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 circuit was found in an Electronics World magazine from 1990. The circuit can be mounted...
This 6-transistor commercial radio with 6 V supply was found in a Japanese publication from the...
This traditional doubler configuration with the 555 can be found in other articles on the author’s site....