Karl Wiegandt's First Amateur Radio Station spark Transmitter in Allentown PA 1917
For more information on Spark Gap Transmitters try the following web pages:
The Spark Gap 2001
http://www.qsl.net/w5mav/sparkgap.htm
AMATEUR RADIO
A Brief HISTORY
SPARK - GAP
http://www.vistech.net/users/w1fji/spark.html