Tuned Transmitter, by Guglielmo Marconi, 1897. Marconi began experimenting with wireless telegraphy in the early 1890s. In 1895 he succeeded in transmitting over a distance of 1 1/4 miles. His first transmitter consisted of an induction coil connected between a wire antenna and ground, with a spark gap across it. Every time the induction coil pulsed, the antenna would be momentarily charged up to tens (sometimes hundreds) of thousands of volts until the spark gap started to arc over. This acted as a switch, essentially connecting the charged antenna to ground, producing a very brief burst of electromagnetic radiation.