Icom IC-910H service manual PLL and Main Units

Page 21

• PLL AND MAIN UNITS

R570

30.2MHz level

adjustment

L193

144M lock voltage adjustment

P251

144M LO level check point

X512

Reference frequency adjustment

J541

30.2MHz level

check point

C402

 

430M lock voltage

adjustment

 

CP300

 

430M lock voltage

check point

 

P421

 

430M LO level

 

check point

 

Referemce level

L551

adjustment

L552

P601

 

Main BFO level check point

P701

Sub BFO level check point

CP100

144M lock voltage check point

P551

Reference frequency check point

L255

FM TX-LO frequency adjustment

J51

FM TX-LO

J52

frequency

 

pre-setting

CP51

FM TX-LO frequency check point

5 - 3

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Contents Service Manual Ordering Parts IntroductionRepair Notes EURTable of Contents General SpecificationsReceiver Inside Views SectionMain and PLL Units FM if ICPA Unit TOP View Bottom ViewPLL IC Disassembly and Option Instructions Opening the transceiver’s caseUX-910 1200MHz Band Unit Opening the PA unit cover FL-132/FL-133 CW Narrow FilterMain SUB 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 PLL Circuits 7 1LO PLL Circuit8 2LO 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 Deviation HPF OFFLPF UX-910 Adjustments CP322 CP321C332 R13APC Power SETPre-setting for APC adjustment Section Parts List Front UnitDisplay Board Resistor ERA3YED Func Board VR-A BoardVR-B 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.