Hi: The original Time Nut, Alfred Loomis (book: Tuxedo Park) patented: 1435073 Gun Mount 1409304 Chronograph 1376890 Chronograph 2884628 Long Range Navigation System (LORAN) Links at: http://www.prc68.com/I/timefreq.shtml#HC so this topic is not as far off topic as it might appear. Have Fun, Brooke Clarke http://www.prc68.com