This transistorized circuit appeared in a Radio Electronics magazine in March 1958. The frequency range depends on the tuned circuit, being within a few megahertz.
This circuit was found in the December 1977 issue of Radio Electronics magazine. The circuit uses...
This is an improved version of the previous circuit that includes speed control. The engine can be...
This electronic siren circuit, found in a 1982 documentation, uses three oscillators mounted...