This circuit from a Popular Electronics from the 90's can generate signals from 0.03 Hz to 3 kHz depending on the value of the capacitor and resistor.
Operating in the range of 3 to 100 MHz, this circuit was found in documentation from the 70s....
This circuit was obtained from an English documentation from 1995. The operational amplifier has...
This amplifier with an OTA has a gain of 40 dB. The power supply must be symmetrical. Found in...