) writes:
http://www.arrl.org/news/features/2007/01/15/2/?nc=1

Spark Gap Experiment Considered a Partial Success...


Spark Gap is as legal as amateur radio in the AM broadcast band.

Meaning, it isn't legal at all.

That group got special permission to experiment with a spark gap
transmitter under very controlled/restrictive conditions. The
special permission included operating it in the middle of the AM
broadcast band.

Without the special authorization, it's not legal at all.

And they were simply playing with it, they weren't doing this
with the hopes of bringing back the spark gap.

Michael VE2BVW