Ericsson 19D902783G1 Maintenance Manual
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Ericsson 19D902783G1 Maintenance Manual

Ericsson 19D902783G1 Maintenance Manual

25khz receiver if module
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MAINTENANCE MANUAL FOR
25kHz RECEIVER IF MODULE
19D902783G1

TABLE OF CONTENTS

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CIRCUIT ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INPUT MATCHING NETWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CRYSTAL FILTERS, IF AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OSCILLATOR/MIXER/DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AUDIO AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SQUELCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Buffer Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Pass Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Noise Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DC Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schmitt Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FAULT DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VOLTAGE REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RECOMMENDED TEST EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The MASTR III Receiver IF Module provides ampli-
fication and demodulation of the 21.4 MHz Intermediate
Frequency signal. The IF Module also includes the re-
ceiver squelch circuitry. However, it does not include de-
emphasis or squelch audio gating circuits. Figure 1 is a
block diagram showing the functional operation of the
IF Module.
The IF Module circuitry contains the following:
• A 50 ohm input impedance matching network and
IF Amplifier
ericssonz
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Front Cover
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• A chain of two crystal filters and two integrated
circuit IF amplifiers
• An integrated circuit containing a crystal
oscillator, mixer, limiter, and quadrature detector
• A variable gain AF amplifier
• A squelch circuit
• A fault detector circuit
• An integrated circuit voltage regulator
Ericsson Inc.
Private Radio Systems
Mountain View Road
Lynchburg, Virginia 24502
1-800-528-7711 (Outside USA, 804-592-7711)
Printed in U.S.A.

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  • Page 1: Table Of Contents

    LBI-38643C MAINTENANCE MANUAL FOR 25kHz RECEIVER IF MODULE 19D902783G1 TABLE OF CONTENTS Page DESCRIPTION ..........

  • Page 2: General Specifications

    Fault output (J2 pin 11C) 5V logic (low = fault) A preferable measurement is at TP3 which should read DC Supply 1 Vrms (adjustable) about 50 mV pk. (Measured using a 10 megohm, 11 pF oscil- loscope probe.) Copyright© February 1992, Ericsson Inc.

  • Page 3: Highpass Filter

    LBI-38643C Highpass Filter 8V regulator. Therefore, if the regulator opens, a fault will still be indicated. The audio frequency highpass filter consists of U7.1 and its associated circuitry. The purpose of this filter is to reject all VOLTAGE REGULATOR voice frequencies and allow only demodulated noise to pass. The functioning of the squelch circuit depends upon the pres- U8 is a monolithic integrated circuit voltage regulator pro- ence or absence of this noise.

  • Page 4: Troubleshooting

    Check presence of 1 Vpk noise U7 at Pin 1 Check presence of 1 Vpk noise U7 Pin 1 Check DC voltage U7 at Pin 8: 7 V U7 or associated components Check DC voltage U7 Pin 14: 0.5 V RECEIVER IF MODULE 19D902783G1 (19D902783, Sh. 1, Rev. 3)
  • Page 5 LBI-38643C OUTLINE DIAGRAM (19D902494, Sh. 1, Rev. 5B) (19D902493, Comp. Side, Rev. 5) RECEIVER IF MODULE 19D902494G1...
  • Page 6 SCHEMATIC DIAGRAM LBI-38643C RECEIVER IF MODULE 19D902494G1 (19D902504, Sh. 1, Rev. 6)
  • Page 7 LBI-38643C SCHEMATIC DIAGRAM RECEIVER IF MODULE 19D902494G1 (19D902504, Sh. 2, Rev. 6)

  • Page 8: Parts List

    DESCRIPTION SYMBOL PART NO. DESCRIPTION 19D902783G1 Tantalum: 1 µF, 16 VDCW; sim to Sprague 293D. 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w. 19A705205P2 - - - - - - - - TRANSISTORS - - - - - - - - - ISSUE 2 Tantalum: 6.8 µF, 10 VDCW;...

  • Page 9: Production Changes

    LBI-38643C PARTS LIST & PRODUCTION CHANGES PRODUCTION CHANGES SYMBOL PART NO. DESCRIPTION Changes in the equipment to improve performance or to simplify circuits are - - - - - - - - - - -CRYSTALS - - - - - - - - - identified by a "Revision Letter"...
  • Page 10 IC DATA LBI-38643C U6 & U7 U4 & U5 19A701789P4 344A3740P1 19A705927P1 19A704125P1 Quad Op-Amp Silicon Bipolar IC Silicon Bipolar IC Quad Comparator 19A704971P10 Voltage Regulator 19A149980P2 FM Receiver...
  • Page 11 ASSEMBLY DIAGRAM ........Back Cover SYNTHESIZER MODULE 19D902780G3, G6 - G10 (19D902780, Sh. 1, Rev. 5) Ericsson Inc. Private Radio Systems Mountain View Road Lynchburg, Virginia 24502 1-800-528-7711 (Outside USA, 804-592-7711) Printed in U.S.A.

  • Page 12: Description

    This manual is published by Ericsson Inc., without any warranty. Improvements and changes to this manual necessitated by typographical errors, inaccuracies of current information, or improvements to programs and/or equipment, may be made by Ericsson Inc., at any time and without notice. Such changes will be incorporated into new editions of this manual. No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, for any purpose, without the express written permission of Ericsson Inc.

  • Page 13: Prescaler And Synthesizer

    LBI-38671H The output of the second buffer (U501B) is applied to a loop PRESCALER AND SYNTHESIZER filter consisting of R506, R507, R508, C505 and C506. This filter controls the bandwidth and stability of the synthesizer Integrated circuit U402 is the heart of the synthesizer. It loop.

  • Page 14: Logic Circuits

    LBI-38671H LOGIC CIRCUITS TEST PROCEDURE ALIGNMENT PROCEDURE SERVICE NOTES Logic circuitry (other than that inside the synthesizer IC - (Steps 5, 6, and 7 can be done using a modulation analyzer Apply +13.8 Vdc and -12 Vdc. Verify the current The following service information applies when or UHF receiver with 750 µs de-emphasis switchable in or U402) consists of the following:...

  • Page 15: Parts List

    LBI-38671H PARTS LIST SYMBOL PART NO. DESCRIPTION UHF TRANSMITTER SYNTHESIZER MODULE TROUBLESHOOTING GUIDE 19D902780G3, G6 - G10 C201 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0 + or - 30 PPM. ISSUE 9 C202 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0 + or -30 PPM/°C.
  • Page 16 PARTS LIST LBI-38671H SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION C504 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0 R212 19B800607P331 Metal film: 330 ohms + or -5%, 1/8 w. 19C851001P1 Coil, RF: sim to Paul Smith SK901-1.
  • Page 17 PRODUCTION CHANGES & IC DATA LBI-38671H PRODUCTION CHANGES U201 and U203 U202 19A705927P11 Changes in the equipment to improve or to simplify circuits are identified by a 344A3907P1 "Revision Letter", which is stamped after the model number of the unit. The Silicon Bipolar MMIC Silicon Bipolar MMIC revision stamped on the unit includes all previous revisions.
  • Page 18 LBI-38671H IC DATA U401 U701 & U705 19A149944P201 19A703483P302 Dual Modulus Prescaler Quad 2-Input NAND Gate U402 19B800902P5 Synthesizer U702 19A703471P120 Address Decoder U502 19A702705P4 Quad Analog Switch...
  • Page 19 LBI-38671H OUTLINE DIAGRAM COMPONENT SIDE SOLDER SIDE (19D902779, Sh. 2, Rev. 9) (19D903361, Layer 1 & 4, Rev. 0) UHF TRANSMITTER SYNTHESIZER BOARD 19D902779G3, G6 - G10...
  • Page 20 SCHEMATIC DIAGRAM LBI-38671H UHF TRANSMITTER SYNTHESIZER 19D902780G3, G6 - G10 (19D903363, Sh. 1, Rev. 10)
  • Page 21 LBI-38671H SCHEMATIC DIAGRAM UHF TRANSMITTER SYNTHESIZER 19D902780G3, G6 - G10 (19D903363, Sh. 2, Rev. 10)
  • Page 22 SCHEMATIC DIAGRAM LBI-38671H UHF TRANSMITTER SYNTHESIZER 19D902780G3, G6 - G10 (19D903363, Sh. 3, Rev. 10)

  • Page 23: Production Changes

    MHz reference signal. Three inputs from the controller; ENABLE, CLOCK, and serial DATA program the PLL di- The logic signals from the controller (U10, U12, and vider circuits. U13) control the synthesizer frequency. Frequency stability Ericsson Inc. Private Radio Systems Mountain View Road Lynchburg,Virginia 24502 1-800-528-7711 (Outside USA, 804-592-7711) Printed in U.S.A.
  • Page 24 This manual is published by Ericsson Inc., without any warranty. Improvements and changes to this manual necessitated by typographical errors, inaccuracies of current information, or improvements to programs and/or equipment, may be made by Ericsson Inc., at any time and without notice.
  • Page 25 LBI-38672J RF AMPLIFIERS PRESCALER AND SYNTHESIZER IC LOOP FILTER CIRCUIT ANALYSIS The RF chain begins with a resistive splitter (R13, R17, The integrated circuit U6 is the heart of the synthesizer. It The error signal, ANOUT, is applied to the loop filter at The Receiver Synthesizer Module consists of the follow- R18, R96, R97, R99 and R100).
  • Page 26 LBI-38672J SERVICE NOTES When the VCO is not on the correct frequency, the synthe- Adjust the trimmer capacitor C52 for 445 MHz TEST AND ALIGNMENT sizer sends a logic low signal to U13. This causes U13 to cutoff (G3), 470 MHz (G7), 420 MHz (G8), 490 MHz The following service information applies when aligning, Q6 which turns on the FAULT LED (CR1).
  • Page 27 LBI-38672J TROUBLESHOOTING CHART SYMPTOM AREAS TO CHECK INDICATIONS I. Loop Fails To Lock 1. Check for: Bad Regulation circuitry. +8 Vdc at U16-3, Troubleshooting using +5 Vdc at U15-3 standard procedures. +8 Vdc at Q8-C. 2. Check for 12.8 MHz Reference Osc.
  • Page 28 OUTLINE DIAGRAM LBI-38672J COMPONENT SIDE UHF RECEIVER SYNTHESIZER BOARD (19D902664, Sh. 2, Rev. 4) (19D902665, Layer 1, Rev. 1) 19D902664G3 ,G7, G8, G10, G12...
  • Page 29 LBI-38672J PARTS LIST UHF RECEIVER SYNTHESIZER MODULE SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION 19D902781G3, G7, G8, G10, G12 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0 19A702052P3 Ceramic: 470 pF + or - 10%, 50 VDCW. - - - - - - - - - - INDUCTORS - - - - - - - - - - ISSUE 8 + or - 30 PPM.
  • Page 30 PARTS LIST & PRODUCTION CHANGES LBI-38672J SYMBOL PART NO. DESCRIPTION PRODUCTION CHANGES SYMBOL PART NO. DESCRIPTION 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w. 19B800607P120 Metal film: 12 ohms + or -5%, 1/8 w. Changes in the equipment to improve performance or to simplify circuits are 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.

  • Page 31: Ic Data

    IC DATA LBI-38672J U2 thru U4 U8 & U9 19A705927P1 19A702293P3 19A703471P120 Dual Operational Amplifier Silicon Bipolar IC Decoder/Demux U12 & U13 19A149944P201 19A703483P302 Modulus Prescaler Logic Gate/Inverter 19A702705P4 19B80090P5 Quad Analog Switch Synthesizer...
  • Page 32 LBI-38672J IC DATA 19A704971P8 19A704971P10 +5V Regulator +8V Regulator 19B801351P12 Crystal Oscillator...
  • Page 33 LBI-38672J ASSEMBLY DIAGRAM RECEIVER SYNTHESIZER MODULE 19D902781G3, G7, G8, G10, G12 (19D902781, Sh. 2, Rev. 5)
  • Page 34 LBI-38672J SCHEMATIC DIAGRAM RECEIVER SYNTHESIZER MODULE 19D902664G3, G7, G8, G10, G12 (19D904091, Sh. 1, Rev. 9A)
  • Page 35 LBI-38672J SCHEMATIC DIAGRAM RECEIVER SYNTHESIZER MODULE 19D902664G3 , G7, G8, G10, G12 (19D904091, Sh. 2, Rev. 9A)
  • Page 36 SCHEMATIC DIAGRAM LBI-38672J RECEIVER SYNTHESIZER MODULE 19D902664G3, G7, G8, G10, G12 (19D904091, Sh. 3, Rev. 9A)

  • Page 37: Outline Diagram

    All but the Fault Detector circuit in the RXFE mod- • Preselector Filter ule have 50 ohm impedance terminations. • Preamplifier Ericsson Inc. Private Radio Systems Mountain View Road Lynchburg, Virginia 24502 1-800-592-7711 (Outside USA, 804-592-7711) Printed in U.S.A.
  • Page 38 It converts an RF signal to the 21.4 MHz first conver- constant voltage and current source. The bias on Q1 is moni- signal from 0 dBm to +25 dBm in the 428 to 449 MHz range Copyright© July 1992, Ericsson GE Mobile Communications, Inc.
  • Page 39 LBI-38673F If the biasing for the amplifiers is not within the proper ten degrees). If an RF Voltmeter is used, connect a TROUBLESHOOTING GUIDE operating range, the fault detector circuit will pull the FLAG Low Pass Filter (LPF)to the IF OUT (J4) to attenuate 0 line low.
  • Page 40 PARTS LIST LBI-38673F RECEIVER FRONT END MODULE SYMBOL PART NUMBER DESCRIPTION SYMBOL PART NUMBER DESCRIPTION SYMBOL PART NUMBER DESCRIPTION 19D902782G3 (450-470 MHz) 19D902782G4 (450-470 MHz ETSI) Coil, Fixed: 0.18 µH; sim to Toko — — — — — JACKS — — — — 19A702061P13 Ceramic: 10 pF,±5%, 50VDCW, 19A705470P16...
  • Page 41 PARTS LIST & PRODUCTION CHANGES OUTLINE DIAGRAM LBI-38673F SYMBOL PART NUMBER DESCRIPTION PRODUCTION CHANGES - CONT. REV. B - RECEIVER FRONT END BOARD 19D902490G7 Metal film: 33K ohms ±5%, 1/8 w. 19B800607P333 To improve receiver sensitivity L8 changed from 18nH (19A705470P4) to 33nH (19A705470P7); R5 changed from 10 ohms (19B800607P100) Metal film: 100K ohms ±5%, 1/8 w.
  • Page 42 OUTLINE DIAGRAM LBI-38673F RECEIVER FRONT END BOARD 19D902490G4 & G7 (19D902490, Sh. 4, Rev. 6A)
  • Page 43 ASSEMBLY DIAGRAM LBI-38673F RECEIVER FRONT END MODULE 19D902782G3 (19D902782 Sh.1 Rev. 6)
  • Page 44 ASSEMBLY DIAGRAM LBI-38673F RECEIVER FRONT END MODULE 19D902782G4 & G7 (19D902782 Sh.2 Rev. 6)
  • Page 45 SCHEMATIC DIAGRAM LBI-38673F RECEIVER FRONT END MODULE 19D902782G4 & G7 (19D904768 Sh.1 Rev. 6)
  • Page 46 SCHEMATIC DIAGRAM LBI-38673F RECEIVER FRONT END MODULE 19D902782G3,G4 & G7 (19D904768 Sh.2 Rev. 6)
  • Page 47 SCHEMATIC DIAGRAM LBI-38673F RECEIVER FRONT END MODULE 19D902782G3 (19D903498, Rev. 7)
  • Page 48 LBI-38673F This page intentionally left blank...
  • Page 49 LOW PASS FILTER ..........7,13 Ericsson Inc.
  • Page 50 The signal from the Small Signal Gain stage, typically Power Control circuitry. input to the Exciter through a 10 dB resistive pad (R1, R2, and 26 dBm (400 mW), is input into the LLA. Under typical Copyright © July 1992, Ericsson GE Mobile Communications Inc.
  • Page 51 LBI-38674F The stripline directional coupler samples the output Zero volts on this line, when the PA is keyed, indicates the of supplying 5 volts at 1.0 mA. The appropriate key sequence POWER CONTROL power and produces a voltage, Vf, proportional to the for- forward power is cutback.
  • Page 52 LBI-38674F UHF POWER AMPLIFIER TYPICAL VOLTAGE READINGS TROUBLESHOOTING GUIDE (cont’d) (50 ohm, room temperature, 13.4 Vdc supply voltage, and rated output) Group High SYMPTOM AREAS TO CHECK INDICATIONS Frequency 450 MHZ 460 MHZ 470 MHZ Low power at PA output port Low RF input to PA from TX Power should be a minimum of 10 403 MHZ...
  • Page 53 LBI-38674F RATED POWER FOR MASTR III UHF BASE STATION FREQUENCY STANDARD ADJUSTABLE WITH WITH WITH DUPLEXER RANGE DUPLEXER ISOLATOR AND ISOLATOR @J104 450-470 110W 65-130W 100W 425-450 55-110W 403-425 55-110W 380-400 45-90W 410-430 55-110W 470-494 55-110W 492-512 55-110W...
  • Page 54 ASSEMBLY DIAGRAM LBI-38674F POWER AMPLIFIER ASSEMBLY 19D902797G3, G6, G7, G8, G9, G10 & G11 (19D902797 Sh. 3, Rev. 10)
  • Page 55 ASSEMBLY DIAGRAM LBI-38674F POWER AMPLIFIER ASSEMBLY COVER ASSEMBLY 19D902797G3, G6, G7, G8, G9, G10 & G11 19B801659G3 (19D902797 Sh. 2, Rev. 10) (19B801659, Sh. 2, Rev. 3)
  • Page 56 ASSEMBLY DIAGRAMS LBI-38674F LOW PASS FILTER MODULE 19D902856G3 (19D902856 Sh. 1, Rev. 0)
  • Page 57 PARTS LIST LBI-38674F SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION 110 WATT UHF POWER AMPLIFIER 19D902797G3 90 WATT UHF POWER AMPLFIER 19D902797G6, G7 & G9 - G11 Mica/teflon: 33 pF ±2%, 100 VDCW. (Used in G3). Porcelain: 15 pF ±5pF, 500 VDCW;...
  • Page 58 PARTS LIST & PRODUCTION CHANGES LBI-38674F SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION - - - - - - - - - - - - - - JACKS - - - - - - - - - - - - - - 19A705469P1 Insulator Plate, TO-220.
  • Page 59 PRODUCTION CHANGES AND OUTLINE DIAGRAM LBI-38674F PRODUCTION CHANGES - CONT. COMPONENT SIDE REV. C POWER AMPLIFIER 19D902797G3 POWER AMPLIFIER BOARD 19D902794G3 To update PWB for new band splits. REV. D POWER AMPLIFIER 19D902797G3 POWER AMPLIFIER BOARD 19D902794G3 To update PWB for new band splits and add power monitor circuitry.
  • Page 60 SCHEMATIC DIAGRAM LBI-38674F POWER AMPLIFIER ASSEMBLY 19D902797G3, G6, G7, G8, G9, G10 & G11 (19D903622 Sh. 1, Rev. 11)
  • Page 61 OUTLINE AND SCHEMATIC DIAGRAMS LBI-38674F TABLE I COMPONENT SIDE REF. DES. 380-400 MHz403-425 MHz 425-450 MHz 450-470 MHz 470-494 MHz 492-512 MHz 410-430 MHz 10.0 pf 12.0 pf 10.0 pf not used not used not used 12.0 pf 15.0 pf 12.0 pf 8.2 pf not used...
  • Page 62 SCHEMATIC DIAGRAM & IC DATA LBI-38674F U100 19A705457P1, P2 AND P4 19A705532P2 PA Amplifier Module Voltage Regulator 344A3907P1 MMIC Amplifier 19A701789P4 Quad Op-Amp LOW PASS FILTER MODULE 470 - 512 MHz 19D902856G9 (19B804157, Rev. 0)
  • Page 63 LBI-38675E Maintenance Manual MASTR ® RF PACKAGE, UHF 380-512 MHz TABLE OF CONTENTS TRANSMIT SYNTHESIZER ..LBI-38671 RECEIVE SYNTHESIZER ..LBI-38672 RECEIVE RF MODULE ..LBI-38673 LBI-39129 IF MODULE .
  • Page 64 Ericsson Inc., at any time and without notice. Such changes will be incorporated into new editions of this manual. No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, for any purpose, without the express written permission of Ericsson Inc.
  • Page 65 LBI-38675E CONVENTIONAL OPTIONS and ACCESSORIES Programmable Options Additional Options • • Transmit Frequencies Service Microphone • • Receive Frequencies Antenna Multicoupler • • Channel Spacing 50 Hz Power Supply • • Channel Guard Digital and Tone Duplexer • • Channel Guard Disable Antenna Relay (VHF/UHF) •...
  • Page 66 LBI-38675E CONVENTIONAL TONE & DC REMOTE CONTROLLED STATIONS - Cont. AUDIO (Receiver-to-Line) Audio Amplifier Input Impedance: 10 KΩ Input Level: 1 V RMS (For 5 kHz Deviation) 600 Ω Output Impedance to Line: Output Level to Line Voice (1 kHz ref): +7 dBm (Adjustable) Tone (1 kHz ref): +7 dBm (Ref.
  • Page 67 LBI-38675E GENERAL INDOOR CABINET (Floor Mount) CABINET 37" (CNV) 69" SIZE [in. (mm)] Height: 37.0 (940) 69.1 (1750) Width: 21.5 (550) 23.1 (590) Depth: 18.25 (460) 21 .0 (533) Weight (min) [(lb. (Kg)] Continuous Duty 150 (68) 300 (136) Packed , Domestic Shipping 165 (75) 317 (147) Number of Rack Units...
  • Page 68 LBI-38675E TRANSMITTER 380-400 403-430 425-450 450-470 470-494 492-512 FREQUENCY RANGE (MHz) RATED POWER OUTPUT (Watts): RF OUTPUT IMPEDANCE (W): CONDUCTED SPURIOUS & HARMONIC EMISSION (dBm): FREQUENCY STABILITY ±0.0001 ±0.0001 ±0.0001 ±0.0001 ±0.0001 ±0.0001 (%): MODULATION 0 to ± 5 0 to ± 5 0 to ±...
  • Page 69 RX FRONT END MODULE (450-470 MHz) ........19D902782G3 (425-450 MHz) ........19D902782G7 (403-425 MHz) ........19D902782G6 (410-430 MHz) ........19D902782G11 (380-400 MHz) ........19D902782G8 (470-494 MHz) ........19D902782G9 (492-512 MHz) ........19D902782G10 IF MODULE ..............19D902783G1 (470-494 MHz, 492-512 MHz)....19D902783G7 Continued...
  • Page 70 MODULE NUMBERS - Cont. POWER AMPLIFIER (450-470 MHz)......... 19D902797G3 (425-450 MHz)......... 19D902797G7 (403-425 MHz)......... 19D902797G6 (410-430 MHz .........19D902797G11 (380-400 MHz)......... 19D902797G8 (470-494 MHz)......... 19D902780G9 (492-512 MHz)........19D902780G10 LOW PASS FILTER ..............19D902856G1 (470-512 MHz)......... 19D902780G9 ANTENNA SWITCH ..............19B235897P2 DUPLEXER (440-470 MHz).......... 344A4047P1 Fig 1 - 69"...
  • Page 71 ACCESSORIES LBI-38675E ANTENNA SWITCH 19B235897P2...
  • Page 72 LBI-38675E Ericsson Inc. Private Radio Systems Mountain View Road Lynchburg, Virginia 24502 1-800-528-7711 (Outside USA, 804-592-7711) Printed in U.S.A.
  • Page 73 • An integrated circuit voltage regulator The IF Module circuitry contains the following: • A 50 ohm input impedance IF Amplifier • An address decoder Ericsson Inc. Private Radio Systems Mountain View Road Lynchburg, Virginia 24502 1-800-528-7711 (Outside USA, 804-592-7711)

  • Page 74: Crystal Filters, If Amplifiers

    Q6 connecting R1 across R40. U6.2 is tion. inaccuracies of current information, or improvements to programs and/or equipment, may be made by Ericsson Inc., at any time and without no- used as a voltage regulator to provide 4 Vdc for biasing the tice.

  • Page 75: Squelch

    LBI-39123E Transistors Q4 and Q5 are drivers for the front panel LED SQUELCH CRI. These are powered from the +13.8 Vdc line before the 8V regulator. Therefore, if the regulator opens, a fault will still be Buffer Amplifier indicated. VOLTAGE REGULATOR Integrated circuit U6.4 is configured as a unity gain buffer amplifier.

  • Page 76: Troubleshooting

    LBI-39123E ASSEMBLY DIAGRAM IF amplifier Q2 has a nominal 8 dB gain. U1 has a nominal 4. Apply a standard input signal to the module input. (-60 gain of 30 dB. The mixer has about 2 dB loss with proper LO dBm, 21.4 MHz signal modulated with 1 kHz AF, 3 injection.

  • Page 77: Outline Diagram

    LBI-39123E OUTLINE DIAGRAM RECEIVER IF MODULE (EARLIER VERSION) RECEIVER IF MODULE 19D902494G7, G11 19D902494G7 & G11 (19D902494, Sh.3, Rev. 6) (19D902494, Sh.4, Rev. 6)

  • Page 78: Schematic Diagram

    SCHEMATIC DIAGRAM LBI-39123E RECEIVER IF MODULE (EARLIER VERSION) 19D902494G7, G11 (188D5586, Sh. 1, Rev. 3)
  • Page 79 LBI-39123E SCHEMATIC DIAGRAM RECEIVER IF MODULE (EARLIER VERSION) 19D902494G7, G11 (188D5586, Sh. 2, Rev. 3)
  • Page 80 LBI-39123E SCHEMATIC DIAGRAM RECEIVER IF MODULE 19D902494G7 & G11 (193D1065, Sh. 1, Rev. 3)
  • Page 81 LBI-39123E SCHEMATIC DIAGRAM RECEIVER IF MODULE 19D902494G7 & G11 (193D1065, Sh. 2, Rev. 3)
  • Page 82 LBI-39123E SCHEMATIC DIAGRAM RECEIVER IF MODULE 19D902494G7 & G11 (193D1065, Sh. 3, Rev. 3)
  • Page 83 LBI-39123E IC DATA U6 & U7 U4 & U5 344A3740P1 19A704125P1 19A701789P4 19A704971P10 Silicon Bipolar IC kQuad Comparator Quad Op-Amp Voltage Regulator RYT3066018/C Bilateral Switch 19A705535P3 FM Receiver...

  • Page 84: Parts List

    PARTS LIST LBI-39123E RECEIVER IF MODULE SYMBOL PART NUMBER DESCRIPTION SYMBOL PART NUMBER DESCRIPTION SYMBOL PART NUMBER DESCRIPTION 19D902783G7, G11 Ceramic: 0.01 µF ±10%, 50 VDCW. Metal film: 47K ohms ±5%, 1/8 w. 19A702052P14 - - - - - - - - - - TRANSISTORS - - - - - - - - - 19B800607P473 ISSUE 5 thru...

  • Page 85: Production Changes

    Fault Detector • Preselector Filter All but the Fault Detector circuit in the RXFE module have 50 ohm impedance terminations. Ericsson Inc. Private Radio Systems Mountain View Road Lynchburg, Virginia 24502 1-800-528-7711 (Outside USA, 804-528-7711) Printed in U.S.A.
  • Page 86 The IF output signal is then routed through a diplexer circuit with a constant current source. The bias on U2 and Q8 is bias on Q1 is monitored by the Fault Detector circuit via R17. to the output connector (J4). Copyright© November 1994, Ericsson GE Mobile Communications, Inc.
  • Page 87 LBI-39129B HEIGHT (in inches) For Major Retuning HEIGHT (in inches) MAINTENANCE Frequency Frequency (MHz) (MHz) The best way to do a major retuning of the RXFE is with TEST PROCEDURE 12/64 12/64 12/64 12/64 12/64 12/64 10/64 10/64 10/64 8/64 swept frequency tuning.
  • Page 88 PARTS LIST & PRODUCTION CHANGES LBI-39129B RECEIVER FRONT END MODULE SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION SYMBOL PART NO. DESCRIPTION 19D902782G6 (403-425 MHz) 19B800607P100 Metal film: 10 ohms + or -5%, 1/8 w. (Used in G6 and 19A705205P15 Tantalum: 33 uf + or - 20%, 16 VDCW.
  • Page 89 OUTLINE DIAGRAM LBI-39129B 19A704125P1 Quad Operational Amplifier RECEIVER FRONT END BOARD (19D902490, Sh. 7, Rev. 5) 19D902490G6, G8 - G12...
  • Page 90 ASSEMBLY DIAGRAM LBI-39129B RECEIVER FRONT END MODULE 19D902782G6, G8 - G12 (19D902782 Sh.2 Rev.3)
  • Page 91 SCHEMATIC DIAGRAM LBI-39129B RECEIVER FRONT END MODULE 19D902782G6, G8-G12 (188D5789 Sh.1, Rev. 6A)
  • Page 92 SCHEMATIC DIAGRAM LBI-39129B RECEIVER FRONT END MODULE 19D902782G6, G8 - G12 (188D5789 Sh.2, Rev. 6A)

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