One that gets me is sending both calls at the start and end of each transmision. Takes so much time! I'll send your call till Im sure its right and then not till end of QSO. Still send mine within 10 minutes but not at the end of each transmission. Back to u de N8TGQ
I tend to abbreviate less once the rst/name/qth/rig/pwr/ant stuff is done. Both because it's probably easier to receive, and because I tend to think in real words rather than abbreviations. De N1OOQ bk
But how is that shorter than "N8TGQ de W7UUU"? It's actually more characters! I could just send "BK de W7UUU" and it would be much shorter than "Back to u de W7UUU" Lots of variations I suppose. I tend to just do whatever the other guy does first and do it the same way, since that's the format he seems to know / prefer Dave W7UUU
