This museum in Huntington, West Virginia has an impressive collection of radio equipment, pictures of which are available on the web.
Video of Rotary Spark Gap transmitter demonstration
http://picasaweb.google.com/WVRadioMuseum/MuseumOfRadioAndTechnology#slideshow/5360804172369787346
Slide show of the Museum
http://picasaweb.google.com/WVRadioMuseum/MuseumOfRadioAndTechnology#slideshow/
Museum of Radio and Technology
http://oak.cats.ohiou.edu/~postr/MRT/
(Southgate
http://www.southgatearc.org/news/september2009/museum_of_radio_and_technology.htm )
Info via DXLD