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 transistor tester was found in a 1980 publication. The transistor can be the BC548 and the...
It can be obtained from Mouser Electronics the new 1,500 W RF high power transistor MRF1K50H fro m...
We found this circuit in a 1968 Electronics World. The potentiometer should be set to trigger the SCR...