Designed to operate with a video camera, this small transmitter was found in the February 1993 issue of Radio Electronics magazine. The microphone is electret.
We found this inverter in a Popular Electronics from the 1980s. The output is not perfectly...
Found in American documentation from the 90s, this circuit uses common FETs. It has a range drift...
The frequency of the sound produced in the speaker depends on the light that falls on the...