This circuit was found in a Popular Electronics from the 90s. The circuit has temperature compensation. Coil and capacitors depend on the frequency at which the circuit will be used.
This circuit is from the 1983 Intersil Databook. In it we have the use of the ICL7135 as an AD...
This MW radio circuit with varicap tuning was found in an English documentation from 1989. The...
This circuit was found in an American publication from the 70s, but it can be assembled with more...