QSO with DL3ZID 5 March 2005 Comparison between DFCW3, QRSS3 and QRSS10 DL3ZID replied to my QRSS3 call on DFCW3, but was unreadable. He then changed to QRSS3 which was an improvement, but we needed to use QRSS10 to make sure of callsigns. The following pictures show the difference between the three modes. This is probably the first time such a comparison has been made on a 'live' marginal signal.

The unreadable DFCW3. I think it says "? G3XDV" but then disappears into QRM The QRSS3 is an improvement, but I could not get his suffix. Now I know the callsign, I can just make it out! A breeze on QRSS10 (10 second dot length) which dramatically improved the signal/noise ratio, but the whole QSO took two hours!.

Index to Gallery of Spectrograms