Mystery NCA Tube (ca. 1960)
This GM tube was manufactured by the Nucleonic Company of America located in Brooklyn, NY. Aside from the company name and logo, there are no helpful identifying marks, e.g., a model number. There appears to be a serial number painted by hand on the base ("SNX64" ?), but it is very hard to make out. The tube does work—at 1200 or so volts, we managed to get some nice pulses out of it.
Size: 8” long and 1” diameter
Operating voltage: 1200 volts
Base: Four prong
Donated by Oak Ridge National Laboratory.