This receiver uses old transistors that are equivalent to BC548 and BC558. The photo diode is of any type. The receiver can be used on a highly sensitive audio link.
This two-output circuit was found in General Electric documentation from the 1990s. The circuit uses...
This Baxandall tone control was obtained in an Argentine publication from the 70s. The circuit uses...
This circuit is from Radio Electronics from March 1985. The circuit uses common components at the...