ISC Technologies ISC-T8311 Licensed Non-Broadcast Station Transmitter User Manual User s Manaul

ISC Technologies Inc Licensed Non-Broadcast Station Transmitter User s Manaul

Contents

User's Manaul

DSP Exciter USER MANUAL P N 9110.0 0172 (old part number = 916-T70A-003) REV P RELEASED Specifications subject to change without notice Copyright © 2011 ISC Technologies 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 ISC Technologies. DSP Exciter Issue 1, Rev. P: 6/6/2012
Print Date: 6/6/2012 Copyright © 2011 ISC Technologies
Document Change Record Issue 1, Rev. P: 6/6/2012 Document Change Record Issue: Rev D Date: 4/25/96 Changes: changed VCO-2 status reading Issue: Rev E Date: 5/14/96 Changes: added Over-The-Link and On-The-Fly information Issue: Rev F Date: 5/23/96 Changes: added one RU space for reinstallation and net channel change time for setup Issue: Rev G Date: 9/03/96 Changes: changed PA fault input pin 11 on Table 4-4 Issue: Rev H Date: 9/20/96 Changes: revised chapter 4 jumper information, added Table 4-5 Issue: Rev I Date: 01/15/97 Changes: added and changed VCO board numbers in Table 3-1 Issue: Rev J Date: 09/22/97 Changes: changed channel select 1 to J4-22, channel select 2 to J4-10, channel select 3 to J4-6 in remote select input vs. channel table; changed channel select 1 to J1-7, channel select 2 to J1-26, and channel select 3 to J1-8 in remote select input vs channel I20 table; changed mode select 2 line to channel select 4 as J1-9, and mode select 1 to J1-27 in remote select input vs. mode I20 table Issue: Rev K Date: 11/12/97 Changes: changed multi-channel adjustment procedure to a reading of 2.8 volts Issue: Rev L Date: 05/14/99 Changes: added nominal powers for different frequency ranges in exciter specifications table Issue: Rev M Date: 07/12/99 Changes: added GL-T8200 to part numbers of VCO/RF amplifier boards table Issue: Rev N Date: 9/25/11 Changes: Changes made to support Narrowband Directive Issue: RevP Date: 6/6/12 Changes: Changes made to support Narrowband Directive DSP Exciter ISC Technologies Document Number: 9110.00172 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Table of Contents 1 GENERAL ................................................................................................................... 1-1 1.1 Manual Scope ..................................................................................................... 1-1 1.1.1 Applicable Documents .................................................................... 1-1 1.2 Manual Sections .................................................................................................. 1-1 1.3 Exciter Identification ..................................................................................... 1-1 2 SPECIFICATIONS ..................................................................................................... 2-1 3 DESCRIPTION ........................................................................................................... 3-1 3.1 Introduction ................................................................................................... 3-1 3.2 Physical Description ........................................................................................... 3-1 3.3 Simplified Block-Diagram Description .............................................................. 3-2 4 INSTALLATION AND SETUP ................................................................................. 4-1 4.1 Precautions and Hazards ..................................................................................... 4-1 4.2 Test Equipment and Tools Required ................................................................... 4-1 4.3 Component and Adjustment Locations ............................................................... 4-1 4.4 Installation ..................................................................................................... 4-1 4.4.1 Inspection ........................................................................................ 4-1 4.4.2 Power Requirement ................................................................................ 4-2 4.4.3 Input/Output Connections ............................................................... 4-2 4.4.4 Signal Functions .............................................................................. 4-2 4.4.5 Switches and Jumpers ..................................................................... 4-4 4.5 Setup .............................................................................................................. 4-4 4.6 Ultimate Disposition ........................................................................................... 4-4 5 OPERATION .............................................................................................................. 5-1 5.1 Front-Panel Controls and Indicators .............................................................. 5-1 5.2 Operating Instructions ................................................................................... 5-1 6 THEORY OF OPERATION ...................................................................................... 6-1 6.1 Exciter/PA Control ............................................................................................. 6-1 6.1.1 Reference Source ............................................................................. 6-1 6.1.2 Main Circuit Frequencies ................................................................ 6-1 ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 Table of Contents Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: i
6.1.3 Controller Interface Connector Functions ....................................... 6-1 6.2 Interface to Controller ......................................................................................... 6-3 6.2.1 General ............................................................................................ 6-3 6.2.2 Interface Conversion Functions ....................................................... 6-3 6.3 DSP Modulator ................................................................................................... 6-4 6.3.1 General ............................................................................................ 6-4
Table of Contents Issue 1, Rev. P: 6/6/2012 6.3.2 DSP Modulator Signal Flow ................................................................. 6-4 6.4 IF Stage .............................................................................................................. 6-7 6.4.1 Mixer-1 ........................................................................................... 6-7 6.4.2 Filter ............................................................................................... 6-7 6.4.3 VCO-1 ............................................................................................ 6-7 6.4.4 Synthesizer-1 .................................................................................. 6-7 6.5 MCU ................................................................................................................... 6-8 6.5.1 Microcontroller Unit (MCU) .......................................................... 6-8 6.5.2 Digital-to-Analog (D/A) Converter ................................................ 6-9 6.5.3 8/16-Bit Converter .......................................................................... 6-9 6.5.4 Read-Only Memory ............................................................................... 6-9 6.5.5 VSWR-Fault Detector ......................................................................... 6-14 6.5.6 Alarm Data-to-Logic Conversion ........................................................ 6-14 6.6 RF Assemblies .................................................................................................. 6-14 6.6.1 RF Stage Location ........................................................................ 6-14 6.6.2 RF Assemblies .............................................................................. 6-14 6.7 Voltage Regulator Circuit ................................................................................. 6-16 7 MAINTENANCE ....................................................................................................... 7-1 7.1 Location of Maintenance Procedures ................................................................. 7-1 7.2 Test Equipment Required ................................................................................... 7-1 7.3 VCO-2 Adjustment Procedure ........................................................................... 7-1 7.3.1 VCO-2 Multichannel Adjustment Procedure ........................................ 7-1 7.3.2 VCO-2 Single-Channel Adjustment Procedure ..................................... 7-1 7.4 Over-The-Link Downloading ............................................................................. 7-2 7.5 On-The-Fly Channel/Mode Changing ................................................................ 7-2 7.5.1 Programming Example ................................................................... 7-3 7.6 16-Channel Operation ........................................................................................ 7-4 7.7 On-The-Fly Interface .......................................................................................... 7-5 8 CHECKOUT AND TROUBLESHOOTING ........................................................... 8-1 8.1 CHECKOUT ...................................................................................................... 8-1 DSP Exciter ISC Technologies Document Number: 9110.00172 Page: ii Copyright © 2011 ISC Technologies Print Date: 6/6/2012
8.2 TROUBLESHOOTING ..................................................................................... 8-1 9 REMOVAL AND REINSTALLATION ................................................................... 9-1 9.1 Exciter/PA Control Chassis ................................................................................ 9-1 9.1.1 Removal Procedure ......................................................................... 9-1 9.1.2 Reinstallation Procedure ................................................................. 9-1 9.2 Exciter Cover ...................................................................................................... 9-2
9.2.1 Removal Procedure ......................................................................... 9-2 9.2.2 Reinstallation Procedure .................................................................. 9-2 9.3 Exciter/Control Board ......................................................................................... 9-5 9.3.1 Removal Procedure ......................................................................... 9-5 9.3.2 Reinstallation Procedure .................................................................. 9-5 9.4 Interface Board ................................................................................................... 9-8 9.4.1 Removal Procedure ......................................................................... 9-8 9.4.2 Reinstallation Procedure .................................................................. 9-8 9.5 VCO/RF Amplifier Board ................................................................................... 9-8 9.5.1 Removal Procedure ......................................................................... 9-9 9.5.2 Reinstallation Procedure .................................................................. 9-9 10 OPTIONS ................................................................................................................. 10-1 10.1 Exciter/PA Control with QT-1000 Interface ................................................... 10-1 10.1.1 Reference Source ............................................................................... 10-1 10.1.2 Controller Interface Connector Functions .......................................... 10-1 10.1.3 QT-1000 Interface Conversion Functions .......................................... 10-1 10.2 Exciter/PA Control with Standard Interface ................................................... 10-5 10.2.1 Reference Source ............................................................................... 10-5 10.2.2 Controller Interface Connector Functions .......................................... 10-6 10.2.3 Standard Interface Conversion Functions .......................................... 10-6 ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 Table of Contents Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: iii
Table of Contents Issue 1, Rev. P: 6/6/2012 10.3 Exciter/PA Control with I20 Interface ............................................................ 10-9 10.3.1 Reference Source ............................................................................... 10-9 10.3.2 Controller Interface Connector Functions ......................................... 10-9 10.3.3 I20 Interface Conversion Functions .................................................. 10-9 DSP Exciter ISC Technologies Document Number: 9110.00172 Page: iv Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 List of Figures List of Figures Figure 1-1 DSP Exciter Isometric View ......................................................................... 1-2 Figure 3-1 DSP Exciter Rear View ................................................................................. 3-3 Figure 3-2 DSP Exciter Top View with Internal Controls and Indicators ........................................................ 3-4 Figure 3-3 DSP Exciter Simplified Functional Diagram ................................................ 3-5 Figure 4-1 DSP Exciter/PA Control Circuit Boards Interconnection Diagram ........................................................................... 4-5 Figure 5-1 Front-Panel Controls and Indicators .............................................................. 5-2 Figure 6-1 DSP Exciter RF Stage Functional Diagram .................................................. 6-2 Figure 6-2 DSP Exciter MCU Circuit Functional Diagram ............................................ 6-6 Figure 6-3 DSP Exciter-to-Controller Functional Diagram ............................................ 6-10 Figure 6-4 DSP Exciter Detailed Functional Diagram .................................................... 6-12 Figure 6-5 DSP Exciter IF-Stage Detailed Functional Diagram ................................................................................... 6-13 Figure 7-1 On-The-Fly C2000 Control Lines to DSP Exciter ........................................ 7-5 Figure 9-1 DSP Exciter Chassis Removal and Reinstallation ...................................................................................... 9-3 Figure 9-2 DSP Exciter Cover Removal and Reinstallation ...................................................................................... 9-4 Figure 9-3 DSP Exciter Control Board Removal and Reinstallation .............................. 9-7 Figure 9-4 DSP Exciter External Interface I/O Board Removal and Reinstallation …….9-10 Figure 9-5 DSP Exciter Interface Board Removal and Reinstallation …………………..9-11 ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: v
Issue 1, Rev. P: 6/6/2012 List of Tables List of Tables Table 1-1 Manual Contents ...................................................................................... 1-1 Table 2-1 Exciter Specifications ............................................................................... 2-1 Table 3-1 Part Numbers of VCO/RF Amplifier Boards ........................................... 3-1 Table 3-2 Part Numbers of Interface Boards ............................................................ 3-1 Table 3-3 Part Numbers of Interface I/O Boards ...................................................... 3-2 Table 3-4 Assembly and Control Board Numbers .................................................... 3-2 Table 4-1 Test Equipment Required ......................................................................... 4-1 Table 4-2 DSP Exciter I/O Connectors ..................................................................... 4-2 Table 4-3 VT100 Interface Connector J3 Pin Assignments ...................................... 4-3 Table 4-4 Control Board Connector J6 Pin Assignments ......................................... 4-3 Table 4-5 Exciter Control Board Jumper Positions .................................................. 4-4 Table 6-1 Exciter RF/Main Circuit Frequencies ....................................................... 6-1 Table 7-1 Deviation and Offset Programming .......................................................... 7-3 Table 10-1 Interface Board Connector J4 (QT-1000) ................................................... 10-3 Table 10-2 Receiver Connector J5 Pin Functions (QT-1000 with external I/O board) .......................................................... 10-4 Table 10-3 Remote Select Input vs. Channel (QT-1000) .............................................. 10-4 Table 10-4 Remote Select Input vs. Mode (QT-1000) .................................................. 10-5 Table 10-5 Interface Board Connector J4 (Standard) .................................................... 10-7 Table 10-6 Remote Select Input vs. Channel (standard) ............................................... 10-8 Table 10-7 Remote Select Input vs. Mode (standard) ................................................... 10-8 Table 10-8 Interface Board Connector J1 ................................................................... 10-10 Table 10-9 Interface Board Connector J2 ................................................................... 10-11 Table 10-10 Remote Select Input vs. Channel (I20) ................................................... 10-12 Table 10-11 Remote Select Input vs. Mode (I20) ....................................................... 10-12 Page: vi Copyright © 2011 ISC Technologies Print Date: 6/6/2012 ISC Technologies Document Number: 9110.00172 DSP Exciter DSP Exciter ISC Technologies Document Number: 9110.00172 Page: viii Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 GENERAL 1 GENERAL 1.1 Manual Scope This manual is intended for use as a technical reference guide to the ISC Technologies DSP exciter and contains information on exciter connection, setup, and maintenance. 1.1.1 Applicable Documents Applicable ISC Technologies documents are listed in the applicable system manual. 1.2 Manual Sections Refer to Table 1-1, Manual Contents. Also refer to table of contents in this manual. Table 1-1 Manual Contents section No. and title contents 1 General this section 2 Specifications exciter specifications 3 Descriptions listing of options and assemblies covered, simplified description, physical description, simplified block theory of operation 4 Installation and Setup exciter installation, setup, and lists of connections 5 Operation list, description, and location of operator controls and indicators 6 Theory of Opera- tion assembly-level description of exciter operation 7 Maintenance exciter maintenance 8 Checkout and Troubleshooting exciter checkout and troubleshooting 9 Removal and Re- installation procedures for removing and reinstalling exciter and exciter as- semblies 10 Options list and discussion of user selectable options 1.3 Exciter Identification Refer to Figure Figure 1-1, DSP Exciter Isometric View, for an overall view of the exciter. ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 1-1
GENERAL Issue 1, Rev. P: 6/6/2012 v 0 2 5 0 . hg l Figure 1-1 DSP Exciter Isometric View DSP Exciter ISC Technologies Document Number: 9110.00172 Page: 1-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 SPECIFICATIONS 2 SPECIFICATIONS Refer to Table 2-1, Exciter Specifications, which lists the DSP exciter specifications. Where possible, EIA or I-EIS A measuring methods were used in determining specifica-tions. Note that some specifications are not addressed by either set of standards or the prescribed methods were impractical. Table 2-1 Exciter Specifications characteristic condition specification adjacent-channel noise 12.5-kHz channel spacing, in analog mode -81 dBc 12.5-kHz channel spacing, in FSK mode -71 dBc alternate channel noise 12.5-kHz channel spacing -91 dBc spurious -90 dBc operating frequency range determined by installed VCO/RF board refer to Table 3-1 RF output power (mW, nominal) keyed 150 MHz 280 300 450 900 (GL-T8500/GL-T8600) 900 (GL-T8501/GL-T8601) 250 500 1000 300 300 15 carrier frequency stability steady state, -30° to +60° C 10-MHz reference, int=0.005 ppm/yr, ext=0.1 ppm/yr FSK frequency/modulation stability relative to carrier frequency stability +/- 10 Hz max FSK adjustment accuracy +/- 10 Hz analog offset resolution 1 Hz number of channels up to 8, depending on interface board and controller frequency spread 3 MHz at 900 MHz (12 MHz wideband option) 7.5 MHz at 450 MHz 5 MHz at 150 MHz audio input level -25 to +10 dBm (N/A for digital only series) ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 2-1
impedance with transformer 600 ohm or 5 kohms balanced
SPECIFICATIONS Issue 1, Rev. P: 6/6/2012 Table 2-1 Exciter Specifications (continued) characteristic condition specification audio response (N/A for digital only series ) flat, 50 to 2800 Hz; not referenced to 1 kHz; 60% deviation +/-0.5 dB preemphasized 6 dB per octave, 300 to 3000 Hz; 60% deviation +/-0.75 dB audio distortion (1-kHz reference at 60% deviation) (N/A for digital only series) 12.5-kHz channel spacing less than 2.0% audio response (tracking between units) (N/A for digital only series) level 0.1 dB max delay 2 usec max FM hum and noise (1-kHz reference at 60% deviation) (N/A for digital only series) 12.5-kHz spacing flat, 8.5-kHz bandwidth -34 dB 12.5-kHz channel spacing preemphasized, 300 to 3000 Hz -49 dB AM hum and noise standard -34 dB modulation types analog, 2-level FSK, 4-level FSK avail- able with some interfaces (N/A for digital only series) channel spacing 6.25 kHz audio-backward compatibility Standard (N/A for digital only series) emissions FCC 15K0F2D, 16K0F1D, 16K0F3E 9K6F1D for 152.0-174.0 MHZ & 406.0-470.0 MHz 5K60F2D for 152.0-174.0 MHz power requirement 22-29 Vdc less than 3 A humidity noncondensing 0 to 95% relative external 10-MHz reference input level 2Vp-p min impedance 50 ohms spurious above 8 MHz -65 dBc max spurious below 8 MHz -50 dBc max weight 4.8 lb (2.2 kg) dimensions 8.75 in (22.25 cm) d x 19 in (48.25 cm) w x 1.75 in (4.5 cm) h temperature range operating (nonderated) -30° to +60° C storage -55° to +70° C DSP Exciter ISC Technologies Document Number: 9110.00172 Page: 2-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
maximum elevation to 10,000 ft (3050 m)
Issue 1, Rev. P: 6/6/2012 DESCRIPTION 3 DESCRIPTION 3.1 Introduction The DSP exciter contains a microprocessor that allows remote or local control of the exciter and consolidates logic for varying degrees of PA control and monitoring through a video display terminal (VDT). Operating characteristics of the exciter are controlled by the selection of hardware options. It is frequency selectable by specifying the appropriate internal frequency determining hardware and software. It is also capable of communicating with several operating protocols through the proper selection of interface boards. 3.2 Physical Description The exciter front panel of one RU (1.75 in) in height contains eight LEDs, two adjustments, and one connector (also see section 5). The exciter chassis is nine inches deep and contains three circuit boards and space for an oscillator (not used with some controllers). Refer to Table 3-1, Part Numbers of VCO/RF Amplifier Boards, which shows subassemblies used for various transmitter operating ranges. ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 3-1
DESCRIPTION Issue 1, Rev. P: 6/6/2012 Table 3-1 Part Numbers of VCO/RF Amplifier Boards transmitter model VCO/RF-amplifier board frequency band (MHz) VCO board assembly part No. control board assembly part No. GL-T85/8601 929-941 263-0082-072 265-0082-001 936-948 263-0082-070 265-0082-001 924-936 263-0082-069 265-0082-001 GL-T85/8600 900-960 (wb) 263-0082-051/052/053/054/ 055/062 265-0082-024/032 948-960 263-0082-055 265-0082-001 936-948 263-0082-054 265-0082-001 929-941 263-0082-068 265-0082-001 924-936 263-0082-053 265-0082-001 GL-T8200 929-941 263-0082-068 265-0082-001 ISC-T53/5540 406-470 263-0084-003 not yet available GL-T83/8531 320-330 263-0082-049 265-0082-001 GL-T83/8521 275-285 263-0082-047 265-0082-001 ISC-T83/84/8611 167-175 2100.00094 265-0082-024 162-172 2100.00093 265-0082-024 157-167 2100.00092 265-0082-024 152-162 2100.00091 265-0082-024 Refer to Table 3-2, Part Numbers of Interface Boards. Table 3-2 Part Numbers of Interface Boards DSP exciter-to-controller interface boards interface board part No. QT-1000 interface bd 265-0082-007 standard Interface bd 263-0082-036 I20 interface bd 265-0082-032, 2000.00436 DSP Exciter ISC Technologies Document Number: 9110.00172 Page: 3-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 DESCRIPTION Refer to Figure 3-1, DSP Exciter Rear View, which shows the exciter rear panel. The back panel contains three BNC-type connectors J3/J7/J8, a DB-15 connector J6, and a terminal board TB 1 as standard items. Other back panel connectors vary depending on which interface and I/O boards are installed. Figure 3-2, DSP Exciter Top View with Internal Controls and Indicators, shows a top view of the exciter with its cover removed. Refer to Table 3-3, Part Numbers of Interface I/O Boards, which shows interface and I/O board part numbers. The I/O boards comprise the means to connect various controllers to the DSP exciter.. Table 3-3 Part Numbers of Interface I/O Boards interface I/O board (control type) interface I/O board part No. QT-1000 Interface I/O bd 261-0082-003 Standard Interface I/O bd 261-0082-004 I20 Interface I/O bd N/A Table 3-4 Assembly and Control Board Numbers exciter assembly No. control board No. Various 265-0082-001 Various 265-0084-024 Various 2000.02090 3.3 Simplified Block-Diagram Description Refer to Figure 3-3, DSP Exciter Simplified Functional Diagram, in the following discus-sion. Inputs from the transmitter controller usually are one or two data bits, two channel-select bits, and keying input. Outputs to the controller are keying output indicator, various ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 3-3
fault outputs, forward-power sample, and reflected-power sample.
DESCRIPTION Issue 1, Rev. P: 6/6/2012 v 0 3 4 3 . hg l Figure 3-1 DSP Exciter Rear View DSP Exciter ISC Technologies Document Number: 9110.00172 Page: 3-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 DESCRIPTION v 0 3 4 4 . hg l ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 2-5 (N/A for digital only series)
DESCRIPTION Issue 1, Rev. P: 6/6/2012 v 0 2 5 1 . hg l Figure 3-3 DSP Exciter Simplified Functional Diagram DSP Exciter ISC Technologies Document Number: 9110.00172 Page: 2-6 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
4 INSTALLATION AND SETUP 4.1 Precautions and Hazards Caution PC boards within this assembly use static-sensitive components. Follow IC-handling precautions. Caution The exciter contains internal memory which is used to characterize exciter operation. Upon exciter replacement, ensure that replacement exciter contains appropriate items in its memory. 4.2 Test Equipment and Tools Required Table 4-1, Test Equipment Required, lists required test equipment. Common hand tools may also be required for most procedures. Table 4-1 Test Equipment Required item description tuning tool Johanson 8777 or equivalent RF power meter Bird model 8327 or equivalent with appropriate RF adapters voltmeter Fluke model 77 DVM or equivalent RF dummy load 50-ohm load 4.3 Component and Adjustment Locations Figure 3-3, DSP Exciter Simplified Functional Diagram, shows the location of assemblies, internal user-adjustable controls, and I/O locations. Note that most adjustments are performed via the front-panel VT100 interface. 4.4 Installation 4.4.1 Inspection Inspect exciter to ensure air flow is not obstructed and cables and wires are securely fastened to their respective connectors. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 INSTALLATION AND SETUP Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 4-1
4.4.2 Power Requirement The DSP exciter, when used as a component of a transmitter, draws its power from system wiring. Current draw is less than three amperes at 22 to 29 volts. It is normally powered by the transmitter power supply but can be powered by an auxiliary supply. 4.4.3 Input/Output Connections Figure 3-3, DSP Exciter Simplified Functional Diagram, shows the locations of I/O connectors; Table 4-2, DSP Exciter I/O Connectors, lists I/O connectors and describes their functions. Normally the exciter is delivered as part of an entire transmitter and has already been installed in a rack, with all connections already made, except for connections to equipment that was not installed in the rack before shipment. If I/O connections are required, refer to the system-interconnect diagram and other instructions in the transmitter manual. 4.4.4 Signal Functions See Table 4-2, DSP Exciter I/O Connectors, which references other tables that describe pinby-pin functions of multipin connectors. Figure 4-1, DSP Exciter/PA Control Circuit Boards Interconnection Diagram, shows interconnections among internal assemblies. Table 4-2 DSP Exciter I/O Connectors stencil/connector description additional detail VT100 INTERFACE: J3 VT100 interface to VDT (front) Table 4-3 RF OUT: J3 RF out, on frequency Figure 6-1 QT-1000 interface I/O J4 interface to QT-1000 interface board Table 10-1 QT-1000 interface I/O J5 DB-9 connector, to receiver Table 10-2 standard interface I/O J4 interface to standard interface I/O board Table 10-1 GL-C2000 interface I/O J4 interface to GL-C2000 interface I/O board PA CONTROL: J6 connects to PA Table 4-4 ISOLATOR IN: J7 VSWR input from PA Figure 3-1 10 MHZ IN: J8 external reference input from interface Figure 3-1 +26 VDC: TB1 exciter input power, +22-29 Vdc Figure 3-1 DSP Exciter ISC Technologies Document Number: 9110.00172 INSTALLATION AND SETUP Issue 1, Rev. P: 6/6/2012 Page: 4-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Table 4-3 VT100 Interface Connector J3 Pin Assignments J3-X (front) signal description 2 TXD transmit data line 3 RXD receive data line 5 GND ground 1,4,6,7,8,9 not used Table 4-4 Control Board Connector J6 Pin Assignments J6-X signal description J6-X signal description 1 A/D1+ multiplex analog input from PA No. 1 multiplexer 9 A/D2+ multiplex analog input from PA No. 2 multi- plexer 2 A/D3+ multiplex analog input from PA No. 3 multiplexer 10 A/D4+ multiplexed analog input from PA No. 4 multi- plexer 3 AGC REF+ GC reference voltage output to PA, 1-12 Vdc 11 PA FAULT PA fault input, HI=fault 4 PA GROUND no connection 12 PA GROUND no connection 5 PA GROUND no connection 13 INPUT SELECT 1 one of four select outputs to PA multiplexers, LO=20 digit enabled for mux input decoder 6 INPUT SELECT 2/ KEY OUT one of four select out- puts to PA multiplexers, LO=21 14 INPUT SELECT 3 one of four select outputs to PA multiplexers, LO=22 digit enabled for mux input decoder 7 INPUT SELECT 4/ KEY OUT one of four select out- puts to PA multiplexers, not used 15 AUX LATCH ENABLE latch-enable output to PA multiplexers, LO=mux input decoder reads the three select inputs 8 REF SAMPLE reflected power sample input from PA ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 INSTALLATION AND SETUP Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 4-3
4.4.5 Switches and Jumpers Figure 3-2, DSP Exciter Top View with Internal Controls and Indicators, shows the locations of user-adjustable switches and jumpers. Refer to Table 4-5 for a list of software related jumper positions found on the exciter/control board. No switches are available to maintenance personnel. Table 4-5 Exciter Control Board Jumper Positions Jumper pre version 2.10 software version 2.10 software JW 1 set to A for external 10 MHz oscillator set to A for external 10 MHz oscillator set to B for internal 10 MHz oscillator set to B for internal 10 MHz oscillator JW2 set to A for password protection set to A for password protection set to B to bypass password protection set to B to bypass password protection JW3 set to A for external VSWR protection always set to B (for internal and/or ex- ternal VSWR protection) set to B for internal VSWR protection 4.5 Setup Note When doing a setup for a wideband DSP exciter, the net channel change time must be set for 300 ms. Refer to the DSP exciter VDT Menus and user manual for transmitter-control setup infor-mation. All setup is done via the front-panel VT100 interface. 4.6 Ultimate Disposition Caution This equipment may contain hazardous materials. Check with the local EPA or other environmental authority before disposing of this equipment. DSP Exciter ISC Technologies Document Number: 9110.00172 INSTALLATION AND SETUP Issue 1, Rev. P: 6/6/2012 Page: 4-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
v 0 1 6 4 . hg l Figure 4-1 DSP Exciter/PA Control Circuit Boards Interconnection Diagram ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 INSTALLATION AND SETUP Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 4-2 P9 P4 P4 P1 J1 J2 J3 J3
5.1 Front-Panel Controls and Indicators Refer to Figure 5-1, Front-Panel Controls and Indicators, which shows and describes front-panel indicators. The DSP exciter contains no front-panel controls. A front-panel access to VCO adjustment is for maintenance purposes only. 5.2 Operating Instructions The transmitter controller operates the exciter and transmitter in an unattended manner during normal system operation. The VT100 interface with a VDT enables the maintenance technician to perform maintenance and observe operational parameters. Refer to the DSP exciter VDT Menus and user manual for detailed operating information. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 OPERATION 5 OPERATION Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 5-1
OPERATION Issue 1, Rev. P: 6/6/2012 v 0 0 7 9 . hg l Figure 5-1 Front-Panel Controls and Indicators DSP Exciter ISC Technologies Document Number: 9110.00172 Page: 2-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
6 THEORY OF OPERATION 6.1 Exciter/PA Control Refer to Figure 6-1, DSP Exciter RF Stage Functional Diagram, which describes the signal flow in the DSP exciter with the transmitter controller interface. The following major para-graphs describe the operation of the major items within the figure. Additional detailed figures are referenced, as required. 6.1.1 Reference Source The ten-MHz reference signal is provided by the transmitter controller or by an optional internal reference oscillator. All other inputs and outputs, except for RF output, are routed through the interface board. 6.1.2 Main Circuit Frequencies The VCO/RF amplifier board installed determines the frequency for the RF output. Table 6-1, Exciter RF/Main Circuit Frequencies lists VCO/RF amplifier board frequencies and the corresponding exciter/output frequencies. Table 6-1 Exciter RF/Main Circuit Frequencies exciter output frequency (MHz) first IF frequency (kHz) second IF frequency (MHz) VCO-1 frequency (MHz) VCO-2 frequency (MHz) 900-960 100 90 89.9 810-870 445-470 100 90 89.9 355-380 275-330 100 90 89.9 365-420 152-174 100 90 89.9 220-270 6.1.3 Controller Interface Connector Functions Refer to Table 4-2, DSP Exciter I/O Connectors and subsequent tables for a pin-by-pin description of signal functions. The exciter interfaces with the transmitter controller through the exciter interface I/O board. Connector P4 on the internal interface board connects directly to J4 on the exciter. Alarm signals, consisting of transmitter alarm, fault, and status signals, are supplied directly to the transmitter controller. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 THEORY OF OPERATION Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 6-1
THEORY OF OPERATION Issue 1, Rev. P: 6/6/2012 v 0 1 2 3 . hg l Figure 6-1 DSP Exciter RF Stage Functional Diagram DSP Exciter ISC Technologies Document Number: 9110.00172 Page: 6-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
6.2 Interface to Controller 6.2.1 General The controller interface is the portion of exciter circuitry that connects the transmitter controller to the exciter. The interface board dictates what kind of transmitter controller may operate the transmitter. The transmitter can be operated through one of several control-lers depending on which interface board is installed in the exciter. The internal interface board may also exhibit an external I/O board. Control commands from the transmitter controller are connected through the interface circuit. This circuit supplies remote control to the microcontroller unit (MCU) control circuit. The VT-100 VDT supplies local control. The MCU control circuit generates all control signals for the other circuits, and monitors their status. The MCU control circuit reports status back to the VT-100 VDT and the interface circuit, which supplies the status to the transmitter controller. 6.2.2 Interface Conversion Functions Some signals exchanged between the controller and the exciter originate with a format, voltage, or requirement incompatible with their destination. The interface performs any signal conversions necessary to provide compatibility between the controller and the exciter. None, some, or all of the following conversion functions may be done by any one particular interface board. 6.2.2.1 Analog-Mode A/D Conversion (N/A for digital only series) The DSP modulator circuit reads synchronized serial data for its analog mode input signal. if the transmitter controller provides an analog signal, the controller interface converts the analog to the appropriate data form for the DSP. The analog (FLAT AUDIO+, -) terminates across a balanced input circuit that also provides a level adjustment. The adjustment, when properly set by the AUDIO INPUT ADJUST pot through the exciter cover, provides analog to an A/D converter at the optimum zero-dBm level. The A/D converts the analog into serial data, which is applied to the DSP through a synchronous data link. A synchronous data link is characterized by an exchange of pulse streams for timing purposes. The A/D converter is clocked by a pulse generator circuit driven by the ten-MHz reference circuit. 6.2.2.2 FSK-Data-Bit Strapping The DSP modulator circuit can read up to four bits for its digital FSK mode input signal. If the controller provides only bit 1 (DATA 1), operation in the four-level mode or higher is precluded. Bits 2 through 4 (DATA2 through DATA4) are available as FSK data inputs; whether they are used or not is a function of the particular controller interface used and the transmitter controller. Refer to Section 10. The controller interface disables unused bits by ground straps. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 THEORY OF OPERATION Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 6-2
6.2.2.3 Channel-Select-Bit Strapping The MCU control circuit reads three bits to determine the remotely selected channel. If the controller provides only bits 1 and 2 (CH SEL 1, 2), the controller can command only four channels. The operation of bit 3 is a function of the controller interface. Refer to Section 10. 6.2.2.4 Mode-Select-Bit Strapping The MCU control circuit reads two bits to determine the remotely selected mode. If the controller provides only bit 1 (MODE CONTROL), the controller can command only two transmitter modes. The operation of bit 2 is a function of the controller interface. Refer to Section 10. If the controller interface does not use bit 2, it straps it to ground (low). 6.2.2.5 Power Sample D/A Conversion The controller reads sample voltages for its forward and reflected power sample inputs, which are stored as data in the MCU control circuit. In some cases the controller interface converts the data to voltages of the appropriate range for the controller. Data from the MCU representing the forward and reflected powers is written into a dual D/A converter, which converts the data into two proportional dc voltages, which are applied to the controller. Control logic gates ensure that data is written to the proper half of the D/A converter. 6.3 DSP Modulator 6.3.1 General The DSP modulator circuit converts the data into the first IF signal, which is fully modu-lated. The IF stage circuit converts the first IF signal into the second IF signal. The RF stage circuit converts the second IF signal into the RF output. Ten MHz is used as frequency reference by each conversion stage. The DSP modulator is the portion of exciter circuitry between the controller interface and the IF stage. The DSP modulator uses digital signal processing to modulate and up-convert the paging information into the first IF signal. The modulation type depends on the transmitter operating mode. The IF stage is the portion of exciter circuitry between the DSP modulator and the RF stage. The IF stage uses hetero-dyne mixing to generate the optimum second IF signal frequency, which depends on the requirement of the VCO/RF amplifier board installed. The MCU control circuit is the command and control hub of the transmitter. The type of control software depends on the transmitter frequency and power output. The following text describes main exciter circuitry that works for all software programs, modulation schemes, and IF signal frequencies. Figure 6-2, DSP Exciter MCU Circuit Functional Diagram shows additional details. 6.3.2 DSP Modulator Signal Flow Refer to Figure 6-2, DSP Exciter MCU Circuit Functional Diagram, in the following discussion. The inputs that provide the paging information to the DSP modulator circuit are digitized audio and FSK data, supplied by the controller interface circuit through connector pair P 1/J1. Digitized audio arrives as serial data. FSK data arrives as parallel data. The DSP modulator circuit processes the digitized audio in the analog mode or the FSK data in the digital mode. The result of this processing is the exciter’s first IF signal, which is applied DSP Exciter ISC Technologies Document Number: 9110.00172 THEORY OF OPERATION Issue 1, Rev. P: 6/6/2012 Page: 6-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
to the IF stage circuit. To produce the first IF signal, the DSP modulator contains two DSPs (a signal modulator and a quadrature modulator), a digital-to-analog converter, and a read-only memory. The following text describes these four components and their signal flow. 6.3.2.1 Digital Signal Modulator The signal modulator (SM) generates modulation that contains the paging information, which is supplied by digitized audio or FSK data. The digitized audio is input into a serial input port. An external edge detector is required to input the FSK data. The SM converts one of the data inputs into a modulated signal, which is mathematically represented within the SM as a vector signal, defined by its rectangular coordinates. These coordinates, commonly known as I and Q, are supplied to the digital quadrature modulator as 16-bit parallel data. The modulated signal output from the SM depends on the following signal characteristics:  modulation scheme  frequency response or rise time  input logic or data inversion  deviation level or bandwidth  offset from carrier frequency  analog gain and deviation limit The SM also performs all communications between the DSP modulator circuit and the MCU control circuit. These communications are through the SM 16-bit parallel data port. External input and output latches expand the capabilities of this port. Control inputs consist of commands such as reset, request status, set paging signal parameter, change mode, and boot program. Requested status outputs consist of current mode, deviation levels, input level, input gain, modulation detected, and current polarity. Nonrequested status outputs indicate the existence of analog limiting and modulation. 6.3.2.2 Digital Quadrature Modulator The digital quadrature modulator (DQM) performs interpolation and up-conversion of the modulated signal. The modulated signal input to the DQM is applied by the SM as I and Q components (16-bit parallel data). The DQM performs trigonometric computations at a much higher sampling rate, which determines the first IF signal value and frequency. The modulated signal output from the DQM is supplied from its serial data port to the D/A converter. 6.3.2.3 Digital-to-Analog Converter The digital input to the digital-to-analog (D/A) converter is the modulated signal from the DQM. This data arrives as serial data. The analog output from the D/A converter is the first IF signal. In addition to the IF stage circuit, the first IF signal is supplied to the MCU control circuit, where it is rectified and filtered to generate fault logic. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 THEORY OF OPERATION Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 6-2
v 0 0 8 3 . hg l 7 Figure 6-2 DSP Exciter MCU Circuit Functional Diagram DSP Exciter ISC Technologies Document Number: 9110.00172 THEORY OF OPERATION Issue 1, Rev. P: 6/6/2012 Page: 6-6 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
6.3.2.4 Read-Only Memory A programmable and erasable read-only memory (PEROM) stores the modulator programs for both DSPs. These programs are transferred to the SM when the exciter is booted up (powered up), then the SM transfers the program to the DQM. The nonvolatile PEROM retains its program for years. Its memory may be individually reprogrammed without erasing the entire chip. 6.4 IF Stage Refer to Figure 6-1, DSP Exciter RF Stage Functional Diagram. The input to the IF stage is the first IF signal, which is supplied by the DSP modulator circuit. The first IF signal carries all the paging information on an intermediate carrier frequency. The IF stage performs direct up-conversion of the first IF signal to create the second IF signal, which carries the same paging information as the first IF signal, but on a higher carrier frequency. The second IF signal is applied to the RF stage through connector pair J10/P 10. To produce the second IF signal, the IF stage contains mixer-1 and filter circuits. Supporting these circuits are VCO-1 and synthesizer-1 circuits. Figure 6-2, DSP Exciter MCU Circuit Func-tional Diagram, and Figure 6-3, DSP Exciter-to-Controller Functional Diagram, show additional detail. 6.4.1 Mixer-1 Mixer-1 is the first heterodyne mixer. Inputs to mixer-1 are a modulated IF and a carrier. The modulated IF input is the first IF signal. The carrier input is supplied by VCO-1. The output from mixer-1 consists of two modulated carriers that are sums and difference frequencies of the inputs. These two frequencies are applied to the filter circuit. 6.4.2 Filter The filter is centered at the second IF signal frequency with a 45-kHz bandwidth. The input to the filter consists of two modulated carriers. These are sum and difference frequencies supplied by mixer-1. The output from the filter is only the sum frequency. This modulated output is the second IF signal. 6.4.3 VCO-1 VCO-1 is the local oscillator for the IF stage. The input to VCO-1 is a dc control voltage. This voltage controls VCO-1 carrier frequency and is supplied by synthesizer-1. The output from VCO-1 is a sine-wave carrier. The output is applied to mixer-1. 6.4.4 Synthesizer-1 Synthesizer-1 controls VCO-1 carrier frequency by means of a phase-locked loop (PLL). PLL inputs are a carrier and a phase reference. The reference input is a ten-MHz carrier supplied by the ten-MHz reference circuit. The carrier input is from VCO-1. The PLL output is a dc control voltage. This voltage, set to cause the VCO-1 carrier to lock phases with the reference, is supplied to VCO-1. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 THEORY OF OPERATION Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 6-2
Synthesizer-1 also performs all communications between the IF stage circuit and the MCU control circuit. A control input specifies the VCO-1 carrier frequency; this data is received over a serial data link when the exciter is booting or changing channels. Status outputs are a lock fault and a VCO1 level. The lock fault indicates loss of the carrier/reference phase lock. The VCO1 level is the VCO-1 control voltage. 6.5 MCU Refer to Figure 6-4, DSP Exciter Detailed Functional Diagram. Control outputs are supplied by the MCU control circuit to the other functional circuits. Likewise, status inputs are applied to the MCU control circuit from the other functional circuits. Discussions of these control and status signals are included with the information on the other major func-tional circuits. To interface these control and status signals, the MCU control circuit contains an MCU, D/A converter, 8/16 bit converter, read-only memory, and a VSWR-fault detector. To light the front-panel LEDs, the MCU control circuit contains a bank of PNP switching transistors. Refer to Figure 6-2, DSP Exciter MCU Circuit Functional Diagram, in the following text which describes this circuitry and its signal flow. 6.5.1 Microcontroller Unit (MCU) The MCU contains a central processing unit (CPU), memories, peripherals, and other hardware on a single chip. The primary internal functions of the MCU and their application in the exciter are described in the following list.  An eight-bit remote input port accepts discrete low power mode, emission mode, keyline, and channel selects from the controller interface circuit. An external edge detector is required to input the channel selects.  Interrupt logic stops RF transmission when a fault or reset input is received, e.g. a VSWR or PA fault.  An on-board oscillator/clock generator, driven by an external crystal, times internal MCU functions. A synchronized clock output times external functions.  The MCU performs most interfacing through a parallel communications link: eight-bit data bus, sixteen-bit address bus, and a read/write line. External input and output latches expand the capability of this link.  An eight-bit input/output port supplies discrete keyline, RF status, and chip select controls to the exciter and the PA.  A serial peripheral interface (SPI) supplies synchronous serial frequency data to the IF stage and RF stage circuits. Individual commands load the program into either IF stage’s synthesizer-1 or RF stage synthesizer-2.  An 8-input analog-to-digital (A/D) converter measures voltage inputs from the exciter and the PA. An external multiplexer expands MCU analog inputs to fifteen.  A serial communications interface (SCI) exchanges asynchronous serial RS-232 data with the VT-100 VDT. An external RS-232 driver buffers the MCU data, allowing it to be exchanged through external connector J3.  A random-access memory (RAM) temporarily stores transmitter fault and alarm values. DSP Exciter ISC Technologies Document Number: 9110.00172 THEORY OF OPERATION Issue 1, Rev. P: 6/6/2012 Page: 6-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
• An electrically-erasable read-only memory (EEPROM) permanently stores transmitter signal parameters. 6.5.2 Digital-to-Analog (D/A) Converter A D/A converter generates an AGC reference voltage. The D/A converter inputs are data and select logic. The data, supplied by the MCU when the D/A is selected, represents the desired transmitter power output. The D/A converter output is an AGC reference voltage. This voltage represents a level proportional to the desired transmitter power output. The AGC reference voltage, output through connector J6, is used by the PA to generate an AGC voltage. 6.5.3 8/16-Bit Converter An 8/16-bit converter allows the MCU eight-bit data bus to communicate with the 16-bit data bus of the DSP modulator circuit. The MCU must perform two read or write proce-dures, a low byte and a high byte, to each one of the DSP modulator circuit. The converter provides two status outputs to the MCU and the DSP modulator circuit. A data-availableto-MCU status indicates that the DSP modulator circuit has written data into the converter that the MCU must read. A data-available-to-DSP status indicates that the MCU has written data into the converter that the DSP modulator circuit must read. In the event that the DSP modulator circuit does not read data that the MCU has written, a DSP communications fault is generated. 6.5.4 Read-Only Memory A programmable and erasable read-only memory (PEROM) stores the control program for the transmitter. This program is transferred to the MCU when the exciter is booted up. The nonvolatile PEROM retains its program for years. Its memory may be individually repro-grammed without erasing the entire chip. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 THEORY OF OPERATION Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 6-2
Figure 6-3 DSP Exciter-to-Controller Functional Diagram v 0 34 5l 7 DSP Exciter ISC Technologies Document Number: 9110.00172 THEORY OF OPERATION Issue 1, Rev. P: 6/6/2012 Page: 6-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
v 0 3 4 5R .h g l ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 THEORY OF OPERATION J1
Figure 6-3 DSP Exciter-to-Controller Functional Diagram (Continued) Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 6-2
v0081.hgll Figure 6-4 DSP Exciter Detailed Functional Diagram DSP Exciter ISC Technologies Document Number: 9110.00172 THEORY OF OPERATION Issue 1, Rev. P: 6/6/2012 Page: 6-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
v0077.hglr Figure 6-5 DSP Exciter IF-Stage Detailed Functional Diagram ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 THEORY OF OPERATION Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 6-2
6.5.5 VSWR-Fault Detector The exciter receives a VSWR signal from the PA through connector J7. This signal is a rectified dc voltage sample generated by the isolator. The voltage sample is monitored by the MCU to provide the value for the total reflected-power indication. The voltage sample is also monitored by a fault circuit in the exciter. If a factory-preset voltage is exceeded, the fault circuit shuts down the transmitter by an interrupt to the MCU. 6.5.6 Alarm Data-to-Logic Conversion The transmitter controller reads logic alarm inputs; most of these alarms are stored as data in the MCU control circuit. If the controller interface converts the data to individual logic signals for the controller, data from MCU control representing the alarms is clocked into a pair of latches. The latches convert the data into continuous logic signals. These signals and others control a bank of NPN switching transistors that supply the actual logic signal to the controller. Control logic gates convert chip controls from the MCU into a clock input for the latches. 6.6 RF Assemblies 6.6.1 RF Stage Location Refer to Figure 3-3, DSP Exciter Simplified Functional Diagram, to locate the assembly. The RF stage circuits are located on two circuit boards, both housed within the exciter chassis.The exciter/control board is the main circuit board and the VCO/RF amplifier board is a selected option. The exciter/control board connects to the VCO/RF amplifier board through three connector pairs: J4/P4, J9/P9, and J10/P10. The VCO/RF amplifier board also contains BNC connector J3, which extends through the rear panel of the exciter. This board contains most of the RF stage components inside an RF shield. A hole in the shield and the front panel provide access to an RF stage adjustment, which is marked VCO ADJ on the front panel. 6.6.2 RF Assemblies 6.6.2.1 RF Stage Description The RF stage is the portion of exciter circuitry between the IF stage and RF out and is the final maj or functional circuit, the RF stage determines the transmitter RF output frequency, and dictates the highest and lowest possible RF output frequencies (RF band). The trans-mitter can be operated at several RF bands, depending on the RF stage circuitry installed in the exciter. 6.6.2.2 RF Stage Bands The selected VCO/RF amplifier board determines the RF band of the transmitter. Table 3-1, Part Numbers of VCO/RF Amplifier Boards, lists the RF bands and the part number of the board with that RF band. DSP Exciter ISC Technologies Document Number: 9110.00172 THEORY OF OPERATION Issue 1, Rev. P: 6/6/2012 Page: 6-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
6.6.2.3 RF Stage Signal Flow Refer to Figure 6-1, DSP Exciter RF Stage Functional Diagram. The input to the RF stage is the second IF signal, supplied by the IF stage circuit through connector pair J10/P 10. The second IF signal carries the paging information on a modulated carrier at the exciter’s second intermediate frequency. The RF stage converts the second IF signal into the exciter’s RF output. This RF output carries the same paging information as the second IF signal, but on a modulated carrier of radio frequency. The RF output is normally applied to the PA through connector J3. To produce the RF output, the RF stage contains mixer-2, a filter, and an amplifier. Supporting these circuits are VCO-2 and synth-2. The following text describes these five circuits and their signal flow. 6.6.2.3.1 Mixer-2 Mixer-2 is the second heterodyne mixer. Inputs to mixer-2 are a modulated IF and a carrier. The modulated IF is the second IF signal. The carrier is supplied by VCO-2. Output from mixer-2 consists of sum and difference frequencies of the inputs. The sum frequency is centered near the channel carrier, and the difference frequency about twice the second IF frequency below that. These two modulated RF carriers are applied to the filter circuit. 6.6.2.3.2 Filter The filter is factory-selected and tuned, with a bandwidth determined by carrier frequency of the transmitter. The inputs to the filter consist of two modulated RF carriers and a key control. The two carriers are sum and difference frequencies, supplied by mixer-2. The key control is supplied by the MCU control circuit through J4/P4. The output from the filter, supplied when the key control is received, is only the sum frequency. This modulated RF, centered near the channel on-frequency, is supplied to the amplifier. 6.6.2.3.3 Amplifier The amplifier provides amplification to the value listed in the specifications as exciter RF power out. The inputs to the amplifier consist of modulated RF and a key control. The modulated RF, mixer-2 sum output frequency, is supplied through the filter. Key control is supplied by the MCU control circuit through J4/P4. Output from the amplifier, supplied when the key control is received, is an amplified version of the modulated RF. This amplified output is the exciter RF output. 6.6.2.3.4 VCO-2 VCO-2 is the RF stage local oscillator. Inputs to VCO-2 are a dc control voltage and an adjustment. Dc control voltage is supplied by synthesizer-2. The adjustment, which varies the VCO2 control voltage level, is controlled through the front-panel VCO ADJ access. This control provides the means for VCO-2 to output a carrier frequency that would otherwise be beyond the range of the control voltage input. The carrier output, always second IF frequency below the channel carrier frequency, is applied to mixer-2. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 THEORY OF OPERATION Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 6-2
6.6.2.3.5 Synthesizer-2 Synthesizer-2 controls VCO-2 carrier frequency by means of a phase-locked loop (PLL). PLL inputs to synthesizer-2 are a carrier and a phase reference. The reference is a ten-MHz carrier supplied by the ten-MHz reference circuit. The carrier is the VCO-2 output. The PLL output from synthesizer-2 is a dc control voltage. This voltage, set to cause VCO-2 to lock phases with the reference, is applied to the VCO-2 control input. Synthesizer-2 also performs all communications between the RF stage circuit and the MCU control circuit. A control input to synthesizer-2 specifies VCO-2 carrier frequency. This data is received over a serial data link when the exciter is booting or changing channels. Status outputs from synthesizer-2 are a lock fault and a VCO2 level. The lock fault indicates loss of the carrier/reference phase lock. VCO2 level is the VCO-2 control voltage. 6.7 Voltage Regulator Circuit Refer to Figure 6-4, DSP Exciter Detailed Functional Diagram (center, toward bottom) in the following discussion. The exciter receives 26-volt operating power through terminal board TB 1. The dc power indicator on the exciter front panel is connected to this input. This voltage is supplied to a 26-volt bus and is monitored by the MCU. An intermediate regulator reduces the 26 volts to 16.5 volts, which is supplied to the two final regulators. One regulator generates 13.5 volts, which is supplied to a 13.5-volt bus and monitored by the MCU. The other regulator generates 5 volts, which is supplied to a five-volt bus and monitored by the MCU. DSP Exciter ISC Technologies Document Number: 9110.00172 THEORY OF OPERATION Issue 1, Rev. P: 6/6/2012 Page: 6-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
7 MAINTENANCE 7.1 Location of Maintenance Procedures The DSP exciter is central to performing transmitter maintenance. Most maintenance of electrical assemblies is done via the VT100 interface. Any maintenance procedures which require adjusting controls within the exciter chassis are listed in this section. Replace the exciter if it has input power, as indicated by the front-panel LED, but does not allow the user to make connection via the VT100 interface. 7.2 Test Equipment Required Table 4-1, Test Equipment Required, lists test equipment required to perform maintenance procedures. 7.3 VCO-2 Adjustment Procedure Perform the VCO-2 adjustment procedure after installing new VCO/RF amplifier board or after setting new channel carrier frequency. If the transmitter is to operate at more than one frequency, perform the multichannel adjustment procedure. If the transmitter is to operate at only one frequency, perform the single-channel adjustment procedure. Refer to the DSP exciter VDT manual as necessary. 7.3.1 VCO-2 Multichannel Adjustment Procedure 1. Set up VT-100 VDT and select local control (see VDT manual). 2. Select transmitter channel of lowest frequency if not already selected. 3. Use tuning tool supplied to adjust VCO AD J control through exciter front panel. Ad-just for a reading of 2.8 volts (3.5 volts for wideband VCO 263-0082-062), on VCO2 status display. 4. Return transmitter to service. Procedure is complete. 7.3.2 VCO-2 Single-Channel Adjustment Procedure This procedure does not apply to wideband option. 1. Set up VT-100 VDT and select local control (see VDT manual). 2. Select transmitter channel of operating frequency if not already selected. 3. Use tuning tool supplied to adjust V CO ADJ control through exciter front panel. Ad-just for reading of 5.0 Vdc on VCO2 status display. 4. Return transmitter to service. Procedure is complete. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 MAINTENANCE Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 7-2
7.4 Over-The-Link Downloading Over-the-link (OTL) code downloading allows C2000 transmitter controller (C2000) software, alarm matrix setup, and exciter software to be downloaded over the C2000 link channel. To properly use OTL downloading, C2000 units must be programmed for the correct control group, site ID, and unit ID, which are integral to C2000 hardware and software. When information is downloaded over the link channel, the control group, site IDs and/or unit IDs that are to receive the code must be specified. Caution If the control group, site ID, and unit ID are not specified, all units in the system accept the download information. In a mixed system, this can result in some of the transmitters being off the air. An example of this would be a GL-T8600 exciter receiving a GL-T8500 exciter programming code. The GL-T8600 exciter would not operate with this software and could result in a site visit to correct the problem. Programming of control groups and site IDs is done via the C2000 front port with a local connection or through a modem from a remote location. The control groups should be setup as a group of transmitters having the same configuration. For example, all GL-T8500 trans-mitters could be in one control group and GL-T8600 transmitters be in another. This would allow one to download exciter software to all GL-T8500 transmitters at one time by selecting their control group. Any transmitter with a different control group would not accept the download information. Site ID must be different for each site location, and is used when downloading information to a specific site location. If there are multiple units at the same site, the site ID and unit ID need to be specified to download to a specific unit. If the unit ID is not specified, all units at that site accept the download. Unit ID is programmed with a rotary switch in the C2000; it must be different for each C2000 at a site location. To download one specific unit, both site and unit ID must be specified for that unit; the unit with that site ID and unit ID is the only one that accepts the download. For assistance on how to perform a download, call ISC Technologies customer support at 217-221-0985. 7.5 On-The-Fly Channel/Mode Changing Different paging formats may require different digital deviation and offsets of paging data on the same RF carrier frequency. In the past, the only way to meet the different deviation requirements on the same frequency was to program two different channels for the same RF carrier frequency and then program those same two channels for a different digital DSP Exciter ISC Technologies Document Number: 9110.00172 MAINTENANCE Issue 1, Rev. P: 6/6/2012 Page: 7-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
deviation and offset. By changing channels, the deviation requirements of the paging formats were met. However, a channel change requires that the transmitter be unkeyed to allow time for PLL lock-up, which is a loss of air time. The on-the-fly feature allows the following:  Each channel can be programmed for four different digital modes (A, B, C, D)  Each mode allows different digital deviation and offsets to be programmed During normal paging operation, the C-2000 controller sends information to the transmitter telling it what channel to operate on and which one of the four digital modes to use. The four different digital modes of operation are controlled by the data 2 and data 3 lines into the C-2000 interface board on the DSP exciter. If the paging data requires a different devi-ation, the C-2000 transmitter controller can change the mode without having to change the channel. This allows the DSP exciter to accommodate different paging format requirements without unkeying the transmitter to change channels. 7.5.1 Programming Example To set up the exciter for the proper digital deviation and offset programming, make up a table similar to the one shown below. Next, access Digital Mode Setup menu and select View Channel Frequencies submenu. Table 7-1 Deviation and Offset Programming Channel 1&9 2&10 3&11 4&12 5&13 6&14 7&15 8&16 Mode/Dev.A 4500 4500 4500 4500 4500 4500 4500 4500 Mode/Offset A 0 +400 -400 +300 0 -300 0 0 Mode/Dev.B 4800 4800 4800 4800 4800 4800 4800 4800 Mode/Offset B 0 +200 -200 +400 0 +400 -400 0 Mode/Dev.C 2400 4200 4200 2400 2400 4200 2400 4200 Mode/Offset C 0 0 0 0 0 0 0 0 Mode/Dev.D 4200 2400 4200 2400 2400 2400 4200 2400 Mode/Offset D 0 0 +400 -400 0 0 0 0 Note Initial release has setup similar to above table. Subsequent releases may have more programming variations ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 MAINTENANCE Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 7-2
Note When on-the-fly software is used with a QT-1000 interface board installed in the exciter, only the deviation and offset programming for mode D is available. References in the exciter menus pertaining to modes A, B, and C are blanked out. 7.5.1.1 Release 2.10 DSP Exciter The C-2000 transmitter controller detects a FLEX baud rate of 1600. When this condition is detected, the mode control lines to the DSP exciter change it to mode B. If the FLEX baud rate is not detected, the mode control lines are set for mode A. This requires that mode A deviation (and offset) be set for POCSAG (512, 1200 or 2400 baud), Golay, NEC and any other paging format other than FLEX requirements. Mode B deviation and offset must be set for FLEX. Mode C and D are not used. 7.6 16-Channel Operation With 16-channel capability, the on-the-fly digital mode programming is only programmable on 8 channels. When channels 1 through 8 are programmed for different modes, channels 9 through 16 follow the same mode programming respectively (i.e. channel 9 is the same as 1, channel 10 is the same as 2, etc.). Selecting additional channels (9 through 16) is achieved by the C-2000 controller pulling mode-1 line low to the C-2000 interface board. DSP Exciter ISC Technologies Document Number: 9110.00172 MAINTENANCE Issue 1, Rev. P: 6/6/2012 Page: 7-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
7.7 On-The-Fly Interface Figure 7-1 On-The-Fly C2000 Control Lines to DSP Exciter ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 MAINTENANCE Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 7-2
Notes: A C-2000 interface board in the DSP exciter must be used with on-the-fly software All J1 pin connections shown on the above diagram are at the input to the C-2000 interface board in the DSP exciter Data 0 at the input of the C-2000 interface board controls Data 1 at its output Data 1 at the input of the C-2000 interface board controls Data 2 at its output Data 2 at the input of the C-2000 interface board controls Data 3 at its output Data 3 at the input of the C-2000 interface board controls Data 4 at its output Mode 0 at the input of the C-2000 interface board controls Mode sel 1 at its output Mode 1 at the input of the C-2000 interface board controls Mode sel 2 at its output Freq 0 at the input of the C-2000 interface board controls Ch select 1 at its output Freq 1 at the input of the C-2000 interface board controls Ch select 2 at its output Freq 2 at the input of the C-2000 interface board controls Ch select 3 at its output DSP Exciter ISC Technologies Document Number: 9110.00172 MAINTENANCE Issue 1, Rev. P: 6/6/2012 Page: 7-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 CHECKOUT AND TROUBLESHOOTING 8 CHECKOUT AND TROUBLESHOOTING 8.1 CHECKOUT The DSP exciter has two functions; it produces on-frequency RF and has a microprocessor to handle input from the PA and transmitter controller. Checkout involves verifying that RF is produced and unkeying occurs during a fault condition. 8.2 TROUBLESHOOTING The recommended troubleshooting level for the exciter is at the unit level. That is, if the exciter fails to provide the transmitter system with a usable, modulated RF-drive signal and all the exciter’s power, control, and signal inputs are normal, you should replace the exciter with a spare. ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 2-1
Issue 1, Rev. P: 6/6/2012 REMOVAL AND REINSTALLATION 9 REMOVAL AND REINSTALLATION Remove all input power from transmitter cabinet before performing these procedures. 9.1 Exciter/PA Control Chassis Refer to Figure 9-1, DSP Exciter Chassis Removal and Reinstallation , for a detailed drawing. Note Memory PROMs in the replacement exciter should be the same as in the original exciter unless the maintenance technician intends to modify exciter characteristics. Also, parameters, such as channel frequencies, may be stored in nonvolatile RAM. Ensure that the replacement exciter is programmed correctly. 9.1.1 Removal Procedure 1. Support exciter while removing the four screws from the front panel that secure it to the cabinet. Save screws for installation procedure. 2. Remove exciter from cabinet far enough to access back panel. 3. Disconnect connector J3 from connector P3 that is pigtailed off terminal board TB 1 (dc power input). 4. If a controller interface I/O panel is mounted on exciter back panel, remove I/O panel; leave all wires connected to I/O panel. 5. Tag all connectors attached to the exciter back panel. 6. Remove all connectors attached to the exciter back panel. Leave P3 connector/wiring assembly connected to terminal board TB1 for now. 7. Remove exciter. 8. Tag wires connected to terminal board TB1 on P3 connector/wiring assembly. 9. Disconnect tagged wires from terminal board TB1. Save P3 connector/wiring assem-bly for installation procedure. Procedure is complete. 9.1.2 Reinstallation Procedure Note A wideband DSP exciter that is installed in a GL-T8500 or GL-T8600 transmitter must have one rack unit of space between it and the power amplifier chassis. ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 9-1
1. Before installing exciter, connect wires on P3 connector/wiring assembly to terminal board TB 1 on exciter back panel. P3 connector/wiring assembly is saved from removal procedure. 2. Connect connectors on transmitter to exciter back panel. 3. If controller requires interface I/O panel, install external interface I/O board on exciter back panel (see Paragraph 9. 4). 4. Connect connector J3 to connector P3 that is pigtailed off of terminal board TB 1. 5. Locate connector P3 that is pigtailed off of terminal board TB 1. Disconnect connector P3 from connector J3. 6. Slide exciter into cabinet and secure with four screws saved from removal procedure. Procedure is complete. Perform setup, adjustment, or calibration procedures as required. 9.2 Exciter Cover These procedures must be performed with the exciter removed from the transmitter cabinet. Refer to Figure 9-2, DSP Exciter Cover Removal and Reinstallation throughout these procedures. 9.2.1 Removal Procedure 1. Remove two sem screws from sides of exciter cover. Save sem screws for installation procedure. 2. Raise front of cover and extract back of cover from channel in back panel extrusion. 3. Remove exciter cover. Procedure is complete. 9.2.2 Reinstallation Procedure 1. Insert exciter cover into channel on exciter back panel extrusion. 2. Lower cover so that fingerstock is behind exciter front panel. 3. While pressing down slightly on exciter cover: install two sem screws saved from re-moval procedure through sides of exciter cover. Procedure is complete. DSP Exciter ISC Technologies Document Number: 9110.00172 REMOVAL AND REINSTALLATION Issue 1, Rev. P: 6/6/2012 Page: 9-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 REMOVAL AND REINSTALLATION ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 9-2
v 0 1 7 1 . hg l Figure 9-2 DSP Exciter Cover Removal and Reinstallation DSP Exciter ISC Technologies Document Number: 9110.00172 REMOVAL AND REINSTALLATION Issue 1, Rev. P: 6/6/2012 Page: 9-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 REMOVAL AND REINSTALLATION 9.3 Exciter/Control Board These procedures must be performed with the exciter removed from the transmitter cabinet, and the exciter cover removed. Refer to Figure 9-3, DSP Exciter Control Board Removal and Reinstallation, throughout these procedures. 9.3.1 Removal Procedure Note Save all hardware for installation procedure. 1. Remove controller interface board (see Table Paragraph 9.4 ). 2. Remove VCO/RF amplifier board (see Table Paragraph 9.5 ). 3. Remove three kep nuts and three screws from regulators U1, U2, and U58. 4. Remove shoulder washer from regulator U58. 5. Remove two jam nuts and two lock washers from connectors J7 and J8. 6. Remove two jack socket screws attached to connector J6 through back panel. 7. Remove four sem screws from back panel and remove back panel from exciter chas- sis. Some exciters use three sem screws and one standoff. 8. Remove insulator between back panel and regulator U58. 9. Remove two jack socket screws attached to connector J3 through front panel. 10. Remove two studded standoffs through exciter/control board. 11. Remove nine sem screws that attach exciter/control board to exciter chassis, and re- move exciter/control board. Procedure is complete. 9.3.2 Reinstallation Procedure Note Use hardware saved from installation procedure. 1. Position exciter/control board onto exciter chassis and secure with nine sem screws. 2. Install two studded standoffs through exciter/control board. 3. Apply Vibra Tite or similar nonpermanent self-locking liquid adhesive to threads of the two jack socket screws to be used for connector J3. Apply only to top 1/4 inch of thread on each jack socket screw. 4. Install two jack socket screws into connector J3 through front panel. 5. Apply thermal compound as follows: between regulator U1 and back panel, between regulator U2 and back panel, between regulator U58 and insulator, and between insulator and back panel. ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 9-2
6. Install insulator between regulator U58 and back panel.
7. Position back panel on exciter chassis and secure with four sem screws. Some excit-ers use three sem screws and one standoff in the bottom right corner. 8. Apply Vibra Tite or similar nonpermanent self-locking liquid adhesive to threads of the two jack socket screws to be used for connector J6. Apply only to top 1/4 inch of thread on each jack socket screw. 9. Install two jack socket screws into connector J6 through back panel. 10. Install two lock washers and two jam nuts over connectors J7 and J8. 11. Install shoulder washer into regulator U58. 12. Install three kep nuts and three screws through regulators U1, U2, and U58. 13. Install VCO/RF amplifier board (see Table Paragraph 9.5 ). 14. Install controller interface board (see Table Paragraph 9.4 ). Procedure is complete. After exciter is installed in transmitter cabinet: perform setup procedure if necessary (refer to the system and menu manuals). DSP Exciter ISC Technologies Document Number: 9110.00172 REMOVAL AND REINSTALLATION Issue 1, Rev. P: 6/6/2012 Page: 9-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 REMOVAL AND REINSTALLATION v 0 1 7 0 . hg l Figure 9-3 DSP Exciter Control Board Removal and Reinstallation ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 9-2
9.4 Interface Board These procedures must be performed with the exciter removed from the transmitter cabinet (see Paragraph 9.1), and the exciter cover removed (see Paragraph 9.2). Refer to Figure 9- 4, DSP Exciter External Interface I/O Board Removal and Reinstallation, throughout the following procedures. 9.4.1 Removal Procedure 1. Remove jack socket screws (2 or 6) securing connector J4 (J1 and J2 not always used) to the rear panel of the exciter. Save jack socket screws for installation procedure. 2. Remove two sem screws securing interface board to standoffs. Save sem screws for installation procedure. 3. Grasp interface board at the center of connector P 1. Pull up on board with a firm ver-tical motion to disengage connector P1 from connector J1 on the exciter/control board. 4. Remove interface board. Procedure is complete. 9.4.2 Reinstallation Procedure 1. Position interface board into place by inserting connector J4 (and J1 and J2 if used) through openings in exciter rear panel. 2. Carefully align connector P1 on interface board with connector J1 on exciter/control board and engage. 3. Secure interface board to standoffs with two sem screws saved from removal proce-dure. 4. Apply Vibra Tite or similar nonpermanent self-locking liquid adhesive to threads of the six jack socket screws saved from removal procedure. Apply only to top 1/4 inch of thread on each jack socket screw. 5. Screw the six jack socket screws through holes on exciter rear panel at either sides of connectors J1, J4, and J2. Procedure is complete. After exciter is installed into transmitter cabinet, perform audio input adjustment procedure (see Section 7). 9.5 VCO/RF Amplifier Board These procedures must be performed with the exciter removed from the transmitter cabinet (see Paragraph 9.1), and the exciter cover removed (see Paragraph 9.2). Refer to Figure 9- 5, DSP Exciter Interface Board Removal and Reinstallation, throughout these procedures. DSP Exciter ISC Technologies Document Number: 9110.00172 REMOVAL AND REINSTALLATION Issue 1, Rev. P: 6/6/2012 Page: 9-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 REMOVAL AND REINSTALLATION 9.5.1 Removal Procedure 1. Remove jam nut and lock washer from connector J3 on rear of exciter. Save jam nut and lock washer for installation procedure. 2. Remove five sem screws securing VCO/RF amplifier board to standoffs on exciter. Save sem screws for installation procedure. 3. Grasp VCO/RF amplifier board near connector P4. Pull up on board with a short ver-tical motion to disengage connectors P4/P9/P10 from connectors J4/J9/J10 on exciter/ control board. 4. Remove VCO/RF amplifier board. Procedure is complete. 9.5.2 Reinstallation Procedure 1. Before installing VCO/RF amplifier board, verify that RF band includes desired transmitter operating frequencies (refer to Section 10). 2. Position VCO/RF amplifier board into place by inserting connector J3 through hole in rear of exciter. 3. Carefully align connectors P4/P9/P10 on VCO/RF amplifier board with connectors J4/J9/J10 on exciter/control board and engage. 4. Secure VCO/RF amplifier board to standoffs on exciter using five sem screws saved from removal procedure. 5. Install lockwasher and jam nut to connector J3 on rear of exciter using lockwasher and jam nut saved from removal procedure. Procedure is complete. After exciter is installed into transmitter cabinet, perform VCO2 adjustment procedure in Section 7. ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 9-9
v 0 3 4 1 . hg l Figure 9-4 DSP Exciter External Interface I/O Board Removal and Reinstallation DSP Exciter ISC Technologies Document Number: 9110.00172 REMOVAL AND REINSTALLATION Issue 1, Rev. P: 6/6/2012 Page: 9-10 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 REMOVAL AND REINSTALLATION v 0 3 4 2 . hg l Figure 9-5 DSP Exciter Interface Board Removal and Reinstallation ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 9-11
Issue 1, Rev. P: 6/6/2012 OPTIONS 10 OPTIONS 10.1 Exciter/PA Control with QT-1000 Interface The controller interface is the portion of exciter circuitry that connects the transmitter controller to the exciter. The controller interface dictates what kind of transmitter controller may operate the transmitter. The transmitter can be operated through one of several control-lers depending on the interface circuitry installed with the exciter. Two boards form this interface, the internal QT-1000 interface board and the external interface I/O board. Control commands from the transmitter controller are connected through the interface circuit. This circuit supplies remote control to the microcontroller unit (MCU) control circuit. The VT-100 VDT supplies local control. The MCU control circuit generates all control signals for the other circuits, and monitors their status. The MCU control circuit reports status back to the VT-100 VDT and the interface circuit, which supplies the status to the transmitter controller. 10.1.1 Reference Source The ten-MHz reference signal is provided by the controller via J8 on the exciter/control board. 10.1.2 Controller Interface Connector Functions Refer to Figure 10-1, Table 10-1, and Table 10-2 for a pin-by-pin description of signal functions. The controller interfaces with the transmitter through connectors J1, J2, and J5 and terminal board TB2 at the exciter back panel. J5 on the external I/O board connects to a standard RL-XX3 receiver, if installed. If a standard receiver is not installed, TB2 on the external I/O board connects to any generic receiver. TB2 also makes connections to optional configurable QT-1000 alarm inputs and switching outputs. J1 on the internal interface board connects directly to TXC connector J1, and interfaces all signals except alarms. Alarm signals, consisting of transmitter alarm, fault, and status signals, are supplied directly to the QT-1000 controller connector J2 though J2 on the internal interface board. 10.1.3 QT-1000 Interface Conversion Functions Many of the signals exchanged between the controller and the exciter originate with a format, voltage, or requirement incompatible with their destination. The QT-1000 interface performs any signal conversions necessary to provide compatibility between the controller and the exciter. The following text describes any signal conversions made by the controller interface. ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 10-1
ISC Technologies Document Number: 9110.00172 Issue 1, Rev. P: 6/6/2012 10.1.3.1 Analog-Mode A/D Conversion The exciter DSP modulator circuit reads synchronized serial data for its analog mode input signal, but the QT-1000 controller provides an analog signal. The controller interface converts the analog to the appropriate data form for the DSP. The analog (FLAT AUDIO+,-) terminates across a balanced input circuit that also provides a level adjustment. The adjustment, when properly set by the AUDIO INPUT ADJUST pot through the exciter cover, provides analog to an A/D converter at the optimum zero-dBm level. The A/D converts the analog into serial data, which is applied to the DSP through a synchronous data link. A synchronous data link is characterized by an exchange of pulse streams for timing purposes. The A/D converter is clocked by a pulse generator circuit driven by the ten-MHz reference circuit. 10.1.3.2 FSK-Data-Bit Strapping The exciter DSP modulator circuit can read up to four bits for its digital FSK mode input signal, but the controller provides two active bits 1 and 2 (DATA1, DATA2). This allows transmitter operation in the two-level or four-level mode. 10.1.3.3 Channel-Select-Bit Strapping The exciter MCU control circuit reads three bits to determine the remotely selected channel, but the QT-1000 controller provides only bits 1 and 2 (CH SEL 1,2). As a result, the QT-1000 controller can command only four channels. The controller interface keeps bit 3 open (high). Table 10-2 defines the transmitter operating channel resulting from the channel select inputs. 10.1.3.4 Mode-Select-Bit Strapping The exciter MCU control circuit reads two bits to determine the remotely selected mode, but the QT-1000 controller provides only bit 1 (MODE CONTROL). As a result, the QT-1000 controller can command only two modes. The controller interface straps bit 2 to ground (low). Table 10-3 defines the transmitter operating mode resulting from the model select input. 10.1.3.5 Power Sample D/A Conversion The QT-1000 controller reads two 0-to-2.5-volt voltages for its forward and reflected power sample inputs, but these power values are stored as data in the exciter MCU control circuit. The controller interface converts the data to voltages of the appropriate range for the QT-1000 controller. Data from the MCU representing the forward and reflected powers is written into a dual D/A converter. The D/A converts the data into two proportional dc voltages ranging from 0 volt to 2.5 volts (FWD PWR SAMPLE, REF PWR SAMPLE), which are applied to the QT-1000 controller. Control logic gates ensure that data is written to the proper half of the D/A converter. DSP Exciter OPTIONS Page: 10-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Issue 1, Rev. P: 6/6/2012 OPTIONS Table 10-1 Interface Board Connector J4 (QT-1000) J4-X signal/description J4-X signal/description 1 FWD PWR SAMPLE, input from PA 14 AUDIO INPUT +, input from re- ceiver or tx controller 2 AUDIO INPUT -, common 15 REF PWR SAMPLE, input from PA 3 TX GND 16 TONE DECODER OUTPUT, logic output to tx controller 4 KEY IN, input from tx controller 17 DATA 1, digital data input from tx controller 5 DATA 2, digital data input from tx controller 18 DATA 3, digital data input from tx controller 6 CH SELECT 3, digital command input from tx controller 19 MODE SELECT 1, digital com- mand input from tx controller 7 MODE SELECT 2, digital com- mand input from tx controller 20 LOW POWER MODE, logic input from PA 8 FAULT ALARM, digital output to tx controller 21 VSWR ALARM, logic output to tx controller 9 DATA4/CLK, input from tx con- troller 22 CH SELECT 1, logic input from tx controller 10 CH SELECT 2, logic input from tx controller 23 MOD IND, logic output to tx con- troller 11 LOW POWER ALARM, output to tx controller 24 TEMP ALARM, logic output to tx controller 12 SHUTDOWN ALARM, output to tx controller 25 RF INPUT ALARM, logic output to tx controller 13 not used -- -- ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 10-2
ISC Technologies Document Number: 9110.00172 Issue 1, Rev. P: 6/6/2012 Table 10-2 Receiver Connector J5 Pin Functions (QT-1000 with external I/O board) J5-X function J5-X function 1 no connection 9 no connection 2 standard receiver audio input for interface, 2 Vp-p, nominal 10 no connection 3 no connection 11 return for standard receiver audio 4 no connection 12 standard receiver RSSI input for interface, 0.5-6.0 Vdc 5 no connection 13 no connection 6 standard receiver ground for inter- face 14 standard receiver-fault alarm input for interface, LO=OK 7 no connection 15 no connection 8 standard receiver squelch output for interface, HI=unsquelched Table 10-3 Remote Select Input vs. Channel (QT-1000) ch sel 1 J1-5 ch sel 2 J1-24 ch sel 3 selecte d channel command open (HI) command open (HI) open (HI) 1 command ground (LO) command open (HI) open (HI) 2 command open (HI) command ground (LO) open (HI) 3 command ground (LO) command ground (LO) open (HI) 4 DSP Exciter OPTIONS Page: 10-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Table 10-4 Remote Select Input vs. Mode (QT-1000) mode sel 1 mode sel 2 J1-25 J2-1 selected mode command ground (LO) ground (LO) analog command open (HI) ground (LO) 2-level command open (HI) command open (HI) 4-level Note Not all transmitters can do all the modes. 10.2 Exciter/PA Control with Standard Interface The following major paragraphs describe the operation of the major items within the standard interface. Detailed figures are referenced, as required. The controller interface is the portion of exciter circuitry that connects the transmitter controller to the exciter. The controller interface dictates what kind of transmitter controller may operate the transmitter. The transmitter can be operated through one of several control-lers depending on the interface circuitry installed at the exciter. The remainder of section 10.2 describes standard controller interface circuitry. Two boards form this interface, the internal standard interface board and the external exciter standard interface I/O board. Control commands from the transmitter controller are connected through the interface circuit. This circuit supplies remote control to the microcontroller unit (MCU) control circuit. The VT-100 VDT supplies local control. The MCU control circuit generates all control signals for the other circuits, and monitors their status. The MCU control circuit reports status back to the VT-100 VDT and the interface circuit, which supplies the status to the transmitter controller. 10.2.1 Reference Source The ten-MHz reference signal is provided by the controller via J8 on the exciter/control board. All other inputs and outputs, except for RF output, are routed through the standard interface board. ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 OPTIONS Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 10-2
ISC Technologies Document Number: 9110.00172 Issue 1, Rev. P: 6/6/2012 10.2.2 Controller Interface Connector Functions Refer to Table 10-1, Interface Board Connector J4 (QT-1000) for a pin-by-pin description of signal functions. The controller interfaces with the transmitter through connector J4 and terminal board TB2 at the exciter back panel. TB2 also makes connections to optional configurable alarm inputs and switching outputs. 10.2.3 Standard Interface Conversion Functions Many of the signals exchanged between the controller and the exciter originate with a format, voltage, or requirement incompatible with their destination. The standard interface performs any signal conversions necessary to provide compatibility between the controller and the exciter. The following text describes any signal conversions made by the controller interface. 10.2.3.1 Analog-Mode A/D Conversion The exciter DSP modulator circuit reads synchronized serial data for its analog mode input signal, but the transmitter controller provides an analog signal. The controller interface converts the analog to the appropriate data form for the DSP. The analog (FLAT AUDIO +,-) terminates across a balanced input circuit that also provides a level adjustment. The adjustment, when properly set by the AUDIO INPUT ADJUST pot through the exciter cover, provides analog to an A/D converter at the optimum zero-dBm level. The A/D converts the analog into serial data, which is applied to the DSP through a synchronous data link. A synchronous data link is characterized by an exchange of pulse streams for timing purposes. The A/D converter is clocked by a pulse generator circuit driven by the exciter’s ten-MHz reference circuit. 10.2.3.2 FSK-Data-Bit Strapping The exciter DSP modulator circuit can read up to four bits for its digital FSK mode input signal, but the controller provides two active bits 1 and 2 (DATA1, DATA2). This allows transmitter operation in the two-level or four-level mode. 10.2.3.3 Channel-Select-Bit Strapping The exciter MCU control circuit reads three bits to determine the remotely selected channel, and the transmitter controller provides bits 1, 2, and 3 (CH SEL 1,2,3). As a result, the transmitter controller can command all eight of the possible channels. Table 10-3, Remote Select Input vs. Channel (QT-1000), defines the transmitter operating channel resulting from the channel select inputs. 10.2.3.4 Mode-Select-Bit Strapping The exciter MCU control circuit reads two bits to determine the remotely selected mode, but the transmitter controller provides only bit 1 (MODE CONTROL). As a result, the transmitter controller can command three of the transmitter’s four possible modes. Table 10-4, Remote Select Input vs. Mode (QT-1000), defines the transmitter operating mode resulting from the model select input. DSP Exciter OPTIONS Page: 10-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
10.2.3.5 Power Sample D/A Conversion The transmitter controller reads two 0-to-2.5-volt voltages for its forward and reflected power sample inputs, but these power values are stored as data within the exciter’s MCU control circuit. The controller interface converts the data to voltages of the appropriate range for the transmitter controller. Data from the MCU representing the forward and reflected powers is written into a dual D/A converter. The D/A converts the data into two proportional dc voltages ranging from 0 volt to 2.5 volts (FWD PWR SAMPLE, REF PWR SAMPLE), which are applied to the transmitter controller. Control logic gates ensure that data is written to the proper half of the D/A converter. Table 10-5 Interface Board Connector J4 (Standard) J4-X signal/description J4-X signal/description 1 FWD PWR SAMPLE, input from PA 14 AUDIO INPUT -, input from re- ceiver or tx controller (N/A for digital only series) 2 AUDIO INPUT +, common (N/A for digital only series) 15 REF PWR SAMPLE, input from PA 3 TX GND 16 TONE DECODER OUTPUT, logic output to tx controller 4 KEY IN, input from tx controller 17 DATA 1, digital data input from tx controller 5 DATA 2, digital data input from tx controller 18 DATA 3, digital data input from tx controller 6 CH SELECT 3, digital command input from tx controller 19 MODE SELECT 1, digital com- mand input from tx controller 7 MODE SELECT 2, digital com- mand input from tx controller 20 LOW POWER MODE, logic input from PA 8 FAULT ALARM, digital output to tx controller 21 VSWR ALARM, logic output to tx controller 9 DATA4/CLK, input from tx con- troller 22 CH SELECT 1, logic input from tx controller 10 CH SELECT 2, logic input from tx controller 23 MOD IND, logic output to tx controller 11 LOW POWER ALARM, output to tx controller 24 TEMP ALARM, logic output to tx controller 12 SHUTDOWN ALARM, output to tx controller 25 RF INPUT ALARM, logic out- put to tx controller 13 not used -- -- ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 OPTIONS Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 10-2
ISC Technologies Document Number: 9110.00172 Issue 1, Rev. P: 6/6/2012 Table 10-6 Remote Select Input vs. Channel (standard) ch sel 1 ch sel 2 ch sel 3 J4-22 J4-10 J4-6 selected channel command open (HI) command open (HI) open (HI) 1 command ground (LO) command open (HI) open (HI) 2 command open (HI) command ground (LO) open (HI) 3 command ground (LO) command ground (LO) open (HI) 4 command open (HI) command open (HI) command ground (LO) 5 command ground (LO) command open (HI) command ground (LO) 6 command open (HI) command ground (LO) command ground (LO) 7 command ground (LO) command ground (LO) command ground (LO) 8 Table 10-7 Remote Select Input vs. Mode (standard) mode sel 1 mode sel 2 J4-19 J4-7 selected mode command ground (LO) ground (LO) analog command open (HI) ground (LO) 2-level command open (HI) command open (HI) 4-level Note DSP Exciter OPTIONS Page: 10-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Not all transmitters can do all the modes.
10.3 Exciter/PA Control with I20 Interface The following major paragraphs describe the operation of the major items within the I20 interface. Detailed figures are referenced, as required. The controller interface is the portion of exciter circuitry that connects the transmitter controller to the exciter. The controller interface dictates what kind of transmitter controller may operate the transmitter. The transmitter can be operated through one of several control-lers depending on the interface circuitry installed at the exciter. The remainder of section 10.3 describes I20 controller interface circuitry. Two boards form this interface, the internal I20 interface board and the external I20 interface I/O board. Control commands from the transmitter controller are connected through the interface circuit. This circuit supplies remote control to the microcontroller unit (MCU) control circuit. The VT-100 VDT supplies local control. The MCU control circuit generates all control signals for the other circuits, and monitors their status. The MCU control circuit reports status back to the VT-100 VDT and the interface circuit, which supplies the status to the transmitter controller. 10.3.1 Reference Source The ten-MHz reference signal is provided by the controller via J8 on the exciter/control board. 10.3.2 Controller Interface Connector Functions Refer to Table 10-8 and Table 10-9 for a pin-by-pin description of signal functions. The exciter interfaces with the transmitter through connector J2 and the controller through J1. 10.3.3 I20 Interface Conversion Functions Many of the signals exchanged between the controller and the exciter originate with a format, voltage, or requirement incompatible with their destination. The I20 interface performs any signal conversions necessary to provide compatibility between the controller and the exciter. The following text describes any signal conversions made by the controller interface. 10.3.3.1 Analog-Mode A/D Conversion The exciter DSP modulator circuit reads synchronized serial data for its analog mode input signal, but the transmitter controller provides an analog signal. The controller interface converts the analog to the appropriate data form for the DSP. The analog (FLAT AUDIO +,-) terminates across a balanced input circuit that also provides a level adjustment. The adjustment, when properly set by the AUDIO INPUT ADJUST pot through the exciter cover, provides analog to an A/D converter at the optimum zero-dBm level. The A/D converts the analog into serial data, which is applied to the DSP through a synchronous data ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 OPTIONS Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 10-2
ISC Technologies Document Number: 9110.00172 Issue 1, Rev. P: 6/6/2012 link. A synchronous data link is characterized by an exchange of pulse streams for timing purposes. The A/D converter is clocked by a pulse generator circuit driven by the ten-MHz reference circuit. 10.3.3.2 FSK-Data-Bit Strapping The exciter DSP modulator circuit can read up to four bits for its digital FSK mode input signal, but the controller provides two active bits 1 and 2 (DATA1, DATA2). This allows transmitter operation in the two-level or four-level mode. 10.3.3.3 Channel-Select-Bit Strapping The exciter MCU control circuit reads three bits to determine the remotely selected channel, and the transmitter controller provides bits 1, 2, and 3 (CH SEL 1,2,3). As a result, the transmitter controller can command all eight of the possible channels. Table 10-3 defines the transmitter operating channel resulting from the channel select inputs. 10.3.3.4 Mode-Select-Bit Strapping The exciter MCU control circuit reads two bits to determine the remotely selected mode, and the transmitter controller provides two bits (MODE SELECT 1, MODE SELECT 2). As a result, the transmitter controller can command three of the transmitter’s four possible modes. Table 10-4 defines the transmitter operating mode resulting from the model select input. 10.3.3.5 Power Sample D/A Conversion The transmitter controller reads two 0-to-2.5-volt voltages for its forward and reflected power sample inputs, but these power values are stored as data within the exciter’s MCU control circuit. The controller interface converts the data to voltages of the appropriate range for the transmitter controller. Data from the MCU representing the forward and reflected powers is written into a dual D/A converter. The D/A converts the data into two proportional dc voltages ranging from 0 volt to 2.5 volts (FWD PWR SAMPLE, REF PWR SAMPLE), which are applied to the transmitter controller. Control logic gates ensure that data is written to the proper half of the D/A converter. Table 10-8 Interface Board Connector J1 J1-X signal/description J1-X signal/description 1 CHASSIS 20 CLOCK- 2 CLOCK+ 21 DATA0- 3 DATA0+ 22 DATA1- 4 DATA1+ 23 DATA2- 5 DATA2+ 24 DATA3- DSP Exciter OPTIONS Page: 10-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
Table 10-8 Interface Board Connector J1 (continued) J1-X signal/description J1-X signal/description 6 DATA3+ 25 GND 7 FREQ0 26 FREQ1 8 FREQ2 27 MODE 0 9 MODE 1 28 MODE/AUX 10 ANALOG+ 29 ANALOG- 11 GND 30 GND 12 RxD- 31 RxD+ 13 TxD- 32 TxD+ 14 KEY- 33 KEY+ 15 DIG OUT 6 34 DIG OUT 7 16 DIG OUT 4 35 DIG OUT 5 17 DIG OUT 2 36 DIG OUT 3 18 DIG OUT 0 37 DIG OUT 1 19 _RESET Table 10-9 Interface Board Connector J2 J2-X signal/description J2-X signal/description 1 not used 8 GND 2 TxD+ 9 TxD- 3 KEY+ 10 KEY- 4 RxD+ 11 RxD- 5 DATA0+ 12 DATA0- 6 CLOCK+ 13 CLOCK- 7 DATA1+ 14 DATA1- ISC Technologies Document Number: 9110.00172 DSP Exciter Issue 1, Rev. P: 6/6/2012 OPTIONS Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 10-2
ISC Technologies Document Number: 9110.00172 Issue 1, Rev. P: 6/6/2012 Table 10-10 Remote Select Input vs. Channel (I20) ch sel 1 ch sel 2 ch sel 3 ch sel 4 J1-7 J1-26 J1-8 J1-9 selected channel command open (HI) command open (HI) open (HI) open (HI) 1 command ground (LO) command open (HI) open (HI) open (HI) 2 command open (HI) command ground (LO) open (HI) open (HI) 3 command ground (LO) command ground (LO) open (HI) open (HI) 4 command open (HI) command open (HI) command ground (LO) open (HI) 5 command ground (LO) command open (HI) command ground (LO) open (HI) 6 command open (HI) command ground (LO) command ground (LO) open (HI) 7 command ground (LO) command ground (LO) command ground (LO) open (HI) 8 command open (HI) command open (HI) open (HI) command ground (LO) 9 command ground (LO) command open (HI) open (HI) command ground (LO) 10 command open (HI) command ground (LO) open (HI) command ground (LO) 11 command ground (LO) command ground (LO) open (HI) command ground (LO) 12 command open (HI) command open (HI) command ground (LO) command ground (LO) 13 command ground (LO) command open (HI) command ground (LO) command ground (LO) 14 DSP Exciter OPTIONS Page: 10-2 Copyright © 2011 ISC Technologies Print Date: 6/6/2012
command open (HI) command ground (LO) command ground (LO) command ground (LO) 15
Issue 1, Rev. P: 6/6/2012 OPTIONS Table 10-10 Remote Select Input vs. Channel (I20) (continued) ch sel 1 ch sel 2 ch sel 3 ch sel 4 J1-7 J1-26 J1-8 J1-9 selected channel command ground (LO) command ground (LO) command ground (LO) command ground (LO) 16 Table 10-11 Remote Select Input vs. Mode (I20) mode sel 1 J1-27 selected mode command ground (LO) analog command open (HI) digital ISC Technologies Document Number: 9110.00172 DSP Exciter Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 10-2
Issue 1, Rev. P: 6/6/2012 List of Referenced Graphic Files List of Referenced Graphic Files /pics/v0077.hgl 6-13 /pics/v0079.hgl 5-2 /pics/v0081.hgl 6-12 /pics/v0083.hgl 6-6 /pics/v0123.hgl 6-2 /pics/v0151.hgl 9-3 /pics/v0170.hgl 9-7 /pics/v0171.hgl 9-4 /pics/v0341.hgl 9-10 /pics/v0342.hgl 9-11 /pics/v0345l.hgl 6-10 /pics/v0345r. hgl 6-11 /pics/v0854.hgl 7-5 s /pics/v0164.hgl 4-5 /pics/v0250.hgl 1-2 /pics/v0251.hgl 3-5 /pics/v0343.hgl 3-3 /pics/v0344.hgl 3-4 ISC Technologies Document Number: 9110.00172 DSP Exciter c Print Date: 6/6/2012 Copyright © 2011 ISC Technologies Page: 1

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