Table Of Contents - Icom IC-228A Service Manual

Table of Contents

Repair Note2
Table Of Contents3
Specifications4
Outside And Inside Views5
Frequency Display5
Front Panel5
Rear Panel5
Main Unit View6
Rx Unit View7
Block Diagram8
Circuit Description9
Receiver Circuits9
Antenna Switching Circuit (Main Unit)9
Rf Circuit (Rx Unit)9
Transmitter Circuits10
Microphone Amplifier (Main Unit)10
Drive Amplifier (Main Unit)10
Apc Circuit (Main Unit)10
Pll Circuits (Main Unit)11
Vco Circuit11
Reference Oscillator11
Subaudible Tone Encoder Circuit11
Logic Circuits (Ef Unit)12
Cpu Port Allocations12
Key Matrix12
Reset Circuit13
S/Rf Indicator Circuit13
Dimmer Circuit13
Disassembly And Assembly Diagrams14
Front Panel Disassembly14
Frame Disassembly16
Main Unit Connector Assembly18
Rx Unit Connector Assembly19
Maintenance And Adjustment20
Preparation Before Servicing20
Pll Adjustment20
Receiver Adjustment22
Transmitter Adjustment24
Board Layouts26
Ef Unit Board26
Main Unit Board29
Ic-228H Board32
Rx Unit Board35
Parts List38
Optional Units44
Ut-40 Tone Squelch Unit Circuit Description44
Encoder Circuit44
Decoder Circuit44
Ut-40 Voltage/Circuit Diagram45
Ut-40 Board Layouts46
Ut-40 Block Diagram47
Ut-40 Parts List47
Voltage Diagram48
Ef And Main Units Diagram48
Rx Unit Diagram53