We found this circuit in the November 1995 Electronics Now magazine. The circuit is more accurate than the previous one using an external multimeter as an indicator.
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
This old fashioned amplifier can source some watts to a low impedance loudspeaker. The circuit...
This 50 Hz rejector or notch filter was found in a 1975 documentation. Other frequencies can be...