Icom IC-T90A manual Receiver, Frequency MHz, Wfm

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M RECEIVER

• Receiver system

: Double-conversion superheterodyne

• Intermediate frequency : 1st

13.350 MHz (FM/AM)

 

 

 

13.350 MHz (WFM)

 

2nd

450 kHz

 

• Sensitivity*1:

 

 

 

 

(except spurious points; typical values)

 

 

 

 

 

 

 

Frequency (MHz)

FM

 

AM

WFM

0.495–1.625

 

1.3 µV

 

1.625–4.995

0.4 µV

 

 

 

5.000–29.995

0.18 µV

 

0.56 µV

 

 

 

 

 

29.995–49.995

 

 

 

 

 

 

 

 

 

 

 

 

50.000–54.000

0.16 µV

 

 

1.0 µV*4

54.005–76.000

 

 

 

 

 

 

 

 

 

 

76.000–108.000

 

 

 

 

108.000–118.000

0.18 µV

 

 

 

118.000–136.000

 

 

0.5 µV

 

 

 

 

 

 

136.000–143.995

 

 

 

 

 

 

 

 

144.000–148.000

0.16 µV

 

 

148.005–175.000

0.4 µV

 

 

 

 

 

 

 

 

 

175.000–221.995

 

 

1.8 µV

 

 

 

 

 

 

 

 

222.000–225.000

0.32 µV

 

0.79 µV*2

 

225.005–246.995

0.4 µV

 

 

 

 

 

247.000–329.995

0.32 µV

 

1.0 µV*3

 

 

 

329.995–429.995

 

 

 

 

 

 

 

 

 

 

 

430.000–450.000

0.16 µV

 

 

 

 

 

 

 

 

450.005–470.000

 

 

 

470.000–770.000

0.32 µV

 

3.2 µV

 

 

770.000–832.995

 

 

 

 

 

 

 

833.000–999.990

1.0 µV

 

 

 

 

 

 

 

 

 

 

*1 FM and WFM are measured at 12 dB SINAD, AM is mea- sured at 10 dB S/N.

*2 The frequency range is between 222.000 MHz and 229.995 MHz.

*3 The frequency range is between 320.000 MHz and 329.995 MHz.

*4 The frequency range is between 40.000 MHz and 108.000 MHz.

• Selectivity

 

 

AM and FM

: Less than 15 kHz/–9 dB

 

More than 30 kHz/–60 dB

WFM

: Less than 350 kHz/–3 dB

 

More than 700 kHz/–20 dB

• Spurious and image rejection ratio

 

 

: • 50 MHz

More than 60 dB

 

IF/2: More than 50 dB

 

IF: More than 40 dB

 

• 145 MHz

More than 60 dB

 

IF/2: More than 50 dB

 

• 440 MHz

More than 50 dB

 

IF: More than 60 dB

• Audio output power

: 200 mW typical at 10 % distor-

 

tion with an 8 Ω load

• AF output impedance : 8 Ω

• Squelch sensitivity*1: (typical; Except sprious points)

Frequency (MHz)

FM

AM

WFM

0.495–1.625

1.3 µV

 

1.625–4.995

0.4 µV

 

5.000–29.995

0.18 µV

0.56 µV

 

 

 

 

29.995–49.995

 

 

 

 

 

 

 

 

 

50.000–54.000

0.16 µV

 

1.0 µV*4

54.005–76.000

 

 

 

76.000–108.000

 

 

 

 

 

 

 

108.000–118.000

0.18 µV

 

 

118.000–136.000

 

0.5 µV

 

 

 

 

 

136.000–143.995

 

 

 

 

 

 

144.000–148.000

0.16 µV

 

148.005–175.000

0.4 µV

 

 

 

 

 

 

175.000–221.995

 

1.8 µV

 

 

 

 

 

 

222.000–225.000

0.32 µV

0.79 µV*2

 

225.005–246.995

0.4 µV

 

 

 

 

 

 

 

247.000–329.995

0.32 µV

1.0 µV*3

329.995–429.995

 

 

 

 

 

 

 

430.000–450.000

0.16 µV

 

 

450.005–470.000

 

 

 

470.000–770.000

0.32 µV

3.2 µV

770.000–832.995

 

 

 

 

 

833.000–1319.995

1.0 µV

 

 

 

 

 

 

 

*1 FM and WFM are measured at 12 dB SINAD, AM is mea- sured at 10 dB S/N.

*2 The frequency range is between 222.000 MHz and 229.995 MHz.

*3 The frequency range is between 320.000 MHz and 330.000 MHz.

*4 The frequency range is between 40.000 MHz and 108.000 MHz.

All stated specifications are subject to change without notice or obligation.

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Contents IC-t90a Ordering Parts IntroductionRepair Notes Sample OrderTable of Contents Transmitter SpecificationsGeneral Frequency MHz ReceiverWFM WFMLogic Unit Inside ViewsTop view Bottom viewTop view Bottom view AF UnitRF Unit Removing the rear panel Removing the AF unit Disassembly InstructionsReceiver Circuits Circuit DescriptionRF Circuit 4 1ST Mixer and 1ST if Circuits RF, AF and VCO Units5 2ND if and Demodulator Circuits AF Unit 2ND if and Demodulator Circuit AF Amplifier Circuit AF UnitSquelch Circuitaf and Logic Units 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 PreparationAD-92SMA ConnectionJIG 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 Tracking DetectorCoil 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 Chassis Parts Mechanical Parts and DisassemblyAccessories 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 EXT.SP EXT.MICREMOTO AF UnitVCO Unit 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