We found this circuit for video games in a Radio Electronics magazine from August 1977. The transistor can be any common RF type that reaches the desired signal frequency.
This circuit was found in a 1968 documentation. The circuit generates three rectangular signals...
We found this circuit in an old documentation from the 70s. The circuit can use any varicap and...
Found in American documentation from the 90's, this circuit is very current and can be implemented with...