This transmitter for the 3.5 and 7 MHz ham radio was found in a 1950s Japan publication. No information was given on the coils and the power supply.
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....