Icom IC-F21 B5604C, Bottom View Sw-A Unit, to the MAIN unit J1, Sw-B Unit, J2 to the MAIN unit J2

Models: IC-F21S

B5604C

•BOTTOM VIEW SW-A UNIT

J2

Manuals / Icom / Communications / Two-Way Radio

1 38

Page 29

to the MAIN unit J2

GND

TLED

RLED

VCC

VOLIN

VOLOUT

CBI0

S1
W1	W2	R2	R3	R1
W1	W2			R1

to the MAIN unit J1

to the MAIN unit J2

GND

TLED

RLED

VCC

VOLIN

VOLOUT

CBI0

9 - 4

Page 29

Image 29

Icom IC-F21S service manual B5604C, Bottom View Sw-A Unit, to the MAIN unit J1, Sw-B Unit, J2 to the MAIN unit J2

Contents

SERVICE MANUAL UHF FM TRANSCEIVERSDANGER INTRODUCTIONORDERING PARTS REPAIR NOTESTABLE OF CONTENTS ‘ GENERAL SECTION 1 SPECIFICATIONS‘ TRANSMITTER ‘ RECEIVERBOTTOM VIEW SECTION 2 INSIDE VIEWSMAIN UNIT TOP VIEW REMOVING THE MAIN UNIT SECTION 3 DISASSEMBLY INSTRUCTIONSREMOVING THE CHASSIS 4-1 RECEIVER CIRCUITS SECTION 4 CIRCUIT DESCRIPTION4-1-1 ANTENNA SWITCHING CIRCUIT 4-1-4 2ND IF AND DEMODULATOR CIRCUITS4-2-3 DRIVE/POWER AMPLIFIER CIRCUITS 4-2 TRANSMITTER CIRCUITS4-1-6 SQUELCH CIRCUIT 4-2-1 MICROPHONE AMPLIFIER CIRCUIT4-3-1 GENERAL 4-3 PLL CIRCUIT4-3-2 TX LOOP 4-3-3 RX LOOP4-4 POWER SUPPLY CIRCUITS VOLTAGE LINE 4-5 PORT ALLOCATIONS4-5-1 CPU IC7 LINE4-5-2 OUTPUT EXPANDER IC IC15 CPU IC7-continued4-5-3 D/A CONVERTOR IC IC9 Port5-1 PREPARATION SECTION 5 ADJUSTMENT PROCEDURESSTARTING SOFTWARE ADJUSTMENT ADJUSTMENT SOFTWARE INSTALLATIONScreen display exampe RF Power HighJIG cable CH NoOPC-478 DC power cable connectionsConnection ADJUSTMENT 5-2 PLL ADJUSTMENTADJUSTMENT CONDITIONS ADJUSTMENTADJUSTMENT 5-3 SOFTWARE ADJUSTMENTADJUSTMENT CONDITION MEASUREMENTADJUSTMENT SOFTWARE ADJUSTMENT - continuedADJUSTMENT CONDITION MEASUREMENTSECTION PARTS LISTSW-A UNIT F21 only UNIT F21S onlyMAIN UNIT MAIN UNITORDER DESCRIPTIONMAIN UNIT MAIN UNITORDER DESCRIPTIONMAIN UNIT MAIN UNITORDER DESCRIPTIONDESCRIPTION MAIN UNITORDER ACCESSORIES SECTION 7 MECHANICAL PARTS AND DISASSEMBLYCHASSIS PARTS MAIN UNITUNIT abbreviation C CHASSIS PARTS, M MAIN UNIT IC-F21SDIODES SECTION 8 SEMI-CONDUCTOR INFORMATIONTRANSISTOR AND FET’S 9-1 MAIN UNIT SECTION 9 BOARD LAYOUTSB5601C TOP VIEWIC11 BOTTOM VIEWB5603C 9-2 SW-A AND SW-B UNITSTOP VIEW SW-A UNIT SW-B UNITBOTTOM VIEW SW-A UNIT B5604Cto the MAIN unit J1 SW-B UNIT10-2 DISASSEMBLY INFORMATION 10-1 PARTS LISTSECTION 10 BC-146 OPTIONAL DESKTOP CHARGER INFORMATION CHARGE UNITMP1 MP2 10-3 VOLTAGE DIAGRAMB5650 10-4 BOARD LAYOUTMAIN UNIT SECTION 11 BLOCK DIAGRAMSW-A/SW-B UNIT S1 EXT.MIC12-1 MAIN UNIT SECTION 12 VOLTAGE DIAGRAMSDEC 12-1 MAIN UNIT VOLTAGE DIAGRAMSECTION 12-2 SW-A AND SW-B UNITS CHASSIS UNITSW-A UNIT SW-B UNITPage 2001 Icom Inc 1-1-32, Kamiminami, Hirano-ku, Osaka, 547-0003, JapanS-13717IZ-C1