The last versions of QSSTV (9.1.x) are not available in the official repository. We have to compile the software in order to benefit the last functionalities. This tutorial explain how to update the program that was installed with the setup tutorial from this site.
1) G to the QSSTV Website via the Links area and dowload the software.
2) Go to the place where both software have been saved.
3) Right click on the "qsstv_9.1.x" archive (9.1.6 in this example) and select "Extract here" in the menu.
4) You will get a folder named "qsstv_9.1.x" beside the archive.
5) Open the "qsstv_9.1.x" folder.
6) Once again, right click beside the files and select "Open in a terminal".
7) Enter the command qmake then press "Enter".
8) Enter the command make and press "Enter" to launch the compilation.
9) Be patient since this step is the longest of the entire process. Once the work is finished, we just have to install the software.
10) Enter the command sudo make install then press "Enter".
11) Once the installation is done you can close the window.