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 configuration can be found in other articles on this site. This is from European...
This 18 V x 300 mA power supply was found in a 1969 documentation. The integrated circuit is...
This experimental 555 circuit sends signals in the medium wave band to a receiver a few meters away....