Recently I bought a new door bell. Unlike my old one, the bell is powered by just pressing the button - no batteries!! I guess you only need power for a few milliseconds. In the past I have seen CW transmitters powered by just pressing the Morse key. Some years ago Michael Rainey in the USA made a CW TX that was powered by shouting in to a loudspeaker.
Do you know of others?
No comments:
Post a Comment