This circuit was found in a 1945 publication. The circuit was stated to be part of a walk talkie. Note that, as it is a portable assembly, it was powered by batteries. The jack was for microphone insertion.
Suggested by National Semiconductor in a documentation of the 90s, this circuit uses a power...
This circuit was obtained from an American 1980s documentation. The frequency depends on the...
The sensor of this circuit is a large surface diode. We believe that a small solar cell can also...