Icom IC-7610 + fldigi Setup Guide

Windows 11/10

1. Download the driver from Icom America IC-7610 Support
2. Install the driver before connecting USB cable
3. Connect USB cable to black USB 2.0 port only
4. Windows will recognize:
   • Virtual COM port (for CI-V control)
   • USB Audio CODEC device (for audio I/O)

macOS

1. Install Silicon Labs Mac OS X driver first
2. Download IC-7610 drivers from Icom's official support page
3. System requirements: Mac OS X 10.9 (Mavericks) or newer

Linux

USB drivers typically work via standard USB serial/audio interfaces. Use Hamlib rigctl for rig control and ALSA for audio management.

Rig Control Settings (Hamlib Method)

1. Navigate to Configure → Rig Control
2. Select Hamlib as rig control method
3. Enter rig number: 3078 (Hamlib 4.x) or 378 (older versions)
4. Device/Port: Select virtual COM port (e.g., COM3 on Windows)
5. Baud rate: 19200 bps
6. Data bits: 8, Stop bits: 1, Parity: None

Alternative: RigCAT XML

1. Download IC-7610 RigCAT XML from K0PIR's guide
2. Place XML file in ~/.fldigi/ (or C:\Users\[username]\.fldigi\ on Windows)
3. Select RigCAT in Configure → Rig Control
4. Choose the XML file and set baud rate to 19200

Audio Device Selection

1. Navigate to Configure → Audio I/O
2. Capture device: Select USB Audio CODEC (input)
3. Playback device: Select USB Audio CODEC (output)
4. Sample rate: 48 kHz or 44.1 kHz
5. Enable "Modem signal of left and right channels" checkbox

PTT Configuration

1. Navigate to Configure → Modems → General
2. Set PTT method: CAT (Hamlib/RigCAT)
3. Do NOT use hardware (RTS/DTR) PTT when using CAT control

DATA Mode Setup

1. Press [MODE] button
2. Select DATA 1, DATA 2, or DATA 3 (USB-D or LSB-D)
3. In MENU → ACC SET, set signal source for your DATA slot to USB
4. Set USB MOD Level to approximately 30%

CI-V Settings

RF Power and ALC

• Power output: Set to 90-100% in the radio
• Compression: Turn OFF
• Monitor ALC to avoid distortion - do NOT allow ALC to flatten waveform peaks
• Typical safe power: 20-50W depending on mode

Digital Mode with Dual Watch

• Main band: Tune to digital mode frequency
• Sub band: Monitor a second frequency (RX only)
• Use F1/F2 buttons to switch between bands
• Note: Only Main band can transmit

No USB Audio Device Appearing

• Verify driver installed BEFORE cable connection
• Uninstall and reinstall Icom USB drivers
• Try different USB port (not USB 3.0 hub)
• Use powered USB hub if on laptop

No Transmit Audio

• Verify ACC SET → DATA slot is set to USB
• Check USB MOD LEVEL (should be 20-50%)
• Enable "Modem signal of left and right channels" in fldigi Audio tab
• Verify playback device is USB Audio CODEC

RigCAT Not Controlling Frequency

• Verify IC-7610 XML file is in correct directory
• Verify CI-V baud rate is 19200 in both radio and fldigi
• Check virtual COM port is correct
• Restart fldigi after changing RigCAT configuration

fldigi Doesn't See IC-7610

• Verify USB cable connected to black USB 2.0 port (not blue)
• Check Device Manager for Icom virtual COM port
• Try Hamlib 378 instead of RigCAT XML
• Install latest Hamlib version