Icom IC-910H service manual Ext, Noise, Blanker, Main Band OFF

Page 24

RECEIVER ADJUSTMENTS (continued)

 

 

 

 

 

 

MEASUREMENT

 

 

 

ADJUSTMENT

ADJUSTMENT

ADJUSTMENT CONDITION

 

 

 

VALUE

POINT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UNIT

 

LOCATION

 

UNIT

ADJUST

 

 

 

 

 

 

 

 

 

 

 

 

430 M PEAK

1

• Display frequency: 435.0200 MHz

 

MAIN

Connect

a

digital

Maximum voltage

PA

L22,

(MAIN BAND)

 

• Mode

 

: FM

 

 

multimeter or oscillo-

 

 

L23,

 

 

• Connect a standard signal generator

 

 

scope to check point

 

 

L282,

 

 

to [UHF ANT] connector and set as:

 

 

CP851.

 

 

 

 

 

L283

 

 

Frequency : 435.0200 MHz

 

 

 

 

 

 

 

 

 

 

 

 

Level

: 1 µV* (–107 dBm)

 

 

 

 

 

 

 

 

 

 

 

 

Modulation : 1 kHz/±5.0 kHz Dev.

 

 

 

 

 

 

 

 

 

 

 

 

• Receiving

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

430 M PEAK

1

• Sub display freq. : 435.0200 MHz

 

MAIN

Connect

a

digital

Maximum voltage

PA

L280,

(SUB BAND)

 

• Mode

 

: FM

 

 

multimeter or oscillo-

 

 

L281

 

 

• Set an SSG as

:

 

 

scope to check point

 

 

 

 

 

Frequency : 435.0200 MHz

 

 

CP852.

 

 

 

 

 

 

 

 

Level

: 1 µV* (–107 dBm)

 

 

 

 

 

 

 

 

 

 

 

 

Modulation : 1 kHz/±5.0 kHz Dev.

 

 

 

 

 

 

 

 

 

 

 

 

• Receiving

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

430 M

1

• Display frequency: 435.0200 MHz

 

Rear

Connect an AC milli-

1.0 V (0 dB)

Front

main [AF]

TOTAL GAIN

 

• Mode

 

: USB

 

panel

volt

meter

to

[EXT

 

panel

volume

(MAIN BAND)

 

• Set an SSG as

:

 

 

SP]

connector with

 

 

 

 

 

Frequency : 435.0215 MHz

 

 

an 8 load.

 

 

 

 

 

 

 

Level

: 1 mV* (–47 dBm)

 

 

 

 

 

 

 

 

 

 

 

 

Modulation : OFF

 

 

 

 

 

 

 

 

 

 

 

 

• Receiving

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

• Set an SSG as

:

 

 

 

 

 

 

 

100 mV (20 dB of AF

PA

R61

 

 

Level

: OFF

 

 

 

 

 

 

 

level difference as step

 

 

 

 

• Receiving

 

 

 

 

 

 

 

 

 

1.)

 

 

 

 

 

 

 

 

 

 

 

NOISE

1

• Display frequency: 145.9800 MHz

 

MAIN

Connect an oscillo- Maximum noise wave-

MAIN

L102,

BLANKER

 

• Mode

 

: USB

 

 

scope to check point

form

 

L103

(MAIN BAND)

 

• [NB]

 

: OFF

 

 

CP101.

 

 

 

 

 

 

Connect an SSG to [VHF ANT] con-

nector and set as :

Frequency : 145.98150 MHz

Level : 5.6 µV* (–92 dBm)

Modulation : OFF

and apply following signal to [VHF ANT] connector.

100msec.

1msec.

Receiving

2 • [NB]

: ON

The noise must be

Verify

• Set an SSG as :

blanked.

 

Level

: 3.2 µV* (–97 dBm)

 

 

Receiving

(SUB BAND) 3

• Sub display freq.

: 145.9800 MHz

Connect an oscillo-

Maximum noise wave-

 

L703,

 

 

• Mode

 

: USB

scope to check point

form

 

L704

 

 

• [NB]

 

: OFF

CP701.

 

 

 

 

 

• Set an SSG as

:

 

 

 

 

 

 

Level

: 5.6 µV* (–92 dBm)

 

 

 

 

 

 

• Receiving

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

• [NB]

 

: ON

 

The noise must be

 

Verify

 

 

• Set an SSG as

:

 

blanked.

 

 

 

 

Level

: 3.2 µV* (–97 dBm)

 

 

 

 

 

 

• Receiving

 

 

 

 

 

 

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

5 - 6

Image 24
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.