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.
We find this filter with three operational of the time in an American documentation of the 80s....
This circuit appears in other articles in this section and even in other sections of the site....
Found in Datel's documentation from the 1980s, this circuit makes use of the company's operational...