Testing that the virtual audio cable works correctly
The digital mode applications should be able to process the received audio from the radio.
In WSJT-X, for example, the received audio should be visible in the WSJT-X audio waterfall spectrum and WSJT-X should be able to decode stations. If decoding is not working, check that the radio control works (e.g by changing the frequency band) and that the current frequency is correctly set for the digital mode in use. Verify also that the client computer clock is synchronized correctly, because many digital modes require the computer clock to be set very accurately.
You can monitor the audio signal transmitted by a digital mode application in Web Radio Control user interface
Show audio and
TX audio. This is how you can make sure that the audio signal is properly
connected between the web browser and the digital mode application.
To verify that transmission works correctly in WSJT-X, for example, it is necessary to attempt a QSO with another
station or to use the WSPR beacon mode. When WSJT-X is transmitting audio, you should be able to see the
audio waterfall spectrum of the transmitted audio (usually a simple carrier wave) in the Web Radio Control
waterfall scope when
TX audio is selected.