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Motorola IC-T81A, IC-T81E service manual Transmitter Adjustment, Output

Models: IC-T81E IC-T81A

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5-4 TRANSMITTER ADJUSTMENT

The following adjustment must be performed at “ADJUSTMENT MODE”.

ADJUSTMENT		ADJUSTMENT CONDITION			MEASUREMENT					VALUE	ADJUSTMENT
											ADJUSTMENT

					UNIT	LOCATION

OUTPUT	1	• Displayed frequency :			Top	Connect	an	RF		more than 5 W	[DIAL]
POWER		51.000 MHz [EUR], [UK], [ITA]			panel	power meter to the
(50 MHz)		52.000 MHz				antenna connector.
		[AUS], [SEA], [USA-1]
		• Output power	: High
		• transmitting

	2	• Output power	: Low							0.5 W
		• Transmitting

(144 MHz)	3	• Displayed frequency :			Top	Connect	an	RF		more than 5 W	[DIAL]
		145.000 MHz [EUR], [UK]			panel	power meter to the
		147.000 MHz				antenna connector.
		[ITA], [AUS], [SEA], [USA-1]
		• Output power	: High
		• Transmitting

	4	• Output power	: Low							0.5 W
		• Transmitting

(440 MHz)	5	• Displayed frequency :			Top	Connect	an	RF		more than 5 W	[DIAL]
		445.000 MHz [USA-1]			panel	power meter to the
		435.000 MHz [Other]				antenna connector.
		• Output power	: High
		• Transmitting

	6	• Output power	: Low							0.5 W
		• Transmitting

(1200 MHz)	7	• Displayed frequency :			Top	Connect	an	RF		more than 5 W	[DIAL]
		1270.000 MHz			panel	power meter to the
		• Output power	: High			antenna connector.
		• Transmitting

	8	• Output power	: Low							0.5 W

•Transmitting

•LOGIC UNIT TOP VIEW

R322

DTMF or TONE CALL deviation adjustment

R326

440 MHz FM deviation adjustment

R327

50 MHz BAND FM deviation adjustment

R338

1200 MHz FM deviation adjustment

R325

144 MHz BAND FM deviation adjustment

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Motorola IC-T81A, IC-T81E service manual Transmitter Adjustment, Output

Contents

Multiband FM Transceiver Repair Notes IntroductionOrdering Parts Sample OrderTable of Contents Transmitter SpecificationsGeneral Version 50 MHz 145 MHz 440 MHz 1200 MHz MHz RX onlyWFM ReceiverBand WFMRF Unit Inside ViewsLogic Unit CPURemoving the Logic Unit Removing the RF Unit Disassembly InstructionsRemoving the Chassis Panel Removing the Shield Plate Logic unitReceiver Circuits Antenna Switching Circuits RF UnitCircuit Description Duplexer Circuit RF Unit7 1ST Mixer Circuit RF Unit Transmitter Circuits MHz PA DRIVE/POWER Amplifier Circuits RF UnitAPC Circuits RF Unit APC Control CircuitLine Description Power Supply Circuits Voltage LinePLL Circuits VCC2 I/O Expander IC RF Unit IC3 Port Allocations1 I/O Expander IC RF Unit IC2 Pin Port Description Number NameCPU Logic Unit IC1 ‘ Required Test Equipment Adjustment ProceduresPreparation ConnectionPLL Adjustment VLV RF Unit Bottom ViewULV RF Unit TOP View 6MLVSensitivity Receiver AdjustmentDial VHFLogic Unit TOP View Top Push and hold MHz band MeterSSG 101 dBm445.000 MHz USA-1 Displayed frequencyPush and hold SQL keyTransmitter Adjustment Dtmf DeviationHPF OFF LPF AUS, SEAParts List =Surface mountTrimmer Ceramic ECUE1H121JCQ Transistor UN911D TX Coil Eljnd R10J 0.1U Themistor Ceramic ECUE1H060CCQ Ceramic ECUE1H390JCQ VCO Board Ceramic ECUE1H120JCQ Chassis Parts Mechanical Parts and DisassemblyAccessories VCO UnitMP29 C Transistor and FET’S SEMI-CONDUCTOR InformationDiodes Logic Unit Board LayoutsTOP View IC3 Bottom ViewIC1 GND Pset IfinL912 RF UnitIC6 J4 to Logic unit J1IC3 MP1IC2 OUT 12VCOOUT VCO BoardJ302 to RF unit VLVCO3 VHF GND VHVCO3 UVCO3 Uhfout GND 12VCO3 GNDQ354 Block Diagram TX/RX Buff Mode Xtal BPF PDA2, CK AMPTX/RX Frequency ANT LPF HPF AMPMOD TX/RX Frequency ResetMode Xtal Initial BPF ANT Buff HPF LPF YGRSection Voltage Diagram Logic UnitDEC Ifout Filout Quad 2NDLOOscin Mixin Oscout GND Mixout REC VCC DET Ifin Rssi WFM NTCCF20124AH 473KCT TXCClonein VCC VIN Cpuhv 12VCO COM2 ResetCOM3 COM2 Reset Power COM4 COM3 COM2 COM1400M RF UnitVHF 1200M1200MHz 50M00M 400MHzENB VCC2 GND1PLST1 IN1 LOK GND2Icom America Inc 5566I-S Icom Inc