This circuit was found in the June 1991 issue of Radio Electronics magazine. The circuit uses two Hall effect sensors of the time. It can be assembled using modern equivalents.
This circuit was found in an old Linear Technology documentation. The working principle can be...
Scratch is the scratching noise that occurs on old, scratched discs and the rumble is the...
This 6-transistor receiver was manufactured in Japan in the 60s. The circuit is superheterodyne and has a 6V...