This can be considered a complete laboratory for the repair professional. A full featured signal tracer with 13 tubes. The circuit is from the March 1946 issue of Radio Craft.
Found in a Popular Electronics from the 90s, this circuit uses components that are still current....
This circuit is based on an operational amplifier that is uncommon today, but that can reach the...
The sophisticated white noise generator we present uses four 741 operational amplifiers. The...