This variable frequency (VFO) oscillator was found in a Japanese publication of 1962. Coil details (in Japanese, but can be deduced) are next to the diagram covering the 3.5 MHz band.
Indicated for applications with a PC, this circuit was obtained in an English publication in 1992....
No information is given on the transformer in this circuit that we found in an American 1967...
This circuit is from an ancient American documentation. The transistors are of the time and the...