Icom IC-T90A manual RF Unit

Page 46

	9 - 2 RF UNIT	The combination of this page and the next page
	• TOP VIEW	The combination of this page and the next page
	• TOP VIEW	shows the unit layout in the same configuration as
		shows the unit layout in the same configuration as
		the actual P.C. Board.

Antenna

		to VCO unit
			J1
		8 VSHFT
			VMOD
			GND
			+10V
			PDA/UL
			CK
			PLSTB
		1	REF
					6
					8
					GND	6
					V1	to VCO unit
					V2	to VCO unit
	to AF unit				+3	J2
	to AF unit				V3
	J51				V3
	J51				LO	1
30	PDA/UL	CK		1	1
	VMOD	DATA		30	1
	VMOD	DATA
	HV	PLSTB
	VSHFT DASTB				1
	+3	T43
	PATMP	T50
	B2C	T14		J251
	+10V	B4C		J251
	+10V	B4C
	BSFT	AGC
	V2	B1C
	FSET	VCC
	V3	B5C			1
	V1	B3C			1
	V1	B3C		16	15
	IF	GND		16	15
16	CHG	REF		15

9 - 3

Image 46

Contents IC-t90a Repair Notes IntroductionOrdering Parts Sample OrderTable of Contents General SpecificationsTransmitter WFM ReceiverFrequency MHz WFMTop view Inside ViewsLogic Unit Bottom viewRF Unit AF UnitTop view Bottom view Disassembly Instructions Removing the rear panel Removing the AF unitCircuit Description Receiver Circuits5 2ND if and Demodulator Circuits AF Unit 4 1ST Mixer and 1ST if Circuits RF, AF and VCO UnitsRF Circuit Squelch Circuitaf and Logic Units AF Amplifier Circuit AF Unit2ND if and Demodulator Circuit Transmitter Circuits General PLL CircuitsAPC Circuit RF Unit APC CircuitVCO Divider Circuit VCO and RF Units PLL CircuitPort Allocations Power Supply Circuits2 R3V Switch IC AF Unit IC51 Voltage LineCPU Logic Unit IC1 LCD CtselDtcs SEG35Operation on the Output Power Adjustment Adjustment ProceduresOperation on the Adjustment Mode PreparationJIG ConnectionAD-92SMA VCO Trimmer AdjustmentPLL Lock VoltageL16 L456 VCO UnitRF Unit L19Dial Adjustment Mode AdjustmentsReference FrequencyAdjustment Mode Adjustments PH ch 53.900 MHz Transmitting 8V 145 MHz Displayed frequency Connect an amme 45 a R365 Logic UnitR325 R326Ctcss Coil DetectorTracking IC151, pin 12 SD line AF UnitCP0 L151Displayed frequency Connect a DC volt Maximum voltage Adjustment Adjustment Condition Operation MeterSection Parts List Order DescriptionCoil Eljre 3N9Z-F Ceramic ECJ0EB1H681K Connector AXK6S30445P Ceramic ECJ0EC1H060C Encoder Trimmer Tantalum ECST1EY474R Ceramic ECJ0EC1H2R5B Accessories Mechanical Parts and DisassemblyChassis Parts Chassis Parts Logic UnitRF Unit AF Unit VCO UnitDiodes SEMI-CONDUCTOR InformationTransistors and Fets NameMC1 Microphone Board LayoutsTOP View DUPSP1 Logic unitBottom View SQL PTTRF Unit RF unit VCO Unit AF UnitEXT.SP EXT.MICREMOTO S253S252 Block Diagram Logic UnitChassis Loop LPF HPF Drive BPF ANT FIL AMPVoltage Diagram 11 1 Logic UnitIC5 11 2 RF Unit 2SK347611 3 AF Unit BU4094BCFVURL 32, Kamiminami, Hirano-ku, Osaka 547-0003, Japan