Glenayre Electronics GL-T8500-CN Base Station User Manual users manual
Glenayre Electronics Inc Base Station users manual
users manual
250-Watt Gold Line Power Amplifier Issue 1, Rev. C: 10/21/96 Gold Line GL-T8500 250-Watt, 900-MHz Power Amplifier USER MANUAL PN 9110.00160 REV C RELEASED (old part number = 916-8500-000) Specifications subject to change without notice Copyright © 1996 Glenayre All rights reserved. No part of this work may be reproduced or copied in any form or by any means—graphic, electronic, or mechanical, including photocopying, recording, taping, or information-retrieval system—without written permission of Glenayre. Print Date: 12/17/96 Copyright © 1996 Glenayre 250-Watt Gold Line Power Amplifier Document Change Record Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Document Change Record Revision: 0, Preliminary Date: 05/04/95 Changes: none, original Issue: Rev B Date: 02/02/96 Changes: new format Issue: Rev C Date: 10/21/96 Changes: made released Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier Table of Contents Table of Contents GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.1 Manual Scope . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.2 Applicable Documents . . . . . . . . . . . . . . . . . . . . . 1-1 1.3 Manual Sections . . . . . . . . . . . . . . . . . . . . . . . 1-1 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3.2 Physical Description. . . . . . . . . . . . . . . . . . . . . . 3-1 3.2.1 Mounting Provisions . . . . . . . . . . . . . . . . . . . . . . . .3-1 3.2.2 PA Front. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1 3.2.3 3.3 Driver Board . . . . . . . . . . . . . . . . . . . . . .3-1 3.2.2.2 PA Boards . . . . . . . . . . . . . . . . . . . . . . . .3-4 3.2.2.3 Combiner Board. . . . . . . . . . . . . . . . . . . . .3-4 3.2.2.4 Metering Board . . . . . . . . . . . . . . . . . . . . .3-4 PA Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4 3.2.3.1 Isolator . . . . . . . . . . . . . . . . . . . . . . . . .3-4 3.2.3.2 Fan . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4 3.2.3.3 Equipment Connectors . . . . . . . . . . . . . . . . .3-4 Functional Description . . . . . . . . . . . . . . . . . . . . . 3-5 3.3.1 RF Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5 3.3.2 Isolator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5 3.3.3 Metering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6 INSTALLATION AND SETUP . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.1 Installation . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.2 Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.3 Ultimate Disposition . . . . . . . . . . . . . . . . . . . . . 4-1 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.1 Controls and Indicators . . . . . . . . . . . . . . . . . . . . 5-1 5.2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.2.1 Turn PA On and Off . . . . . . . . . . . . . . . . . . . . . . . .5-1 5.2.2 Turn Fan On and Off . . . . . . . . . . . . . . . . . . . . . . . .5-1 5.2.3 Key and Unkey PA . . . . . . . . . . . . . . . . . . . . . . . . .5-1 THEORY OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 6.1 Power Distribution . . . . . . . . . . . . . . . . . . . . . . 6-1 6.1.1 Print Date: 12/17/96 3.2.2.1 Primary Power . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1 Copyright © 1996 Glenayre Page: -i 250-Watt Gold Line Power Amplifier Table of Contents 6.1.2 6.1.3 6.2 6.3 6.4 Page: -ii Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 6.1.1.1 Metering Board +25V Signal Flow. . . . . . . . . . . 6-1 6.1.1.2 Power Amplifiers +25V Signal Flow. . . . . . . . . . 6-1 Secondary Power . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2 6.1.2.1 Metering Board +13.5V Signal Flow . . . . . . . . . . 6-2 6.1.2.2 Preamplifier Module +13.5V Signal Flow . . . . . . . 6-2 Fan Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2 RF Distribution . . . . . . . . . . . . . . . . . . . . . . . 6-3 6.2.1 Driver Board RF Flow . . . . . . . . . . . . . . . . . . . . . . . 6-3 6.2.2 PA Board RF Flow . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 6.2.3 Combiner Board RF Flow . . . . . . . . . . . . . . . . . . . . . 6-4 6.2.4 Isolator RF Flow . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 Control Distribution . . . . . . . . . . . . . . . . . . . . . 6-5 6.3.1 AGC Signal Flow . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 6.3.2 Multiplexer Control Signal Flow . . . . . . . . . . . . . . . . . . 6-6 Status Distribution . . . . . . . . . . . . . . . . . . . . . . 6-6 6.4.1 Mux Analog Status Signal Flow . . . . . . . . . . . . . . . . . . 6-6 6.4.2 PA Fault Signal Flow . . . . . . . . . . . . . . . . . . . . . . . . 6-6 MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 CHECKOUT AND TROUBLESHOOTING . . . . . . . . . . . . . . . . . . 8-1 REMOVAL AND REINSTALLATION . . . . . . . . . . . . . . . . . . . . 9-1 9.1 PA Chassis Removal and Reinstallation . . . . . . . . . . . . . 9-1 9.2 PA RF Module Removal and Reinstallation . . . . . . . . . . . . 9-1 9.3 Metering Board Removal and Reinstallation . . . . . . . . . . . . 9-1 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier List of Figures List of Figures Figure 3-1 250-Watt, 900-MHz Power Amplifier Front View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 Figure 3-2 250-Watt, 900-MHz Power Amplifier Rear View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 Figure 3-3 PA Simplified-Block Diagram . . . . . . . . . . . . . . . . . . . . . . 3-5 Figure 5-1 Front-Panel View with Cover Removed . . . . . . . . . . . . . . . . . 5-2 Figure 6-1 250-Watt PA Interconnection Diagram . . . . . . . . . . . . . . . . . . 6-8 Figure 6-2 250-Watt PA Functional Diagram . . . . . . . . . . . . . . . . . . . . 6-9 Figure 6-3 250-Watt PA Detailed Functional Diagram . . . . . . . . . . . . . . .6-10 Figure 6-4 Metering Board Functional Diagram . . . . . . . . . . . . . . . . . . .6-12 Figure 9-1 PA Removal and Reinstalllation . . . . . . . . . . . . . . . . . . . . . 9-2 Figure 9-2 PA RF Module Removal and Reinstallation . . . . . . . . . . . . . . . 9-3 Figure 9-3 Metering Board Removal and Reinstallation . . . . . . . . . . . . . . . 9-5 Print Date: 12/17/96 Copyright © 1996 Glenayre Page: -iii 250-Watt Gold Line Power Amplifier List of Figures Page: -iv Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier List of Tables List of Tables Table 1-1 Applicable Documents . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Table 1-2 Manual Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 Table 2-1 Power Amplifier Specifications. . . . . . . . . . . . . . . . . . . . . . 2-1 Table 3-1 PA Circuit Boards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 Table 6-1 Multiplexer Analog Status Inputs. . . . . . . . . . . . . . . . . . . . . 6-7 Print Date: 12/17/96 Copyright © 1996 Glenayre Page: -v 250-Watt Gold Line Power Amplifier List of Tables Page: -vi Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 GENERAL 1.1 Manual Scope 250-Watt Gold Line Power Amplifier GENERAL This manual provides information for the 250-watt, 900-MHz Gold Line power amplifier, part number 265-0082-013. Also included is information for the optional triple isolator, part number 7914.00010. 1.2 Applicable Documents This manual is incomplete without additional Gold Line manuals. Refer to Table 1-1 for a listing and function of these manuals. Table 1-1 Applicable Documents document 1.3 part number function GL-T8500/8600 system man- 9110.00163 ual describes fully racked-up Gold Line transmitter VDT manual 9110.00164 describes PA control software installed in exciter exciter manual 9110.00172 describes exciter/PA control equipment in transmitter 250-watt PA 9110.00160 this manual power supply manual 9110.00159 describes 50A/90A power supply equipment in transmitter Manual Sections Table 1-2 lists the sections of this manual with a summary of their contents. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 1-1 250-Watt Gold Line Power Amplifier GENERAL Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Table 1-2 Manual Sections Page: 1-2 section contents 1. General introduction and purpose of manual 2. Specifications significant measurements of power amplifier 3. Description introduction and principal characteristics of power amplifier 4. Installation and Setup initial installation and activation of power amplifier 5. Operation operation of power amplifier 6. Theory of Operation detailed functional description of circuitry within power amplifier 7. Maintenance procedures to be performed on specific intervals to maintain optimum performance of power amplifier 8. Checkout and Troubleshooting verification of proper operation, correction to proper operation of power amplifier 9. Removal and Reinstallation replacement procedures for power amplifier and selected subassemblies Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier SPECIFICATIONS SPECIFICATIONS Table 2-1 lists the significant equipment-level specifications for the Gold Line power amplifier. Table 2-1 Power Amplifier Specifications Print Date: 12/17/96 measurement specification height 8.75 in (22.23 cm) width 19 in (48.3 cm) depth 8 in (20.3 cm) weight 26 lb (12 kg) RF output power 100 - 250 watts RF bandwidth 900 - 960 MHz RF input power 200 - 400 mW RF impedance 50 ohms operating voltages 25 vdc, 25 Vdc, 13.5 Vdc PA 25 Vdc current 72 mA - 33 A fan 25 Vdc current 750 mA 13.5 Vdc current 3.3 A ambient temperature -30° - +70° C humidity 0 - 95% noncondensing altitude to 10,000 ft (3050 m) Copyright © 1996 Glenayre Page: 2-1 250-Watt Gold Line Power Amplifier SPECIFICATIONS Page: 2-2 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 3.1 250-Watt Gold Line Power Amplifier DESCRIPTION DESCRIPTION Introduction Figure 3-1, 250-Watt, 900-MHz Power Amplifier Front View, and Figure 3-2, 250-Watt, 900-MHz Power Amplifier Rear View,show the Gold Line power amplifier (PA). This is a 250-watt PA intended for use in a GL-T8500 paging transmitter with an RF of 900 MHz nominal. This PA is characterized by integrated monitoring devices that supply critical status information to a Gold Line exciter/PA control (exciter). This exciter contains diagnostic software that can detect and report a faulty PA circuit board. 3.2 Physical Description 3.2.1 Mounting Provisions The PA is mounted to the front of most standard 19-inch equipment racks by means of eight screws. The front panel of the PA may by removed while the PA is mounted in the rack. Two quarter-turn fasteners secure the front panel to the PA. Most PA circuit boards may be replaced while the PA is mounted in the rack. 3.2.2 PA Front Figure 5-1 shows the front view of the PA with the front panel removed. This exposes the RF and shielded compartments, which contain the PA circuit boards. Table 3-1 lists the PA circuit boards. Table 3-1 PA Circuit Boards nomenclature part number location driver board A1 263-0082-022 RF compartment PA1 board A2 263-0082-007 RF compartment PA2 board A3 263-0082-007 RF compartment combiner board A4 263-0082-021 RF compartment metering board A5 263-0082-018 shielded compartment 3.2.2.1 Driver Board The driver board (A1) contains the preamp module, the intermediate PA (IPA), and the PA drivers (driver-1 and driver-2). These devices, in addition to one resistor, are mounted directly on the PA heat sink. The driver board contains three connectors: two on the front (J1 and J2) and one on the back (J3). Two RG316-type cables (not shown) are attached to the front of the board. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 3-1 250-Watt Gold Line Power Amplifier DESCRIPTION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 v0222.hgl Figure 3-1 250-Watt, 900-MHz Power Amplifier Front View Page: 3-2 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier DESCRIPTION v0221.hgl Figure 3-2 250-Watt, 900-MHz Power Amplifier Rear View Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 3-3 250-Watt Gold Line Power Amplifier DESCRIPTION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 3.2.2.2 PA Boards Two PA boards, PA1 (A2) and PA2 (A3), contain the power amplifiers. The PA boards are identical but are mounted with different orientations. Each PA board contains an A and a B pair of power amplifiers. These amplifiers and six resistors are mounted directly on the PA heat sink. Connectors J1 and J3 and an RG142-type cable (not shown) are attached to the front of each board. 3.2.2.3 Combiner Board The combiner board combines the outputs of the PA boards. The combiner board contains a resistor, mounted directly on the PA heat sink. Connectors J1, J2, and J3 are on the front of the board. An RG393-type cable is attached to the back of the board. This cable terminates with a type-N connector and extends through the rear of the PA. 3.2.2.4 Metering Board The metering board contains the monitoring circuits for the PA. A bank of nine automotive spade-type fuses protect the PA. A transistor is mounted directly on the PA heat sink. The metering board contains connectors J1, J2, J4, J5, and P1 on the front and J3 on the back. The board contains one LED (DC POWER). 3.2.3 PA Rear Figure 3-2 shows the back view of the PA. The PA back panel conceals the fan compartment. The isolator and fan are mounted on the back panel. The PA equipment connectors terminate on cables that are routed through grommeted holes in the back panel. 3.2.3.1 Isolator The standard isolator (shown) improves the intermodulation performance of the PA by 25 dB. This isolator is mounted on its own heat sink, which extends into the fan compartment. The optional triple isolator (not shown) improves the intermodulation performance of the PA by 75 dB, and is mounted on the PA. Both isolators contains three connectors: two typeN and one BNC. 3.2.3.2 Fan A single fan provides cooling for the PA and standard isolator. The fan is located within the fan compartment and is covered by a finger guard. The fan runs continuously whenever power is applied by the power supply equipment. 3.2.3.3 Equipment Connectors There are five equipment connectors in addition to those on the isolator. Two 1/4-inch ring lugs are designated as plus (red) and minus (black). A 9-pin plug-and-socket connector is designated as P2. A DB15-type connector is designated as PA CONTROL. A BNC connector is designated as P3. Page: 3-4 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 3.3 250-Watt Gold Line Power Amplifier DESCRIPTION Functional Description Figure 3-3 shows a simplified, functional diagram of the PA. The driver, combiner, and PA boards constitute the RF amplifier circuitry of the PA. Monitoring and controlling this RF amplifier is the metering board. Figure 3-1 shows the RF amplifier, isolator, and metering circuitry within the PA. BNC RF IN AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA TYPE N TYPE N AAA AAA AAA AAA AAA AAA AAA AAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA RF AMPLIFIER METERED POWER 1/4 LUGS DC IN 25V STATUS VOLTAGES ISOLATOR AAAA AAAA AAAAAAAA AAAAAAAA BNC VSWR SAMPLE AAAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA METERING RF OUT STATUS/ CONTROL DB-15 AAAA AAAA AAAA AAAA 13.5V AAAA AAAA AAAA AAAA POWER AMPLIFIER P2 Figure 3-3 PA Simplified-Block Diagram 3.3.1 RF Amplifier The RF amplifier receives its RF input through the BNC connector P3. A detector circuit in the RF amplifier monitors this RF input. The RF input is amplified by means of four amplifier stages. Each amplifier stage receives its dc input power through the metering circuit. Power detectors at critical locations throughout the RF amplifier provide sample voltages to the metering circuit. The amplified output of the RF amplifier is applied to the input type-N connector on the isolator. 3.3.2 Isolator The isolator prevents intermodulation of the RF signal that may occur from nearby transmissions. The RF signal is routed through input and output type N connectors. A detector circuit in the isolator monitors the reflected power (VSWR) present at the output type-N connector. A sample voltage representing the VSWR level is output through the BNC connector. The optional triple isolator functions identically to the standard isolator except with a higher level of intermodulation prevention. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 3-5 250-Watt Gold Line Power Amplifier DESCRIPTION 3.3.3 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Metering The metering board performs control and status reporting for the PA. The metering board accepts a 25-Vdc power input through the 1/4-inch lugs and a 13.5-Vdc power input through connector P2. These voltages are regulated and distributed. Page: 3-6 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 4.1 250-Watt Gold Line Power Amplifier INSTALLATION AND SETUP INSTALLATION AND SETUP Installation The PA is shipped already installed in a cabinet. To remove or reinstall the PA, refer to Section 9. 4.2 Setup Setup of the PA is performed at the system level using an exciter/PA control unit. Refer to the GL-T8500 system manual. The system manual includes instructions for these applicable setup procedures: • adjust forward power • set low power alarm • calibrate reflected power 4.3 Ultimate Disposition Caution This equipment may contain hazardous materials. Check with the local EPA or other environmental authority before disposing of this equipment. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 4-1 250-Watt Gold Line Power Amplifier INSTALLATION AND SETUP Page: 4-2 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 5.1 250-Watt Gold Line Power Amplifier OPERATION OPERATION Controls and Indicators The PA has one indicator and no controls. Figure 5-1, Front-Panel View with Cover Removed shows the location of the PA indicator LED1. 5.2 Operation 5.2.1 Turn PA On and Off The PA does not contain an on/off switch, but turns on and off whenever the power supply equipment is turned on and off. When the PA is on, it remains in a standby condition until keyed. Refer to the power supply manual for turn-on and turn-off procedures. 5.2.2 Turn Fan On and Off The fan does not contain an on/off switch, but turns on and off whenever the power supply equipment is turned on and off. The fan runs continuously whenever the power supply equipment is on. Refer to the power supply manual for turn-on and turn-off procedures. 5.2.3 Key and Unkey PA The PA does not contain a key switch, but is keyed and unkeyed by the exciter/PA control equipment. This exciter must be keyed and unkeyed remotely through transmitter controller, or locally through a video display terminal (VDT). Refer to the controller manual for remote key and unkey instructions, or to the VDT manual for local key and unkey instructions. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 5-1 250-Watt Gold Line Power Amplifier OPERATION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 v0224.hgl Figure 5-1 Front-Panel View with Cover Removed Page: 5-2 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 6.1 250-Watt Gold Line Power Amplifier THEORY OF OPERATION THEORY OF OPERATION Power Distribution The PA requires three separate power inputs: primary 25-volt dc power, secondary 13.5volt dc power, and fan 25-volt dc power. All power inputs are normally provided by the Gold Line power supply. 6.1.1 Primary Power Refer to Figure 6-2. Primary 25-volt dc operating power is received through the power cables terminating with 1/4-inch ring lugs. The (-) input (black cable) is bolted directly to PA chassis ground. The (+) input (red cable) is bolted to P1 on the metering board. P1 powers the +25V power bus on the metering board. This bus distributes primary power to the metering board and to each common-base collector (CBC) power amplifier in the PA. 6.1.1.1 Metering Board +25V Signal Flow Refer to Figure 6-4. +25 volts from the power bus is supplied through fuse F13 to these places on the metering board: LED1, +25V components, divider circuitry, +5V regulator and divider circuitry, and +1.2V regulator circuitry. • LED1 activates to illuminate the DC POWER indicator on the front of the PA. • +25V components receive operating power. These components include the current detector amplifiers. • Divider circuit reduces the input to a sample voltage, which determines the PA 25V metering. • +5V regulator/divider circuitry generates +5V operating power for the metering board +5V components. A portion of this +5V is reduced to a sample voltage, which determines the PA 5V metering. • +1.2V regulator circuitry generates the compensation voltage for the current detector amplifiers. 6.1.1.2 Power Amplifiers +25V Signal Flow Refer to Figure 6-1. +25 volts operating power from the power bus is paralleled through seven resistors. These resistors are a component of a current detection circuit. Current-Detection Theory Current-detection monitoring occurs on the metering board. The monitored current is routed through a small resistor, resulting in a slight voltage drop across the resistor. This voltage drop is amplified by a current detector amplifier, which generates an output voltage proportional to the current flowing through the resistor. This output voltage is the current sample for the monitored current. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 6-1 250-Watt Gold Line Power Amplifier THEORY OF OPERATION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 The seven monitored +25-volt signals are individually fused before leaving the metering board. The signals provide operating power for power amplifiers located on the driver and PA boards. Each signal is routed through a dc bias network. Dc-Bias Network Theory Dc bias networks are located on the driver board and PA boards. +25-volt operating power from the metering board is applied to the power amplifiers through a dc bias network. The network is tuned and filtered to cause a high impedance to signals from dc to above operating frequency. This prevents RF from transmitting backwards into the metering board. 6.1.2 Secondary Power Secondary 13.5-volt dc power for the PA is externally fused, at the power supply equipment. Refer to Figure 6-1. Secondary power is received through connector P2, which mates with J2 on the system interconnect harness. Secondary power is connected to J5 on the metering board. The +13.5 input from J5 is distributed to the metering board and the preamp module. 6.1.2.1 Metering Board +13.5V Signal Flow Refer to Figure 6-2. +13.5-volt power from J5 is paralleled to these places on the metering board: +13.5V components, divider circuitry, and heat sink temperature transducer U17. • +13.5V components receive operating power. These components include those within the AGC integrator circuit. • Divider circuit reduces the input to a sample voltage, which determines the system PA 13.5V metering. • Heat-sink-temperature transducer U17 generates a voltage proportional to the temperature of the PA heat sink, which determines the temperature metering. 6.1.2.2 Preamplifier Module +13.5V Signal Flow Refer to Figure 6-2. +13.5-volt power from J5 is routed through a resistor, a component of a current-detection circuit. The sample provided by this circuit determines the preamplifier current metering. The +13.5-volt power through the resistor is fused by F4 before distribution to the metering board and preamplifier module, on the driver board. 6.1.3 Fan Power 25-volt dc fan power is fused externally at the power supply equipment. Refer to Figure 61. Fan power is received through connector P2, which mates with J2 on the system interconnect harness. Fan power is applied directly to the fan via a quick-release jack (not shown). Page: 6-2 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 6.2 250-Watt Gold Line Power Amplifier THEORY OF OPERATION RF Distribution Refer to Figure 6-1. The PA RF input is received through a BNC connector, which mates with J3 on the exciter/PA control. This RF input signal (at a nominal 350 mW) is split and amplified into two RF signals (at a nominal 40 watts) by the driver board. Each RF signal is amplified (to a nominal 150 watts) by a PA board. These RF signals are combined into one RF signal (at a nominal 275 watts) by the combiner board. This is the PA RF output, and is applied to an isolator. The isolator RF output (at a nominal 250 watts for standard) is supplied to an antenna for transmission. All power levels given here and in the following paragraphs are typical; actual power levels will vary from those given. 6.2.1 Driver Board RF Flow The driver board splits and amplifies a 350-mW RF input into two 40-watt RF outputs. Refer to Figure 6-3. The RF input to the driver board is applied to the preamplifier module (Q1). A portion of the RF input is applied to an RF-detection circuit on the board. This circuit rectifies and filters the RF input into an OK signal. Loss of the RF input and the OK signal results in an exciter output fault. The preamplifier module is a three-stage RF power amplifier on a single IC. The first and third stages are powered by an AGC signal. These are the variable gain stages, and control the forward power output of the PA. The first and third stages of the preamp module are powered by an AGC signal, generated on the metering board. AGC signal voltage is monitored for status only. The second stage of the preamplifier module is a nonvariablegain stage, powered by +13.5-volt power. The current drawn by the AGC and +13.5-volt power signals contributes to the preamplifier current metering. The amplified RF output from the preamp module is applied to the IPA (Q2). The current drawn from the IPA’s +25-volt power source is monitored to determine the IPA current metering. The amplified RF output from the IPA is monitored for forward and reflected power levels. The power samples detected at this location determine the IPA forward - and reflected-power metering. Power-Monitoring Theory Power-monitor circuits are located on the driver board, PA boards, and combiner board. A microstrip line parallel to the RF signal path couples a small portion of the ac signal across a rectifier and filtering circuit. The ac signal may be rectified to detect either the forward or reflected power. After filtering, a dc sample voltage is available that is proportional to the power detected at the monitored location. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 6-3 250-Watt Gold Line Power Amplifier THEORY OF OPERATION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 After monitoring, the amplified RF output from the IPA is split in two by means of an RF splitter, commonly known as a Wilkinson splitter. The two split RF signals are applied to driver-1 (Q3) and driver-2 (Q4). The current drawn from each driver’s +25-volt power source is monitored to determine the driver-1 and driver-2 current metering. The amplified RF outputs from the two drivers are the driver board’s 40-watt RF outputs. Wilkinson Splitter/Combiner Theory Wilkinson splitter and combiner networks are located in the RF signal path on the driver board, PA boards, and combiner board. A waster resistor is located a precise distance from the signal junction. This resistor dissipates any out-of-phase imbalance or amplifier imbalance that may exist between the RF signals being split or combined, resulting in a more stable amplifier. 6.2.2 PA Board RF Flow Each PA board amplifies a 40-watt RF input into a 150-watt RF output. Refer to Figure 63. The RF input to the PA board is split into four signals by means of three Wilkinson splitters. Each RF signal drives a power amplifier, for a total of four amplifiers (Q1, Q2, Q3, and Q4). Q1 and Q2 receive operating power from a common +25-volt power source. The current drawn by this source is monitored to determine the PA board’s A-pair current. Likewise, the current drawn by Q3 and Q4 common +25-volt power source is monitored to determine the PA board’s B-pair current. The amplified RF outputs from the four power amplifiers are combined into one by means of three Wilkinson combiners. The RF signal from the last Wilkinson combiner is monitored for forward and reflected power levels. The power samples detected at this location determine the PA board’s forward and reflected power metering. The combined and monitored RF signal is the PA board’s 150-watt RF output. 6.2.3 Combiner Board RF Flow The combiner board combines two 150-watt RF inputs into a single 275-watt RF output. Refer to Figure 6-3. The two RF inputs are combined by a Wilkinson combiner. The combined RF is monitored for forward power level. The power sample detected at this location determines the total forward power metering. The combined and monitored signal is the combiner board’s 275-watt RF output. 6.2.4 Isolator RF Flow The isolator conducts its 275-watt RF input only in the forward direction, suppressing any intermodulation or VSWR present at its RF output. Refer to Figure 6-3. The RF input is applied through a circulator. The optional triple isolator RF input is applied through three circulators. Circulator Theory A circulator consists of several circular layers of copper, ferrite, and a magnetic material that biases the ferrite. The circulator has three inputs/outputs. The biased ferrite conducts electricity only in one direction, outputting the signal applied at its previous input. Each circulator provides 25 dB of isolation. Page: 6-4 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier THEORY OF OPERATION The circulator RF output is applied through a notch filter to remove the second harmonics generated by the circulator. This filtered RF is the isolator’s RF output. This RF output is typically 250 watts for a standard isolator or 225 watts for a triple isolator. Any reflected power present at the isolator RF output is conducted back through the circulator to a rectifier and filtering circuit. This circuit generates a dc sample voltage proportional to the VSWR present at the isolator RF output. The sample voltage determines the total reflectedpower metering. 6.3 Control Distribution Refer to Figure 6-1. The PA control inputs are received through a DB15 connector, which mates with J6 on the exciter/PA control. Two types of control inputs are received: AGC reference and multiplexer. 6.3.1 AGC Signal Flow The metering board compares the AGC reference signal (from the exciter) with the total forward power sample (from the combiner board) to create an AGC signal (to the driver board). Refer to Figure 6-2. The AGC reference signal and the total forward power sample are applied to an integrator circuit, which generates the AGC signal. An increase in the AGC reference signal or a decrease in the total forward power sample causes an increase in the AGC signal. This AGC signal provides operating power for the first and third amplifier stages of the preamplifier. Divider circuitry reduces a portion of the AGC signal to a sample voltage, which determines the AGC metering. 6.3.2 Multiplexer Control Signal Flow Analog Multiplexer Theory Three analog multiplexers are located on the metering board. Each multiplexer receives as many as eight analog inputs, at a sample voltage which represents a PA parameter or status. Control lines from the exciter command the multiplexer to connect one of the inputs to a common output, which is measured by the exciter. The multiplexer is switched quickly between the analog inputs, resulting in a multiplexed analog output. Refer to Figure 6-2. The exciter controls each multiplexer by four control lines: three address lines and a latch. The address lines (0, 1, and 2) are binary signals with a total of eight possible states. The address lines sequence through the eight states in about 360 microseconds. As each state occurs, the latch line is toggled, selecting the analog input corresponding to that address state. The voltage present at the multiplexer common output is the most recently latched analog input. 6.4 Status Distribution Refer to Figure 6-1. The PA status outputs are supplied through the same DB15-type connector as the PA control inputs, which mates with J6 on the exciter/PA control. Two types of status outputs are supplied: multiplexed (mux) analog and PA fault. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 6-5 250-Watt Gold Line Power Amplifier THEORY OF OPERATION 6.4.1 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Mux Analog Status Signal Flow Mux analog status signals consist of dc voltages that represent a parameter or fault within the PA. These signals are generated by current detectors, power monitors, and metering dividers, which supply a status voltage proportional to the level of parameter it is representing, or the existence of the fault it is representing. Refer to Figure 6-2. These status voltages are applied to one of the three multiplexers located on the metering board. The multiplexers route the appropriate status voltage to the exciter in the form of mux analog. Table 6-1 lists all status voltage nomenclature, the multiplexer that routes that voltage, and the control address that directs the multiplexer to route that voltage. 6.4.2 PA Fault Signal Flow A PA fault signal is activated when a reflected power threshold is exceeded by the PA1 or PA2 board. Refer to Figure 6-2. A portion of the PA1 board and PA2 board reflected power status voltages are applied to a comparator and switching circuit. When either status exceeds a voltage representing about 20 watts, the switch is activated. The switch applies a PA fault to the exciter, which shuts down the transmitter. Table 6-1 Multiplexer Analog Status Inputs Page: 6-6 addr multiplexer 1 multiplexer 2 multiplexer 3 000 PA1-A current preamp current total forward power 001 PA1-B current IPA current (no input) 010 PA2-A current driver-1 current IPA forward power 011 PA2-B current driver-2 current IPA reflected power 100 PA1 forward power (no input) +25V voltage level 101 reflected power (no input) +13.5V voltage level 110 PA2 forward power exciter output fault +5V voltage level 111 PA2 reflected power AGC voltage level PA heat sink temp Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier THEORY OF OPERATION v0229.hgl Figure 6-1 250-Watt PA Interconnection Diagram Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 6-7 250-Watt Gold Line Power Amplifier THEORY OF OPERATION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 v0203.hgl Figure 6-2 250-Watt PA Functional Diagram Page: 6-8 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier THEORY OF OPERATION v0202l .hgl Figure 6-3 250-Watt PA Detailed Functional Diagram Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 6-9 250-Watt Gold Line Power Amplifier THEORY OF OPERATION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 v0202r.hgl 250-Watt PA Detailed Functional Diagram Page: 6-10 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier THEORY OF OPERATION v0204l .hgl Figure 6-4 Metering Board Functional Diagram Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 6-11 250-Watt Gold Line Power Amplifier THEORY OF OPERATION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 0204r.hgl Metering Board Functional Diagram Page: 6-12 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier MAINTENANCE MAINTENANCE Refer to the system and VDT manuals. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 7-1 250-Watt Gold Line Power Amplifier MAINTENANCE Page: 7-2 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier CHECKOUT AND TROUBLESHOOTING CHECKOUT AND TROUBLESHOOTING Refer to the system and VDT manuals. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 8-1 250-Watt Gold Line Power Amplifier CHECKOUT AND TROUBLESHOOTING Page: 8-2 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 9.1 250-Watt Gold Line Power Amplifier REMOVAL AND REINSTALLATION REMOVAL AND REINSTALLATION PA Chassis Removal and Reinstallation Figure 9-1 shows details of removing and reinstalling the chassis. Calibration of forward and reflected power is required after reinstallation. 9.2 PA RF Module Removal and Reinstallation Figure 9-2 shows details of removing and reinstalling PA RF modules. 9.3 Metering Board Removal and Reinstallation Figure 9-3 shows details of removing and reinstalling the metering board. Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 9-1 250-Watt Gold Line Power Amplifier REMOVAL AND REINSTALLATION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 v0223.hgl Figure 9-1 PA Removal and Reinstalllation Page: 9-2 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Print Date: 12/17/96 250-Watt Gold Line Power Amplifier REMOVAL AND REINSTALLATION Copyright © 1996 Glenayre Page: 9-3 250-Watt Gold Line Power Amplifier REMOVAL AND REINSTALLATION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 v0225.hgl Figure 9-2 PA RF Module Removal and Reinstallation Page: 9-4 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier REMOVAL AND REINSTALLATION Figure 9-2 PA RF Module Removal and Reinstallation (continued) Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 9-5 250-Watt Gold Line Power Amplifier REMOVAL AND REINSTALLATION Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 v0228.hgl Figure 9-3 Metering Board Removal and Reinstallation Page: 9-6 Copyright © 1996 Glenayre Print Date: 12/17/96 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 250-Watt Gold Line Power Amplifier REMOVAL AND REINSTALLATION v0227.hgl Figure 9-3 Metering Board Removal and Reinstallation (continued) Print Date: 12/17/96 Copyright © 1996 Glenayre Page: 9-7 250-Watt Gold Line Power Amplifier REMOVAL AND REINSTALLATION Page: 9-8 Glenayre Document Number: 9110.00160 Issue 1, Rev. C: 10/21/96 Copyright © 1996 Glenayre Print Date: 12/17/96
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