Joined: Jun Wed 08, 2011 2:33 am Posts: 2064 Location: Ohio
What a wicked looking torture implement! Actually they usually sell cheap as without the cavity, it is of no use, and probably would still be of no use with one. They are practically a display item, so owning one is enough!
Joined: Jan Thu 01, 1970 1:00 am Posts: 23542 Location: Pocasset, Cape Cod, MA
Somewhere around here I have a subassembly that takes these. Without the fancy hardware that clamps them in position, you can't use them anyway. I remember unearthing some in the college EE junkbox, and the prof called them MacNally oscillators. I think I looked them up later and found NacNally had published the original paper on them, or else was mentioned in the appropriate Rad Lab book where they are described.