Found in a February 1949 Radio Electronics magazine, this dual tube mixer has 4 inputs. Power must come from a 250V source.
This circuit, already explored on this site, can be applied to other comparators in the same...
This two-door doorbell was found in a 1990s US publication. The circuit is still current as...
We found this circuit in the March 1995 issue of Electronics Now magazine. The circuit has a...