IC-7300 USB Serial Backend Setup (macOS)¶

This guide shows how to control the IC-7300 via USB serial CI-V + USB audio devices instead of the default LAN backend.

Why Use the Serial Backend?¶

No network required — direct USB connection
Lower latency — no UDP/network overhead
Simpler setup — no IP config, username, or password
Field operation — works with battery-powered USB (e.g., Powerex)
Alternative to LAN — for users without Ethernet/WiFi on IC-7300

Hardware Requirements¶

IC-7300 transceiver (HF/50 MHz)
Micro-USB cable (IC-7300 uses Micro-USB)
macOS computer (tested on Ventura+ arm64/Intel)

Radio Configuration¶

Critical Setup Step

On the IC-7300, navigate to Menu → Set → Connectors → CI-V → CI-V USB Port and set it to Link to [CI-V], NOT [REMOTE].

Link to [CI-V] — serial CI-V commands work (required for icom-lan serial backend)
[REMOTE] — RS-BA1 mode, serial CI-V is blocked

This is the same critical setting as IC-7610 and IC-705.

Recommended Radio Settings¶

Setting	Value	Why
CI-V USB Port	`Link to [CI-V]`	✅ Required — enables serial CI-V
CI-V USB Baud Rate	`115200`	Recommended for scope/waterfall
CI-V Address	`0x94` (IC-7300 default)	Library auto-detects from profile
USB Audio TX	Enabled	Allows browser/WSJT-X TX via USB audio
USB Audio RX	Enabled	Exports RX audio to computer

Baud Rate

115200 baud is recommended for scope/waterfall capability
Lower baud rates (19200, 9600) work for basic control (freq, mode, PTT) but scope/waterfall is disabled by a guardrail due to high packet rate
CI-V baud rate IS significant on IC-7300 — it must match between radio and library

IC-7300 Single Receiver

The IC-7300 has a single receiver (unlike IC-7610's dual receiver or IC-9700's dual). The library automatically enforces this via the IC-7300 profile — operations on receiver=1 will fail with CommandError.

macOS Setup¶

1. Install icom-lan¶

pip install icom-lan[serial]

2. Connect USB and Verify Devices¶

Plug in the USB cable and verify the serial port:

ls /dev/cu.usbserial-* | head -5
# Output example: /dev/cu.usbserial-A602RVAV

Check for audio devices exported by the radio:

python -c "from icom_lan.usb_audio_resolve import list_usb_audio_devices; import json; print(json.dumps(list_usb_audio_devices(), indent=2))"

You should see input and output devices for the IC-7300: - Input (RX): e.g., "IC-7300 (In 1)" - Output (TX): e.g., "IC-7300 (Out 1)"

3. Connect via Python¶

import asyncio
from icom_lan import IcomRadio

async def main():
    # Create serial radio for IC-7300
    radio = IcomRadio(backend="serial", model="IC-7300", device="/dev/cu.usbserial-A602RVAV")

    async with radio:
        # Read frequency
        freq = await radio.get_frequency()
        print(f"Frequency: {freq / 1e6:.6f} MHz")

        # Set frequency
        await radio.set_frequency(7_074_000)

        # Read mode
        mode, _ = await radio.get_mode()
        print(f"Mode: {mode}")

        # Enable scope
        await radio.enable_scope()

        # Scope data is now available via radio.scope_data

asyncio.run(main())

4. CLI Usage¶

# Check connection
icom-lan --backend serial --model IC-7300 --device /dev/cu.usbserial-A602RVAV status

# Set frequency
icom-lan --backend serial --model IC-7300 --device /dev/cu.usbserial-A602RVAV freq 7074000

# Monitor metrics
icom-lan --backend serial --model IC-7300 --device /dev/cu.usbserial-A602RVAV meters

5. Web UI¶

icom-lan web --backend serial --model IC-7300 --device /dev/cu.usbserial-A602RVAV
# Open http://localhost:8000

Supported Features¶

Feature	Status	Notes
Frequency	✅ Full	Get/set HF/50 MHz
Mode	✅ Full	USB, LSB, CW, FM, AM, RTTY, PSK, etc.
Power	✅ Full	RF power 0-100W
Scope/Waterfall	✅ Full	Real-time scope at 115200 baud
Audio RX/TX	✅ Full	PCM and Opus codecs
Meters	✅ Full	S-meter, SWR, ALC, Power, Vd, Id
Filters	✅ Full	Filter width selection
DSP	✅ Full	NB, NR, APF, Twin Peak, PBT
Dual Watch	⚠️ Single RX	IC-7300 has single receiver only

Audio Subsystem¶

IC-7300 exports USB audio devices that icom-lan can use:

# Receive audio from radio
async def on_audio(pcm_data: bytes, sample_rate: int):
    print(f"RX audio: {len(pcm_data)} bytes @ {sample_rate} Hz")

async with radio:
    radio.start_audio_rx(callback=on_audio)
    await asyncio.sleep(5)
    radio.stop_audio_rx()

# Transmit audio to radio
async with radio:
    radio.start_audio_tx(sample_rate=16000, channels=1)
    # Push 160ms of PCM data (2560 bytes @ 16kHz)
    radio.push_audio(pcm_data)
    radio.stop_audio_tx()

WSJT-X Integration¶

Use macOS BlackHole (or Loopback) to bridge icom-lan audio to WSJT-X:

Install BlackHole 2ch: https://github.com/ExistentialAudio/BlackHole
Create aggregate device:
Audio Midi Setup → + → "IC-7300 Bridge"
Add "IC-7300" input + "BlackHole 2ch" output

Start audio bridge:

icom-lan audio bridge --device ic-7300-usb-in --loopback "BlackHole 2ch"

WSJT-X settings:
Input Device: "IC-7300 Bridge"
Output Device: "BlackHole 2ch" or USB audio device

Troubleshooting¶

"Device not found" Error¶

ConnectionError: failed to open serial port /dev/cu.usbserial-XXXXX

Solution: Verify USB cable connection and check /dev/cu.usbserial-* listing.

Low Baud Rate Warning¶

WARNING: Scope disabled due to low baud rate (9600 < 115200 minimum)

Solution: Set CI-V USB Baud Rate to 115200 in radio menu → Set → Connectors.

Audio Devices Not Found¶

WARNING: audio subsystem not detected; TX/RX disabled

Solution: Verify USB Audio TX/RX are enabled in radio settings. Check with:

python -c "from icom_lan.usb_audio_resolve import list_usb_audio_devices; import json; print(json.dumps(list_usb_audio_devices(), indent=2))"

CI-V Commands Timing Out¶

CommandError: timeout waiting for CI-V response

Solution: Verify CI-V USB Port is set to Link to [CI-V], not [REMOTE].

Performance Tuning¶

Serial CI-V Pacing¶

If commands are arriving too fast, adjust the minimum interval between CI-V commands:

radio = IcomRadio(
    backend="serial",
    model="IC-7300",
    device="/dev/cu.usbserial-A602RVAV",
)
# Set 100ms minimum between CI-V commands (default is 50ms)
import os
os.environ["ICOM_SERIAL_CIV_MIN_INTERVAL_MS"] = "100"

Scope Baud Rate Tradeoff¶

115200 baud: Full scope resolution, ~50 spectra/sec
57600 baud: Reduced scope rate, more headroom for CI-V
19200 baud: Minimal scope rate, most headroom

Hardware Notes¶

Micro-USB connector: Strain relief recommended for field use
USB power: IC-7300 can be powered via USB; use quality cable
Cable length: Keep under 3m to avoid signal integrity issues
macOS driver: No additional driver needed; built-in CDC ACM support