The Icom Service Manual for the 144MHz FM Transceiver models IC-T21A/E and IC-S21A/E provides detailed instructions on disassembly, circuit descriptions, adjustment procedures, and specifications for each version of the transceiver. It also includes troubleshooting guidelines, such as ensuring the transceiver is disconnected from power before opening and using insulated tools for adjustments to prevent damage.
Manual Overview
The Icom IC-T21A/E and IC-S21A/E service manual provides detailed instructions for servicing the 144 MHz FM transceivers. It includes troubleshooting flowcharts to diagnose common issues, with emphasis on ensuring problems are internal before disassembly. Error codes and diagnostics are addressed, focusing on the correct use of test equipment and avoiding damage through incorrect connections or excessive signal input. Calibration and adjustments are covered in detail, particularly for the PLL, receiver, and transmitter circuits, using insulated tuning tools to prevent short circuits. Board-level guidance includes layouts and descriptions for the logic, 1F, 2F, and 3F units, with specific attention to the VCO circuits and power modules. The manual advises against connecting the transceiver to power sources exceeding 16 V and stresses the importance of using attenuators when connecting to deviation or spectrum analyzers. The manual also provides part ordering information, requiring specific details such as order numbers and component names.
Quick Issues Covered
- Diagnose power-up failures due to incorrect voltage supply.
- Calibrate PLL circuits for optimal frequency stability.
- Trace circuit schematics for troubleshooting receiver issues.
Overview
This service manual provides the latest service information for the IC-T21A/E and IC-S21A/E 144 MHz FM Transceivers. It covers various versions of these models, detailing specifications, disassembly instructions, circuit descriptions, adjustment procedures, parts lists, mechanical parts, board layouts, block diagrams, and voltage diagrams. The manual includes warnings about proper usage and handling of the transceivers to prevent damage.
Specifications
- Frequency coverage: U.S.A. 144-148 MHz (TX); 144-148, 440-450 MHz (RX)
- Frequency coverage: IC-T21A Australia 144-148 MHz (TX); 144-148, 430-440 MHz (RX)
- Frequency coverage: Asia 144-148 MHz (TX); 138-174, 430-440 MHz (RX)
- Frequency coverage: Europe 144-146 MHz (TX); 144-146, 430-440 MHz (RX)
- Frequency coverage: IC-TO1E Taiwan 145-146 MHz (TX); 145-146, 430-432 MHz (RX)
- Frequency coverage: Denmark 144-146 MHz (TX); 144-146, 432-438 MHz (RX)
- Frequency coverage: Italy 144-148 MHz (TX); 138-174, 430-440 MHz (RX)
- Frequency coverage: U.S.A. 144-148 MHz (TX/RX)
- Frequency coverage: IC-S21A Australia 144-148 MHz (TX/RX)
- Frequency coverage: Asia 144-148 MHz (TX); 138-174 (RX)
- Frequency coverage: Europe 144-146 MHz (TX); 144-146, 430-440 MHz (RX)
- Frequency coverage: IC-T21E Taiwan 145-146 MHz (TX/RX)
- Frequency coverage: Italy 144-148 MHz (TX); 138-174 (RX)
- Mode: FM (F3E)
- Tuning steps: 5, 10, 12.5, 15, 20, 25, 30 or 50 kHz
- Number of memory channels: 100 plus 12 scan edge, 1 call, 1 repeat memory channels
- Antenna impedance: 50 OQ (unbalanced)
- Usable battery packs/case: BP-151, BP-152, BP-153, 4 dry cell batteries with BP-159
- External DC power: 4-16 V DC (negative ground)
- Current drain (at 13.5 V, typical) HIGH: 1.8A
- Current drain (at 13.5 V, typical) Transmit LOW 1: 1.0A
- Current drain (at 13.5 V, typical) LOW: 90 mA
- Current drain (at 13.5 V, typical) Power saved: 8 mA (average)
- Current drain (at 13.5 V, typical) Receive Rated audio output: 160 mA
- Usable temperature range: -—10°C to +60°C (+14°F to +140°F)
- Frequency stability: +10 ppm (at 0°C to +50°C; +32°F to +122°F)
- Dimensions (with BP-151): 54 (W) x 111 (H) x 35.5(D) mm
- Weight (with BP-151): 315g (11.1 oz)
- Output power (at 13.5 V): 6 W (HIGH), 4 W (LOW 3), 1.4 W (LOW 2), 1.0 (LOW 1), 15 mW (E LOW)
- Modulation system: Variable reactance frequency modulation
- Max. frequency deviation: +5.0 kHz
- Spurious emissions: Less than —60 dB
Controls & Indicators
Refer to the PDF for details.
Installation / Setup
Refer to the PDF for details.
Operation
Refer to the PDF for details.
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 that uses more than 16 V. This will ruin the transceiver. 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 AF signal of more than 20 dBm (100 mW) to the antenna connector. This could damage the transceiver’s front end. Make sure a 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 tuning 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 40 dB–50 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 – 18.5 MB)
Icom IC-S21A/IC-S21E service manual PDF for troubleshooting and calibrating radio equipment. File size: 18.5 MB.
- Brand: Icom-ic-s21a-ic-s21e-service
- Model: MANUAL
- Type: Service manual
- File size: 18.5 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-S21A / IC-S21E Service Manual Overview
The Icom IC-S21A and IC-S21E are compact, handheld VHF transceivers designed for reliable two-way communication. Widely used by amateur radio enthusiasts and professionals alike, these models offer clear audio quality and robust performance in a durable, portable form factor. This service manual provides detailed guidance on maintenance, repair, and operation to ensure optimal functionality and longevity of your device.
Main Features and Specifications
- Frequency Range: VHF 136-174 MHz
- Power Output: Up to 5 Watts
- Channel Capacity: 16 memory channels
- Battery Type: Rechargeable Ni-Cd or Ni-MH battery pack
- Display: Simple LED indicator for channel and status
- Operating Voltage: 7.2V DC
- Compact and lightweight design for portability
- Built-in squelch control and noise reduction circuitry
Basic Usage and Operation Tips
To operate the IC-S21A/E, first ensure the battery is fully charged. Turn the unit on using the power switch and select the desired channel using the channel selector knob. Adjust the volume and squelch controls to optimize audio clarity and minimize background noise. When transmitting, press the push-to-talk (PTT) button firmly and speak clearly into the microphone. Release the PTT button to listen. Regularly check battery levels and recharge as needed to maintain consistent performance.
Troubleshooting and Maintenance
If you experience poor audio quality or transmission issues, verify antenna connections and inspect for physical damage. Clean the battery contacts periodically to ensure proper power flow. Should the unit fail to power on, confirm the battery charge and replace if necessary. Refer to the detailed schematics and parts list in this manual for advanced troubleshooting and repair procedures. Routine maintenance, including cleaning and inspection, will extend the life of your transceiver.
Safety Reminder
Always operate the Icom IC-S21A/E in accordance with local regulations and licensing requirements. Avoid using the transceiver near explosive materials or in hazardous environments. Do not attempt repairs beyond your technical expertise to prevent injury or further damage. Use only manufacturer-approved batteries and accessories to ensure safe and reliable operation.