He worked out how to use a spark-gap transmitter to remotely ignite gunpowder.
From the newscientist.com
The Poldhu spark transmitter was only broadly tuned, and may have radiated significant energy at these frequencies.
From the en.wikipedia.org
The development of a rotary-spark transmitter was something of a stop-gap measure, to be used until a superior approach could be perfected.
From the en.wikipedia.org
This noise was due to irregularities in the spark gap transmitter he used.
From the en.wikipedia.org
It would be difficult today to get permission to put a 46 kilowatt poorly tuned spark transmitter on the air, to say nothing of the expense of reproducing the equipment and antennas.
From the en.wikipedia.org
The next year, he added a spark-gap transmitter.
From the en.wikipedia.org
In 1888, Heinrich Hertz was the first to demonstrate the existence of radio waves by building a spark gap radio transmitter that produced 450 MHz microwaves, in the UHF region.
From the en.wikipedia.org
This consists of spark gaps and gas-filled surge arresters to limit the voltage that appears on the transmitter terminals.