Icom IC-T90A manual VCO Unit, RF Unit, L16 L456, L19

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• VCO UNIT

CP

PLL lock voltage check point

• RF UNIT

L16

L456

TX power balance adjustment (435 MHz)

L19

TX power balance adjustment (145 MHz)

5 - 4

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Contents IC-t90a Ordering Parts IntroductionRepair Notes Sample OrderTable of Contents Specifications GeneralTransmitter Frequency MHz ReceiverWFM WFMLogic Unit Inside ViewsTop view Bottom viewAF Unit RF UnitTop view Bottom view Removing the rear panel Removing the AF unit Disassembly InstructionsReceiver Circuits Circuit Description4 1ST Mixer and 1ST if Circuits RF, AF and VCO Units 5 2ND if and Demodulator Circuits AF UnitRF Circuit AF Amplifier Circuit AF Unit Squelch Circuitaf and Logic Units2ND if and Demodulator Circuit Transmitter Circuits APC Circuit RF Unit PLL CircuitsGeneral APC CircuitPLL Circuit VCO Divider Circuit VCO and RF Units2 R3V Switch IC AF Unit IC51 Power Supply CircuitsPort Allocations Voltage LineCPU Logic Unit IC1 Dtcs CtselLCD SEG35Operation on the Adjustment Mode Adjustment ProceduresOperation on the Output Power Adjustment PreparationConnection JIGAD-92SMA PLL Lock Trimmer AdjustmentVCO VoltageRF Unit VCO UnitL16 L456 L19Reference Adjustment Mode AdjustmentsDial FrequencyAdjustment Mode Adjustments PH ch 53.900 MHz Transmitting 8V 145 MHz Displayed frequency Connect an amme 45 a R325 Logic UnitR365 R326Ctcss Detector CoilTracking CP0 AF UnitIC151, pin 12 SD line L151Displayed frequency Connect a DC volt Maximum voltage Meter Adjustment Adjustment Condition OperationOrder Description Section Parts ListCoil Eljre 3N9Z-F Ceramic ECJ0EB1H681K Connector AXK6S30445P Ceramic ECJ0EC1H060C Encoder Trimmer Tantalum ECST1EY474R Ceramic ECJ0EC1H2R5B Mechanical Parts and Disassembly AccessoriesChassis Parts RF Unit Logic UnitChassis Parts AF Unit VCO UnitTransistors and Fets SEMI-CONDUCTOR InformationDiodes NameTOP View Board LayoutsMC1 Microphone DUPBottom View Logic unitSP1 SQL PTTRF Unit RF unit AF Unit VCO UnitEXT.SP EXT.MICREMOTO S253S252 Logic Unit Block DiagramLoop LPF HPF Drive BPF ANT FIL AMP Chassis11 1 Logic Unit Voltage DiagramIC5 2SK3476 11 2 RF UnitBU4094BCFV 11 3 AF UnitURL 32, Kamiminami, Hirano-ku, Osaka 547-0003, Japan