Because of the vast number of hams operating worldwide, at any moment there are tens of thousands of them transmitting and receiving. Add to this the breadth of the ham channels, and it is easy to see that you can never be sure who you will connect up with.
由於全世界「火腿」眾多，隨時都有幾十萬人打開主機收、發；加上無線電波涵蓋的範圍極廣，所以在未收到回訊之前，並不知今天會和那位「火腿」通話？