Icom IC-910H service manual Receiver

Page 5

RECEIVER

• Receive system

:

 

 

 

 

 

 

 

 

 

 

 

 

VHF

SSB, CW

 

Single conversion superheterodyne

 

 

 

 

 

FM

 

Double conversion superheterodyne

 

 

 

 

UHF

SSB, CW

 

Double conversion superheterodyne

 

 

 

 

 

FM

 

Triple conversion superheterodyne

 

 

 

 

• Intermediate frequencies

:

 

 

 

 

 

 

 

 

 

 

(Unit: MHz)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MAIN BAND

 

 

SUB BAND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1st

 

2nd

 

3rd

1st

 

2nd

 

3rd

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SSB

10.8500

 

 

10.9500

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

144 MHz

CW

10.8491

 

 

10.9491

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FM

10.8500

 

0.455

 

10.9500

 

0.455

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SSB

71.2500

 

10.8500

 

71.3500

 

10.9500

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

430 (440) MHz

CW

71.2491

 

10.8491

 

71.3491

 

10.9491

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FM

71.2500

 

10.8500

 

0.455

71.3500

 

10.9500

 

0.455

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SSB

243.9500

 

10.8500

 

243.9500

 

10.9500

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1200 MHz

CW

243.9491

 

10.8491

 

243.9491

 

10.9491

 

 

 

 

FM

243.9500

 

10.8500

 

0.455

243.9500

 

10.9500

 

0.455

 

 

 

 

 

 

 

 

 

 

 

 

 

• Sensitivity

: SSB, CW (10 dB S/N)

Less than 0.11 µV

 

 

 

 

 

 

 

FM (12 dB SINAD)

Less than 0.18 µV

 

 

 

 

 

 

• Squelch sensitivity

: SSB, CW

 

Less than 1.0 µV

 

 

 

 

 

 

(threshold)

FM

 

Less than 0.18 µV

 

 

 

 

 

 

• Selectivity

: SSB, CW

 

More than 2.3 kHz/–6 dB

 

 

 

 

 

 

 

 

 

Less than 4.2 kHz/–60 dB*

 

 

 

 

 

 

FM

 

More than 15.0 kHz/–6 dB

 

 

 

 

 

 

 

 

 

Less than 30.0 kHz/–60 dB*

 

 

 

 

 

 

FM-N

 

More than 6.0 kHz/–6 dB

 

 

 

 

 

 

 

 

 

Less than 18.0 kHz/–36 dB

 

 

 

 

 

 

CW-N

 

More than 0.5 kHz/–6 dB

 

 

 

 

 

 

(w/FL-132 or FL-133)

Less than 1.34 kHz/–60 dB*

 

 

 

 

 

 

 

 

 

*Except 1200 MHz band

 

 

 

 

 

• Spurious and image rejection ratio:

 

 

 

 

 

 

 

 

 

 

 

 

144/430 (440) MHz

More than 60 dB

 

 

 

 

 

 

 

1200 MHz

 

More than 50 dB

 

 

 

 

 

 

AF output power (at 13.8 V DC):

More than 2.0 W at 10% distortion with an 8 load

• RIT variable range

: 144/430 (440) MHz

±1.0 kHz (SSB, CW)

 

 

±5.0 kHz (FM)

 

1200 MHz

±2.0 kHz (SSB, CW)

 

 

±10.0 kHz (FM)

• IF SHIFT variable range

: More than ±1.2 kHz

 

• PHONES connector

: 3-conductor 6.35(d) mm (14)

• Ext. SP connectors

: 2-conductor 3.5 (d) mm (18) /8 Ω ⋅ 2 (for MAIN and SUB)

1 - 2

Image 5
Contents Service Manual Ordering Parts IntroductionRepair Notes EURTable of Contents General SpecificationsReceiver Inside Views SectionMain and PLL Units FM if ICPA Unit PLL IC TOP ViewBottom View UX-910 1200MHz Band Unit Disassembly and Option InstructionsOpening the transceiver’s case Main SUB Opening the PA unit coverFL-132/FL-133 CW Narrow Filter Installing 2nd DSP unit rear panel side Installing 1st DSP unit front panel sideUT-102 Voice Synthesizer Unit UT-106 DSP UnitCR-293 High Stability Crystal Unit Receiver Circuit Circuit DescriptionDemodulator Circuit Main Unit 6 10 MHz if Circuit Main UnitSquelch Control Circuit Main Unit Squelch Circuit Main UnitNoise Blanker Circuit Main Unit Transmitter CircuitsAGC Circuit Main Unit Meter Circuit Main UnitModulation Circuit Main Unit Transmit if Amplifier Circuit Main UnitCW Keying Circuit Main Unit RF Circuit PA UnitPLL Circuits 8 2LO PLL Circuit PLL Circuits7 1LO PLL Circuit Preparation Before Sarvicing Adjustment ProceduresRequired Test Equipment ‘ ConnectionsFrequency Adjustment PLL AdjustmentsPLL and Main Units Receiver Adjustments P501 R547L353 L354 R360Noise EXTBlanker Main Band OFFL22 L283CP851 CP852Transmitter Adjustments C659 R503R138 R131Main Gain If TotalGND LO LeakR202 R504CP1613 R1613Software Adjustment Meter Software AdjustmentNoise SQL Calibration FilterTX Power LPF DeviationHPF OFF UX-910 Adjustments CP322 CP321C332 R13APC Power SETPre-setting for APC adjustment Display Board Section Parts ListFront Unit Resistor ERA3YED VR-B Board Func BoardVR-A Board Jack Board RIT BoardMIC Board PLL UnitResistor ERA3YEB Thermistor Tantalum ECST1AD107R REG BA09T Main UnitDiode DAN222TL Resistor ERA3YKD R364 7030003320 R915 7030003520 Tantalum Temsva 1C 335M-8L Electrolytic ECEV1EA4R7SR Electrolytic Relay Diode HSU88TRF Coil Eljre 15NG-F Resistor ERJ1WYJ181U Resistor ERJ1TYJ102U JB 1H JB 1C Mica BARISTOR-A Board DRV BoardVARISTOR-B Board BARISTOR-C BoardMain Unit UX-910 2UX-910MAIN UnitResistor RGB3L R15 Resister ERA3YED Tantalum ECST1CC226R CH 1H Connectot 25FMN-BTK Display Unit Mechanical PartsCover Parts Chassis PartsUX-910 Chassis Parts UnpackingUX-910 Main Unit UX-910 UnpackingTransistors and FET’S SEMI-CONDUCTOR InformationDTA114 EE TL MA29B DiodesSection Board Layouts Page Icom America Inc 13714HZ-C1

IC-910H specifications

The Icom IC-910H is a highly regarded and versatile transceiver that is designed for amateur radio operators who are particularly interested in V/UHF and microwave communications. Known for its exceptional performance, the IC-910H encompasses a suite of features that make it a standout choice for both casual and dedicated hams.

One of the main features of the IC-910H is its dual-band capability, allowing for simultaneous operation on both 144 MHz (2 meters) and 430 MHz (70 centimeters) bands. This dual operation enables users to engage in various communication modes, including SSB, CW, FM, and digital. Its high frequency stability ensures that users can rely on the transceiver for accurate and consistent transmissions.

The IC-910H is equipped with a high-performance 10 MHz IF filter that improves selectivity and reduces adjacent channel interference. The optional 1.2 GHz module enhances the transceiver’s capabilities, allowing operators to venture into microwave frequencies. This expandability is a significant advantage for users who wish to progress in their amateur radio pursuits.

Another notable aspect of the IC-910H is its large, easy-to-read LCD display, which features various color options for enhanced visibility. The front panel layout is user-friendly, providing quick access to important controls and functions. The built-in DSP (Digital Signal Processing) technology offers noise reduction and filtering capabilities, significantly improving overall audio quality and making weak signals more intelligible.

The transceiver also includes extensive memory functions, with up to 1,000 memory channels available for storing frequencies, modes, and operational settings. Additionally, it supports CTCSS and DCS tones, which facilitate the use of repeater systems and private group communications.

In terms of build quality, the IC-910H features a robust construction designed for durability and long-term use. Its efficient power supply management ensures excellent performance while minimizing heat generation, making it suitable for extended operating sessions.

Overall, the Icom IC-910H is a powerful and feature-rich transceiver that is favored by many amateur radio enthusiasts. With its versatile operating modes, advanced filtering capabilities, and clear display, it stands out as a reliable tool for both casual operators and serious DXers. Its well-thought-out design and comprehensive features make it a valuable addition to any ham's station collection.