Icom IC-F21S service manual SW-A and SW-B Units, TOP View SW-A Unit

Page 28

9-2 SW-A AND SW-B UNITS

•TOP VIEW SW-A UNIT

F1	DS1
Q1

SW-B UNIT

B5603C

F1

Q1

DS1

9 - 3

Image 28

Contents UHF FM Transceivers Ordering Parts IntroductionRepair Notes Table of Contents Specifications ‘ General‘ Transmitter ‘ ReceiverMain Unit TOP View Inside ViewsBottom View Removing the Chassis Disassembly InstructionsRemoving the Main Unit Circuit Description Receiver CircuitsTransmitter Circuits PLL Circuit GeneralVCO Circuit PLL CircuitPort Allocations Power Supply Circuits Voltage LinePin Port Description Number Output Expander IC IC15 3 D/A Convertor IC IC9Adjustment Procedures PreparationScreen display exampe JIG cableSPE GNDDC Power Supply GND DC power cable connectionsConnection PLL Adjustment PLL LockMain VoltageSoftware Adjustment Sensitivity SquelchLevel SQLUnit Section Parts ListMain Unit Coil Eljfc R68M-F Array Electrolytic ECEV1CA470SP Connector Mechanical Parts and Disassembly AccessoriesChassis Parts Screw abbreviations B0, BT Self-tappingIC-F21S Transistor and FET’S SEMI-CONDUCTOR InformationDiodes Board Layouts Main UnitFT1 IC6TOP View SW-A Unit SW-A and SW-B UnitsSW-B Unit CBI0 CBI1 CBI2 CBI3 Bottom View SW-A UnitGND Tled Rled VCC Volin Volout Parts List Disassembly InformationBC-146 Optional Desktop Charger Information Charge UnitVoltage Diagram Board LayoutBlock Diagram SW-A/SW-B Unit S1Voltage Diagram 2SC4215 ODTC144EU Section Voltage Diagram SW-A Unit Q1 XP4216Page 32, Kamiminami, Hirano-ku, Osaka, 547-0003, Japan