Inverter Amplifier (CB6431E)

This high input impedance circuit was found in a Popular Electronics of the 90s. The circuit supports modern operational.

Noise Reducer (CB19824E)
The integrated circuit used in this configuration for noise reduction on FM radios is not common...
Current to Voltage Converter (CB15727E)
The presented circuit provides an output voltage proportional to the input current, according to...
Fifth Order Filter (30 dB / Octave) (CB12561E)
The low-pass filter shown in the figure uses two operational amplifiers with JFET at the input to...