Found in a Popular Electronics from the 90s, this circuit is intended to measure the harmonic distortion of an audio signal. The circuit can be tuned between 970 and 1030 Hz.
This analog thermometer was obtained from an English documentation. The sensor is a common diode...
This circuit is a kind of Hertz Loop that can be used to check the operation of transmitters and...
Two 3-terminal regulators like the LM317 can be used to "clip" a sinusoidal signal, in order to...