We found this circuit in a 73, magazine for radio amateurs of the 90s. The circuit is passive and most telecommunications receivers can be added.
Presented as an electronic siren, this circuit was found in Radio Electronics magazine from June...
This oscillator with emitter follower was found in an American documentation from the 80's. The...
We found this circuit in documentation from the 1980s. It drives an old cassette or roller type...