The Icom Service Manual for the 144MHz FM Transceiver models IC-T21A/E and IC-S21A/E provides detailed instructions on setup, operation, and troubleshooting, including disassembly instructions, circuit descriptions, and adjustment procedures. It warns against connecting the transceiver to an AC outlet or a DC power supply exceeding 16 V, and provides guidelines for safely handling and testing the equipment.
Manual Overview
The Icom Service Manual for the IC-T21A/E and IC-S21A/E 144 MHz FM transceivers provides detailed guidance on troubleshooting, error diagnostics, calibration, and board-level repairs. For troubleshooting, the manual emphasizes confirming internal issues before disassembly and ensuring the transceiver is disconnected from power. It warns against reversing power supply polarities and applying excessive AF signals to the antenna connector. Calibration procedures include adjustments for the PLL, receiver, and transmitter circuits, with specific instructions for using insulated tuning tools and attenuators when connecting test equipment. The manual outlines the board layouts for the logic, 1F, 2F, and 3F units, detailing component locations such as the lithium backup battery, reset IC, and various crystals. Error diagnostics involve checking voltage diagrams and block diagrams to identify faulty components. The manual also provides part ordering information, specifying the need for 10-digit order numbers and component details. Proper handling of variable components and adherence to safety precautions are stressed to prevent damage during service operations.
Quick Issues Covered
- Diagnose power-up failures due to incorrect DC voltage connection.
- Calibrate PLL circuits for optimal frequency stability.
- Trace circuit schematics for receiver and transmitter troubleshooting.
Overview
This service manual provides the latest service information for the IC-T21A/E and IC-S21A/E 144 MHz FM Transceivers. It covers multiple versions of these models, including those for the USA, Australia, Asia, Europe, Taiwan, Denmark, and Italy. The manual includes sections on specifications, disassembly instructions, circuit descriptions, adjustment procedures, parts lists, mechanical parts, board layouts, block diagrams, and voltage diagrams. The transceivers operate in FM mode with various tuning steps and have specific frequency coverage depending on the model version. The manual also includes safety warnings and repair notes for handling the transceivers.
Specifications
- Frequency coverage: U.S.A. 144-148 MHz (TX); 144-148, 440-450 MHz (RX)
- Frequency coverage: 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: 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)
- 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) LOW 1: 1.0A
- Current drain (at 13.5 V, typical) E 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
- Dimensions (with BP-151): 2.1 (W) x 4.4(H) x 1.4(D) in
- 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 (HIGH), Less than —40 dB (E LOW)
- Microphone impedance: 2kQ
- Receive system: Double-conversion superheterodyne
- Intermediate frequency: 1st 30.85 MHz
- Intermediate frequency: 2nd 455 kHz
- Sensitivity (for 12 dB SINAD): Less than 0.16 pV for VHF; Less than 0.22 pV for UHF {IC-T21A/E only)
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 it 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-T21A/T21E Service Manual PDF (18.5 MB) for troubleshooting, repair, and calibration guidance.
- Brand: Icom-ic-t21a-ic-t21e-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-T21A / IC-T21E Service Manual Overview
The Icom IC-T21A and IC-T21E are compact, handheld transceivers designed for reliable two-way radio communication. Widely used by amateur radio enthusiasts and professionals alike, these models offer clear audio transmission and a durable design ideal for various communication needs. This service manual provides detailed guidance on maintenance, repair, and operation to ensure optimal performance of your Icom transceiver.
Main Features and Specifications
- Frequency Range: VHF 144–148 MHz
- Power Output: Up to 5 Watts
- Channel Capacity: 128 memory channels
- Display: LCD with backlight for easy readability
- Battery Type: Rechargeable Ni-Cd or Ni-MH battery pack
- Operating Voltage: 7.2V DC
- Compact and lightweight design for portability
- Built-in CTCSS and DCS tone capabilities
Basic Usage and Operation Tips
To operate the IC-T21A/E, first ensure the battery is fully charged. Turn the radio on using the power switch and select the desired channel using the channel selector knob or keypad. Adjust the volume to a comfortable level. When transmitting, press and hold the push-to-talk (PTT) button; release it to listen. Use the built-in squelch control to minimize background noise. Regularly update memory channels to suit your communication requirements.
Troubleshooting and Maintenance Notes
If you experience weak transmission or reception, check the antenna connection and battery charge level. Clean the contacts periodically to prevent corrosion. In case of display issues or erratic operation, resetting the unit by turning it off and on may help. Refer to the service manual for detailed circuit diagrams and component replacement procedures. Avoid exposing the radio to extreme temperatures or moisture to prolong its lifespan.
Safety Reminder
Always operate the Icom IC-T21A/E in accordance with local regulations and licensing requirements. Avoid using the radio near explosive gases or in hazardous environments. Use only approved batteries and accessories to prevent damage or injury. Keep the device dry and handle it gently to ensure safe and reliable operation.