This sonic key or vox was found in old English documentation. The operational admits equivalent as well as the transistors. The microphone is crystal.
27 MHz Transmitter (CB14008E) This circuit was found in a Japanese publication from the 1970s. The...
This circuit reproduces in a small loudspeaker the sound of the signal that modulates a...
The integrated circuit used in this multivibrator is no longer common today. With the components...