Motorola IC-T81A, IC-T81E service manual Meter, Ssg, Top Push and hold MHz band, 101 dBm, 113 dBm

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RECEIVER ADJUSTMENT (Continued)

The following adjustment must be performed on the normal mode after “SENSITIVITY ADJUSTMENT” in SECTION 5-3.

ADJUSTMENT		ADJUSTMENT CONDITION		MEASUREMENT		VALUE	ADJUSTMENT
ADJUSTMENT		ADJUSTMENT CONDITION				VALUE	ADJUSTMENT
				UNIT	LOCATION

S-METER	1	• Displayed frequency :		Top			Push and hold
(50 MHz band)		51.000 MHz	[EUR], [UK], [ITA]	panel			the [SQL] key
		52.000 MHz
		[AUS], [SEA], [USA-1]
		• Connect the SSG to the antenna
		connector and set as:
		Level	: 1 µV*
			(– 107 dBm)
		Modulation	: 1 kHz
		Deviation	: ± 3.5 kHz

•Connect a terminator to the [SP] jack.

•Receiving

2		• Set an SSG output level for the			0.56 µV – 1.8 µV	Verify
		S-meter to S3.			(-112dBm – -102 dBm)
		• Receiving

3		• Increase an SSG output level.		Front S-meter	Full scale	Verify
		• Receiving		panel

(WFM band) 4		• Displayed frequency :		Top		Push and hold
		92.000	MHz [SEA], [USA-1]	panel		the [SQL] key
		98.000	MHz
		[EUR], [UK],[ITA], [AUS]

•Connect the SSG to the antenna connector and set as:

Level	: 2 µV*
	(– 101 dBm)
Modulation	: 1 kHz
Deviation	: ± 52.5 kHz

•Connect a terminator to the [SP] jack.

•Receiving

5		• Increase an SSG output level.		Front S-meter	Full scale	Verify
		• Receiving		panel

(144 MHz band) 6		• Displayed frequency :		Top		Push and hold
		145.000	MHz [EUR], [UK]	panel		the [SQL] key
		146.000	MHz
		[ITA], [AUS], [SEA], [USA-1]

•Connect the SSG to the antenna connector and set as:

Level	: 0.5 µV*
	(– 113 dBm)
Modulation	: 1 kHz
Deviation	: ± 3.5 kHz

•Connect a terminator to the [SP] jack.

•Receiving

7	• Set an SSG output level for the	SSG	Output level	0.28 µV – 0.89 µV	Verify
	S-meter to S3.			(-118dBm – -108 dBm)
	• Receiving

8	• Increase an SSG output level.	Front	S-meter	Full scale	Verify
	• Receiving	panel

*This output level of the standard signal generator (SSG) is indicated as SSG’s open circuit.

5 - 6

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Contents Multiband FM Transceiver Introduction Ordering PartsRepair Notes Sample OrderTable of Contents Specifications GeneralTransmitter Version 50 MHz 145 MHz 440 MHz 1200 MHz MHz RX onlyReceiver BandWFM WFMInside Views Logic UnitRF Unit CPUDisassembly Instructions Removing the Chassis Panel Removing the Shield PlateRemoving the Logic Unit Removing the RF Unit Logic unitAntenna Switching Circuits RF Unit Circuit DescriptionReceiver Circuits Duplexer Circuit RF Unit7 1ST Mixer Circuit RF Unit Transmitter Circuits DRIVE/POWER Amplifier Circuits RF Unit APC Circuits RF UnitMHz PA APC Control CircuitPower Supply Circuits Voltage Line PLL CircuitsLine Description VCCPort Allocations 1 I/O Expander IC RF Unit IC22 I/O Expander IC RF Unit IC3 Pin Port Description Number NameCPU Logic Unit IC1 Adjustment Procedures Preparation‘ Required Test Equipment ConnectionPLL Adjustment RF Unit Bottom View ULVVLV RF Unit TOP View 6MLVReceiver Adjustment DialSensitivity VHFLogic Unit TOP View Meter SSGTop Push and hold MHz band 101 dBmDisplayed frequency Push and hold445.000 MHz USA-1 SQL keyTransmitter Adjustment Deviation HPF OFF LPFDtmf AUS, SEAParts List =Surface mountTrimmer Ceramic ECUE1H121JCQ Transistor UN911D TX Coil Eljnd R10J 0.1U Themistor Ceramic ECUE1H060CCQ Ceramic ECUE1H390JCQ VCO Board Ceramic ECUE1H120JCQ Mechanical Parts and Disassembly AccessoriesChassis Parts VCO UnitMP29 C Diodes SEMI-CONDUCTOR InformationTransistor and FET’S TOP View Board LayoutsLogic Unit Bottom View IC1IC3 GND Pset IfinRF Unit IC6L912 J4 to Logic unit J1IC2 MP1IC3 VCO Board J302 to RF unitOUT 12VCOOUT VLVCO3 VHF GND VHVCO3 UVCO3 Uhfout GND 12VCO3 GNDQ354 Block Diagram Mode Xtal BPF PDA2, CK AMP TX/RX FrequencyTX/RX Buff ANT LPF HPF AMPReset Mode Xtal Initial BPFMOD TX/RX Frequency ANT Buff HPF LPF YGRSection Voltage Diagram Logic Unit2NDLO Oscin Mixin Oscout GND Mixout REC VCC DET Ifin RssiDEC Ifout Filout Quad WFM NTCCF20124AH 473KCT TXC12VCO COM2 Reset COM3 COM2 Reset PowerClonein VCC VIN Cpuhv COM4 COM3 COM2 COM1RF Unit VHF400M 1200M50M 00M1200MHz 400MHzGND1 PLST1 IN1ENB VCC2 LOK GND2Icom America Inc 5566I-S Icom Inc