下面是一段真实的历史记录了以前的业余无线电爱好者的经历：ERIC, K1NUN writes "When I was first licensed in the early 1960s, we ended our CW conversations withdi dididi di (Shave and a haircut) to which the other station would reply di di (two bits). Then station 2 sentdi dididi di and the first would reply di di. Sometimes, and particularly among us young teenagers, this reparte might continue for several minutes. Over time, this back and forth terminal handshake shortened just to di di. Also, about that time, sometimes instead of calling CQ, one would just go di dididi di over and over on a frequency (remember, we were crystal controlled in the novice bands) while tuning the receiver, listening for anyone who sent a synchronized di di. After enough back and forth to ensure proper syncronicity, one of the stations would send QRZ? (with the question mark so as to really ask who is calling me). Thus, dit dit also began a QSO in some cases. Fortunately , this custom died within a very few years as the rules changed and more of us could use transceivers that put us right on frequency and we did not have to tune around and search for responders And that's my story and I lived it.