In the figure we have a stereo decoder from the 70's with pilot lamp for signal indication. The circuit employs a component of the time, which is uncommon today.
This circuit with SCR is from a Radio Electronics magazine from September 1965. It is a commercial...
This circuit was found in the July 1986 issue of Radio Electronics magazine. The circuit has a...
This circuit was found in a QST from the 1990s. The circuit expands the scale of a 10V instrument to...