Icom IC-728 - Service Manual

Critical warnings for operating the transceiver safely.

Important precautions for disassembling and servicing the transceiver.

General transceiver specifications including transmitter and receiver performance.

Internal view of the main unit with component labels.

Internal views of PLL, PA and Filter units with component labels.

Detailed description of the transceiver's receiver circuits.

Noise blanker circuit to reduce pulse noise.

PBT circuit for shifting 3rd IF frequency.

AGC circuit for automatic gain control.

Detailed description of the transceiver's transmitter circuits.

IF amplifier for signal processing.

ALC circuit for automatic level control.

General description of the PLL system.

Main loop circuit of the PLL system.

Band selection data used by the CPU.

List of chassis parts with order numbers and descriptions.

List of PA parts and accessories with order numbers.

Parts list for the AF, Jack, and VR units.

Parts list for the MIC, LED, and PBT units.

Continued parts list for the MAIN unit.

Continued parts list for the PLL unit.

Parts list for the Filter unit.

Parts list for the PA unit.

Required test equipment and connection setup for servicing.

Adjustment procedures for the PLL circuits.

BFO frequency adjustment steps.

Total gain adjustment steps for receiver.

Idling current adjustment for drive and final transistors.

Output power adjustment for transmitter.

CW delay time adjustment.

Board layouts for AF, VR, and Jack units.

Board layouts for Front, LED, and PBT units.

Board layout for the Main unit.

Board layout for the PLL unit.

Board layout for the PA unit.

Board layout for the Filter unit.

Board layout for the DDS unit.

Voltage diagram for Front and Main units.

Voltage diagram for PLL and PA units.