This circuit with a differential pair was found in the August 1974 Radio Electronics magazine. The frequency is determined by L1 and the variable capacitor.
This useful inductance bridge was found in a Radio Electronics from September 1963. The...
This circuit uses a 7-segment display to indicate the logic level of a test circuit. The power...
Powered by voltages from 6 to 12 V, this circuit from a Popular Electronics from the 90s,...