= WSJT Setup =

The wsjt package is used for weak-signal amateur radio communications.

== Configuring Audio Devices ==

Wsjt allows configuration to select your sound card device, but there is insufficient information presented in the GUI interface to troubleshoot problems.

Start wsjt from a command line, and during startup, a list of all available audio devices will be printed. You can then select a device number from the "Audio Device" column, and enter it in the setup dialog of wsjt.

After changing the configuration, you must restart wsjt for changes to take effect.

== Known Issue with audio sample rate ==

Wsjt requires that the audio stream be opened at a single, fixed sample rate. If the Audio device does not support that sample rate, wsjt will fail with the following error:

  {{{
Error opening input audio stream.
	Errortext: Invalid sample rate
	Number: -9997
Error opening output audio stream.
	Errortext: Invalid sample rate
	Number: -9997
Error  3 in JTaudio, you will only be able to work offline.
}}}

In order to provide a resampled audio stream that can support the rate requested by wsjt, you can create a .asoundrc file in your home directory, and add the following to it:

  {{{
pcm.SignalLink-USB {
        type hw
        card 1
        device 0
}
pcm_slave.SignalLinkIn {
        pcm SignalLink-USB
        rate 44100
}
pcm.SignalLinkOut {
        type rate
        slave SignalLinkIn
}
}}}

Once you create this file, you'll have to restart the pulse audio system:

  {{{
sudo service pulseaudio –restart
}}}

Now, reconfigure wsjt to use the audio device named "SignalLinkOut", and it should work.
(Thanks to [[http://foxgulch.com/WordPress/?p=557|LarryJ2]] for documenting this workaround)