The Icom IC-728 HF Transceiver service manual provides detailed instructions for setting up, operating, and troubleshooting the device, including specifications, block diagrams, and adjustment procedures. It emphasizes safety precautions such as avoiding exposure to liquids and ensuring correct power supply connections to prevent damage to the transceiver.
Overview
The product is the IC-728 HF Transceiver by Icom Inc. The service manual provides the latest service information for this transceiver, covering specifications, block diagrams, circuit descriptions, mechanical parts, disassembly, parts lists, adjustment procedures, board layouts, and voltage diagrams. It includes details on receiver and transmitter circuits, PLL circuits, logic circuits, and regulator circuits. The manual also outlines repair notes and precautions for handling the transceiver, such as avoiding exposure to liquids and ensuring correct power supply connections.
Specifications
- Frequency coverage: Receive 500 kHz~30 MHz, Transmit 1.800~1.900 MHz, 18.068~18.168 MHz, 3.500~4.000 MHz, 21.000~21.450 MHz, 7.000~7.300 MHz, 24.890~24.990 MHz, 10.100~10.150 MHz, 28.000~29.700 MHz
- Mode: SSB, CW, AM, FM
- Number of memory channels: 26
- Antenna impedance: 50 Ω nominal
- Usable temperature range: —10°C~+60°C (+14 °F~+140 °F)
- Frequency stability: Less than 200 Hz from 1 min. to 60 min. after power ON, Less than +30 Hz/hr after one hour at +25 °C (+77 °F), Temperature fluctuations (0 °C~ +50 °C; +32 °F~+122 °F) less than +350 Hz
- Power supply requirement: 13.8V DC ±15%
- Current drain (at 13.8 V DC): Transmit 20A, Receive squelched 1.3 A max. audio output 1.6 A
- Dimensions: 241 (W) x 94 (H) x 239 (D) mm, 9.5 (W) x 3.7 (H) x 9.4 (D) in (Projections not included)
- Weight: 4.6 kg (10.1 lb)
- TRANSMITTER
- Output power: SSB, CW, FM 10~100 W continuously adjustable, AM 10~40 W continuously adjustable
- Spurious emissions: Less than -50 dB
- Carrier suppression: More than 40 dB
- Unwanted sideband: More than 50 dB
- Microphone impedance: 600 Ω
- RECEIVER
- Receive system: Triple-conversion superheterodyne
- Intermediate frequencies: MODE 1st 2nd 3rd, SSB 70.4515 MHz 9.0115 MHz 455 kHz, CW 70.4506 MHz 9.0106 MHz 455 kHz, AM, FM 70.4500 MHz 9.0100 MHz 455 kHz
- Sensitivity (Preamp ON): SSB, CW (0 dB S/N) 1.8~30 MHz Less than 0.16 μV, AM (10 dB S/N) 0.5~1.8 MHz Less than 13.0 μV, 1.8~30 MHz Less than 2.0 μV, FM (12 dB SINAD) 28~30 MHz Less than 0.5 μV
- Selectivity: SSB, CW More than 2.1 kHz/—6 dB Less than 4.0 kHz/-60 dB, AM More than 6.0 kHz/—6 dB Less than 20.0 kHz/~40 dB, FM More than 12 kHz/—6 dB Less than 30 kHz/-50 dB
- Spurious and image rejection ratio: More than 70 dB
- Audio output power: More than 2.6 W with an 8 Ω load
- RIT variable range
Controls & Indicators
Refer to the PDF for details.
Installation / Setup
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Operation
Refer to the PDF for details.
Troubleshooting & Error Codes
Refer to the PDF for details.
Safety & Warnings
Refer to the PDF for details.
Download MANUAL Service manual (PDF – 12.3 MB)
Icom IC-728 Service Manual PDF: 12.3 MB. Assists technicians in troubleshooting and calibrating the IC-728 radio model.
- Brand: Icom-ic-728-service
- Model: MANUAL
- Type: Service manual
- File size: 12.3 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-728 Service Manual Overview
The Icom IC-728 is a high-performance HF transceiver designed for amateur radio enthusiasts. It provides reliable communication across multiple bands with excellent audio clarity and robust signal processing. This service manual offers detailed instructions for maintenance, repair, and troubleshooting to ensure optimal operation of the IC-728 transceiver.
Main Features and Specifications
- Frequency Coverage: 1.8 MHz to 30 MHz (HF bands)
- Modes: SSB, CW, AM, and FM
- Output Power: Up to 100 watts
- Digital Signal Processing (DSP) for noise reduction
- Multiple tuning and memory channels
- Built-in automatic antenna tuner
- Large, easy-to-read LCD display
- Compact and durable design suitable for mobile and base station use
Basic Usage and Operation Tips
To operate the IC-728, first ensure the antenna and power supply are properly connected. Use the tuning dial to select the desired frequency and mode. Adjust the volume and squelch controls for clear audio reception. Utilize the memory channels for quick access to frequently used frequencies. For optimal performance, regularly calibrate the frequency and check the antenna tuner settings.
Troubleshooting and Maintenance Notes
If you experience issues such as weak transmission or distorted audio, verify all cable connections and antenna integrity. Consult the manual’s troubleshooting section for common fault codes and corrective procedures. Regularly clean the exterior and ventilation slots to prevent overheating. Replace fuses and worn components as detailed in the service manual to maintain reliable operation.
Safety Reminder
Always disconnect the transceiver from the power source before performing any maintenance or repairs. Avoid operating the device in wet or humid conditions to prevent electric shock or damage. Follow all safety instructions in the manual to ensure safe and effective use of the Icom IC-728 transceiver.