Setting up WSJT-X to work with your SDR program

This document will help you get amateur radio digital modes up and running. I haven't set up a transmitter yet.

We will use the SDR receivers and other software previously installed and send the audio to WSJT-X, which will decode it and send it to GridTracker to be mapped. We will set up Hamlib to control the SDR radios that support it.
This section assumes that Hamlib is installed.

Install PulseAudio Volume Control

sudo apt-get install pavucontrol paprefs

CubicSDR/WSJT-X integration
- Start the Virtual0 virtual audio cable device in a terminal as follows:
```
pacmd load-module module-null-sink sink_name=Virtual0
pacmd update-sink-proplist Virtual0 device.description=Virtual0
pacmd update-source-proplist Virtual0.monitor device.description=Virtual0
```
- Start rigctld in a terminal:
```
rigctld -v -m 1 -T 127.0.0.1 -t 7356 &
```
- In CubicSDR, from the Rig Control menu, choose Model>Hamlib>Hamlib NET rigctl.
  From the Rig Control menu, Control Port, enter 127.0.0.1:7356.
  From the Rig Control menu, select the following options: Control Rig, Follow Rig, Floating Center and Track Modem.
  Tune the center frequency of CubicSDR into the range you want; place a modem on the waterfall that you'd like to frequency track and then click 'Enable Rig' from the Rig Control menu. I suggest that you set the bandwidth to at least 3 KHz.
  Select the default Audio Out device. The sound will not be heard after the audio has been configured.
  Start WSJT-X
  Open the PulseAudio Volume Control.
  On the playback tab, for ALSA plug-in [CubicSDR], set ASLA playback on Virtual0
  On the Recording tab, for ALSA plug-in [wsjtx]: set ALSA Capture from Virtual0
- In WSJT-X, go to File>Settings and select the Radio tab. In the Rig: menu choose Hamlib NET rigctl and insert 127.0.0.1:7356 in Network server. Click the Test CAT button and if everything is correctly set up, the button color should change to green. Once WSJT-X has been configured for Rig Control, it will throw an error if rigctld is not running.
  
  In the settings window, click the Audio tab. For Soundcard Input: select default. default has been configured to be Virtual0. Click OK.
  
  Change mode to the desired mode, such as ft8. To change the frequency, select a wavelength from the combo box located on the left of the frequency display. The change should be visible in CubicSDR. Otherwise, WSJT-X will throw a rig error and you need to check your virtual rig configuration.
  
  There should be a signal level with a green bar on the lower left part of the window. Set the PulseAudio Volume Control level to something acceptable. Data should begin to appear in the Band Activity window. The waterfall display of WSJT-X shows at least 2000 Hz of the spectrum. Look there and click on a broadcast to set the decoding frequency. As soon as new packets are broadcast on that frequency, new messages should appear in the Rx Frequency window.
- Once you see that you are decoding the signals and see data in the main window, start GridTracker, which will locate all of the stations that you receive on a map.
- You may now shift-click on another part of the spectrum in CubicSDR to create a new modem. Select the desired mode, Audio Out device, etc. You may now listen to another signal in the speakers or headphones without disturbing the digital signal. If you shift-click to start another demodulator, you can set its Audio Out to the headphones. You will then have 3 receivers all at the same time, each going to a different device.
  
  Note: Only the currently selected modem (frequency) will be used by WSJT-X. While you add the modems in the previous section, WSJT-X will change to those frequencies. However, it will continue to decode the audio channel selected. Click on the frequency in CubicSDR with the digital signals to restore WSJT-X.
Setup for SdrGlut
- Start SdrGlut and select a frequency for the desired digital mode, such as 3.573 MHz USB. You should be able to hear the signals.
  You may not need to change anything in the PulseAudio Volume Control to get this to work.
  Start WSJT-X
  Open the PulseAudio Volume Control.
  On the playback tab, for ALSA plug-in [sdrglut.x], set ASLA playback on Built-in Audio Stereo
  On the Recording tab, for ALSA plug-in [wsjtx], set ALSA Capture from Monitor of Built-in Audio Stereo
  On the Output tab, Built-in Audio Stereo (for the speakers) should be set to Port: Analog Output
  In wsjt-x, select the default device (File>Settings>Audio>Input: default). Change mode to the desired mode, such as ft8.
  Set the volume control level to something acceptable to wsjt-x. You can see the audio level in WSJT-X on the lower left side.
  
  Once you see that you are decoding the signals and see data in the main window, start GridTracker, which will locate all of the stations that you receive on a map.
GQRX/WSJT-X integration. Watch out for high CPU usage with GQRX and all of programs running.
You will be able to select the band in WSJT-X and GQRX will change to the associated frequency.
- Start the Virtual0 virtual audio cable device in a terminal as follows:
```
pacmd load-module module-null-sink sink_name=Virtual0
pacmd update-sink-proplist Virtual0 device.description=Virtual0
pacmd update-source-proplist Virtual0.monitor device.description=Virtual0
```
- Launch GQRX. Go to File - I/O Devices or use the toolbar button. Select your SDR device, adjust input rate and decimation to get a sample rate as small as possible in order to have a better view of the narrowband signal on the waterfall and reduce CPU load. Select the Virtual0 Audio device. Do not go below 48000 sample rate (integer multiples of this number are preferred). Click OK. If GQRX crashes, use the default audio device.
  
  From the Tools menu, select Remote control settings and note the allowed IP and port (usually 127.0.0.1:7356). You may have to set Listen on port to 7356 and add 127.0.0.1 to allowed hosts.
  From the Tools menu or using the toolbar button enable Remote control. In the right pane of GQRX, Input controls tab, drag the gain sliders close to the middle position. You can optimize them later. Click the Receiver Options tab and select USB, with normal filter. Start the SDR from the File menu or click the play button.
- Launch WSJT-X. Go to File>Settings and select the Radio tab. In the Rig: menu choose Hamlib NET rigctl and insert the correct IP:port of GQRX (usually 127.0.0.1:7356). Click the Test CAT button and if everything is correctly set up, the button color should change to green.
  
  In the settings window, click the Audio tab. For Soundcard Input: select default. default has been configured to be Virtual0. Click OK.
- Open the PulseAudio Volume Control.
  On the playback tab, for GQRX output on, select Virtual0.
  On the Recording tab, for ALSA plug-in [wsjtx]: set ALSA Capture from Virtual0.
- In WSJT-X, from the Mode menu, select FT8 or whatever mode you want to use. To change the frequency, select a wavelength from the combo box located on the left of the frequency display. The change should be visible in GQRX. Otherwise, WSJT-X will throw a rig error and you need to check your virtual rig configuration.
  
  There should be a signal level with a green bar on the lower left part of the window. Data should begin to appear in the Band Activity window. The waterfall display of WSJT-X shows at least 2000 Hz of the spectrum. Look there and click on a broadcast to set decoding frequency. As soon as new packets are broadcast on that frequency, new messages should appear in the Rx Frequency window.
- Once you see that you are decoding the signals and see data in the main window, start GridTracker, which will locate all of the stations that you receive on a map. Watch that the CPU load is not excessive.
Chrony
- Time synchronization is somewhat critical for WSJT-X. If your time is off by about 2 seconds, you may not receive the packets. This can be caused by latency in your SDR software. With Chrony, we can add an offset to the time server to compensate. If you are not receiving data from WSJT-X, this may be why.
  Install Chrony with this command in a terminal:
```
sudo apt-get install chrony -y
```
- Open Chrony's config file by typing this in a terminal:
```
sudo mousepad /etc/chrony/chrony.conf
```
- Edit the following line in the file to look something like this. Don't overdo the offset as it will also affect your transmit time.
```
pool 2.debian.pool.ntp.org iburst offset -1.5
```
- Save and close the config file, then restart Chrony with the following:
```
sudo invoke-rc.d chrony restart
```

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