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.
We found this circuit in the 1994 Linear Applications Handbook by National Semiconductor. The...
This circuit has more historical value than practical, unless the reader find all the components...
This circuit was found in documentation from the 1970s. It eliminates contact bouncing, providing...