Maintenance Manual

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Maintenance Manual

MM101886V1 R1A

21.4 MHz RECEIVER IF MODULE

12.5/25 kHz CHANNEL SPACING

CB101128V1

TABLE OF CONTENTS

Page

1.0 SPECIFICATIONS................................................................................................................................................. 3

2.0 DESCRIPTION ...................................................................................................................................................... 4

3.0 CIRCUIT ANALYSIS............................................................................................................................................ 5

3.1 INPUT AMPLIFIER NETWORK...................................................................................................................... 5

3.2 CRYSTAL FILTERS, IF AMPLIFIER.............................................................................................................. 5

3.3 INTEGRATED CIRCUIT AGC AMPLIFIER................................................................................................... 5

3.4 OSCILLATOR/MIXER/DETECTOR................................................................................................................ 6

3.5 AUDIO AMPLIFIER ......................................................................................................................................... 6

3.6 SQUELCH.......................................................................................................................................................... 7

3.6.1 Buffer Amplifier ............................................................................................................................................. 7

3.6.2 Bandpass Filter ............................................................................................................................................... 8

3.6.3 Noise Detector ................................................................................................................................................ 8

3.6.4 DC Amplifier .................................................................................................................................................. 8

3.6.5 Schmitt Trigger............................................................................................................................................... 8

3.7 FAULT DETECTORS ....................................................................................................................................... 8

3.8 VOLTAGE REGULATORS .............................................................................................................................. 9

3.9 ADDRESS DECODER ...................................................................................................................................... 9

4.0 MAINTENANCE................................................................................................................................................. 10

4.1 RECOMMENDED TEST EQUIPMENT......................................................................................................... 10

4.2 ALIGNMENT PROCEDURE.......................................................................................................................... 10

4.3 CRYSTAL FILTER TUNING ......................................................................................................................... 11

4.3.1 Tuning FL1 and FL2..................................................................................................................................... 11

4.3.2 Tuning FL3 and FL4..................................................................................................................................... 11

4.4 AUDIO AND DATA OUTPUT ADJUSTMENTS.......................................................................................... 11

4.5 TROUBLESHOOTING.................................................................................................................................... 11

5.0 ASSEMBLY DIAGRAM..................................................................................................................................... 13

6.0 PARTS LIST ........................................................................................................................................................ 14

7.0 IC DATA .............................................................................................................................................................. 23

8.0 OUTLINE DIAGRAM......................................................................................................................................... 30

9.0 SCHEMATIC DIAGRAM ................................................................................................................................... 31

Summary of content (34 pages)

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Maintenance Manual MM101886V1 R1A 21.4 MHz RECEIVER IF MODULE 12.5/25 kHz CHANNEL SPACING CB101128V1 TABLE OF CONTENTS Page 1.0 SPECIFICATIONS................................................................................................................................................. 3 2.0 DESCRIPTION ...................................................................................................................................................... 4 3.0 CIRCUIT ANALYSIS............................
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NOTE This device made under license under one or more of the following US patents: 4,590,473; 4,636,791; 5,148,482; 5,185,796; 5,271,017; 5,377,229. NOTE The voice coding technology embodied in this product is protected by intellectual property rights including patent rights, copyrights, and trade secrets of Digital Voice Systems, Inc.
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SPECIFICATIONS 1.0 SPECIFICATIONS1 Item I.F. (Intermediate Frequency) Input Impedance l2 dB SINAD Adj. CH Rejection Image Rejection Intermodulation Rejection Signal Displacement Bandwidth 2nd I.F. (Intermediate Frequency) 455 kHz Balanced Output Level 2nd L.O. Frequency AF Output (J2, Pin 31C) AF Output Impedance AF Distortion AF Response 10 Hz 300 Hz 1000 Hz 3 kHz (25 kHz Channel) 3 kHz (12.
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DESCRIPTION 2.0 DESCRIPTION The MASTR III Receiver IF Module 19D902783G7/G11 provides amplification and demodulation of the 21.4 MHz Intermediate Frequency (IF) signal as well as Automatic Gain Controlled (AGC) 455 kHz outputs to the DSP Modem module(Figure 1 - 21.4 MHz Receiver IF Module). The IF Module also includes the receiver squelch circuitry. However, it does not include de-emphasis or squelch audio gating circuits. Figure 2 – 21.
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CIRCUIT ANALYSIS 3.0 CIRCUIT ANALYSIS 3.1 INPUT AMPLIFIER NETWORK The input amplifier consisting of transistor Q1 and transformer TX1, provides a 50 ohm load for the receiver IF module. Capacitor C1 provides AC coupling and a DC block on the input line (J1). This DC block protects the module in the event of a failure in a preceding module. Capacitor C1 and inductor L1 are series-resonant at 21.4 MHz and provide a lowimpedance path from J1 to amplifier transistor Q1.
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CIRCUIT ANALYSIS 3.4 OSCILLATOR/MIXER/DETECTOR Integrated circuit U101 performs several functions. The 20.945 MHz crystal oscillator provides local oscillator injection to the mixer in U101. This mixer converts the 21.4 MHz IF signal to 455 kHz. Capacitors C119 and C120 are oscillator feedback capacitors and have been chosen to provide the proper capacitance for crystal Y100. The frequency can be adjusted by means of L102.
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CIRCUIT ANALYSIS module (1 kHz AF, 3 kHz peak deviation in the 25 kHz mode). The typical amplifier gain is approximately 5. In the 12.5 kHz mode the standard deviation is 1.5 kHz. To provide the same 1 Vrms output, the gain is increased by shunting resistor R202 with resistor R201 by means of electronic switch U207. Operational amplifier U200B is used as a voltage regulator to provide 6 VDC for biasing U200C. DIPLEXER 21.4 MHz XTAL FILTER IF AMP IF AMP AGC AMP UPC3206 21.4 MHz XTAL FILTER 21.
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CIRCUIT ANALYSIS 3.6.2 Bandpass Filter Bandpass filter U203A, together with its associated circuitry, performs the function of an audio frequency bandpass filter, centered at 6 kHz with a gain of 2. The purpose of this filter is to reject all voice frequencies and allow only demodulated noise to pass. The functioning of the squelch circuit depends upon the presence or absence of this noise. When a signal is being received, i.e.
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CIRCUIT ANALYSIS emitter drop) Q101 will turn on and a fault will be indicated. Transistors Q3 and Q4 are drivers for the front panel LED D2. These are powered from the +13.8VDC supply. Therefore, if the 8V regulator opens, a fault will still be indicated. 3.8 VOLTAGE REGULATORS 8V regulator U201 is a monolithic integrated circuit voltage regulator providing 8 VDC (+8V). This powers all 8-volt circuitry in the module with the exception of U100 and Q100.
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MAINTENANCE 4.0 MAINTENANCE 4.1 RECOMMENDED TEST EQUIPMENT The following test equipment is required to test the IF Module 1. FM Signal Generator; HP 8640B, HP 8657A, or equivalent 2. AF Generator or Function Generator 3. Audio Analyzer; HP 8903B, HP 339A, or equivalent 4. Oscilloscope 5. Frequency Counter; Racal-Dana 9919 or equivalent 6. DC Meter for troubleshooting 7. Power Supply; 13.8 VDC @ 180 mA 8. Power Supply; 12 VDC @40 mA 9. M/A-COM Test Box TS101285V11 4.2 ALIGNMENT PROCEDURE 1. Apply 13.
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MAINTENANCE 4.3 CRYSTAL FILTER TUNING 4.3.1 Tuning FL1 and FL2 1. Connect test equipment as shown in Fig. 10.1. 2. Connect the high impedance probe to either side of resistor R152. 3. Set the span of the network analyzer to 20 kHz, and the center frequency to 21.4 MHz. 4. Set the analyzer RF output level to obtain –75 dBm at the input of the module. 5. Adjust C9, C12, and C17 for maximum response at 21.4 MHz. 4.3.2 Tuning FL3 and FL4 1. Adjust C24, C29, and C36 for maximum response at 21.4 MHz. 2.
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MAINTENANCE IF amplifier transistor Q2 has a nominal 8 dB gain. Transistor Q2 has a nominal gain of 8.5 dB. The mixer has about 14 dB voltage gain with proper LO injection. The proper crystal oscillator level is 10 mV pk measured at TP3. The following four test points are provided on the PWB for additional test capability: TP1: 45 mV pk @ 21.4 MHz with -20 dBm input signal TP3: 10 mV pk @ 20.
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ASSEMBLY DIAGRAM 5.0 ASSEMBLY DIAGRAM Item 1 2 3 4 5 6 7 8 9 Part Number Description 21.4 MHz Receiver IF Module EA101401V1 19D902508P1 Chassis 19D902509P1 Cover 19D902555P1 Handle 19A702381P506 Screw, torq 19A702381P513 Screw, torq 19B235310P1 NP, Blank 19B802690P1 Grommet 19A702381P508 Screw, torq CB101128V1 Board, Component Qty 1 1 1 6 6 1 1 1 1 RECEIVER IF MODULE EA101401V1 (AD-EA101401, Rev.
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PARTS LIST 6.0 PARTS LIST MASTR III RECEIVER IF CIRCUIT BOARD ASSEMBLY 2 PL-CB101128V1 Revision: A Symbol Part Number Description - - - - CAPACITORS - - - C1 and C2 C3 C4 C5 C6 C7 and C8 C9 C10 C11 C12 C13 C14 and C15 C16 C17 C18 and C19 C20 C21 C22 C23 C24 C25 C26 C27 and C28 C29 C30 C31 C32 C33 C34 2 RJC 463 4043/12 120pF RJC 464 2045/47 RJC 464 2045/1 RJC 464 3044/47 RJC 464 2045/1 RJC 463 6042/15 47nF 10nF 4.
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PARTS LIST Symbol C35 C36 C37 C38 C39 C40 thru C99 C100 and C101 C102 C103 C104 C105, C106 C107 C108 C109, C110, C111 C112 C113 C114 C115 and C116 C117 C118 C119 C120 C121 C122 C123 and C124 C125 and C126 C127 C128 C129 C130 thru C135 C136 MM101886V1 R1A Part Number Description 19A704350P102 RJC 464 3046/1 RJC 463 4042/1 RJC 463 0041/1 Not Used 3-10pF 100nF 10pF 1pF Not Used RJC 464 3045/22 22nF RJC 464 3067/1 RJC 464 3045/22 RJC 464 3046/1 RJC 464 3045/22 RJC 464 3046/1 RJC 464 3045/22 RJC 464 3044
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PARTS LIST Symbol 16 Part Number Description C137 and C138 C139 C140 thru C144 C145 C146 C147 C148 C149 and C150 C151 and C152 RJC 464 3046/1 100nF RJC 463 4042/22 RJC 464 3046/1 22pF 100nF RJC 463 4043/1 19A705205P5 RJC 464 3046/1 RJC 463 4043/12 RJC 464 3046/1 100pF 6.
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PARTS LIST Symbol C218 C219 C220 and C221 C222 C223 C224 thru C226 C227 C228 thru C232 C233 and C234 C235 and C236 C237 thru C242 C243 and C244 C245 and C246 C247 C248 C249 C250 C251 C252 Part Number Description RJC 464 3067/1 RJC 463 4043/1 1µF 100pF 19A705205P2 RJC 464 3046/1 RJC 463 4043/1 1µF POL 100nF 100pF RJC 463 4043/1 Not Used 100pF RJC 464 2045/1 10nF RJC 464 3046/33 0.
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PARTS LIST Symbol Part Number Description - - - - CONNECTORS - - - - J1 J2 19A115938P24 19B801587P7 BNC 96 PIN L1 and L2 L3 and L4 L5 and L6 L7 and L8 L9 L10 REG704593/47 0.47µH: TDK REG704594/68 6.8µH: TDK L100 L101 L102 L103 REG 704 14/37 REG 704 593/27 19A703311P1 REG 704 14/37 10µH. 0.27µH: TDK 0.
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PARTS LIST Symbol R8 R9 R10 R11 R12 R13 R14 R15 R16 and R17 R18 R19 R20 R21 R22 R23 R24 and R25 R26 and R27 R28 thru R34 R35 R36 thru R99 R100 R101 R102 R103 R104 R105 R106 R107 R108 R109 R110 R111 R112 R113 R114 R115 R117 MM101886V1 R1A Part Number Description 344A3304P9090 344A3304P1000 344A3304P1002 344A3304P3321 344A3304P8250 344A3304P9090 19B801251P5R6 344A3304P9090 344A3304P3321 909 Ohms 100 Ohms 10k Ohms 3.32k Ohms 825 Ohms 909 Ohms 5.62 Ohms 909 Ohms 3.
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PARTS LIST Symbol R118 R119 R120 R121 R122 R123 R124 R125 R126 R127 R128 R129 R130 R131 R132 R133 R134 R135 R136 R137 R138 R139 R140 R141 R142 R143 R144 R145 R146 R147 R148 and R149 R150 and R151 R152 and R153 R154 R155 R156 thru R200 R201 R202 R203 20 Part Number 344A3304P6811 344A3304P1212 344A3304P4750 344A3304P2211 344A3304P4750 344A3304P8250 344A3304P1002 344A3304P1211 344A3304P3921 344A3304P1211 344A3304P1821 344A3304P4751 344A3304P8251 344A3304P1002 344A3304P1502 344A3304P1003 344A3304P1002 344A330
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PARTS LIST Symbol R204 R205 thru R207 R208 R209 R210 and R211 R212 R213 R214 R215 R216 R217 and R218 R219 R220 and R221 R222 R223 R224 R225 and R226 R227 R228 R229 R230 R231 R232 R233 thru R235 R236 R237 thru R239 R240 R241 thru R244 R245 R246 R247 R248 MM101886V1 R1A Part Number Description 344A3304P1502 344A3304P1003 15k Ohms 100k Ohms 344A3304P6811 344A3304P1001 344A3304P3322 6.81k Ohms 1k Ohms 33.2k Ohms 344A3304P5622 344A3304P8251 344A3304P1002 344A3304P1003 344A3304P3323 344A3304P1002 56.
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PARTS LIST Symbol R249 R250 R251 R252 and R253 R254 TP1 TP2 TP3 and TP4 TP5 Part Number Description 344A3304P1001 Not Used 1k Ohms Not Used 1k Ohms 344A3304P1003 100k Ohms 344A3304P1001 344A3367P1 - - - - TEST POINTS - - - A trace on the printed wire board TEST POINT Traces on the printed wire board 344A3367P1 TEST POINT REGUA10003/1 B5F - - - - TRANSFORMERS - - - TX1,TX2 U1 U100 U101 U102 and U103 U104 U105 22 - - - - INTEGRATED CIRCUITS - - - GNLM239D Quad Operational Amplifier LM239A/SO:
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IC DATA 7.
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IC DATA Continued 24 MM101886V1 R1A
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IC DATA U101 FM Receiver Module 19A705535P3 U102, U103, U207 Dual Analog Switch (Single-Pole/Double-Throw) RYT 101 6239/C (MAX4544) U105 Dual High Speed, Low Power, Low Distortion Voltage Feedback Amplifier VELM6172IM (LM6172IM) MM101886V1 R1A 25
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IC DATA U200 Rail–to-Rail Operational Amplifier RYT 101 6140/2 (TLC2274/SO) 26 MM101886V1 R1A
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IC DATA U201, U208 +8 Volt Regulator 19A704971P10 (MC78M08C/TO) U202 +5 Volt Regulator 19A704971P9 (LM78L05AC/SO) Pinout: 1 - Vout 2 - Ground 3 - Ground 4 - N.C. 5 - N.C.
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IC DATA U203 Low Power Quad Operation Amplifier RYT 101 6002/2C (LM2902/SO) U204 3-8 Inverting Line Decoder/Demultiplexer 344A3064P201 (74HCT138/SO)m 28 MM101886V1 R1A
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IC DATA U205 Quad 2-Input OR Gate 19A703483P311 (74HC32/SO) U206 8-Bit Shift Register 19A703987P324 (74HC595/SO) MM101886V1 R1A 29
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OUTLINE DIAGRAM 8.0 OUTLINE DIAGRAM RECEIVER IF MODULE CB101128V1 (AD-CB101128V1, Sh.3, Rev.
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SCHEMATIC DIAGRAM 9.0 SCHEMATIC DIAGRAM RECEIVER IF MODULE CB101128V1 (WD-CB101128V1, Sh. 1, Rev.
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SCHEMATIC DIAGRAM RECEIVER IF MODULE CB101128V1 (CB101128V1, Sh. 2, Rev.
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SCHEMATIC DIAGRAM RECEIVER IF MODULE CB101128V1 (CB101128V1, Sh. 3, Rev.
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M/A-COM Wireless Systems 3315 Old Forest Road Lynchburg, Virginia 24501 (Outside USA, 434-385-2400) Toll Free 800-528-7711 www.macom-wireless.com Printed in U.S.A.