WSJT-X waterfall freezes in Linux? Fix it with a udev rule!

Lately I’ve been playing around with WSJT-X at my home station on twenty meters, trying to make contact with KM4BBD and a few other fine folks across North America.

All was well and good, except that the WSJT-X waterfall would periodically freeze solid, requiring a restart whenever PulseAudio had new devices connect. It would happily watch all night long, but the moment my HDMI monitor powered back on, it would freeze solid. Same for jumping between machine in my KVM, or even sometimes interference from a cat video in the web browser. Asking around, it seems that other folks had this problem, but none quite knew what to do.

I stumbled across an item in the JackD FAQ that PulseAudio interferes with Jack’s scheduling, suggesting that detaching PulseAudio from the device might fix the problem.

Sure enough, creating a udev rule to disable PulseAudio on my Yaesu FT-991D did the trick. KDE’s taskbar now only shows my other speakers and microphones, and WSJT-X never locks up or freezes.

#/etc/udev/rules.d/89-pulseaudio-usb.rules

## Run 'lsusb | grep CODEC' if your radio model number is different.

# Ignore the Yaesu FT-991A so that WSJT-X isn't disturbed.
ATTRS{idVendor}=="08bb", ATTRS{idProduct}=="29b3", ENV{PULSE_IGNORE}="1"

73 de KK4VCZ