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.
This circuit, found in documentation from the 1990s, uses a common 7-segment LED display. The...
We found this circuit in an early American 80's documentation. We note that the first gate of the...
Using a V/F converter this circuit was found in the June 1991 issue of Radio Electronics magazine. The...