Icom IC-R3 Service Manual

Also see for COMMUNICATIONS RECEIVER IC-R3: Instruction manual Brochure & specs Service manual

Contents

Icom IC-R3 Service Manual Manual pdf 14 page image

4 - 8Pin Port Descriptionnumber name567891011121617B1CB2CB3C65MC30MCSHIFTDBL1DBL2470MC600MCOutputs low-pass filter select signal.Low : When frequencies 0.5 to 1.9MHz are displayed.Outputs bandpass filter select signal.Low : When frequencies 1.9 to 15MHz are displayed.Outputs bandpass filter select signal.Low : When frequencies 15 to 30MHz are displayed.Outputs bandpass filter select signal.Low : When frequencies 65 to 108MHz are displayed.Outputs bandpass filter select signal.Low : When frequencies 30 to 65MHz are displayed.Outputs control signal for the VCO shiftcircuit (VCO unit; Q21, D61).High : While the 1st VCO is shifting.Outputs control signal for the doubler1circuit (RF unit; Q26, D65, D67).Outputs control signal for the doubler2circuit (RF unit; Q26, D66, D68).Outputs low-pass and bandpass filtersselect signal.Low : When frequencies 470 to 600MHz are displayed.Outputs low-pass and bandpass filtersselect signal.Low : When frequencies 600 to 750MHz are displayed.LINEBATVVCCHV+3V3VR3V4.5V5V12V15VDESCRIPTIONThe voltage from the attached battery.The same voltage as the BATV line (battery volt-age).Common 3V converted from VCC line by the+3V converter circuit (LOGIC unit; Q6, Q39)using the “POWERC” signal from the CPU(LOGIC unit; IC11, pin 28).Common 3V converted from the VCC line by the+3V regulator circuit (LOGIC unit; IC3).The output voltage is applied to the RESET cir-cuit (LOGIC unit; IC5, pin 2).Receive 3V controlled by the R3V regulator cir-cuit (LOGIC unit; Q4, Q5) using the +3SC signalfrom the CPU (LOGIC unit; IC11, pin 27).Common 4.5V converted from the VCC line bythe DC-DC converter (LOGIC unit; IC801).The output voltage is applied to the TFT driver(LOGIC unit; IC901) and the TFT back light dri-ver (LOGIC unit; Q821).Common 5V converted from the VCC line by theDC-DC converter (LOGIC unit; T1).The output voltage is applied to the OSD IC(LOGIC unit; IC902), etc.Common 12V converted from VCC line by theDC-DC converter (LOGIC unit; T1).The output signal is applied to the TFT driver(LOGIC unit; IC901).Common 15V converted from the VCC line bythe DC-DC converter (LOGIC unit; T1).The output signal is applied to the TFT LCD(LOGIC unit; DS54).4-4 POWER SUPPLY CIRCUITSVOLTAGE LINE4-5 PORT ALLOCATIONS4-5-1 EXPANDER IC (RF UNIT; IC5)