That schematic of a Tesla coil is the same as a spark-gap transmitter, except of course the latter is designed to emit as much as possible and has an antenna connected where the output torus would be; see page 375 of this excellent book: https://archive.org/details/principlesunderl00unit
(Although very old, that book is great at explaining the basics of what radio actually is.)
(Although very old, that book is great at explaining the basics of what radio actually is.)