Motorola HT1250-LS+ - Page 4

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3.5 200 MHz Transmitter..............................................................................................3-5
3.5.1 Power Amplifier (PA)........................................................................................... 3-5
3.5.2 Antenna Switch ................................................................................................... 3-6
3.5.3 Harmonic Filter.................................................................................................... 3-6
3.5.4 Antenna Matching Network................................................................................. 3-6
3.5.5 Power Control Integrated Circuit (PCIC)............................................................. 3-6
3.5.6 Temperature Cut Back Circuit............................................................................. 3-6
3.6 200 MHz Receiver..................................................................................................3-6
3.6.1 Receiver Front-End............................................................................................. 3-7
3.6.2 Receiver Back-End ............................................................................................. 3-7
3.7 200 MHz Frequency Generation System ...............................................................3-8
3.7.1 Overview ............................................................................................................. 3-8
3.7.2 Fractional-N Synthesizer..................................................................................... 3-9
3.7.3 Voltage Controlled Oscillator (VCO) ................................................................... 3-9
3.8 700 MHz Transmitter............................................................................................3-11
3.8.1 Power Amplifier................................................................................................. 3-11
3.8.2 Antenna Switch ................................................................................................. 3-11
3.8.3 Harmonic Filter.................................................................................................. 3-12
3.8.4 Antenna Matching Network............................................................................... 3-12
3.8.5 Power Control Integrated Circuit (PCIC)........................................................... 3-12
3.8.6 Temperature Cut Back Circuit........................................................................... 3-12
3.9 700 MHz Receiver................................................................................................3-12
3.9.1 Receiver Front-End........................................................................................... 3-13
3.9.2 Receiver Back-End ........................................................................................... 3-13
3.10 700 MHz Frequency Generation System .............................................................3-14
3.10.1 Overview ........................................................................................................... 3-14
3.10.2 Fractional-N Synthesizer................................................................................... 3-14
3.10.3 Voltage Controlled Oscillator (VCO) ................................................................. 3-15
3.11 Trunked Radio Systems .......................................................................................3-17
3.11.1 LTR™ Trunked Systems................................................................................... 3-17
3.11.2 PassPort™ Trunked Systems........................................................................... 3-17
Chapter 4 Maintenance
4.1 Introduction.............................................................................................................4-1
4.3 Inspection ...............................................................................................................4-1
4.3.1 Cleaning.............................................................................................................. 4-1
4.4 Safe Handling of CMOS and LDMOS ....................................................................4-2
4.5 General Repair Procedures and Techniques .........................................................4-2
4.6 Recommended Test Tools .....................................................................................4-4
4.7 Replacing the Circuit Board Fuse...........................................................................4-5