Table Of Contents - Icom IC-47A Maintenance Manual

Table of Contents

Table of Contents2
Specifications3
Operating Controls4
Front Panel4
Vfo/Memory Switch4
VFO Switch4
Rear Panel6
Under the Access Cover7
Circuit Description8
Receiver Circuits8
Transmitter Circuits8
RF Amplifier and First Mixer8
Voltage Regulation and Receive-Transmit Switch Circuit9
ALC and RF Power Meter Circuits9
PLL Circuit9
PLL Circuit Block Diagram9
Local Oscillator Circuit10
Mixer, Low-Pass Filter and Amplifier Circuits10
PLL Local Oscillator10
Logic Circuits12
VCO and FM Modulation Circuits12
Cpu12
CPU Control Circuit12
Clock Pulse Generator Circuit16
MIC Up/Down Control Circuit16
Scanning Control Circuit16
Priority Circuit17
PTT Circuit17
Tone Generator Circuit17
Voltage Regulator and Memory Backup Circuits17
Block Diagram18
Inside Views20
Main Unit Side20
Logic Unit Side21
Mechanical Parts and Disassembly22
Frame Disassembly22
Front Panel Disassembly24
Connector Connections26
Bottom View27
Maintenance and Adjustment28
Preparation before Servicing28
PLL Adjustment29
PLL/VCO Unit30
Receiver Adjustment31
Main/Pll Unit32
Transmitter Adjustment33
Voltage Diagrams35
EF Unit35
Logic Unit43
PA Unit47
Board Layouts48
RF, Main & PLL Units49
IC Specifications54
LED Level Meter Indicator55
PIN Connection55
Dual Audio Amplifier55
Dual Comparator56
Narrow Band FM if56
FM if Amplifier57
3-Output 8.2 V Voltage Regulator57
5.4W Audio Power Amplifier58
Dual Operational Amplifier58
Programmable Phase Locked Loop60
5-Unit 400Ma Darlington Transistor Array60
I/O Expander61
Programmable Tone Generator62
Diode Array62
25W UHF RF Power Amplifier63
Parts List64
UT-16 Voice Synthesizer Unit73
Operation after Installation73
Timing Chart of IC 274
Schematic77