GenLog`s Burst CW Burst CW (as I call it) was incorporated in my CW keyer software back in the 80`s and users liked the concept. So I added it to an early version of GenLog. Multi-speed CW messaging can be heard in many HF CW contests. Burst CW is when portions of a CW message are sent at increased speed, >30 wpm. During HF contests, the repetitive components of a message can be sent at very high speeds. (5NN), (TEST) or (BK) for example. The main QSO exchange is sent at the normal speed, although guys can get going ~30 wpm at times.