Now that its all boxed up (apart from the QLG1 GPS module), Im running the U3S on 40m WSPR at aprox. 200mW today, as a final 'acceptance' test.
First transmission went out at 11:40 UTC, about seven minutes ago, and was uncalibrated - yet 34 stations around Europe reported my signal!
Later, I might QSY to one of the high WARC bands for a further test. But for the next few hours, i'll be WSPRing on 40m at 23dBm.