aFirst of all, it is a very useful communication tool. When you are out and you need to contact someone urgently, a mobile phone will enable you to do this if there is no telephone box nearby. A beeper is not always sufficient for your purposes. 首先,它是一个非常有用的通信工具。 当...
Morse Tone Generator (low Power CW Beeper): Here I describe how to build a simple low power tone generator that I use to teach my son morse code.While cleaning up my cellar I found my old Wehrmacht morse keyer. This keyer was used by German forces during