I’ve been bitten by the QRPP/QRSS bug, and am considering a project where I build a MEPT (that stands for Manned Experimental Propagation Transmitter, apparently), which is a simple beacon transmitter that many people are using to experiment with on the 30m band. QRSS activity is usually in the range from 10.140 to 10.1401 (yes, only 100 Hz of spectrum space), but above that some other people are using KJ1T’s WSPR (“whisper”) mode, which is an FSK digital mode. I don’t have a decoder for it (KJ1T seems to only have written a Windows version of it, and it’s new enough that a Linux version doesn’t exist) but I can see some of the signals in the recording I did on 30m this evening.

The spectrum goes from about 10.1406 on the left to 10.1410 on the right, with about five rows per second scanning down. You can see several WSPR signals, and the wider signals are PSK31.