PLL Adjustment | Motorola IC-T81A, IC-T81E instruction

5-2 PLL ADJUSTMENT

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

				MEASUREMENT						ADJUSTMENT
ADJUSTMENT		ADJUSTMENT CONDITION		MEASUREMENT					VALUE	POINT
ADJUSTMENT		ADJUSTMENT CONDITION							VALUE	POINT
				UNIT	LOCATION					UNIT	ADJUST

PLL LOCK	1	• Displayed frequency :		RF	Connect	the	DC	0.8	V – 1.8 V		Verify
VOLTAGE			51.000 MHz		voltmeter	or	an
		• Receiving			oscilloscope to VLV.


	2	• Transmitting			Connect	the	DC	1.8	V – 2.8 V
					voltmeter	or	an
					oscilloscope		to
					6MLV.

	3	• Displayed frequency :			Connect	the	DC	1.4	V – 2.4 V
			88.000 MHz		voltmeter	or	an
		• Receiving			oscilloscope to VLV.

	4	• Displayed frequency :						1.5	V – 2.5 V
			145.000 MHz
		• Receiving

	5	• Transmitting						1.5	V – 2.5 V

	6	• Displayed frequency :			Connect	the	DC	2.0	V – 2.5 V
			440.000 MHz		voltmeter	or	an
		• Receiving			oscilloscope to ULV.

	7	• Transmitting						2.0	V – 2.5 V

	8	• Displayed frequency :			Connect	the	DC	1.9	V – 2.9 V
			1270.000 MHz		voltmeter	or	an
		• Receiving			oscilloscope		to
					12LV.
		• Transmitting			12LV.
		• Transmitting

REFERENCE	1	• Displayed frequency :		Top	Loosely couple		the	1270.0000 MHz		Top	Push and
FREQUENCY			1270.000 MHz	Pannel	frequency	counter				panel	hold the
		• Transmitting			to the antenna con-						[SQL] key,
					nector.						then turn
											the [DIAL]

DETECTER	1	• Displayed frequency :		LOGIC	Connect	a digital-		1.0	V	LOGIC	L702
OUTPUT		445.000 MHz [USA-1] only			voltmeter	to	the
VOLTAGE		435.000 MHz [ohter]			check point Q.
		• Connect an SSG to the antenna
		connector and set as:
		Level	: 1 mV* (–47dBm)
		Modulation	: OFF
		• Receiving

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

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Motorola IC-T81A, IC-T81E service manual PLL Adjustment

Contents

Multiband FM Transceiver Introduction Ordering PartsRepair Notes Sample Order Table of Contents Specifications GeneralTransmitter Version 50 MHz 145 MHz 440 MHz 1200 MHz MHz RX only Receiver BandWFM WFM Inside Views Logic UnitRF Unit CPU Disassembly Instructions Removing the Chassis Panel Removing the Shield PlateRemoving the Logic Unit Removing the RF Unit Logic unit Antenna Switching Circuits RF Unit Circuit DescriptionReceiver Circuits Duplexer Circuit RF Unit 7 1ST Mixer Circuit RF Unit Transmitter Circuits DRIVE/POWER Amplifier Circuits RF Unit APC Circuits RF UnitMHz PA APC Control Circuit Power Supply Circuits Voltage Line PLL CircuitsLine Description VCC Port Allocations 1 I/O Expander IC RF Unit IC22 I/O Expander IC RF Unit IC3 Pin Port Description Number Name CPU Logic Unit IC1 Adjustment Procedures Preparation‘ Required Test Equipment Connection PLL Adjustment RF Unit Bottom View ULVVLV RF Unit TOP View 6MLV Receiver Adjustment DialSensitivity VHF Logic Unit TOP View Meter SSGTop Push and hold MHz band 101 dBm Displayed frequency Push and hold445.000 MHz USA-1 SQL key Transmitter Adjustment Deviation HPF OFF LPFDtmf AUS, SEA Parts List =Surface mount Trimmer 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 Unit MP29 C Transistor and FET’S SEMI-CONDUCTOR InformationDiodes Logic Unit Board LayoutsTOP View Bottom View IC1IC3 GND Pset Ifin RF Unit IC6L912 J4 to Logic unit J1 IC3 MP1IC2 VCO Board J302 to RF unitOUT 12VCOOUT VLVCO3 VHF GND VHVCO3 UVCO3 Uhfout GND 12VCO3 GND Q354 Block Diagram Mode Xtal BPF PDA2, CK AMP TX/RX FrequencyTX/RX Buff ANT LPF HPF AMP Reset Mode Xtal Initial BPFMOD TX/RX Frequency ANT Buff HPF LPF YGR Section Voltage Diagram Logic Unit 2NDLO Oscin Mixin Oscout GND Mixout REC VCC DET Ifin RssiDEC Ifout Filout Quad WFM NTCCF20124AH 473KCT TXC 12VCO COM2 Reset COM3 COM2 Reset PowerClonein VCC VIN Cpuhv COM4 COM3 COM2 COM1 RF Unit VHF400M 1200M 50M 00M1200MHz 400MHz GND1 PLST1 IN1ENB VCC2 LOK GND2 Icom America Inc 5566I-S Icom Inc