Icom IC-910H service manual Transmitter Adjustments

Page 26

5-5 TRANSMITTER ADJUSTMENTS

 

 

 

 

 

MEASUREMENT

 

 

 

 

 

 

ADJUSTMENT

ADJUSTMENT

ADJUSTMENT CONDITION

 

 

VALUE

POINT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UNIT

LOCATION

 

 

 

 

 

 

UNIT

ADJUST

 

 

 

 

 

 

 

 

 

 

 

 

 

PA UNIT

1

• Preset R131, R135, R150, R650 (PA unit) to max. counter clockwise.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PRESETTING

 

• Preset R3, R138, R503 (PA unit) to center position.

 

 

 

 

 

 

 

 

 

• Preset C154, C659 (PA unit) to center position as illustration at right.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IDLING

1

• Display frequency:

 

PA

Connect an ammeter

At the point where the PA

R131

CURRENT

 

[EUR], [KOR]

 

145.0000 MHz

(3 A) between power

TX current increases

 

 

(for 144 M)

 

[USA-1], [AUS]

 

146.0000 MHz

supply and the IC-

0.5 A.

 

 

 

 

• Mode

: CW

910H.

 

 

 

 

 

 

 

Transmitting

 

2

• Transmitting

 

 

 

 

 

 

 

At the point where the

 

R135

 

 

 

 

 

 

 

 

 

 

TX

current increases

 

(R138)

 

 

 

 

 

 

 

 

 

 

1.0 A as step 1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

• Transmitting

 

 

 

 

 

 

 

At the point where the

 

R650

 

 

 

 

 

 

 

 

 

 

TX

current increases

 

 

 

 

 

 

 

 

 

 

 

 

0.5 A as step 2.

 

 

 

 

 

 

 

 

 

 

 

 

 

(for 430 M)

4

• Display frequency:

 

 

 

 

At the point where the

 

R150

 

 

[EUR], [KOR]

435.0000 MHz

 

 

 

 

TX

current increases

 

 

 

 

[USA-1], [AUS]

450.0000 MHz

 

 

 

 

1.0 A.

 

 

 

 

• Mode

 

: CW

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RF PEAK

1

• Display frequency: 440.0000 MHz

Rear

Connect

an

RF

 

Maximum output

PA

L1, L2

(for 430 M)

 

• Connect an SSG to P1 on the PA

panel

power meter to [UHF

 

power

 

 

 

 

unit via the JIG cable (A) and set as:

 

ANT] connector.

 

 

 

 

 

 

Frequency : 10.850 MHz

 

 

 

 

 

 

 

 

 

 

Level

: 18 mV* (–22 dBm)

 

 

 

 

 

 

 

 

 

 

Modulation : OFF

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

• Set an SSG as:

 

 

 

 

 

 

 

 

 

C154

 

 

Level

: 0.79 µV* (–2 dBm)

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(for 144 M)

3

• Connect an SSG to P501 on the PA

 

Connect

an

RF

Refer page 5-16 software adjustment 6.

 

 

unit via the JIG cable (A) and set as:

 

power meter to [VHF

 

 

 

 

 

 

Frequency : 10.850 MHz

 

ANT] connector.

 

 

 

 

 

 

Level

: 18 mV* (–22 dBm)

 

 

 

 

 

 

 

 

 

 

Modulation : OFF

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

• Display frequency: 146.0000 MHz

 

 

 

 

 

Maximum output

PA

C659

 

 

• Set an SSG as:

 

 

 

 

 

 

 

power

 

 

 

 

Level

: 0.79 µV* (–2 dBm)

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IF PEAK

1

• Display frequency: Any

MAIN

Connect an RF volt-

 

Maximum level

MAIN

L2, L3

 

 

• Mode

 

: USB

 

meter to check point

 

 

 

 

 

 

• MIC gain

 

: Center

 

J51 via the JIG cable

 

 

 

 

 

 

• Connect an audio generator to

 

(B).

 

 

 

 

 

 

 

 

[MIC] connector and set as:

 

 

 

 

 

 

 

 

 

 

Frequency

 

: 1.5 kHz

 

 

 

 

 

 

 

 

 

 

Level

 

: 2 mVrms

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CARRIER

1

• Display frequency: Any

MAIN

Connect a spectrum

Minimum carrier level

MAIN

R206,

SUPPRESSION

 

• Mode

 

: USB

 

analyzer

to

check

 

 

 

R215

 

 

• Mic gain

 

: Minimum

 

point J51 via the JIG

 

 

 

 

 

 

• Apply no audio signals to [MIC]

 

cable (B).

 

 

 

 

 

 

 

 

connector.

 

 

 

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

• Mode

 

: LSB

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

• Repeat step 1, step 2 several times.

 

 

 

 

 

 

 

 

5 - 8

Image 26
Contents Service Manual Repair Notes IntroductionOrdering Parts EURTable of Contents Specifications GeneralReceiver Main and PLL Units SectionInside Views 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 UT-102 Voice Synthesizer Unit Installing 1st DSP unit front panel sideInstalling 2nd DSP unit rear panel side UT-106 DSP UnitCR-293 High Stability Crystal Unit Circuit Description Receiver CircuitSquelch Control Circuit Main Unit 6 10 MHz if Circuit Main UnitDemodulator Circuit Main Unit Squelch Circuit Main UnitAGC Circuit Main Unit Transmitter CircuitsNoise Blanker Circuit Main Unit Meter Circuit Main UnitCW Keying Circuit Main Unit Transmit if Amplifier Circuit Main UnitModulation Circuit Main Unit RF Circuit PA UnitPLL Circuits 8 2LO PLL Circuit PLL Circuits7 1LO PLL Circuit Required Test Equipment Adjustment ProceduresPreparation Before Sarvicing ‘ ConnectionsPLL Adjustments Frequency AdjustmentPLL and Main Units Receiver Adjustments L353 R547P501 L354 R360Blanker EXTNoise Main Band OFFCP851 L283L22 CP852Transmitter Adjustments R138 R503C659 R131GND If TotalMain Gain LO LeakCP1613 R504R202 R1613Software Adjustment Software Adjustment MeterNoise SQL Filter CalibrationTX Power LPF DeviationHPF OFF UX-910 Adjustments C332 CP321CP322 R13Power SET APCPre-setting for APC adjustment Display Board Section Parts ListFront Unit Resistor ERA3YED VR-B Board Func BoardVR-A Board MIC Board RIT BoardJack Board PLL UnitResistor ERA3YEB Thermistor Tantalum ECST1AD107R Main Unit REG BA09TDiode 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 VARISTOR-B Board DRV BoardBARISTOR-A Board BARISTOR-C Board2UX-910MAIN Unit Main Unit UX-910Resistor RGB3L R15 Resister ERA3YED Tantalum ECST1CC226R CH 1H Connectot 25FMN-BTK Cover Parts Mechanical PartsDisplay Unit Chassis PartsUX-910 Main Unit UnpackingUX-910 Chassis Parts UX-910 UnpackingSEMI-CONDUCTOR Information Transistors and FET’SDTA114 EE TL Diodes MA29BSection 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.