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 Intersil circuit was found in a 1980s documentation. Operational are of the time, but current...
New Low-Power PIC24 “GA7” Microcontroller Family Now Available CHANDLER, Ariz., Dec. 12, 2016 — The...
This circuit was found in a 1976 NASA manual, making use of components of the time. The transistor...