Motorola CDM Series - Chapter 4: Vhf (136-174 Mhz) 1-25 W Service Information

Chapter 4: i
6881091C63-A
Chapter 4: VHF (136-174 MHz) 1-25W
Service Information
Table of Contents
Section 1 Model Charts and Technical Specifications
1.0 VHF (136-174 MHz) 1-25W Model Charts........................................................4:1-1
1.1 CDM Series Model Chart ............................................................................4:1-1
1.2 PRO Series Model Chart.............................................................................4:1-2
2.0 Technical Specifications ...................................................................................4:1-2
Section 2 Theory of Operation
1.0 Introduction .......................................................................................................4:2-1
2.0 VHF (136-174 MHz) 1-25W Receiver Front-End..............................................4:2-1
2.1 Receiver Front-End .....................................................................................4:2-1
2.2 Front-End Bandpass Filters and Pre-Amplifier............................................4:2-2
2.3 First Mixer and High Intermediate Frequency (IF).......................................4:2-2
2.4 Low Intermediate Frequency (IF) and Receiver Back-End .........................4:2-2
3.0 VHF (136-174 MHz) 1-25W Transmitter Power Amplifier (PA) 25W ................4:2-3
3.1 First Power Controlled Stage ......................................................................4:2-3
3.2 Power Controlled Driver Stage....................................................................4:2-4
3.3 Final Stage ..................................................................................................4:2-4
3.4 Directional Coupler......................................................................................4:2-4
3.5 Antenna Switch ...........................................................................................4:2-5
3.6 Harmonic Filter ............................................................................................4:2-5
3.7 Power Control..............................................................................................4:2-5
4.0 VHF (136-174 MHz) 1-25W Frequency Synthesis ...........................................4:2-5
4.1 Reference Oscillator....................................................................................4:2-6
4.2 Fractional-N Synthesizer .............................................................................4:2-6
4.3 Voltage Controlled Oscillator (VCO)............................................................4:2-7
4.4 Synthesizer Operation.................................................................................4:2-8
Section 3 Troubleshooting Charts
1.0 Troubleshooting Flow Chart for Receiver .........................................................4:3-1
2.0 Troubleshooting Flow Chart for 25W Transmitter.............................................4:3-3
3.0 Troubleshooting Flow Chart for Synthesizer.....................................................4:3-6
4.0 Troubleshooting Flow Chart for VCO................................................................4:3-7