Icom IC-910H service manual UX-910 Adjustments

Page 36

5-7 UX-910 ADJUSTMENTS

 

 

 

 

 

MEASUREMENT

 

 

 

 

ADJUSTMENT

ADJUSTMENT

ADJUSTMENT CONDITION

 

VALUE

 

POINT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UNIT

LOCATION

 

 

 

UNIT

ADJUST

 

 

 

 

 

 

 

 

 

 

 

2ND LO LOCK

1

• Connect an optional UX-910 (1200

MAIN

Connect

a

digital

2.6–3.8 V

 

 

Verify

VOLTAGE

 

MHz band unit).

 

(UX-910)

multimeter or oscillo-

 

 

 

 

 

 

 

• Display frequency: 1270.5000 MHz

 

scope to check point

 

 

 

 

 

 

 

• Receiving

 

 

 

CP701.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1ST LO LOCK

1

• Display frequency: 1240.0000 MHz

MAIN

Connect

a

digital

6.0–7.0 V

 

 

Verify

VOLTAGE

 

• Receiving

 

 

(UX-910)

multimeter or oscillo-

 

 

 

 

 

 

 

 

 

 

 

scope to check point

 

 

 

 

 

 

 

 

 

 

 

CP501.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

• Display frequency: 1300.0000 MHz

 

 

 

 

3.4–4.4 V

 

 

 

 

 

• Receiving

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RECEIVER

1

• Display frequency: 1280.0000 MHz

MAIN

Connect a spectram

–34 dBm (16 dB gain)

MAIN

R224

GAIN

 

• Connect a standard signal generator

(UX-910)

analyzer

to

check

 

 

 

(UX-910)

 

 

 

to [12 ANT] connector and set as:

 

point CP311.

 

 

 

 

 

 

 

 

Frequency : 1280.0000 MHz

 

 

 

 

 

 

 

 

 

 

 

Level

: 710 µV* (–50 dBm)

 

 

 

 

 

 

 

 

 

 

 

Modulation : OFF

 

 

 

 

 

 

 

 

 

 

 

• Receiving

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ATT GAIN

1

• Display frequency: 1280.0000 MHz

MAIN

Connect a spectram

–14 dBm (20 dB of gain

MAIN

R288

 

 

• [ATT]

 

: ON

(UX-910)

analyzer

to

check

difference between the

(UX-910)

 

 

 

• Set an SSG as

:

 

point CP311.

 

attenuator

ON

and

 

 

 

 

Frequency : 1280.0000 MHz

 

 

 

 

OFF.)

 

 

 

 

 

 

Level

: 710 µV* (–50 dBm)

 

 

 

 

 

 

 

 

 

 

 

Modulation : OFF

 

 

 

 

 

 

 

 

 

 

 

• Receiving

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IDLING

1

• Display frequency: Any

MAIN

Connect

a

digital

0.5 V

 

MAIN

R13

 

 

• Mode

 

: CW

(UX-910)

multimeter

between

voltage difference

(UX-910)

 

 

 

• Preset R61, R67, R83 to max.

 

check points CP321

 

 

 

 

 

 

 

clockwise, R13 to max. counter

 

and CP322.

 

 

 

 

 

 

 

 

clockwise, and C332 to center.

 

 

 

 

 

 

 

 

 

 

 

• Connect an RF power meter to [12

 

 

 

 

 

 

 

 

 

 

 

ANT].

 

 

 

 

 

 

 

 

 

 

 

 

 

• Connect an SSG to the check point

 

 

 

 

 

 

 

 

 

 

 

CP311 and set as :

 

 

 

 

 

 

 

 

 

 

 

Frequency : 10.8500 MHz

 

 

 

 

 

 

 

 

 

 

 

Level

: OFF

 

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

POWER

1

• Display frequency: Any

Rear

Connect

an

RF

5 W

 

 

Adjust

BALLANCE

 

• Mode

 

: CW

panel

power meter

to [12

 

 

 

 

SSG’s

 

 

• Connect an SSG to the check point

 

ANT].

 

 

 

 

 

 

level

 

 

CP311 and set as :

 

 

 

 

 

 

 

 

 

 

 

Frequency : 10.8500 MHz

 

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

• Display frequency: 1240.0000 MHz

 

 

 

 

Read the

RF

power

 

Verify

 

 

• Transmitting

 

 

 

 

 

 

meter indication.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

• Display frequency: 1300.0000 MHz

 

 

 

 

Same power as step 2

MAIN

C332

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

(UX-910)

 

 

 

 

 

 

 

 

 

 

 

 

4

Repeat step 2 and step 3 several times until power difference is minimum.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TRANSMITTER

1

• Display frequency: 1270.0000 MHz

Rear

Connect

an

RF

5 W

 

MAIN

R83

GAIN

 

• Set an SSG as

:

panel

power meter

to [12

 

 

 

(UX-910)

 

 

 

Frequency : 10.8500 MHz

 

ANT].

 

 

 

 

 

 

 

 

 

Level

: 18 mV* (–22 dBm)

 

 

 

 

 

 

 

 

 

 

 

• Transmitting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*This output level of a standard signal generator (SSG) is indicated as SSG’s open circuit.

5 - 18

Image 36
Contents Service Manual Introduction Ordering PartsRepair Notes EURTable of Contents Specifications GeneralReceiver Section Inside ViewsMain 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 1st DSP unit front panel side Installing 2nd DSP unit rear panel sideUT-102 Voice Synthesizer Unit UT-106 DSP UnitCR-293 High Stability Crystal Unit Circuit Description Receiver Circuit6 10 MHz if Circuit Main Unit Demodulator Circuit Main UnitSquelch Control Circuit Main Unit Squelch Circuit Main UnitTransmitter Circuits Noise Blanker Circuit Main UnitAGC Circuit Main Unit Meter Circuit Main UnitTransmit if Amplifier Circuit Main Unit Modulation Circuit Main UnitCW Keying Circuit Main Unit RF Circuit PA UnitPLL Circuits PLL Circuits 7 1LO PLL Circuit8 2LO PLL Circuit Adjustment Procedures Preparation Before SarvicingRequired Test Equipment ‘ ConnectionsPLL Adjustments Frequency AdjustmentPLL and Main Units Receiver Adjustments R547 P501L353 L354 R360EXT NoiseBlanker Main Band OFFL283 L22CP851 CP852Transmitter Adjustments R503 C659R138 R131If Total Main GainGND LO LeakR504 R202CP1613 R1613Software Adjustment Software Adjustment MeterNoise SQL Filter CalibrationTX Power Deviation HPF OFFLPF UX-910 Adjustments CP321 CP322C332 R13Power SET APCPre-setting for APC adjustment Section Parts List Front UnitDisplay Board Resistor ERA3YED Func Board VR-A BoardVR-B Board RIT Board Jack BoardMIC 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 DRV Board BARISTOR-A BoardVARISTOR-B Board BARISTOR-C Board2UX-910MAIN Unit Main Unit UX-910Resistor RGB3L R15 Resister ERA3YED Tantalum ECST1CC226R CH 1H Connectot 25FMN-BTK Mechanical Parts Display UnitCover Parts Chassis PartsUnpacking UX-910 Chassis PartsUX-910 Main Unit 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.