These are the settings that work for me, using a Dell XPS-15 laptop running Kubuntu Linux 22.04.02 LTS:
Connections
- Computer to Digirig: USB-C to USB-C
- Digirig: Green plug to serial, black plug to audio
- KX2: Green plug to phones, red plug to mic, black plug to ACC
KX2 settings
- USB mode (NOT data)
- Split off
- Power 5 watts max (per Elecraft)
- AF Gain: 2 (30-50db on JTDX, see PAVU volume control below))
Flrig settings
- Rig KX3
- Port- click update, then /dev/serial/by-id/usb-Silicon_Labs…
- Baud 38400
- 1 stop bit
- Everything else unchecked
- Retries 2
- Timeout 50
- Cmds 5
- Poll Intvl 200
- Byte Intvl 0
JTDX settings
Radio
- Rig: Flrig
- PTT: CAT
- Mode: USB
- Split: Fake it
Audio input and output - Input: alsa_input_usb-C_Media_Electronics…
- Output: alsa_input_usb-C_Media_Electronics…
Main window - Adust radio AF gain for 30-50db
PAVU volume control
- Playback: Mute system sounds
- Recording: Audio from CM108 Audio Controller Mono, level about 16%- set for 30-50db on JTDX
- Output devices: CM108, level 100%
- Input devices: CM108, level 100%