The Icom service manual for the IC-91A and IC-91AD transceivers provides detailed instructions for setup, operation, and troubleshooting, including disassembly instructions, circuit descriptions, and adjustment procedures. It also includes specifications, parts lists, and repair notes to ensure proper maintenance and handling of the transceivers.
Manual Overview
The Icom IC-91A and IC-91AD service manual provides detailed guidance for technicians on troubleshooting, diagnostics, and maintenance of these VHF/UHF transceivers. The manual emphasizes a structured troubleshooting flow, advising technicians to confirm internal issues before disassembly and to disconnect power before opening the device. It highlights the importance of using insulated tools for adjustments and cautions against prolonged power-on states when defects are present. Error codes and diagnostics are not explicitly detailed, but the manual stresses careful handling of test equipment, recommending the use of attenuators when connecting to deviation meters or spectrum analyzers. Calibration and adjustments require precise handling of variable components, with instructions to turn them slowly to avoid damage. Board-level guidance includes detailed disassembly instructions, such as removing the rear panel and RF unit, with specific steps for unsoldering and screw removal. The manual also covers the layout of the logic and main units, providing insights into the internal circuitry for effective troubleshooting and repairs.
Quick Issues Covered
- Diagnose power-up failures with voltage diagrams and circuit tracing.
- Adjust receiver circuits for optimal performance using detailed procedures.
- Identify and resolve error codes specific to IC-91A/IC-91AD models.
Overview
This service manual provides the latest service information for the IC-91A VHF/UHF FM Transceiver and the IC-91AD VHF/UHF Digital Transceiver. It covers various model versions including those for the USA, Taiwan, Korea, Australia, and Export markets. The manual includes sections on specifications, inside views, disassembly instructions, circuit descriptions, adjustment procedures, parts list, mechanical parts, semiconductor information, board layouts, block diagrams, and voltage diagrams. The manual also provides cautions for safe operation and notes for ordering parts and repair.
Specifications
- Frequency coverage: Tx: 144-148, 420-450
- Operating mode: FM, AM, WFM, DV
- Memory channels: 1304 channels
- Frequency stability: +2.5 ppm
- Tuning steps: 5, 6.25, 8.33, 9, 10, 12.5, 15, 20, 25, 30, 50, 100, 125, 200 kHz
- Antenna impedance: 50 Q (SMA type)
- Power supply: 10.0-16.0 V DC for external DC power
- Digital transmission speed: 4.8 kbps
- Voice coding speed: 2.4 kbps
- Current drain: TRANSMIT VHF High 2.1 A, Low 0.8 A, UHF High 2.2 A, Low 0.8 A
- Operating temp. range: -20°C to +60°C
- Dimensions: 58.4 (W) x 103 (H) x 34.2 (D) mm
- Weight: 300 g
- Output power: 5.0 W (High), 0.5 W (Low)
- Modulation system: FM: Variable reactance frequency modulation
- Maximum deviation: 5.0 kHz (FM wide), 2.5 kHz (FM narrow)
- Spurious emissions: Less than -60 dB
- Ext. mic. connector: 3-conductor 2.5 (d) mm
Controls & Indicators
Refer to the PDF for details.
Installation / Setup
Refer to the PDF for details.
Operation
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Troubleshooting & Error Codes
Refer to the PDF for details.
Safety & Warnings
NEVER connect the transceiver to an AC outlet or to a DC power supply 3.7 V. Such a connection could cause a fire or electric hazard. DO NOT expose the transceiver to rain, snow or any liquids. DO NOT reverse the polarities of the power supply when connecting the transceiver. DO NOT apply an RFF signal of more than 20 dBm (100 mW) to the antenna connector. This could damage the transceiver’s front end. Make sure the problem is internal before disassembling the transceiver. DO NOT open the transceiver until the transceiver is disconnected from its power source. DO NOT force any of the variable components. Turn them slowly and smoothly. DO NOT short any circuits or electronic parts. An insulated turning tool MUST be used for all adjustments. DO NOT keep power ON for a long time when the transceiver is defective. DO NOT transmit power into a signal generator or a sweep generator. ALWAYS connect a 30 dB to 40 dB attenuator between the transceiver and a deviation meter or spectrum analyzer when using such test equipment. READ the instructions of test equipment thoroughly before connecting equipment to the transceiver.
Download MANUAL Service manual (PDF – 3.3 MB)
Icom IC-91A/IC-91AD service manual PDF: 3.3 MB. Guides technicians in troubleshooting and calibrating radio equipment.
- Brand: Icom-ic-91a-ic-91ad-service
- Model: MANUAL
- Type: Service manual
- File size: 3.3 MB
Overview
Brief overview of the product.
Specifications
- Key spec 1
- Key spec 2
Controls & Indicators
Control panel/button layout.
Installation / Setup
- Step 1…
- Step 2…
Operation
Basic usage, modes, cycles.
Troubleshooting & Error Codes
| Issue / Code | Fix |
|---|---|
| Example | How to fix… |
Safety & Warnings
- Important warning…
Downloads
Download MANUAL service manual (PDF)
Icom IC-91A / IC-91AD Service Manual Overview
The Icom IC-91A and IC-91AD are dual-band amateur radio transceivers designed for reliable communication across VHF and UHF frequencies. These handheld devices are widely used by amateur radio enthusiasts for both local and extended range communication, offering clear audio quality and robust performance. The service manual provides comprehensive technical details, schematics, and repair instructions to assist technicians and users in maintaining and servicing these radios effectively.
Main Features and Specifications
- Dual-band operation: VHF (144 MHz) and UHF (430 MHz) coverage
- Output power: Up to 5 watts on both bands
- Wide frequency coverage with programmable memory channels
- Built-in CTCSS and DCS tone encoder/decoder for selective calling
- LCD display with backlight for clear readability
- Battery-powered handheld design for portability
- Compatible with various accessories including external microphones and antennas
Basic Usage and Operation Tips
To operate the IC-91A/IC-91AD, first ensure the battery is fully charged and properly installed. Use the channel selector to tune to the desired frequency or memory channel. Adjust the volume and squelch controls to optimize audio clarity and reduce background noise. Utilize the built-in CTCSS/DCS tones to communicate selectively with specific groups. For extended use, consider programming frequently used channels into memory for quick access. Always monitor the battery level indicator to avoid unexpected power loss during communication.
Troubleshooting and Maintenance Notes
If you experience weak transmission or reception, check antenna connections and ensure the antenna is suitable for the operating frequency. Intermittent audio or power issues may indicate battery problems or internal component wear. Refer to the service manual’s schematic diagrams for detailed diagnostics and component replacement procedures. Regularly clean the exterior and connectors to prevent dust buildup, and store the radio in a dry, cool place when not in use to prolong its lifespan.
Safety Reminder
Always operate the Icom IC-91A/IC-91AD in accordance with local regulations and licensing requirements. Avoid transmitting near sensitive electronic equipment or medical devices to prevent interference. Do not attempt repairs unless qualified, as improper servicing can cause damage or personal injury. Use only manufacturer-approved batteries and accessories to ensure safe and reliable operation.