A short demo video on the Wobbulator. It was originally made in the 1970's by Nam June Paik and video engineer Shuya Abe. I was curious why there wasn't a lot of information out there concerning it since it's such a great piece of equipment. Most of the Wobbulator's source images in this video were either from a camera pointed out a window, or just from straight video feedback.
There is a great detailed writeup with wiring diagrams on the Experimental Television Center's website: experimentaltvcenter.org/history/tools/ttool.php3?id=28&page=1
Addition: I was told by Benton Bainbridge that S. Walter Wright is the artist that called it the "Wobulator" but Wobbulator also seems to be the common spelling, at least at the ETC.
Additional addition: Ollie Williams was inspired to create one of their own of these and it turned out really well..check it out: vimeo.com/24636740
Music is Hammock - Tristia