"Tesla coil circuits were used commercially in sparkgap radio transmitters
for wireless telegraphy until the 1920s,[1"
From: http://en.wikipedia.org/wiki/DRSSTC

But in 1929 was wrote: "It is not generally appreciated that this curious
apparatus, often associated with pretty or spectacular demonstrations of
high voltage electricity, is really a fundamental part of modern radio. For
all the tuning apparatus and circuits in every transmitting and receiving
set are simply variations of Tesla coils and Tesla coil circuits".
From: http://www.tfcbooks.com/tesla/1929-09-22.htm

Now is 2012. Is " this curious apparatus" the "fundamental part of modern
radio"? Of course in form of the " variations of Tesla coils and Tesla
coil circuits".
S*