Use the schematic diagram for the PA unit. Find the drain of the PA transistor. Note the reference designator (e.g., “TP801 – PA Drain”). Then flip to the PCB layout diagram to see exactly where TP801 is on the physical board.
The opening sections provide an overview of the radio’s architecture. The IC-705 is a direct sampling SDR for HF and 6m, while VHF/UHF uses a separate superheterodyne receiver. The block diagram shows how the RF signal flows from the antenna connector through low-pass filters, preamps, attenuators, and into the RF/IF ICs. Understanding this flow is the first step in any hardware-level diagnosis.
Icom Ic705 Service Manual [repack] Here
Use the schematic diagram for the PA unit. Find the drain of the PA transistor. Note the reference designator (e.g., “TP801 – PA Drain”). Then flip to the PCB layout diagram to see exactly where TP801 is on the physical board.
The opening sections provide an overview of the radio’s architecture. The IC-705 is a direct sampling SDR for HF and 6m, while VHF/UHF uses a separate superheterodyne receiver. The block diagram shows how the RF signal flows from the antenna connector through low-pass filters, preamps, attenuators, and into the RF/IF ICs. Understanding this flow is the first step in any hardware-level diagnosis. icom ic705 service manual