Icom IC-F21S service manual Connection, DC power cable connections, DC Power Supply GND

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Connection

Standard signal generator to the antenna connector	to [MIC]
0.1 V to 32 mV	Audio generator
(—127 dBm to —17 dBm)

CAUTION:

DO NOT transmit while an SSG is connected to the antenna connector.

to an RS-232C port
	Personal
OPC-478	computer

FM

deviation meter

Attenuator

40 dB or 50 dB

RF power meter 0.1—10 W/50 ‰

Frequency

counter

DB9 female plug

(incl. level converter circuit)

to [SP]

SINAD meter JIG cable

Speaker (8 ‰)

DC power cable connections

+

DC POWER

SUPPLY

GND

Battery type detector

NOTE: When you adjust the output power (high power), the battery type detector must be con- nected to GND (see illustration at above). Ohterwise the transceiver does not transmit high power, the output power will be low.

5 - 3

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Contents UHF FM Transceivers Repair Notes IntroductionOrdering Parts Table of Contents ‘ Transmitter Specifications‘ General ‘ ReceiverBottom View Inside ViewsMain Unit TOP View Removing the Main Unit Disassembly InstructionsRemoving the Chassis Circuit Description Receiver CircuitsTransmitter Circuits VCO Circuit PLL CircuitGeneral PLL CircuitPin Port Description Number Power Supply Circuits Voltage LinePort Allocations Output Expander IC IC15 3 D/A Convertor IC IC9Adjustment Procedures PreparationSPE Screen display exampeJIG cable GNDConnection DC power cable connectionsDC Power Supply GND Main PLL AdjustmentPLL Lock VoltageSoftware Adjustment Level SensitivitySquelch SQLMain Unit Section Parts ListUnit Coil Eljfc R68M-F Array Electrolytic ECEV1CA470SP Connector Chassis Parts Mechanical Parts and DisassemblyAccessories Screw abbreviations B0, BT Self-tappingIC-F21S Diodes SEMI-CONDUCTOR InformationTransistor and FET’S Board Layouts Main UnitFT1 IC6SW-B Unit SW-A and SW-B UnitsTOP View SW-A Unit GND Tled Rled VCC Volin Volout Bottom View SW-A UnitCBI0 CBI1 CBI2 CBI3 BC-146 Optional Desktop Charger Information Parts ListDisassembly 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