Decoding data transmissions is an essential part of shortwave monitoring. The use of data modes is steadily increasing in the amateur radio community. The SDR-RADIO.com console uses a very high performance set of decoders which are tightly integrated in the signal processing flow.
The Data Decoder is started from the Windows pane in the ribbon bar:
Select either USB for a waterfall bandwidth up to 4kHz, or Data USB (from the More... button) for a waterfall bandwidth up to 16kHz.
The data shown in the waterfall is generated after the filtering, so set the filter width to the maximum for a full waterfall. Normally a SDR radio has such a high dynamic range that there is no need to use a narrow filter when decoding.
The currently supported modes are: BPSK, QPSK, Contestia, CW, DominoEx, MFSK, MT63, Olivia, RTTY, RTTYM, Thor, Throb.
To adjust the waterfall bandwidth use these buttons:
As well as selecting the bandwidth you can shift the visible portion of the bandwidth using these buttons:
To enhance traces use the contrast slider:
Adjust the decoding frequency by clicking or dragging anywhere in the waterfall. You can also use these buttons to 'nudge' the frequency:
There is also AFC (Automatic Frequency Control) for PSK, RTTY and CW. When enabled the software attempts to automatically keep the decoding frequency in the Center of the signal.