This circuit was found in an ancient American documentation. With it is possible to double the frequency of a transmitter For the range of 6 meters obtaining 8 W. The circuit makes use of varicap.
This control circuit for direct current motors uses a 741 and an operational one of unusual power...
This is the traditional voltage follower configuration with the 741 operational amplifier. The...
This type of configuration can be seen elsewhere in this section. This is from a 1965 General...