Feed Line No. 8
NIKOLA TESLA — THE TRUE FATHER OF RADIO
by Gary Peterson
In this age of advanced telecommunications, a thought is
seldom given to those early wireless pioneers who laid the groundwork for our present
wireless system. While most people associate the word wireless with radio, in
reality this term can be applied to any system by which electrical energy is transmitted without
wires from one location and received at another. The first investigations focused
primarily on four different methods of accomplishing this: electrical
conduction, electrostatic induction, electromagnetic induction, and electromagnetic radiation. All
four methods showed some degree
of promise, but only one of them—radio—won out.
Radio is that form of wireless communications in which the
transmitter output takes the form of dissipating electromagnetic radiation, the radio
waves spreading outward in all directions from an elevated antenna. Because the signal
strength drops off quite rapidly as the distance from the source of radiation increases,
faraway radio receivers have to be very sensitive to detect signals that may measure only
a fraction of a microvolt per meter in strength. These radio waves had remained
practically unknown until the 19th century when a number of important steps were taken by
early investigators who developed techniques for their detection and measurement. This led
to the 1886-1888 experiments of Heinrich Hertz which firmly established their existence.
Nikola Tesla's contribution to this story involved
reworking the primitive sources of radio frequency current and crude tuned receiving
circuits developed by his predecessors. A most important step was introduction of the
coupled tuned circuit into his preliminary transmitter design. Some might recognize this
as the configuration of the now familiar Tesla coil, with its primary and secondary
circuits both tuned to vibrate together in harmony. By 1896 further refinements had
resulted in a transmitter that could have signaled across the Atlantic, had such an
attempt been made. Additional work resulted in the development of wireless receivers that
also included two synchronized circuits. Between 1898 and 1903 Tesla was granted 10 U.S.
patents covering his inventions in these two areas.
In 1904 Marconi was able to obtain his own patent using
some of Tesla's own ideas. The issue of Marconi's patent infringement was addressed in a
lawsuit brought by Tesla 1915. Nothing truly significant resulted from this action, and in
a 1916 turn-around the Marconi Wireless Telegraph Company of America itself sued the
United States Government for alleged damages resulting from the use of wireless during
WWI. In 1943, the year of Tesla's death, a landmark ruling by the U.S. Supreme Court
invalidated the Marconi patent because the fundamental radio circuit had been anticipated
by Tesla. It is worthwhile noting the following definition of radio that was developed as
a result of this case:
"A radio communication system requires two tuned circuits each at the transmitter
and receiver, all four tuned to the same frequency."
So, the next time you pick up a wireless telephone, listen
to your car radio or turn on a television set, give a quick thought to Nikola Tesla
true father of radio.