VCO Unit, RF Unit, L16 L456, L19 | Icom IC-T90A instruction

• 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

Image 21

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

Contents

IC-t90a Ordering Parts IntroductionRepair Notes Sample Order Table of Contents Specifications GeneralTransmitter Frequency MHz ReceiverWFM WFM Logic Unit Inside ViewsTop view Bottom view AF Unit RF UnitTop view Bottom view Removing the rear panel Removing the AF unit Disassembly Instructions Receiver Circuits Circuit Description 4 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 Circuit PLL Circuit VCO Divider Circuit VCO and RF Units 2 R3V Switch IC AF Unit IC51 Power Supply CircuitsPort Allocations Voltage Line CPU Logic Unit IC1 Dtcs CtselLCD SEG35 Operation on the Adjustment Mode Adjustment ProceduresOperation on the Output Power Adjustment Preparation Connection JIGAD-92SMA PLL Lock Trimmer AdjustmentVCO Voltage RF Unit VCO UnitL16 L456 L19 Reference Adjustment Mode AdjustmentsDial Frequency Adjustment Mode Adjustments PH ch 53.900 MHz Transmitting 8V 145 MHz Displayed frequency Connect an amme 45 a R325 Logic UnitR365 R326 Ctcss Detector CoilTracking CP0 AF UnitIC151, pin 12 SD line L151 Displayed frequency Connect a DC volt Maximum voltage Meter Adjustment Adjustment Condition Operation Order Description Section Parts List Coil 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 Unit Transistors and Fets SEMI-CONDUCTOR InformationDiodes Name TOP View Board LayoutsMC1 Microphone DUP Bottom View Logic unitSP1 SQL PTT RF Unit RF unit AF Unit VCO UnitEXT.SP EXT.MICREMOTO S253S252 Logic Unit Block Diagram Loop LPF HPF Drive BPF ANT FIL AMP Chassis 11 1 Logic Unit Voltage Diagram IC5 2SK3476 11 2 RF Unit BU4094BCFV 11 3 AF Unit URL 32, Kamiminami, Hirano-ku, Osaka 547-0003, Japan