Motorola Mtx Series Detailed Rev 6881088c46 E Manual
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MANUAL REVISION 12-26-03 ® © Motorola, Inc. 2003 8000 West Sunrise Boulevard Fort Lauderdale, Florida 33322 *FMR2045A-2* FMR-2045A-2 HT Series, MTX Series, PRO Series Professional Series Two-Way Portable Radios Detailed Service Manual 6881088C46-E REVISION CHANGE: This manual revision contains theories of operation, schematics, board layouts, and troubleshooting flowcharts for Professional Series radios with the following boards installed: Use the information provided in this manual revision to...
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December 26, 2003 2 FMR-2045A-2 This page intentionally left blank.
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Table of Contents REVISION CHANGE: ................................................................................................................................. 1 Chapter 1 UHF Theory of Operation ............................................................................... 7 1.1 Transmitter........................................................................................................................................ 7 1.1.1 General...
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4Table of Contents December 26, 2003FMR-2045A-2 5.1 Notes For All Schematics and Circuit Boards .................................................................................45 5.2 Circuit Board/Schematic Diagrams and Parts List .......................................................................... 47 Chapter 6 UHF Band 2 Troubleshooting Charts .......................................................... 61 6.1 Troubleshooting Flow Chart for Controller...
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Table of Contents5 FMR-2045A-212/26/03 List of Figures Transmitter Block Diagram .................................................................................................................. 7 UHF Receiver Block Diagram .............................................................................................................. 9 Frequency Generation Unit Block Diagram ....................................................................................... 10 Synthesizer Block Diagram...
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FMR-2045A-2December 26, 2003 UHF Theory of Operation: Transmitter7 Chapter 1 UHF Theory of Operation 1.1 Transmitter Figure 1-1. Transmitter Block Diagram 1.1.1 General (Refer to Figure 1-1.) The UHF transmitter contains five basic circuits: Power amplifier Antenna switch Harmonic filter Antenna matching network Power control integrated circuit (PCIC) 1.1.2 Power Amplifier The power amplifier consists of two devices: 9Z67 LDMOS driver IC (U101) PRF1507 LDMOS PA (Q110) The 9Z67 LDMOS driver...
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December 26, 2003FMR-2045A-2 8UHF Theory of Operation: Transmitter 1.1.3 Antenna Switch The antenna switch circuit consists of two PIN diodes (CR101 and CR102), a pi network (C107, L104 and C106), and two current limiting resistors (R101, R170). In the transmit mode, B+ at PCIC (U102) pin 23 will go low and turn on Q111 where a B+ bias is applied to the antenna switch circuit to bias the diodes “on.” The shunt diode (CR102) shorts out the receiver port, and the pi network, which operates as a quarter...
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FMR-2045A-2December 26, 2003 UHF Theory of Operation: Receiver9 1.2 Receiver Figure 1-2. UHF Receiver Block Diagram 1.2.1 Receiver Front-End (Refer to the UHF Receiver Front-End Schematic Diagram on page 20 and the UHF Transmitter Schematic Diagram on page 25.) The RF signal is received by the antenna and applied to a low-pass filter. For UHF, the filter consists of L101, L102, C102, C103, C104. The filtered RF signal is passed through the antenna switch. The antenna switch circuit consists of two...
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December 26, 2003FMR-2045A-2 10UHF Theory of Operation: Frequency Generation Circuitry The output of the post-RF amplifier filter which is connected to the passive double balanced mixer consists of T301, T302 and CR306. Matching of the filter to the mixer is provided by C381. After mixing with the first LO signal from the voltage controlled oscillator (VCO) using low side injection, the RF signal is down-converted to the 44.85 MHz IF signal. The IF signal coming out of the mixer is transferred to the...