Featured in the February 1949 Radio Electronics magazine, this benchtop instrument generates multi-range audio signals. The circuit has 6 tubes including the rectifier.
This circuit is from a Popular Electronics from April 1991. The magazine no longer exists, but the...
This two-color LED indicator was found in a Popular Electronics from the 90's. The transistor...
This circuit causes an LED to flash at a frequency determined by the capacitor. The circuit has an...