Motorola GP series

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Table of Contents
Chapter 1 MODEL CHART AND TECHNICAL SPECIFICATIONS
1.0 GP640/GP680 Model Chart .................................................................................1-1
2.0 GP1280 Model Chart ...........................................................................................1-1
3.0 Technical Specifications ......................................................................................1-2
Chapter 2 THEORY OF OPERATION
1.0 Introduction ..........................................................................................................2-1
2.0 UHF2 Transmitter ................................................................................................2-1
2.1 Power Amplifier ..............................................................................................2-1
2.2 Antenna Switch...............................................................................................2-2
2.3 Harmonic Filter ...............................................................................................2-2
2.4 Antenna Matching Network ............................................................................2-2
2.5 Power Control Integrated Circuit (PCIC) ........................................................2-2
3.0 UHF2 Receiver (All models except those with PCB 8486686Z02)......................2-3
3.1 Receiver Front-End ........................................................................................2-3
3.2 Receiver Back-End.........................................................................................2-4
3.3 Automatic Gain Control (AGC) .......................................................................2-5
4.0 UHF2 Receiver (Models with PCB 8486686Z02) ................................................2-6
4.1 Receiver Front-End ........................................................................................2-6
4.2 Receiver Back-End.........................................................................................2-7
5.0 Frequency Generation Circuit ..............................................................................2-8
5.1 Synthesizer.....................................................................................................2-9
5.2 Voltage Controlled Oscillator (VCO).............................................................2-10
6.0 Voice Storage (GP1280 Only) ...........................................................................2-12
Chapter 3 TROUBLESHOOTING CHARTS
1.0 Troubleshooting Flow Chart for Receiver (All models except those with PCB
8486686Z02) (Sheet 1 of 2).................................................................................3-1
2.0 Troubleshooting Flow Chart for Receiver (All models except those with PCB
8486686Z02)(Sheet 2 of 2)..................................................................................3-2
3.0 Troubleshooting Flow Chart for Receiver (Models with PCB 8486686Z02)
(Sheet 1 of 2) .......................................................................................................3-3
4.0 Troubleshooting Flow Chart for Receiver (Models with PCB 8486686Z02)
(Sheet 2 of 2) .......................................................................................................3-4
5.0 Troubleshooting Flow Chart for Transmitter ........................................................3-5
6.0 Troubleshooting Flow Chart for Synthesizer........................................................3-6
7.0 Troubleshooting Flow Chart for VCO...................................................................3-7
8.0 Troubleshooting Flow Chart for Receive Message/Personal Memo Recording ..3-8
9.0 Troubleshooting Flow Chart for Message Playback ............................................3-9