The diagram shows a tone control with the LM381 IC. The circuit is from a Radio Electronics from February 1990. The power supply is simple.
This transistor flasher was found in an English magazine that no longer exists from 1975. The...
In the figure we have a typical detector stage for a radio receiver. The circuit is from 1963,...
This is one of many Morse code audio oscillators that can be found in this section. The circuit...