This transistorized siren was found in the patent section of Radio Electronics magazine from March 1968. The circuit uses components from the time and has a very elaborate configuration.
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...