Found in a 1968 American documentation, this circuit uses an operational amplifier that is uncommon today. The feed must be symmetrical. The gain is 40 dB.
This circuit was found in an Analog Devices publication from the 1990s. The circuit performs input...
Found in Motorola documentation from the 90s, this circuit can be implemented with current...
We found this circuit in an old documentation for hams. In it we have the way to use a varicap to...