We found this circuit in an old General Electric documentation. In fact, PUTs are not common components today. The circuit is valid as a reference.
This circuit was obtained from an American 80's documentation. The balanced mixer can be shown in...
This circuit was found in an application note of the LTC1164 from Linear Technology of the 1990s....
This circuit has a type of bias called "virtual earth" providing good gain, given by R2. The...