This 3-tube receiver is from a 1924 publication. The circuit has 3 supply voltages and a high-impedance headphone output.
We found this common application of the 741 operational amplifier in a 1977 documentation. The...
This circuit, found in an old 1967 publication, cuts the current from a source when the current...
This LED bar graph circuit was found in the October 1980 issue of Radio Electronics magazine. The...