Indicated for discriminators adjustment in FM and VHF receivers, this circuit was found in a 90s 73 magazine for radio amateurs. The operational amplifier can be a general-purpose type.
This low drift or offset circuit is from an 80's documentation. The configuration can be made with...
This circuit has a logarithmic response as a function of the light falling on the sensor. The...
Found in 80's Electronic Engineering, this circuit can tune the frequency to be rejected. The power...