 4.4 PRESTART-UP CHECKS There are no special start-up procedures that must be observed to turn the beacon monitoring receiver on.

4.3.1 Front Panel Controls and Indicators Figures MD-1 depicts the controls and indicators on the front panel. Table 4-2 is keyed to the reference designations assigned to the controls and indicators and explains their functions.

NRB4 Technical Instructions Section 4 Operating Instructions

Page 4-1 Original Issue 1.0

4.5 FIELD OPERATION Place the beacon monitoring receiver in operational service, by observing the following: (a)

Verify the PWB assemblies are properly installed, are securely fastened and their mating connectors are fully meshed.

(b)

Verify the desired external audio and alarm monitoring circuit is connected to the appropriate terminals of TB1 (Figure MD-2).

(c)

(d) -

Calibrate or verify the receiver has been calibrated in accordance with the instructions in Section 5. This calibration is performed at Nautel prior to equipment delivery. Verify the beacon transmitter being monitored is: transmitting the desired coded identification message. transmitting in the 'main' operating state. operating at the desired RF power level. operating at the desired modulation level.

(e)

Set RF ATTENUATION dB switches A5A1S1 and A5A1S2 for 0 dB.

(f)

Set RF TUNE switch A5A1S3 (see Figure MD-7) as tabulated in Table 5-1 for the frequency to be monitored.

(g)

Set SENSITIVITY potentiometer A1R13 (see Figure MD-3) fully clockwise.

(h)

Verify an active antenna, such as the Nautel NLA/2, is connected to the RF input connector (J1, see Figure MD-2). Ensure that the Gnd/+V DC shorting jumper (A5A1E1) has been installed in the +V DC position (shorting pins 2 and 3) as described in paragraph 3.7.2.

Page 4-2 Original Issue 1.0

(i)

Set FREQUENCY switches A1S1 through A1S5 to the transmitter’s RF carrier frequency. Note that A1S1 is the most significant digit (MHz) and A1S5 is the least significant digit (hundreds of Hz) (e.g., for 495kHz, A1S1 is set to ‘0’; A1S2 is set to ‘4’; A1S3 is set to ‘9’; A1S4 is set to ‘5’ position; and A1S5 is set to ‘0’ position. Enable the selected frequency by switching POWER switch S1 OFF and then ON.

(j)

Observe the CARRIER LEVEL meter (M1) reading on the front panel.

(k)

If the reading in step (j) is greater than 0 dB, adjust the SENSITIVITY potentiometer A1R13 for a meter reading of 0 dB. If necessary, add attenuation, in 20 dB increments, using RF ATTENUATION dB switches A5A1S1 and A5A1S2.

(l)

Adjust RF TUNE capacitor A5A1C2 for a peak (more positive) reading on CARRIER LEVEL meter M1.

NOTE If CARRIER LEVEL meter deflection is at maximum, it will be necessary to adjust the SENSITIVITY potentiometer and/or the RF ATTENUATION dB switches in order to observe peak meter deflection. (m)

If the peak carrier level occurs when the RF TUNE capacitor is near its maximum setting (Figure 4-1), increase the circuit capacitance by setting switch A5A1S3 for the next lower frequency range in Table 5-1 and readjust RF TUNE capacitor for a peak reading. If the peak carrier level occurs when the RF TUNE capacitor is near its minimum setting (Figure 4-1), decrease the circuit capacitance by setting switch A5A1S3 for the next higher frequency range in Table 5-1 and readjust RF TUNE capacitor for a peak reading.

NRB4 Technical Instructions Section 4 Operating Instructions

MINIMUM CAPACITANCE

MAXIMUM CAPACITANCE

Figure 4-1 - RF TUNE Capacitor Settings (End View)

(n)

Reset the CARRIER LEVEL meter (M1) reading to 0 dB by adjusting SENSITIVITY potentiometer A1R13 and, if necessary, RF ATTENUATION dB switches A5A1S1 and A5A1S2. Optimum performance will be obtained when the SENSITIVITY potentiometer is in its mid-range position.

4.6 OPERATIONAL INDICATIONS The local operational indicators are located on the front panel. Any extended or remote indicators are beyond the scope of this document since they are customer selected and installed. When the beacon transmitter being monitored is operating satisfactorily, the local indications should be as follows: (a) (b)

POWER lamp (DS1, Figure MD-1) shall be on. CARRIER LEVEL indicator (M1, Figure MD-1) should indicate the received carrier signal level relative to the signal level used as a reference during calibration. Any change from zero is an indication of a change in the received signal strength.

NOTE Changes in the CARRIER LEVEL meter indication may be the result of a variation in the atmospheric/ environmental conditions. In this case the change should not exceed ±1 dB. NRB4 Technical Instructions Section 4 Operating Instructions

(c)

CARRIER ALARM lamp (DS2, Figure MD-1) shall be off.

(d)

MOD ALARM lamp (DS3, Figure MD-1) shall be off.

4.7 ABNORMAL INDICATION When the transmitter being monitored is not operating satisfactorily, the indicators on the front panel will indicate the occurrence of the abnormal condition and the type of malfunction. Table --1 provides a listing of possible alarm indications and their probable causes. 4.8 GO/NO GO TEST Check the carrier/modulation alarm monitoring circuits as follows: (a)

Note CARRIER LEVEL meter indication.

NOTE If detected carrier signal has increased above level used as a reference during calibration, CARRIER LEVEL meter will indicate a +dB. When this occurs the go/no go test will not function correctly. (b)

If the indication noted in step (a) is +dB, continue to step (c). If not, proceed to step (e).

(c)

Note and record setting of the SENSITIVITY potentiometer (A1R13, Figure MD-3).

(d)

Adjust SENSITIVITY potentiometer A1R13 for 0 dB reading on CARRIER LEVEL meter M1.

(e)

Press and hold TEST switch (S2, Figure MD-1).

(f)

MOD ALARM lamp DS3 shall turn on after 0.2 - 3.0 second (0.5 - 60 seconds optional) time delay.

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(g)

CARRIER ALARM lamp DS2 shall turn on after approximately 15 seconds.

(j)

CARRIER ALARM lamp DS2 shall turn off after approximately 20 seconds.

(h)

Release TEST switch S2.

(k)

(i)

MOD ALARM lamp DS3 shall turn off after 100 milliseconds.

If SENSITIVITY potentiometer A1R13 setting was changed in step (d), return it to its original setting recorded in step (c).

Table 4-1 Alarm Indications/Probable Cause

CARRIER ALARM lamp DS2 on (MOD ALARM lamp DS3 may be on)

ALARM INDICATION

PROBABLE CAUSE Carrier level -3 dB or more from reference threshold (CARRIER LEVEL meter indication should be -3 dB or greater

MOD ALARM lamp DS3 on

(a)

Modulation level -3 dB from reference threshold

(b)

Modulation not present (confirm by monitoring speaker)

(c)

Modulation continuous (confirm by monitoring speaker)

MOD ALARM lamp DS3 flashes every keying cycle

Page 4-4 Original Issue 1.0

Mod alarm time delay set for a period that is less than the time between the last ident character of one frame and the first ident character of the next frame

NRB4 Technical Instructions Section 4 Operating Instructions

Table 4-2 Front Panel Controls and Indicators REF DES DS1

FIG No. MD-1

PANEL MARKING

FUNCTION

POWER

Indicates receiver is turned on and ac or dc input voltage is being applied when on.

DS2

MD-1

CARRIER ALARM

DS3

MD-1

MOD ALARM

F1

MD-1

POWER-AC Supply

Fuses the line of the ac source voltage (115 or 220 V ac) being applied to transformer T3 at 0.5 amperes.

F2

MD-1

POWER-DC Supply

Fuses the dc source voltage (between 24 and 28 V) being applied to +24/+12 V power supply assembly A4 at 1.0 amperes.

M1

MD-1

CARRIER LEVEL (-10 to +10 dB)

R10

MD-1

AUDIO LEVEL

S2

MD-1

TEST

S3

MD-1

POWER ON/OFF

NRB4 Technical Instructions Section 4 Operating Instructions

Indicates abnormal carrier level when on. Indicates abnormal modulation signal when on or flashing.

Displays the detected carrier signal level relative to the signal level used as a reference during calibration. Any change from zero is an indication of a change in the received carrier level. Adjusts speaker LS1’s audio level. Simulates a -3 dB reduction in the detected carrier and modulation levels to test monitoring circuits. Controls the application of source voltage (ac or dc) to the receiver.

Page 4-5 Original Issue 1.0

Table 4-3 Printed Wiring Board-Mounted Controls and Indicators REF DES A1E1

FIG No. MD-3

A1E2

MD-3

High/Low Band - Filter Input

A1E3

MD-3

High/Low Band - Filter Output

A1R13

MD-3

SENSITIVITY (0 - 10)

A1S1

MD-3

X 1000

A1S2

MD-3

X 100

A1S3

MD-3

X10

A1S4

MD-3

X1

A1S5

MD-3

X 0.1

A2C2 A2C4

MD-5 MD-5

Not Marked Not Marked

Page 4-6 Original Issue 1.0

PANEL MARKING

FUNCTION

Sideband Selection (DSB, USB, LSB)

Three-position shorting jumper that is configured according to the type of transmission being monitored to generate the correct DDS local oscillator frequency. Set to DSB (pins 2 and 3 shorted) for double-sideband transmissions. Set to LSB (pins 1 and 2 shorted) for single-sideband (lower) transmissions. Set to USB (pins 3 and 4 shorted) for single-sideband (upper) transmissions. Two-position shorting jumper that connects the input of the DDS RF amplifier’s appropriate low-pass filter circuit. Set to Low Band (pins 1 and 2 shorted) when the operating frequency is between 190 and 650 kHz. Set to High Band (pins 2 and 3 shorted) when the operating frequency is between 1600 and 1800 kHz. Two-position shorting jumper that connects the output of the DDS RF amplifier’s appropriate low-pass filter circuit. Set to Low Band (pins 1 and 2 shorted) when the operating frequency is between 190 and 650 kHz. Set to High Band (pins 2 and 3 shorted) when the operating frequency is between 1600 and 1800 kHz. Adjusts output signal level of the DDS RF amplifier. Precisely adjusted during calibration to establish carrier level reference. Rotary 10-position BCD switch that selects the carrier frequency’s thousands digit (either ‘0’ or ‘1’), in kHz. Rotary 10-position BCD switch that selects the carrier frequency’s hundreds digit, in kHz. Rotary 10-position BCD switch that selects the carrier frequency’s tens digit, in kHz. Rotary 10-position BCD switch that selects the carrier frequency’s units digit, in kHz. Rotary 10-position BCD switch that selects the carrier frequency’s tenths digit, in kHz. Peak tunes 1st IF amplifier stage to 4.4 MHz. Peak tunes 2nd IF amplifier stage to 4.4 MHz.

NRB4 Technical Instructions Section 4 Operating Instructions

Table 4-3 Printed Wiring Board-Mounted Controls and Indicators (continued) REF DES A2C10 A2R12

FIG No. MD-4 MD-4

A2R16

MD-4

A2R25

MD-4

A5A1S1 and A5A1S2

MD-7

RF ATTENUATION dB (0, 20, 40, 60, 80)

A5A1S3

MD-7

RF TUNE switch

A5A1C1

MD-7

RF TUNE (Fine)

A5A1E1

MD-7

Gnd/+V DC

NOTE:

PANEL MARKING

FUNCTION

Not Marked MOD ( 0-10)

Peak tunes 3rd IF amplifier stage to 4.4 MHz. Adjusts detected modulation signal to the desired level, relative to the modulation alarm threshold level, during calibration. Adjusts audio input signal level to audio amplifier.

AUDIO LEVEL (010) TIME DELAY (0-10)

Determines clock frequency of programmable counter U2 by adjusting oscillator R/C network. Provides variable time delay of 0.2 to 3.0 seconds (optionally, 0.5 to 60 seconds). Five-position DIP switches that provides coarse RF level control and permit the monitoring of high level RF signals. Attenuates input in 20 dB steps from 0 to 80 dB. Both switches must be set (closed) in the same position to pass the RF input signal. Eight-position DIP switch that selects the appropriate tuning components for the operating frequency. Refer to Table 5-1 to determine in-circuit components for a given frequency. Tunes RF input circuitry, in conjunction with capacitors selected by DIP switch A5A1S3, to desired frequency. Ensures carrier and sideband frequencies are within receiver's selectivity passband. Two-position shorting jumper that is installed depending on the type of receiving antenna. If an active antenna is used, such as the Nautel NLA2, shorting jumper should be installed in its +V DC position (shorting pins 2 and 3). If a non-active antenna is used, shorting jumper should be installed in its GND position (shorting pins 1 and 2).

REF DES items prefixed with: A1 are located on the DDS RF amplifier PWB. A2 are located on the IF amplifier/monitor PWB. A5A1 are located on the switch bracket assembly’s switch PWB.

NRB4 Technical Instructions Section 4 Operating Instructions

Page 4-7 Original Issue 1.0

Table 4-4 Test Point Functions REF DES A1TP1 A1TP2 A1TP3 A1TP4 A1TP5 A1TP6 A2TP1 A2TP2 A2TP3 A2TP4 A2TP5

FIG No. MD-3 MD-3 MD-3 MD-3 MD-3 MD-3 MD-4 MD-4 MD-4 MD-4 MD-4

Page 4-8 Original Issue 1.0

FUNCTION Measure/monitor RF input to DDS RF amplifier PWB. Monitor 10 MHz reference clock for DDS local oscillator. Ground (dc return) Ground for use with A1TP6 Monitor output of DDS local oscillator Monitor IF output of 4.4 MHz filter Monitor 4.4 MHz IF input to IF amplifier Ground (dc return) Measure/monitor envelope detector output (carrier and mod signals). Monitors state of modulation alarm relay drive: 28 V - alarm; 0V - no alarm. Monitors state of carrier alarm relay drive: 0 V - alarm; 28 V - no alarm.

NRB4 Technical Instructions Section 4 Operating Instructions

NRB4 TECHNICAL INSTRUCTIONS Section 5

ALIGNMENT, CALIBRATION AND TESTING 5.1 GENERAL This section contains step-by-step calibration and functional test procedures using integral meters and precision test equipment. It is recommended that personnel who are not familiar with detailed circuit theory or do not realize what impact a specific adjustment will have on other functions, follow instructions in order presented. WARNING The following procedures involve the interruption of the identification (Morse code) portion of the beacon transmission for short periods. They also interrupt operation of the monitoring facility. Calibration and testing should be co-ordinated with user agencies to ensure air safety is not affected. 5.2 TEST EQUIPMENT The test equipment required is listed in Table 1-1. 5.3 OPERATION OF EQUIPMENT Observe the instructions presented in Section 4. Detailed control and indicator information is presented in Tables 4-1 and 4-2. 5.4 ALIGNMENT Alignment is interpreted to mean the meshing or assembly of mechanical parts to very close fits or tolerances. There are no alignment procedures to be observed for the beacon monitoring receiver.

NRB4 Technical Instructions Section 5 Alignment, Calibration and Testing

5.5 CALIBRATION Calibration is defined as adjustment of electrical components to bring the operation of electrical circuits to within defined parameters. Initial calibration is performed using precision test equipment to simulate the RF input and to measure the frequency of the local oscillator. Final stages of calibration use the RF signal received from the beacon transmitter to be monitored as the RF input source. Calibrate the electrical circuits as follows: 5.5.1 Pre-Calibration Procedures Perform the following prior to attempting a calibration procedure: (a) Visually inspect the receiver to ensure all assemblies and components are free from obvious damage, are properly installed and securely fastened. (b) Determine the carrier frequency of the beacon transmitter to be monitored. (c) Connect or verify the power cord is connected to the appropriate power source. 5.5.2 LOCAL OSCILLATOR CALIBRATION (See Figure MD-3) Calibrate the frequency of the local oscillator as follows: (a) Connect a frequency counter to test point A1TP5 using high impedance test leads.

Page 5-1 Original Issue 1.0

Table 5-1 RF Tuning Chart FREQUENCY (kHz)

1

2

190 – 196 197 – 210 211 – 225 226 – 240 241 – 250 251 – 272 273 – 309 310 – 369 370 – 650 1600 – 1800

X O X O O X O X O O

X X O O O X X O O O

RF TUNE SWITCH (A5A1S3) SETTINGS

(b) Set FREQUENCY switches A1S1 through A1S5 to the transmitter’s RF carrier frequency. Note that A1S1 is the most significant digit (MHz) and A1S5 is the least significant digit (hundreds of Hz) (e.g., for 495 kHz, A1S1 is set to ‘0’; A1S2 is set to ‘4’; A1S3 is set to ‘9’; A1S4 is set to ‘5’ position; and A1S5 is set to ‘0’ position. (c) Configure SIDEBAND jumper A1E1 for the type of transmission (USB/LSB or DSB) being monitored. Install A1E1 between: pins 2 and 3 for double sideband (DSB). pins 1 and 2 for lower sideband (LSB). pins 3 and 4 for upper sideband (USB). (d) Turn on the receiver by switching POWER switch S1 to its ON position. Observe that POWER lamp DS1 is on.

3

4

O X O X O X O X X O O O O O O O O O O O X = closed, O = open

5

6

7

8

O O O O O O O O O O

O O O O O O O O O O

X X X X X X X X X O

O O O O O O O O O X

(e) Adjust screw on A1U4 (10 MHz oscillator) for a frequency counter reading of: 4.4 MHz - ƒc for DSB transmissions 4.4 MHz - (ƒc + 500 Hz) for USB transmissions 4.4 MHz - (ƒc – 500 Hz) for LSB transmissions (f) Disconnect frequency counter from A1TP5. 5.5.3 Calibration of RF/IF Circuits Calibrate the RF and IF amplifier circuits as follows: NOTE Disregard any alarm indications during tuning of the RF and IF stages. (a) Connect an RF signal generator to RF input connector J1, through a 0.1 uF capacitor, using a suitable coaxial cable. (b) Connect a frequency counter to measure the frequency of the RF signal generator.

Page 5-2 Original Issue 1.0

NRB4 Technical Instructions Section 5 Alignment, Calibration and Testing

(c) Configure High/Low Band jumpers A1E2 and A1E3 to connect to the appropriate low-pass filter circuit. 190-650 kHz - Low Band (pins 1 and 2 shorted) 1600-1800 kHz - High Band (pins 2 and 3 shorted) (d) Set RF ATTENUATION dB switches A5A1S1 and A5A1S2 for 20 dB. (e) Set SENSITIVITY potentiometer A1R13 (see Figure MD-3) to mid-range position (5). (f) Set RF TUNE switch A5A1S3 (see Figure MD-7) as tabulated in Table 5-1 for the frequency to be monitored. (g) Set the RF signal generator frequency to the carrier frequency (no modulation) of the beacon transmitter to be monitored, as measured by the frequency counter. (h) Adjust the RF signal generator output for an approximate zero reading on CARRIER LEVEL meter M1. (i) Adjust RF TUNE capacitor A5A1C2 and IF amplifier capacitors (A2C10, A2C4 and A2C2, Figure MD-4) for a peak (more positive) reading on CARRIER LEVEL meter M1. If the peak carrier level occurs when the RF TUNE capacitor is near its maximum setting (Figure 5-1), increase the circuit capacitance by setting switch A5A1S3 for the next lower frequency range in Table 5-1 and readjust RF TUNE capacitor for a peak reading. If the peak carrier level occurs when the RF TUNE capacitor is near its minimum setting (Figure 5-1), decrease the circuit capacitance by setting switch A5A1S3 for the next higher frequency range in Table 5-1 and then readjust RF TUNE capacitor for a peak reading.

NRB4 Technical Instructions Section 5 Alignment, Calibration and Testing

MINIMUM CAPACITANCE

MAXIMUM CAPACITANCE

Figure 5-1 - RF TUNE Capacitor Settings (End View)

NOTE Decrease RF signal generator power output to maintain a CARRIER LEVEL meter reading of zero while making adjustments in step (h). (j) Set RF signal generator output to 100 uV. (k) Adjust SENSITIVITY potentiometer A1R13 for a CARRIER LEVEL meter reading of zero. 5.5.4 Carrier Alarm Check There are no calibration adjustments for the carrier alarm. The following verifies the carrier alarm circuit is functioning within design tolerances. (a) Verify the requirements of paragraph 5.5.3 have been completed. (b) Verify the RF signal generator is connected to RF input connector J1, through a 0.1 uF capacitor and its output is being monitored by a frequency counter. (c) Verify the RF signal generator frequency is set to the carrier frequency (no modulation) of the beacon transmitter to be monitored, as measured by the frequency counter. (d) Set RF signal generator output to 100 uV.

Page 5-3 Original Issue 1.0

(e) Verify CARRIER LEVEL meter reading is zero.

(e) Verify CARRIER LEVEL meter reading is zero.

(f) CARRIER ALARM lamp DS2 shall be off.

(f) CARRIER ALARM lamp DS2 shall be off.

(g) Set the RF signal generator output to 75 uV (-2.5 dB) and wait for 20 seconds.

(g) Set MOD potentiometer (A2R12, Figure MD-4) fully counter clockwise.

(h) CARRIER ALARM lamp DS2 shall remain off.

(h) Set TIME DELAY potentiometer (A2R25, Figure MD-4) fully counter clockwise.

(i) Set the RF signal generator output to 67 uV (-3.5 dB).

(i) Set the RF signal generator for 80% modulation at 1000 Hz.

(j) CARRIER ALARM lamp DS2 shall turn on after 15 ±5 seconds.

(j) MOD ALARM lamp DS3 shall be on.

(k) Set the RF signal generator output to 75 uV (-2.5 dB). (l) CARRIER ALARM lamp DS2 shall turn off after 15 ± 5 seconds. 5.5.5 Modulation Alarm Calibration The calibration described in the following is used to verify the modulation alarm circuit is operating within design tolerances. Final calibration of this circuit is accomplished using an appropriate antenna and the RF signal received from the beacon to be monitored as the RF signal source. (a) Verify the requirements of paragraphs 5.5.3 and 5.5.4 have been completed. (b) Verify the RF signal generator is connected to RF input connector J1, through a 0.1 uF capacitor and its output is being monitored by a frequency counter.

(k) Press and hold TEST switch S2 (Figure MD-1) while simultaneously adjusting MOD potentiometer A2R12 clockwise until MOD ALARM lamp DS3 turns off. (l) Adjust MOD potentiometer A2R12 counter clockwise until MOD ALARM lamp DS3 just turns on. (o) Release TEST switch S2. (p) MOD ALARM lamp DS3 shall turn off and then turn on after 20 ±5 seconds. (q) Set TIME DELAY potentiometer A2R25 fully clockwise. (r) Set the RF signal generator output to 75 uV (-2.5 dB) (s) Momentarily switch the RF signal generator modulation off, then return it to on and wait for five seconds. (t) MOD ALARM lamp DS3 shall remain off.

(c) Verify the RF signal generator frequency is set to the carrier frequency (no modulation) of the beacon transmitter to be monitored, as measured by the frequency counter.

(u)

Momentarily switch the RF signal generator modulation off, then return it to on.

(d) Set RF signal generator output to 100 uV.

Page 5-4 Original Issue 1.0

NRB4 Technical Instructions Section 5 Alignment, Calibration and Testing

(v) Set the RF signal generator output to 67 uV (-3.5 dB) within ten seconds of step (u).

(j) Adjust AUDIO LEVEL potentiometer (A2R16, Figure MD-4) for an ac voltmeter reading of 2.45 volts rms (10 dBm).

(w) MOD ALARM lamp DS3 shall turn on after approximately 60 seconds (optionally three seconds).

(k) Switch RF signal generator modulation to off.

5.5.6 Audio Calibration Calibrate the audio circuits as follows:

(l) Ac voltmeter reading shall be less than 770 mV (0 dBm).

(a) Verify the requirements of paragraphs 5.5.3 through 5.5.5 have been completed.

(m) Set the RF signal generator for 30% modulation at 1000 Hz.

(b) Connect a 600Ω load between terminals 1 and 4 of the external monitor connection terminal block (TB1, Figure MD-2), with terminals 2 and 3 shorted. (c) Connect an ac voltmeter across the 600Ω load connected in step (b). (d) Verify the RF signal generator is connected to RF input connector J1, through a 0.1 uF capacitor and its output is being monitored by a frequency counter. (e) Verify the RF signal generator frequency is set to the carrier frequency (no modulation) of the beacon transmitter to be monitored, as measured by the frequency counter. (f) Set the RF signal generator for 30% modulation at 1000 Hz. (g) Set RF signal generator output to 5.0 uV. (h) Set RF ATTENUATION dB switches A5A1S1 and A5A1S2 to 0 dB. (i) Adjust SENSITIVITY potentiometer A1R13 for a CARRIER LEVEL meter reading of zero.

NRB4 Technical Instructions Section 5 Alignment, Calibration and Testing

(n) Verify AUDIO LEVEL potentiometer R10 controls speaker (LS1) volume. 5.5.7 Audio Distortion Check Check the audio distortion with the RF input signal at the design maximum as follows: (a) Verify the requirements of paragraphs 5.5.3 through 5.5.6 have been completed. (b) Verify the RF signal generator is connected to RF input connector J1, through a 0.1 uF capacitor and its output is being monitored by a frequency counter. (c) Verify the RF signal generator frequency is set to the carrier frequency (no modulation) of the beacon transmitter to be monitored, as measured by the frequency counter. (d) Verify a 600Ω load is connected between terminals 1 and 4 of the external monitor connection terminal block (TB1, Figure MD-2), with terminals 2 and 3 shorted. (e) Verify an ac voltmeter is connected across the 600Ω load.

Page 5-5 Original Issue 1.0

(f) Connect an oscilloscope across 600 Ω load. (g) Set RF ATTENUATION dB switches A5A1S1 and A5A1S2 to 80 dB. (h) Set RF signal generator output to 500 mV. (i) Set RF signal generator for 95% modulation at 1000 Hz. (j) Adjust SENSITIVITY potentiometer A1R13 and RF ATTENUATION dB switches A5A1S1 and A5A1S2 for a zero reading on CARRIER LEVEL meter, using RF ATTENUATION dB switches for coarse adjustment. (k) Adjust AUDIO LEVEL potentiometer A2R16 for an ac voltmeter reading of 2.45 V RMS (10 dBm). (l) Waveform on oscilloscope display should not show evidence of clipping. (m) Disconnect the test equipment (600 Ω load, oscilloscope, ac voltmeter, frequency counter and RF signal generator). 5.6 OPERATIONAL ADJUSTMENTS After any calibration using a signal generator input, certain controls must be readjusted with the receiver connected to its antenna and monitoring a beacon transmission. These adjustments ensure the receiver monitor circuits are precisely set to the reference levels required to detect abnormal transmissions from the beacon being monitored. 5.6.1 NRB4 Configured With 0.2 to 3 Second Time Delay (This option is NOT standard and is only used in conjunction with single sideband, longdash transmissions):

Page 5-6 Original Issue 1.0

(a) Verify the beacon being monitored is operating at the desired RF carrier and modulation levels and is transmitting in the 'main' operating state. (b) Verify an appropriate antenna such as the Nautel NLA/2 antenna is connected to the RF input connector (J1, Figure MD-2). CAUTION Do not adjust local oscillator 10MHz clock (A1U4, figure MD-3) or IF amplifier tuning capacitors (A2C2/A2C4/A2C10, Figure MD-4) in this procedure. Adjustment without the use of precision test equipment may result in erroneous monitoring results. (c) Adjust SENSITIVITY potentiometer A1R13 and RF ATTENUATION dB switches A5A1S1 and A5A1S2 for a CARRIER LEVEL meter reading of zero, during the continuous tone portion of the beacon transmission, using RF ATTENUATION dB switches as the coarse adjustment. (d) Adjust RF TUNE variable capacitor A5A1C2 (Figure MD-7) for a peak (more positive) reading on CARRIER LEVEL meter M1 during the continuous tone portion of the beacon transmitter. (e) Repeat step (c). (f) Set MOD potentiometer A2R12 fully clockwise. (g) Set TIME DELAY potentiometer A2R25 (Figure MD-4) fully counter clockwise. (h) CARRIER ALARM lamp DS2 shall be off or turn off within 15 ± 5 seconds.

NRB4 Technical Instructions Section 5 Alignment, Calibration and Testing

(i) MOD ALARM lamp DS3 shall be off. (j) Adjust AUDIO LEVEL potentiometer R10 for desired volume from speaker (LS1) to aurally monitor the coded identification portion of the beacon transmission. (k) Press and hold TEST switch S2 (Figure MD-1). (l) CARRIER LEVEL meter M1 reading shall decrease by 3 dB. (m) Adjust MOD potentiometer A2R12 counter clockwise until MOD ALARM lamp DS3 just turns on. (n) Release TEST switch S2. (o) Press and hold TEST switch S2. (p) MOD ALARM lamp shall be on continuously. (q) CARRIER ALARM lamp DS2 shall turn on after 15 ± 5 seconds. (r) Release TEST switch S2. (s) Adjust TIME DELAY potentiometer A2R25 clockwise, during keying sequence, until MOD ALARM lamp just flashes during the key-up periods immediately before and after the continuous tone portion of coded message. (t) Adjust TIME DELAY potentiometer A2R25 counter clockwise until MOD ALARM lamp DS3 just stops flashing during key-up periods immediately before and after the continuous tone portion of the coded message. (u) Have transmission from beacon being monitored changed to its 'standby' operating state.

NRB4 Technical Instructions Section 5 Alignment, Calibration and Testing

(v) MOD ALARM lamp DS3 shall flash once (normally every ten seconds), immediately before continuous tone portion of message. (w) Have the transmission from the beacon being monitored returned to 'main' operating state. (x) MOD ALARM lamp DS3 shall stop flashing. WARNING The beacon identification code is interrupted during the following tests. Notify user agencies prior to starting. Ensure testing time is held to a minimum. (y) Have the transmission from the beacon being monitored changed to continuous carrier (CW) operation. (z) MOD ALARM lamp DS3 shall turn on after the pre-set time delay [see step (s)]. (aa) Have the transmission from the beacon being monitored returned to normal operation. (ab) MOD ALARM lamp DS3 shall turn off. (ac) Change transmission from the beacon being monitored to continuous tone (MCW). (ad) MOD ALARM lamp DS3 shall turn on after 20 ±5 seconds. (ae) Have the transmission from the beacon being monitored returned to normal operation. (af) MOD ALARM lamp DS3 shall turn off.

Page 5-7 Original Issue 1.0

Optional Test: (ag) Connect or verify a 600 Ω load is connected to the external monitor connection terminal block (TB1, Figure MD-4) as depicted in Figure 3-1 or Figure 3-2. (ah) Connect an ac voltmeter across the load. (ai) Adjust AUDIO LEVEL potentiometer A2R16 for an ac voltmeter reading of 2.45 VRMS (10 dBm) during the period of continuous tone. (aj) Disconnect the ac voltmeter. 5.6.2 NRB4 Configured with 0.5 to 60 Second Time Delay (Standard Time Delay): (a) Verify the beacon being monitored is operating at the desired RF carrier and modulation levels and is transmitting in the 'main' operating state. (b) Verify an appropriate antenna such as the Nautel NLA/2 antenna is connected to the RF input connector (J1, Figure MD-2). CAUTION Do not adjust local oscillator 10 MHz clock (A1U4, Figure MD-3) or IF amplifier tuning capacitors (A2C2, A2C4 and A2C10, Figure MD-7) in this procedure. Adjustment without the use of precision test equipment may result in erroneous monitoring results. (c) Adjust SENSITIVITY potentiometer A1R13 and RF ATTENUATION dB switches A5A1S1 and A5A1S2 for a zero reading on CARRIER LEVEL meter, using RF ATTENUATION dB switches for coarse adjustment. (d) Adjust RF TUNE variable capacitor A5A1C2 (Figure MD-7) for a peak

Page 5-8 Original Issue 1.0

(more positive) indication on CARRIER LEVEL meter M1. (e) Repeat step (c). (f) Set MOD potentiometer A2R12 (Figure MD-4) fully clockwise. (g) Set TIME DELAY potentiometer A2R25 (Figure MD-4) fully counter clockwise. (h) CARRIER ALARM lamp DS2 shall be off or turn off with 15 ± 5 seconds. (i) MOD ALARM lamp DS3 shall flash during each keying cycle. (j) Adjust AUDIO LEVEL potentiometer for desired volume from speaker LS1 to aurally monitor the coded identification portion of the beacon transmission. (k) Press and hold TEST switch S2. (l) CARRIER LEVEL meter M1 indication shall decrease by 3dB. (m) Adjust MOD potentiometer A2R12 (Figure MD-4) counter clockwise until MOD ALARM lamp DS3 just turns on. (n) Release TEST switch S2. (o) Press and hold TEST switch S2. (p) MOD ALARM lamp DS3 shall be on continuously. (q) CARRIER ALARM lamp DS2 shall turn on after 15 ±5 seconds. (r) Release TEST switch S2. (s) Adjust TIME DELAY potentiometer A2R25 clockwise, during keying sequence, until MOD ALARM lamp DS3 does not flash during the key-up periods.

NRB4 Technical Instructions Section 5 Alignment, Calibration and Testing

WARNING The beacon identification code is interrupted during tests. Notify user agencies prior to starting. Ensure testing time is held to a minimum. (t) Have the transmission from the beacon being monitored changed to continuous carrier (CW) operation. (u) MOD ALARM lamp DS3 shall turn on after the pre-set time delay [see step (s)]. (v) Have the transmission from the beacon being monitored returned to normal operation. (w) MOD ALARM lamp DS3 shall turn off. (x) Change transmission from the beacon being monitored to continuous tone (MCW).

Optional Test: (ab) Connect or verify a 600-ohm load is connected to the external monitor connection terminal block (TB1, Figure MD-2) as depicted in Figure 3-1 or Figure 3-2. (ac) Connect an ac voltmeter across 600Ω load. (ad) Adjust AUDIO LEVEL potentiometer for an ac voltmeter indication of 2.45 V RMS (10 dBm) during the period of continuous tone. (ae) Disconnect ac voltmeter. 5.7 GO/NO GO TEST Paragraph 4.8 contains a detailed go/no go test procedure.

(y) MOD ALARM lamp DS3 shall turn on after 20 ± 5 seconds. (z) Have the transmission from the beacon being monitored returned to normal operation. (aa) MOD ALARM lamp DS3 shall turn off.

NRB4 Technical Instructions Section 5 Alignment, Calibration and Testing

Page 5-9 Original Issue 1.0

NRB4 TECHNICAL INSTRUCTIONS Section 6

MAINTENANCE 6.1 GENERAL This section contains scheduled and corrective maintenance information for the subject unit. Fault symptoms should be analyzed to determine the corrective action required. Ensure the beacon transmitter being monitored is operating satisfactorily prior to performing any maintenance action. 6.2 MAINTENANCE AIDS The following information is provided as a maintenance aid: 6.2.1 Parts Information Parts information for the beacon monitor receiver is provided in Section 7 of this manual. Refer to Section 7 preamble for details. 6.2.2 Wiring Information Wiring information for the beacon monitor receiver and its assemblies is provided in Section 8 of this manual. Refer to Section 8 preamble for details. 6.2.3 Electrical Schematics Electrical schematics for the beacon monitor receiver and its assemblies are provided in Section 9 of this manual. Refer to Section 9 preamble for details. 6.2.4 Mechanical Drawings Assembly detail drawings for the beacon monitor receiver and its assemblies are provided in Section 10 of this manual. Refer to Section 10 preamble for details. 6.3 SCHEDULED MAINTENANCE There are no rotary or moving mechanical parts that require periodic inspection and/or lubrication. Scheduled maintenance is limited

NRB4 Technical Instructions Section 6 Maintenance

to performing a visual inspection and an operational adjustment (see paragraph 5.6) at scheduled intervals. The recommended scheduled maintenance interval is three months. It is recommended that any scheduled maintenance of the receiver be performed in conjunction with scheduled maintenance of the beacon transmitter being monitored. 6.4 CORRECTIVE MAINTENANCE Corrective maintenance procedures consist of identifying and correcting defects or deficiencies identified during calibration and testing procedures. Tables 6-1 through 6-5 provide troubleshooting assistance information. 6.4.1 Semiconductors and Integrated Circuits Although transients, capacitive leakage currents, resistive leakage currents, and static discharges may not affect vacuum tubes, semiconductor devices can be severely damaged. It is important, therefore, that body static be discharged and external grounds and ac lines be disconnected to eliminate ground return paths before touching semiconductor terminals with hand tools; especially with soldering guns or irons (element windings have high capacitance to ground). (a) To avoid transients, never unsolder transistors, diodes or other semiconductor devices; never remove them from plug-in mountings without first de-energizing sources of element voltages.

Page 6-1 Original Issue 1.0

(b) Installation with reversed leads and polarity reversal of supply voltages may result in serious degradation or failure. Do not test any integrated or microelectronic circuit device without carefully observing input/output limitations and other applicable precautions. Minute semiconductor junctions are easily damaged rendering the entire device unserviceable.

(d) Do not obstruct the airflow in the vicinity of heat sinks. Loss of cooling and subsequent failure may result.

(c) Before attempting to use digital multimeters (ohmmeters) for semiconductor device testing or for circuit tracing where such devices (especially transistors) are present, take the following precautions (see Figure 6-1):

6.4.3 Semiconductor Checking After taking precautions outlined in paragraph 6.4.1, a semiconductor device may be easily checked without applying operating voltages by a simple resistance check of its junction(s). On a transistor, the base lead should be disconnected from all associated circuitry and a multimeter set to resistance - ohms x 1, connected between the collector/base and base/ emitter junctions. Two terminal devices can be checked in the same manner, often without removal from circuit. Typical meter readings are shown in Figure 6-1.

-

Beware of destructive high currents often present at low ohm ranges.

-

Beware of voltages on high ohm ranges which may be in excess of rated breakdown voltages of transistors, diodes, etc.

-

Determine the ohmmeter internal battery polarity present on the test leads (usually the reverse of the markings that apply only to the voltages or current ranges of multimeters). The internal voltages should not exceed 1.5 V (see Figure 6-1).

Page 6-2 Original Issue 1.0

6.4.2 Transistor Bias Voltages Tables 6-2 through 6-5 provide typical bias voltages on the transistor junctions. The voltages are typical when measured on a high impedance voltmeter with the receiver adjusted for normal operation.

NRB4 Technical Instructions Section 6 Maintenance

Table 6-1 Receiver Troubleshooting Chart SYMPTOM POWER lamp not on

when receiver is switched on Power supply fuse (F1 for ac; F2 for dc) blows when receiver is switched on

PROBABLE CAUSE a. No ac power b. c. d. a.

Fuse F1 blown Defective lamp DS1 Defective power supply Defect on +28/+12 volt supply rail. +28 volts, A2, A3 and relays, +12 volts, A1, A2.

b. Defective power supply

c. Wiring fault Meter M1 reading below 0 dB, no audio

a. Receiver mistuned b. Defective local oscillator c. Defective RF amplifier

d. Defective crystal filter e. Defective IF amplifier/ detector

NRB4 Technical Instructions Section 6 Maintenance

CORRECTIVE MEASURE a. Check ac line voltage on terminals of ac line filter U1 b. Replace fuse F1 c. Replace DS1 d. Check output of power supply A4 a. Disconnect +28 V and +12 V from A4TB1-1/3. If this stops fuse blowing, remove P1 from A1, P2 and P3 from A2 and P4 from A3. Replace wire to A4TB1. If fuse blows, check wiring. If necessary, replace each board (A1, A2 and A3) one at a time to find fault. b. Check transformer T3 power supply components (for ac input only) A4CR1 through A4CR4, A4Q1 through A4Q4 and C2 c. Check wiring from U1 through to A4TB1-5/6 a. Retune RF TUNE capacitor A5A1C2 b. Check oscillator output at A1TP5. Check 10 MHz clock A1U4 (A1TP2) c. Apply 5 mV RMS RF input to J1, attenuator A5A1S1 at zero dB and A1R13 fully counter clockwise. Check for 300 mV RMS at A1Q2 collector. Check components. d. Turn A1R13 to maximum. Check for 350 mV RMS at A1TP6. Change filter. e. Check bias voltages and components A2Q1 through A2Q5

Page 6-3 Original Issue 1.0

Table 6-1 Receiver Troubleshooting Chart (continued) SYMPTOM No audio output. Alarm status and M1 reading OK. Incorrect operation of carrier alarm function but correct audio output and modulation alarm Incorrect operation of modulation alarm function, but correct audio output and correct alarm No -48 volts to remote alarm indicators

Page 6-4 Original Issue 1.0

PROBABLE CAUSE a. Audio amplifier on A2 defective b. Audio amplifier A3 defective a. Defective carrier alarm circuitry b. No alarm LED indication

CORRECTIVE MEASURE a. Check for audio at P2-7. Check components. b. Check for output at P4-3. Check components. a. Check operation of comparator on A2 (U1A, U1C, U1D and Q7) b. Check relay K1

a. Defective modulation alarm circuitry

a. Check operation of comparator on A2 (U1B, trimmer U2, NAND gates U3C and U3D and Q6) b. Check relay K2

b. No alarm LED indication a. No -48 volts into receiver b. No -48 volts to relays K1 and K2 c. Defective interconnections on TB1

a. Check TB1-13 b. Check -48 volts decoupler A2 c. Check interconnections on TB1

NRB4 Technical Instructions Section 6 Maintenance

Table 6-2 Typical Transistor Bias Voltages for DDS RF Amplifier PWB A1

E B C

Q1 3.6 4.3 9.1

Q2 9.8 9.2 3.8

Q3 0.3 0.6 12.4

Q4 1.1 1.1 12.1

Q5 0.3 0.6 12.4

Table 6-3 Typical Transistor Bias Voltages for IF Amplifier/Monitor PWB A2 Q6

E B C

Q1

Q2

Q3

Q4

Q5

12 11.4 9.6

9.6 9 5.2

5.2 4.5 0

11.8 11.2 0.7

4.4 5.0 12.5

No Alarm 0 0 26.7

Alarm 0 0.7 0.1

Q7 No Alarm 0 0.7 0.1

Alarm 0 0 26.7

Q8

Q9

Q10

Q11

-

4.8 5.4 23.3

22.9 22.3 2.4

23.5 22.9 10.1

Table 6-4 Typical Transistor Bias Voltages for Audio Amplifier PWB A3

E B C

Q1 1.5 2 25.2

Q2 26.2 25.2 17.4

Q3 17 17.4 26.2

Q4 16.9 16.1 0

Table 6-5 Typical Transistor Bias Voltages for Power Supply Assembly A4

E B C

Q1 26.8 28 33.9

NRB4 Technical Instructions Section 6 Maintenance

Q2 26.6 26.8 28

Q3 12.5 13.7 26.7

Q4 6.1 6.8 13.7

Page 6-5 Original Issue 1.0

NPN TRANSISTOR

METER SHOULD READ BETWEEN 1000 AND 2000 OHMS

METER SHOULD READ

METER SHOULD READ

PNP TRANSISTOR

METER SHOULD READ BETWEEN 1000 AND 2000 OHMS

METER SHOULD READ

METER SHOULD READ

DIODE

METER SHOULD READ B2010082 V1

METER SHOULD READ BETWEEN 1000 AND 2000 OHMS

NOTE: THE POLARITY INDICATED ON THIS FIGURE MATCHES THE USUAL MULTIMETER IDENTIFICATION MARKINGS FOR USE WHEN MEASURING VOLTAGES AND CURRENTS. IN THE ABOVE EXAMPLE, THE ACTUAL METER INTERNAL VOLTAGE FOR RESISTANCE MEASUREMENTS IS THE REVERSE OF THAT SHOWN. ALTHOUGH THIS IS THE USUAL SITUATION WHEN MEASURING RESISTANCES, THE INTERNAL VOLTAGE OBTAINED FROM THE MULTIMETER BEING USED SHOULD BE DETERMINED IF DOUBT EXISTS. THE INTERNAL VOLTAGE SHOULD NOT EXCEED 1.5 VOLTS. Figure 6-1 Semiconductor Checking

Page 6-6 Original Issue 1.0

NRB4 Technical Instructions Section 6 Maintenance

A1TP1 – DDS RF Input RF signal generator input connected to RF input connector J1 through 0.1uF capacitor. Signal generator set to carrier frequency at 100 mV, modulated by 1000Hz at 50%. RF ATTENUATION (dB) switches S1 set to

'0'

0.1 volts/division 0.5 milliseconds/division A1TP6 - Crystal Filter Output RF signal generator input connected to RF input connector J1 through 0.1uF capacitor. Signal generator set to carrier frequency at 100 mV, modulated by 1000Hz at 50%. RF ATTENUATION (dB) switches S1 set to

'0'. SENSITIVITY potentiometer (A1R13) set fully

clockwise. 0.2 volts/division 0.5 milliseconds/division A2TP3 - Audio detector output RF signal generator input connected to RF input connector J1 through 0.1uF capacitor. Signal generator set to carrier frequency at 100 mV, modulated by 1000Hz at 50%. RF gain adjusted for '0' indication on CARRIER LEVEL meter (M1) 0.5 volts/division 0.5 milliseconds/division

Figure 6-2 Waveforms

NRB4 Technical Instructions Section 6 Maintenance

Page 6-7 Original Issue 1.0

A1TP5 - Local Oscillator Output

2.0 volts/division 0.1 microseconds/division

TB1-1 to TB1-4 - 600 Ohm Audio Output (A2A) RF signal generator input connected to RF input connector J1 through 0.1uF capacitor. Signal generator set to carrier frequency at 100 millivolts, modulated by 1000Hz at 50%. Receiver sensitivity set for a CARRIER LEVEL meter reading of '0'.

2.0 volts/division 0.5 milliseconds/division

TB1-1 to TB1-4 - 600 Ohm Audio Output (H2A) RF signal generator input connected to RF input connector J1 through 0.1uF capacitor. Signal generator set to carrier frequency at 100 millivolts, modulated by 1000Hz at 50%. Receiver sensitivity set for a CARRIER LEVEL meter reading of '0'.

2.0 volts/division 0.5 milliseconds/division Figure 6-2 Waveforms (continued) Page 6-8 Original Issue 1.0

NRB4 Technical Instructions Section 6 Maintenance

NRB4 TECHNICAL INSTRUCTIONS Section 7

PARTS LIST 7.1 INTRODUCTION This section contains reference designation indexes that provide descriptive and provisioning information for all electrical and mechanical parts that have been assigned a reference designation and form a part of the subject equipment.

Refer to the Table of Contents (List of Tables), for this manual and identify which table is the reference designation index for that assembly.

7.2 FAMILY TREE Figure 7-1 depicts the family tree for the subject equipment. It is based on the descending order of the reference designation hierarchy and identifies all assemblies that have been assigned a Nautel configuration control number.

7.4.2 When Ref Des Is Known Locate the information for a part when the full reference designation is known, as follows:

7.3 MANUFACTURER'S INDEX Table 7-1 provides a cross-reference from the original equipment manufacturers (OEM) codes to the manufacturer's name and address. The listing is sorted alphanumerically by the manufacturers' codes. 7.4 HOW TO LOCATE INFORMATION FOR A SPECIFIC PART To locate the information for a specific part, the user must know the reference designation assigned to the part. In addition, the user must know the Nautel configuration control number assigned to the assembly that contains the part or the full reference designation, which includes the reference designation of all higher assemblies. 7.4.1 When Nautel Configuration Control Number Is Known Locate the information for a part when the Nautel configuration control number is known, as follows:

NRB4 Technical Instructions Section 7 Parts List

Locate the part's reference designation in the identified table.

Enter the family tree depicted in Figure 7-1 with the full reference designation. Follow the family tree branches to the block that represents the lowest level assembly assigned a Nautel configuration control number. Delete the reference designation and then go to the table specified in the block with the balance of the reference designation. Locate the part's reference designation in the specified table. 7.5 REFERENCE DESIGNATION INDEXES Individual reference designation indexes are provided for all assemblies that have been assigned a Nautel configuration control number. To obtain the full reference designation for a specific part, the tabulated designation must be prefixed with the reference designation of the assembly that contains the part and the reference designation of all higher level assemblies. Notes at the end of each table identify possible higher level assemblies. The reference designation indexes are divided into six columns to aid in locating specific information.

Page 7-1 Original Issue 1.0

7.6 COLUMN CONTENT EXPLANATION The following paragraphs provide an explanation of the purpose and contents of each column in the reference designation indexes. 7.6.1 Use Code Column This column contains a symbol/letter code that is part of a configuration control management system. When there is more than one variation of an assembly, each variation will be assigned a code in this column and the parts that are unique to a variation will be assigned the same code. Parts that are common to all variations will not have an entry in this column. Notes at the end of each table explain the code's significance. 7.6.2 Ref Des Column The ref des column contains the reference designation for a specific part. These designations are assigned in accordance with the requirements of American National Standard Specification ANSI Y32.16. Each reference designation index is sorted and listed alpha/numerically according to the reference designations in this column. 7.6.3 Name of Part and Description Column This column contains the name and descriptive information for each part. The key word or noun is presented first, followed by the adjective identifiers. 7.6.4 Nautel's Part No. Column This column contains the Nautel part number assigned to each part. This number is Nautel's drawing number for Nautel manufactured parts, Nautel's configuration control number for assemblies that are under configuration control management or Nautel's inventory management number for purchased parts. 7.6.5 Vendor No. Column This column contains an original equipment manufacturer's part number for a part. A single part number is listed for each part, Page 7-2 Original Issue 1.0

even though there may be more than one known manufacturer. The listed number is Nautel's usual or preferred choice. The use of this number does not restrict Nautel from selecting and using commercial equivalents during manufacture, where their use will not degrade circuit operation or reliability. 7.6.6 OEM Code Column This column contains a five digit coded group as the original equipment manufacturer's (OEM) identifier. The code was extracted from Cataloging Handbook H4/H8 Commercial and Government Entity (Cage) Code. Manufacturers that were not listed in the catalog when this listing was compiled have been assigned a unique five-letter code. This code is assigned arbitrarily and has no other significance. The manufacturers identified for parts that have vendor part numbers are Nautel's normal supply source for that part. NOTE OEM code 37338 is listed for parts manufactured by Nautel or to a Nautel control drawing. United States of America customers should refer all replacement part orders to Nautel Maine Incorporated (OEM code 57655). 7.7 OEM CODE TO MANUFACTURER CROSS-REFERENCE The OEM (CAGE) codes listed in the reference designation lists are representative of the original equipment manufacturers of those parts. To determine a specific part’s manufacturer contact information, enter the five-character OEM (CAGE) code for that part in the following website: https://www.bpn.gov/bincs/begin_search.asp

After entering the OEM (CAGE) code number, manufacturer pertinent information (address, telephone number, fax number, etc.) will be displayed. Please contact Nautel if a part cannot be obtained (see also ONLINE PART QUOTES in the Warranty section of this manual). NRB4 Technical Instructions Section 7 Parts List

7.7.1 Manufacturer’s Index For customers without web access, Table 7-1 provides a cross-reference from the original equipment manufacturer’s (OEM) codes to the manufacturer’s name. The listing is sorted alphanumerically by the OEM code.

NRB4-0XXX BEACON MONITOR RECEIVER (SINGLE SIDEBAND)

A1

A2

A3

A4

DDS RF AMPLIFIER PWB NAPA15/01

IF AMPLIFIER/MONITOR PWB NAPC15/?

AUDIO AMPLIFIER PWB NAPA01

+24/+12V POWER SUPPLY NAS22

(SEE TABLE 7-3)

(SEE TABLE 7-4)

(SEE TABLE 7-5)

(SEE TABLE 7-6)

NRB4-1XXX BEACON MONITOR RECEIVER (DOUBLE SIDEBAND)

A1

A2

A3

A4

DDS RF AMPLIFIER PWB NAPA15/02

IF AMPLIFIER/MONITOR PWB NAPC15/?

AUDIO AMPLIFIER PWB NAPA01

+24/+12V POWER SUPPLY NAS22

(SEE TABLE 7-3)

(SEE TABLE 7-4)

(SEE TABLE 7-5)

(SEE TABLE 7-6)

F1720045 V1

Figure 7-1 Family Tree - NRB4 Beacon Monitor Receiver

NRB4 Technical Instructions Section 7 Parts List

Page 7-3 Original Issue 1.0

Table 7-1 Manufacturer’s Code to Address Index 00213 00779 00853 02660 04713 07263 08372 09353 09482 13150 14552 15513 27014 29990 3AE22 32979 33062 34361 37338 44655 45496 50434 55459

Struthers-Dunn LLC Tyco Electronics Corporation Cornell Dubilier Electronics Div. Amphenol Corporation Freescale Semiconductor Inc. Fairchild Semiconductor Corp. Eaton Yale Ltd, Cutler-Hammer Industrial Controls C&K Components Incorporated Tyco Electronics Canada Limited Axsys Technologies Incorporated Microsemi Corporation Data Display Products National Semiconductor Corp. American Technical Ceramics Northern Piezo Devices Inc. Northrup Grumman Space & Missions Corporation Ferronics Incorporated Omron Electronics Incorporated Nautel Limited Heico Ohmite Holding LLC Digital Systems Avago Technologies US Inc. Eaton Corporation

Page 7-4 Original Issue 1.0

56289 57655 59474 5M411 62483 63426 72982

Sprague Electric Company Nautel Incorporated Jeffers Electronics Incorporated Harris Semiconductor Division Densitron Development Inc. NKK Switches of America Inc. Erie Specialty Products Inc.

73138 73831 73949 74199 75042 75915 80294 81073 82389

BI Technologies Corporation Hammond Mfg Company Limited Guardian Electric Mfg Company Quam Nichols Company TRW Incorporated (see 32979) Littelfuse Incorporated Bourns Incorporated Grayhill Incorporated Switchcraft Incorporated

89473 91637 96095 97525 99800 0VUE0 SR893

General Electric Dist. Corporation Vishay-Dale Electronics Inc. AVX Corporation Transico Incorporated American Precision Industries Raltron Electronics Shaffner Holding AG

NRB4 Technical Instructions Section 7 Parts List

Table 7-2 Reference Designation Index

NRB4 Technical Instructions Section 7 Parts List

Page 7-5 Original Issue 1.0

Table 7-2 Reference Designation Index (continued)

Page 7-6 Original Issue 1.0

NRB4 Technical Instructions Section 7 Parts List

Table 7-2 Reference Designation Index (continued)

NRB4 Technical Instructions Section 7 Parts List

Page 7-7 Original Issue 1.0

Table 7-2 Reference Designation Index (continued)

Page 7-8 Original Issue 1.0

NRB4 Technical Instructions Section 7 Parts List

Table 7-2 Reference Designation Index (continued)

NRB4 Technical Instructions Section 7 Parts List

Page 7-9 Original Issue 1.0

Table 7-2 Reference Designation Index (continued)

Page 7-10 Original Issue 1.0

NRB4 Technical Instructions Section 7 Parts List

Table 7-2 Reference Designation Index (continued)

NRB4 Technical Instructions Section 7 Parts List

Page 7-11 Original Issue 1.0

Table 7-2 Reference Designation Index (continued)

Page 7-12 Original Issue 1.0

NRB4 Technical Instructions Section 7 Parts List

Table 7-2 Reference Designation Index (continued)

NRB4 Technical Instructions Section 7 Parts List

Page 7-13 Original Issue 1.0

Table 7-2 Reference Designation Index (continued)

Page 7-14 Original Issue 1.0

NRB4 Technical Instructions Section 7 Parts List

Table 7-2 Reference Designation Index (continued)

NRB4 Technical Instructions Section 7 Parts List

Page 7-15 Original Issue 1.0

NRB4 TECHNICAL INSTRUCTIONS Section 8

WIRING INFORMATION 8.1 INTRODUCTION This section contains wiring information for hard-wired assemblies of the subject unit. Refer to Table 8-1 for an itemized listing of assemblies that have wiring lists. 8.2 WIRING LISTS NOT PROVIDED Separate wiring lists are not provided for some assemblies. These assemblies include: 8.2.1 Assemblies that have separate maintenance manuals are not provided. Refer to the associated maintenance manual for detailed wiring information of these assemblies. 8.2.2 Assemblies that have their wiring information adequately depicted/tabulated on their assembly detail drawings are not provided. Refer to the associated assembly detail drawing detailed wiring information of these assemblies.

8.4 WIRE COLORS Every effort is made to manufacture the assemblies using wire that is the color tabulated in the 'Code' column of the wiring list tables. In some instances, a white wire will be substituted. In this case identification must be determined by locating the assigned identification number. 8.5 WIRING LISTS PROVIDED The wiring lists tabulated in Table 8-1 are provided. These lists provide, non-printed wiring pattern, point-to-point (source/destination) interconnecting information. Table 8-1 Wiring Lists Provided Table 8-2

Wiring List – NRB4 Beacon Monitor Receiver

8.3 PRINTED WIRING PATTERNS The need for printed wiring pattern information is beyond the scope of this manual, therefore, detailed printed wiring patterns for printed circuit boards are not included.

NRB4 Technical Instructions Section 8 Wiring Information

Page 8-1 Original Issue 1.0

Table 8-2 Wiring List – NRB4 Beacon Monitor Receiver SOURCE XK1-14 (Anode) XK2-14 (Anode) TB1-14 (Anode) XK1-1 XK2-5 XDS1-Cathode U1-L S3-3 XF1-Side A4TB1-4 A4TB1-1 A4TB1-1 A4TB1-3 A4TB1-3 A5A1-A P2-2 P2-4 P2-3 P2-8 P2-5 P3-1 P3-2 P3-3 P3-4 XK1-2 XK1-10 XK1-6 XK1-4 XK1-9 XK1-9 XK2-2 XK2-10 XK2-6 XK2-8 P2-12 P2-11 A5T1-4 A5T1-3 S2-1 J1-Centre J1-Ground A4TB1-2 P2-7 R10-2 A4TB1-1 P4-3 P4-2 R10-3 Page 8-2 Original Issue 1.0

DESTINATION XK1-13 XK2-13 E1 XK1-4 XK2-8 Ground S3-5 XF1-Centre TT1 C2 (+) XDS1-Anode P2-9 P2-10 P1-8 P1-8 M1 (+) TB1-12 TB1-13 XK2-14 XK1-14 TB1-1 TB1-2 TB1-3 TB1-4 TB1-11 TB1-10 TB1-9 XDS2-Anode P2-9 XK2-9 TB1-8 TB1-7 TB1-6 XDS3-Anode P1-1 P1-2 P1-4 P1-3 P2-1 A5A1-B A5A1-C P1-3 R10-1 P4-1 P4-4 LS1-2 Ground Ground

CODE Diode Diode Diode Resistor Resistor Resistor 1 Grey 2 Grey 3 Grey 4 White 5 White 6 White 7 White 8 White 9 White 10 White 11 White 12 White 13 White 14 White 15 White 16 White 17 White 18 White 19 White 20 White 21 White 22 White 23 White 24 White 25 White 26 White 27 White 28 White 29 White Shield 30 White Shield 31 White 32 Core Shield 33 Not Used 34 Black 35 Not Used 36 White 37 White 38 White 39 White 40 Black 41 Black

SIZE 1N4938 1N4938 1N5624 1800 Ohms 1800 Ohms 1800 Ohms 18 18 18 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 RG58U

REMARKS CR1 CR2 CR3 R11 R12 R13

1-Conductor Shielded 1-Conductor Shielded Coaxial Cable

22 22 22 22 22 22 22 NRB4 Technical Instructions Section 8 Wiring Information

Table 8-2 Wiring List – NRB4 Beacon Monitor Receiver (continued) SOURCE S2-2 C2(-) XF2-Centre TB1-15 E1 XK1-13 XK2-13 LS1-1 M1(-) TB1-5 XDS2-Cathode XDS3-Cathode S3-4 Ground (Frnt Pnl) U1-E

DESTINATION Ground Ground A4TB1-1 A4TB1-2 S3-6 XK1-9 XK2-9 Ground Ground Ground Ground Ground SF2-Side Ground Safety Ground

T3-Green T3-Green T3-Grn/Yel T3-Orange T3-Black T3-Brown T3-White

115 V ac Line Voltage Operation A4TB1-5 Green A4TB1-6 Green Not Connected Grn/Yel U1-Neutral Orange TT1 Black TT1 Brown U1-Neutral White -

Lead of T3 Lead of T3 Lead of T3 Lead of T3 Lead of T3 Lead of T3 Lead of T3

T3-Green T3-Green T3-Grn/Yel T3-Orange T3-Black T3-Brown T3-White

230 V ac Line Voltage Operation A4TB1-5 Green A4TB1-6 Green Not Connected Grn/Yel U1-Neutral Orange TT1 Black TT2 Brown TT2 White -

Lead of T3 Lead of T3 Lead of T3 Lead of T3 Lead of T3 Lead of T3 Lead of T3

NRB4 Technical Instructions Section 8 Wiring Information

CODE 42 Not Used 43 Black 44 Not Used 45 Black 46 White 47 Black 48 White White White Black Black Black Black Black White Grn/Yel Grn/Yel

SIZE

REMARKS

22 22 22 22 18 22 22 22 22 22 22 22 18 14 14

Jumper Jumper Jumper Jumper Jumper Jumper Jumper Jumper

Page 8-3 Original Issue 1.0

NRB4 TECHNICAL INSTRUCTIONS Section 9

ELECTRICAL SCHEMATICS 9.1 INTRODUCTION This section contains electrical schematics for the subject equipment. Simplified electrical schematics, block diagrams and/or logic diagrams may be included. Refer to Table 9-1 for an itemized listing. Schematics for assemblies that have separate maintenance manuals are not included. Refer to the appropriate maintenance manual for the electrical schematic(s) of these assemblies. 9.2 COMPONENT VALUES Unless otherwise specified on the logic/schematic diagram: -

Resistor values are shown in ohms. (K = 1 000 and M = 1 000 000).

-

Capacitor values are shown in microfarads (uF).

-

Unidentified diodes are part number 1N4938.

9.3 GRAPHIC SYMBOLS The graphic symbols used on electrical schematics are in accordance with American National Standard ANSI Y32.2-1975 Graphic Symbols for Electrical and Electronic Diagrams.

9.4 LOGIC SYMBOLS The logic symbols used on electrical schematics and logic diagrams are in accordance with American National Standard ANSI Y32.14-1975 - Graphic Symbols for Logic Diagrams. 9.5 REFERENCE DESIGNATIONS Reference designations have been assigned in accordance with American National Standard ANSI Y32.16-1975 - Reference Designations for Electrical and Electronic Parts and Equipments. Each electrical symbol has been identified with its basic reference designation. To obtain the full reference designation for a specific part, this basic identifier must be prefixed with the reference designation assigned to all higher assemblies. 9.6 LOCATING LOGIC/SCHEMATIC DIAGRAMS Each illustration in this section is identified by a number that is both the figure number and the page number. The numbers are assigned sequentially and are prefixed by the letters 'SD-'. The electrical schematics/logic diagrams included in this section are listed in Table 9-1.

Table 9-1 List of Electrical Schematics Figure # Figure SD-1 Figure SD-2 Figure SD-3 Figure SD-4 Figure SD-5

NRB4 Technical Instructions Section 9 Electrical Schematics

Description Block Diagram – NRB4 Beacon Monitor Receiver Electrical Schematic – NRB4 Beacon Monitor Receiver Electrical Schematic – NAPA15 DDS RF Amplifier PWB Electrical Schematic – NAPC15 IF Amplifier/Monitor PWB Electrical Schematic – NAPA01 Audio Amplifier PWB

Page 9-1 Original Issue 1.0

Dimensions = mm (inches)

Block Diagram – NRB4 Beacon Monitor Receiver Original Issue 1.0

Not to Scale

Figure SD-1

Sheet 1 of 1

0 dB 6

A

+12V

E1:3

E1:2

E1:1

+VDC

J1

20 dB

20 dB

4

8

R5 R1 221 56.2

R10 56.2

60 dB

2

9

S1:2

R7 R3 33.2K 56.2

R8 R4 2740 56.2

R14 R13 2740 56.2

R12 56.2

R15 56.2

MOD ALARM

S3:7

3

12 J2

11

11

NO

9

C

7

NC

8

1

6

2 6

10

9

1 5

+28V

2 6

10

9

1 5

5

R11 1800

K1

R

+12V

10

+28V

9

K2

R

R10 1000

IF AMPLIFIER PWB

P4

1

AUDIO LEVEL

+28V

J1

4

15

CR3 1N5624

L U1 AC LINE LE SUPPLY N

4

E

P4 LS1

2

AUDIO AMPLIFIER PWB

M1

CARRIER LEVEL

5

DS3

VARIATION

AC LINE SUPPLY

NAY08/01

115VAC

NAY08/02

220VAC

POWER ON4 6 2

5 1

OFF

F2 1A

3

S3

F1 0.5A 115VAC

N

BLK

T3

WHT BRN

220VAC

GRN

GRN T3

A4

5

GRN/YEL

ORN BLK

S1720064 V1

3

J1

2

8

-

A3

J1

MOD ALARM

14

VDC IN

P1

DDS RF AMPLIFIER PWB

7

A2

DS2

R12 1800

CR2

J1 1

CARRIER ALARM

14

13

+28V

S2

13 CR1

+28V

14

A1

3

J1

3

+28V

+

C7 NOT USED

7

TEST

10

NC

5

8

4

CW

13

C6 68pF

J1 +12V

4

4

2

4 P2

1

C5 56pF

S3:4

P1

3T

3

13

P2

3

12T

1

C4 33pF

S3:3

L4 820μH

1

3

OUT

14

9

S3:8

A5T1

2

E

2

S3:2

8

L3 820μH

C3 18pF

S3:5

2

12

NO

1

15

12

2

IN

C

2

L2 4700μH

10

S2:1

4

CARRIER ALARM

12T

3

7

D

1

1

P3

1

-48V

3T

2

10

TB1

AUDIO OUTPUT

1

80 dB

1

S1:1

T1

S2:2

R11 56.2

80 dB 10

4

3

S2:3

60 dB 9

16

S3:1

40 dB R2 56.2

C2 2.9-24pF

SWITCH PWB

4

8

R6 2740

RF TUNE

A5A1

S2:4

R9 56.2

3

S1:3

C1 1.0 50V

C

7

40 dB

B

5

S2:5

S1:4

L1 1000μH

RF INPUT

6

S1:5 7

GND

0 dB 5

2

6

CR3 1N5624 CR4 1N5624

POWER SUPPLY

CR1 1N5624 CR2 1N5624

R1 1800 C1 1.0 50V

GRN

WHT BRN

GRN/YEL

ORN

GRN

Q1 2N6295

R2 1.0

Q2 2N2222A

CR5 1N3030B 27V

R3 3300 C2 22 35V

Q3 2N6295 Q4 2N2222A CR6 1N753A 6.2V

R4 2700 R5 3300

1

+28V

3

+12V G

DS1

POWER R13 1800

4 C2 1100 75V

Dimensions = mm (inches)

Electrical Schematic – NRB4 Beacon Monitor Receiver Original Issue 1.0

Not to Scale

Figure SD-2

Sheet 1 of 1

+12V +12V

P1.0/T2 P1.1/T2EX

SIDEBAND

P1.2

E1:2

C16 0.1

P2.6/A14

+3.3V-A

P3.3/INT1 P3.4/T0

R30 22 2W

V_IN

U1 3 MC7805ACT V_OUT

14

L3

GND 2

C8 10 35V

C9 0.1

U4

VCC RTXT//10.0MHz OUT N/C GND SHIELD 1 7 5

8

69

R5 1000

C13 12pF

23

+3.3V-D

24 25

+12V 8 7

J1 J1

C1 L1 10 35V

C2 10 35V

C4 0.22

S1720051 SHEET 1 OF 1 V1

+12V

1

C6 10 35V

C7 0.47

IN

U3 3 LM3940IT-3.3 OUT GND 2

C22 0.1 C11 10 35V

C12 47 20V

L4

L5

C14 10 35V

C15 10 35V

+3.3V-A

26 27 28

+3.3V-D

63

58

57

68 REFCLKB

N/C

N/C

N/C

35

30

36 VOUT

N/C

29

62

60 AVDD

66

67

18

AGND AGND

DGND

33

C45 0.1

34

37

+3.3V-A

38

39

C46 0.1

40 41

DGND AVDD REFCLK AGND DVDD

AGND

DVDD

AGND

44 45

C47 0.1

+3.3V-A

46 47

DVDD DIFF_CLK_EN

DGND DGND DGND

+3.3V-D

C27 0.1

+3.3V-D

C31 0.1

R14 100

R15 100

R16 47.5

R18 47.5

S/P_SELECT

R19 47.5

64 70

D0

12

AGND

U6 AD9852ASQ

DVDD

D1

11

DVDD

+3.3V-A

32

8

10

C21 0.1

AVDD AVDD

9

+3.3V-D

PLL_FILTER

D2

R6 100

61

R7 1210

7

XTAL1

C19 0.01

AGND

D3

TP2

DACBP

6

P0.3/AD3

C20 0.1

5

21

55

+3.3V-A

P0.2/AD2

31

RDB/CSB AGND

P0.1/AD1

D4

40

AVDD

4

6

P0.0/AD0

AVDD

MASTER_RESET

D5

41

22

48

A0/SDIO

3

3

71

D6

8

42

16

IOUT1

2

4

4

19

D

I/O_UD_CLK

D7

2

43

C

15

WRB/SCLK

1

1

1

20

C37 0.1

DAC_RSET

S5

B

14

C34 0.1

SHAPED_KEYING

P0.7/AD7

+3.3V-A

56

36

P3.2/INT0

21

DVDD

6

P0.6/AD6

A

13

73

37

P3.1/TxD

P0.5/AD5

74

3

P0.4/AD4

AGND

38

AGND

4

DGND

8

39

+3.3V-A

C30 0.1

DGND

4

1

+3.3V-A

A1/SD0

VSS

P2.7/A15

22

77

2

1

R29 68.1

44

78

1

C43 0.1

35

FSK/BPSK/HOLD

VCC

17

EA/VPP P2.5/A13

16

P2.4/A12

C26 0.1

S4

OSC

R23 1000

A2/IO_RESET

8

31

TP5 LCL

C42 0.01

R24 3920

Dimensions = mm (inches)

Electrical Schematic – NAPA15 DDF RF Amplifier PWB Original Issue 1.0

Not to Scale

Figure SD-3

J1

2 3

+3.3V-D

15

6

TP6

1

R26 56.2

A3

30

10T

O/P

Q4 2N3904

C36 1.5pF

P2.3/A11

1

6

5T

R22 5620

C40 0.01

R17 100

C38 330pF

IOUT2

3

GND GND

34

L10 5.6μH

C32 470pF

52

29

N/C

33

14

28

4

P2.2/A10

TP4

A4

1

ALE

TP3

13

27

P2.1/A9

5

15T

32

A5

26

6

PSEN

N/C

4

3

N/C

P2.0/A8

IOUT2B

2

25

4

5T

C41 0.047

51

24

23

53

10

L11 1000μH

AGND

9

+12V

C48 22pF

4T

12 20

CASE 5

T2

IOUT1B

8

XTAL2

3

49

1

2 5

7

U5 190-5047-01

GND 4

R28 56.2

2

50

S3

X0.1

6

N/C RST

R25 56.2

11

AVDD

8

X1

5

10

9

VINN

4

2 5

4

4

2

2 5

3

C10 2.2 20V

R21 56.2

GND 2

3

T3

R20 56.2

3

43

1

1

X10

2

9x4700

P3.0/RxD

59

S2

2 5

U2

6

P1.7

+3.3V-D

1 4610X-101-472

Q5 2N3904

CR1

AGND

4 8

X100

+3.3V-D

3

8

Q3 2N3904

OUTPUT

4

16T

2

INPUT

C44 0.01

4

16T

VINP

2

2 5

P3.7/RD

P1.6

4

7

65

X1000

P1.5

R10 2210

T1

1

L9 12μH

42

1

19

6

C25 C29 820pF 0.1

C24 33pF

54

1

P1.4

C49 100pF

C35 1.0 35V

HIGH

AVDD

S1

P3.6/WR

C18 1000pF

L7 270μH

E3:3

DGND

18

E1:1

5

SENSITIVITY

R9 825

E2:3

HIGH

R13 500

DGND

LSB

P1.3

3 4

+12V

L6 C17 1.0 8.2μH 35V

76

E1:3

DSB

+12V

2

75

J1

P3.5/T1

USB

R4 562

BAND

FL1 4.4MHz

1

L12 C39 330μH 0.047

Q2 2N3906

AGND

E1:4 C5 1.0 35V

N/C

R27 562 +12V

E3:2

DGND

J1

17

AVDD

3

BAND

LOW

1

+12V

R12 332

C33 1.0 35V

E3:1

C28 470pF

DVDD

4

LOW

R3 47.5

DVDD

RF INPUT

L8 C23 680pF 150μH

79

TP1

R8 562

E2:1

E2:2

80

I/P

Q1 2N3904

R2 5620

72

C3 1.0 35V L2

R11 18.2

DVDD

R1 10K

+12V

CW

+12V

Sheet 1 of 1

J1

1

2

RF OUTPUT

Dimensions = mm (inches)

Electrical Schematic – NAPC15 IF Amplifier/Monitor PWB Original Issue 1.0

Not to Scale

Figure SD-4

Sheet 1 of 1

Dimensions = mm (inches)

Electrical Schematic – NAPA01 Audio Amplifier PWB Original Issue 1.0

Not to Scale

Figure SD-5

Sheet 1 of 1

NRB4 TECHNICAL INSTRUCTIONS Section 10

MECHANICAL DRAWINGS 10.1 INTRODUCTION This section contains mechanical drawings for assemblies of the subject equipment. Dimensional drawings may be included. Refer to Table 10-1 for an itemized listing. Assembly detail drawings for assemblies/modules that have separate maintenance manuals are not included. Refer to the appropriate maintenance manual for the assembly detail of these assemblies. 10.2 LOCATING ASSEMBLY DETAIL DRAWINGS Each illustration in this section is identified by a number that is both the figure number and the page number. The numbers are assigned sequentially and are prefixed by the letters 'MD-'. Drawings in this section are listed in Table 10-1.

10.3 CONTENT OF MECHANICAL DRAWINGS Mechanical drawings are illustrations that depict the location of electrical components and show assembly outline detail. Where appropriate, dimensional information will be included. 10.3.1 When a module/assembly is the subject of its own assembly detail drawing and it is also shown in a higher level assembly, the detail depicted in the higher level assembly may have minor differences from the module/assembly actually installed. In this case, always refer to the assembly detail drawing for the module/assembly for detailed information.

Table 10-1 List of Mechanical Drawings Figure # Figure MD-1 Figure MD-2 Figure MD-3 Figure MD-4 Figure MD-5 Figure MD-6 Figure MD-7

NRB4 Technical Instructions Section 10 Mechanical Drawings

Description Assembly Detail – NRB4 Beacon Monitor Receiver Hinged Panel (Front and Rear Views) Assembly Detail – NRB4 Beacon Monitor Receiver Chassis (Front and Rear Views) Assembly Detail – NAPA15 DDS RF Amplifier PWB Assembly Detail – NAPC15 IF Amplifier/Monitor PWB Assembly Detail – NAPA01 Audio Amplifier PWB Assembly Detail – NAS22 +24/+12 V Power Supply Assembly Assembly Detail – Switch Bracket Assembly (P/N 172-5116)

Page 10-1 Original Issue 1.0

Dimensions = mm (inches)

Assembly Detail – NRB4 Beacon Monitor Receiver Hinged Panel (Front & Rear Views) Original Issue 1.0

Not to Scale

Figure MD-1

Sheet 1 of 1

Dimensions = mm (inches)

Assembly Detail – NRB4 Beacon Monitor Receiver Chassis (Front & Rear Views) Original Issue 1.0

Not to Scale

Figure MD-2

Sheet 1 of 1

FL1

WASHER (124-1041) INSTALL ON INPUT AND OUTPUT PINS WASHER,PLAIN,6 PWB WASHER,PLAIN,6 WASHER,SPLIT,6

#4 HEX NUT

654

1

654

2 3

8 7

3 8 7 SHOWN SET FOR 387.5 kHz

2 3

8 7

901 654

2 3

8 7

901 654

2 3

8 7

901 654

2 3

6 9 4 SHOWN SET FOR 1694.0 kHz

654

2

USB DSB

5

LSB S1 x1000

8 7

901 654

0

L10

2 3

1

8 7

901 654

2 3

+

8 7

C8

C12

FREQUENCY (kHz) S2 S3 S4 x100 x10 x1

S5 C11 x0.1

901

901

654

2 3

8 7

L3

901 654

2 3

8 7

+

901 654

1

C48

1 R29

2 3

U2

8 7

T1 L12

L11

+

654

2 3

R27

TP5

C42 2

LCL OSC

1

3 2 1

3

U3

C39

R20 5 T2

C6 R30

+

C35

C1

0

C25

R28 R25

R12

C33

C17

R1

R9 R10

HIGH

R2 +

LOW

C3 C23

C28

Q2 5

Q1

+

E2

C29

LOW

+

R3

L9

E3 HIGH

C5 R4

C24

Q5

R11

+

C7 +

4 6

R21

4 U1

1

Q3

L7 3

2

+

C49 L6

R26

R23 R22 C41

C18

C44 CR1

L4

C10

C43

C40

U5

E1

GND TP1 I/P

C38

+ C15

C9

TP4

C4 L1

10 SENSITIVITY

J1

C14

TP3 GND

TP6 O/P

R17

Q4

2 3

GND

+

C2

L8 R8

M1720052 V1

Dimensions = mm (inches)

Assembly Detail – NAPA15 DDF RF Amplifier PWB Original Issue 1.0

2 3

4

INPUT

R15

T3

1

8 7

FL1

1

654

2 3

OUTPUT

R13

8 7

901

8 7

C32

3

0

654

2 3

901

R16

2

8 7

901

901

C34

GND

1

654

2 3

901

R18

L5

8 7

901

S5 x0.1

C20

1 SIDEBAND

S1 x1000

R19

+

U4 FREQUENCY (kHz) S2 S3 S4 x100 x10 x1

R24

R14 C16

A

3

R7 C30

C47 C46

C

1

SER.

C37

B C45

D

NAPA

C36

C19

C26

C31 U6

C21

R5

U1 MOUNTING METHOD

TP2 CLK

NAUTEL ASSY 172-1060 RF AMPLIFIER

R6

4

C13

TORQUE ATTACHING HARDWARE TO TO 4.0 INCH POUNDS (0.45 NEWTON METERS)

C27

FL1 MOUNTING METHOD

C22

#4 BELLEVILLE WASHER

#4 FLAT WASHER

SEMICONDUCTOR

ECCOTHERM (HAT46)

#4 PAN HEAD SCREW

HEATSINK

NUT,SMALL PATTERN,SS,6-32

Not to Scale

Figure MD-3

Sheet 1 of 1

L2

Dimensions = mm (inches)

Assembly Detail – NAPC15 IF Amplifier/Monitor PWB Original Issue 1.0

Not to Scale

Figure MD-4

Sheet 1 of 1

Dimensions = mm (inches)

Assembly Detail – NAPA01 Audio Amplifier PWB Original Issue 1.0

Not to Scale

Figure MD-5

Sheet 1 of 1

Dimensions = mm (inches)

Assembly Detail – NAS22 +24/+12 V Power Supply Assembly Original Issue 1.0

Not to Scale

Figure MD-6

Sheet 1 of 1

Dimensions = mm (inches)

Assembly Detail – Switch Bracket Assembly (P/N 172-5116) Original Issue 1.0

Not to Scale

Figure MD-7

Sheet 2 of 2