valutazioni - 3, GPA: 3.7
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Facilità d'uso
. . . . . . . . . . . LBI- 30032 (DF1107) OSCILLATOR/MULTIPLIER BOARD . . . . . . . . . . . . . . . . . . . . LBI- 30029 (DF1106) IF AUDIO AND SQUELCH BOARD . . . . . . . . . . . . . . . . . . . . LBI- 38507 Ericsson Inc. Private Radio Systems Mountain View Road Lynchburg, Virginia 24502 ericsson . 1- 800- 528- 7711 (Outside USA, 804-528-7711) Printed in U. S.A. LBI- 38505 LBI- 38505 TABLE OF CONTENTS Page SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 MODIFICATION INSTRUCTIONS (High Side Injection) . . . . . . . . . . . . . . . . . . . . . . . . 3 FRONT ENDALIGNMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 ICOMFREQUENCYADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 COMPLETE RECEIVER ALIGNMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 TEST PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Audio Power Output And Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Usable Sensitivity ( 12 dBSinad) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 ModulationAcceptanceBandwidth(IF Bandwidth) . . . . . . . . . . . . . . . . . . . . . . . . . 8 TROUBLESHOOTING PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 ILLUSTRATIONS FIGURE 1 - DISASSEMBLYPROCEDURE (Top View) . . . . . . . . . . . . . . . . . . . . . . . . 2 FIGURE 2 - RECEIVER BLOCK DIAGRAM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 FIGURE 3 - DISASSEMBLYPROCEDURE (Bottom View) . . . . . . . . . . . . . . . . . . . . . . . 3 FIGURE 4 - RECEIVER MODULE LOCATION DIAGRAM . . . . . . . . . . . . . . . . . . . . . . 3 FIGURE 5 - TEST POINTS AND ALIGNMENT CONTROLS . . . . . . . . . . . . . . . . . . . . . . 4 FIGURE 6 - TEST SETUP FOR 20 Hz DOUBLE-TRACE SWEEP ALIGNMENT . . . . . . . . . . . . . . 4 FIGURE 7 - FREQUENCY CHARACTERISTICS vs. TEMPERATURE . . . . . . . . . . . . . . . . . . 5 SPECIFICATIONS* Audio Output (to 8-ohm Speaker) 1 Watt at less than 3% distortion Sensitivity With Pre- Ampl Without Pre- Ampl 12 dB SINAD (EIA Method) 0.20 m V 0.35 mV 20 dB Quieting Method 0.25 m V 0.50 mV SELECTIVITY EIA Two- Signal Method (25 kHz Spacing) -90 dB -90 dB Spurious Response -90 dB -100 dB Intermodulation (EIA) - 75 dB -80 dB Copyright © May 1990, Ericsson GE Mobile Communications Inc. Squelch Sensitivity Critical Squelch Maximum Squelch 0.25 m V Greater than 0.1 mV 12 dB NQ (less than 1.0 m V) Frequency Stability 2C-ICOMs ± 0.0002% ( 40° C to + 70° C) Modulation Acceptance ± 7 kHz ( narrow- band) Maximum Frequency Separation Full Specifications 3 dB Degradation 406- 470 MHz 470- 494 MHz 494- 512 MHz 1.60 MHz 1.50 MHz 1.50 MHz 2.0 MHz 2.0 MHz 2.0 MHz Frequency Response Within +2 and -8 dB of a standard 6 dB per octave de-emphasis curve from 300 to 3000 Hz (1000 Hz reference) RF Input Impedance 50 ohms * These specifications are intended primarily for the use of the serviceman. Refer to the appropriate Specification Sheet for the complete specifications. Although the highest DC voltage in MASTR II receiver is +12 Volts DC, high current may be drawn under short circuit conditions. These currents can possibly heat metal objects such as tools, rings, watchbands, etc. , enough to cause burns. Be careful when working near energized circuits! High-level RF energy in the transmitter Power Amplifier assembly can cause RF burns upon contact. Keep away from these circuits when the transmitter is energized! WARNING LBI- 38505 LBI- 38505 DESCRIPTION MASTR II Base Station, 406 to 512 megahertz receivers are single conversion, superheterodyne FM receivers designed for one- through eight- frequency operation. The solid state receiver utilizes integrated circuits ( ICs), monolithic crystal filters and discrete components with each of the crystal filters located between gain stages to provide 100 dB selectivity and maximum protection from de- sensitization and intermodulation. The receiver consists of the following modules: • RF Assembly (Includes Mixer) • IF- Filter • Oscillator/ Multiplier ( Osc/Mult) • IF/Audio and Squelch ( IFAS) • Optional Ultra- High Sensitivity (UHS) Pre- Amplifier Audio, supply voltages and control functions are connected to the system board through P903 on the Osc/ Mult board, and P904 on the IFAS board. The regulated + 10 Volts is used for all receiver stages except the audio PA stage which operates from the A+ system supply. Centralized metering jack J601 on the IFAS board is provided for use with Test Set 4EX3A11 or Test Kit 4EX8K12. The test set meters the oscillator, multiplier, IF Detector and IF amplifier stages. Speaker high and low are metered on the system board metering jack. A block diagram of the complete re...